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Meijer T, Raad F, Leonard M, Meier F, Jennings P, Wilmes A. P11-14 Characterisation of transport capacity of human iPSC-derived proximal tubular-like cells. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Meijer T, Verkaik N, Deurzen CV, Dubbink H, Toom DD, Dinjens W, Kanaar R, Gent DV, Jager A. PO-492 Ex vivo functional homologous recombination (HR) test detects BRCA reversal and resistance to PARPi in metastatic breast cancer patients. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Meijer T, Verkaik N, Sieuwerts A, Deurzen CV, Dubbink H, Kanaar R, Martens J, Jager A, Gent DV. PO-462 Functional ex vivo assay reveals homologous recombination deficiency in breast cancer beyond BRCA gene defects. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Dalerum F, Freire S, Angerbjörn A, Lecomte N, Lindgren Å, Meijer T, Pečnerová P, Dalén L. Exploring the diet of arctic wolves (Canis lupus arctos) at their northern range limit. CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The grey wolf (Canis lupus Linnaeus, 1758) is one of the most widespread large carnivores on Earth, and occurs throughout the Arctic. Although wolf diet is well studied, we have scant information from high Arctic areas. Global warming is expected to increase the importance of predation for ecosystem regulation in Arctic environments. To improve our ability to manage Arctic ecosystems under environmental change, we therefore need knowledge about Arctic predator diets. Prey remains in 54 wolf scats collected at three sites in the high Arctic region surrounding the Hall Basin (Judge Daly Promontory, Ellesmere Island, Canada, and Washington Land and Hall Land, both in northwestern Greenland) pointed to a dietary importance of arctic hare (Lepus arcticus Ross, 1819; 55% frequency of occurrence) and muskoxen (Ovibos moschatus (Zimmermann, 1780); 39% frequency of occurrence), although we observed diet variation among the sites. A literature compilation suggested that arctic wolves (Canis lupus arctos Pocock, 1935) preferentially feed on caribou (Rangifer tarandus (Linnaeus, 1758)) and muskoxen, but can sustain themselves on arctic hares and Greenland collared lemmings (Dicrostonyx groenlandicus (Traill, 1823)) in areas with limited or no ungulate populations. We suggest that climate change may alter the dynamics among wolves, arctic hare, muskoxen, and caribou, and we encourage further studies evaluating how climate change influences predator–prey interactions in high Arctic environments.
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Affiliation(s)
- F. Dalerum
- Research Unit of Biodiversity (UMIB, UO–CSIC–PA), Mieres Campus, University of Oviedo, 33600 Mieres, Asturias, Spain
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Hatfield 0028, Pretoria, South Africa
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - S. Freire
- Research Unit of Biodiversity (UMIB, UO–CSIC–PA), Mieres Campus, University of Oviedo, 33600 Mieres, Asturias, Spain
| | - A. Angerbjörn
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - N. Lecomte
- Canada Research Chair in Polar and Boreal Ecology and Centre d’Études Nordiques, Department of Biology, University of Moncton, Moncton, NB E1A 3E9, Canada
| | - Å. Lindgren
- Swedish Polar Research Secretariat, Box 50003, SE-104 05 Stockholm, Sweden
| | - T. Meijer
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - P. Pečnerová
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, P.O. Box 50007 SE-104 05 Stockholm, Sweden
| | - L. Dalén
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, P.O. Box 50007 SE-104 05 Stockholm, Sweden
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Erlandsson R, Meijer T, Wagenius S, Angerbjörn A. Indirect effects of prey fluctuation on survival of juvenile arctic fox (Vulpes lagopus): a matter of maternal experience and litter attendance. CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0103] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reproductive experience affects juvenile survival in a wide range of species with possible links to differences in foraging capacity and predation. Using supplementary feeding, we aimed to limit direct effect of prey abundance to investigate indirect effects of small-rodent availability and maternal experience on juvenile summer survival rates in an endangered population of arctic fox (Vulpes lagopus (L., 1758)). We used data spanning 7 years, included a complete small-rodent cycle, comprising 49 litters and 394 cubs. The effect of small-rodent abundance on juvenile survival depended on maternal breeding experience. Cubs born by first-time-breeding females had lower survival rate when small-rodent abundance was low compared with juveniles born to experienced mothers who remained unaffected. It was unlikely due to starvation, as physical condition was unrelated to survival. Instead, we favour the explanation that intraguild predation was an important cause of mortality. There was a negative relationship between survival and amount of time cubs were left unattended, suggesting that parental behaviour affected predation. We propose that a prey switch related to small-rodent abundance caused fluctuations in intraguild predation pressure and that inexperienced females were less able to cope with predation when small rodents were scarce.
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Affiliation(s)
- R. Erlandsson
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - T. Meijer
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - S. Wagenius
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - A. Angerbjörn
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
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Warpman Berglund U, Sanjiv K, Gad H, Kalderén C, Koolmeister T, Pham T, Gokturk C, Jafari R, Maddalo G, Seashore-Ludlow B, Chernobrovkin A, Manoilov A, Pateras IS, Rasti A, Jemth AS, Almlöf I, Loseva O, Visnes T, Einarsdottir BO, Gaugaz FZ, Saleh A, Platzack B, Wallner OA, Vallin KSA, Henriksson M, Wakchaure P, Borhade S, Herr P, Kallberg Y, Baranczewski P, Homan EJ, Wiita E, Nagpal V, Meijer T, Schipper N, Rudd SG, Bräutigam L, Lindqvist A, Filppula A, Lee TC, Artursson P, Nilsson JA, Gorgoulis VG, Lehtiö J, Zubarev RA, Scobie M, Helleday T. Validation and development of MTH1 inhibitors for treatment of cancer. Ann Oncol 2016; 27:2275-2283. [PMID: 27827301 DOI: 10.1093/annonc/mdw429] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/01/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Previously, we showed cancer cells rely on the MTH1 protein to prevent incorporation of otherwise deadly oxidised nucleotides into DNA and we developed MTH1 inhibitors which selectively kill cancer cells. Recently, several new and potent inhibitors of MTH1 were demonstrated to be non-toxic to cancer cells, challenging the utility of MTH1 inhibition as a target for cancer treatment. MATERIAL AND METHODS Human cancer cell lines were exposed in vitro to MTH1 inhibitors or depleted of MTH1 by siRNA or shRNA. 8-oxodG was measured by immunostaining and modified comet assay. Thermal Proteome profiling, proteomics, cellular thermal shift assays, kinase and CEREP panel were used for target engagement, mode of action and selectivity investigations of MTH1 inhibitors. Effect of MTH1 inhibition on tumour growth was explored in BRAF V600E-mutated malignant melanoma patient derived xenograft and human colon cancer SW480 and HCT116 xenograft models. RESULTS Here, we demonstrate that recently described MTH1 inhibitors, which fail to kill cancer cells, also fail to introduce the toxic oxidized nucleotides into DNA. We also describe a new MTH1 inhibitor TH1579, (Karonudib), an analogue of TH588, which is a potent, selective MTH1 inhibitor with good oral availability and demonstrates excellent pharmacokinetic and anti-cancer properties in vivo. CONCLUSION We demonstrate that in order to kill cancer cells MTH1 inhibitors must also introduce oxidized nucleotides into DNA. Furthermore, we describe TH1579 as a best-in-class MTH1 inhibitor, which we expect to be useful in order to further validate the MTH1 inhibitor concept.
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Affiliation(s)
- U Warpman Berglund
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - K Sanjiv
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - H Gad
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - C Kalderén
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - T Koolmeister
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - T Pham
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - C Gokturk
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - R Jafari
- Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology
| | - G Maddalo
- Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology
| | - B Seashore-Ludlow
- Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - A Chernobrovkin
- Division of Physiological Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - A Manoilov
- Division of Physiological Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - I S Pateras
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - A Rasti
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - A-S Jemth
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - I Almlöf
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - O Loseva
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - T Visnes
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - B O Einarsdottir
- Sahlgrenska Translational Melanoma Group (SATMEG), Sahlgrenska Cancer Center, Department of Surgery, Institute of Clinical Sciences, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg
| | - F Z Gaugaz
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics.,Department of Pharmacy and
| | - A Saleh
- Science for Life Laboratory Drug Discovery and Development Platform, ADME of Therapeutics facility, Department of Phamracy, Uppsala University, Uppsala, Sweden
| | - B Platzack
- Swedish Toxicology Sciences Research Center, Södertälje, Sweden
| | - O A Wallner
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - K S A Vallin
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - M Henriksson
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - P Wakchaure
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - S Borhade
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - P Herr
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - Y Kallberg
- National Bioinformatics Infrastructure Sweden (NBIS), Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, Stockholm
| | - P Baranczewski
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics.,Science for Life Laboratory Drug Discovery and Development Platform, ADME of Therapeutics facility, Department of Phamracy, Uppsala University, Uppsala, Sweden
| | - E J Homan
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - E Wiita
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - V Nagpal
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics.,SP Process Development, Södertälje, Sweden
| | - T Meijer
- SP Process Development, Södertälje, Sweden
| | - N Schipper
- SP Process Development, Södertälje, Sweden
| | - S G Rudd
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - L Bräutigam
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - A Lindqvist
- Science for Life Laboratory Drug Discovery and Development Platform, ADME of Therapeutics facility, Department of Phamracy, Uppsala University, Uppsala, Sweden
| | - A Filppula
- Uppsala Drug Optimisation and Pharmaceutical Profiling Platform (UDOPP), Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - T-C Lee
- Institute of biomedical sciences, Academia Sinica, Taipei-115, Taiwan
| | - P Artursson
- Department of Pharmacy and.,Science for Life Laboratory Drug Discovery and Development Platform, ADME of Therapeutics facility, Department of Phamracy, Uppsala University, Uppsala, Sweden.,Uppsala Drug Optimisation and Pharmaceutical Profiling Platform (UDOPP), Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - J A Nilsson
- Sahlgrenska Translational Melanoma Group (SATMEG), Sahlgrenska Cancer Center, Department of Surgery, Institute of Clinical Sciences, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg
| | - V G Gorgoulis
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece.,Faculty Institute for Cancer Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - J Lehtiö
- Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology
| | - R A Zubarev
- Division of Physiological Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - M Scobie
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
| | - T Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics
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Van Gent D, Naipal K, Verkaik N, Meijer T, Hoeijmakers J, Van Deurzen C, Kanaar R, Jager A. DNA damage responses and chemosensitivity of breast cancer tissue slices ex vivo. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61062-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Meijer T, Vriens D, Looijen-Salamon M, Visser E, Geus-Oei LD, Bussink J. EP-1851: Quantitative assessment of glucose metabolic rate within NSCLC histologies using dynamic 18F-FDG PET. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)33102-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Norén K, Hersteinsson P, Samelius G, Eide N, Fuglei E, Elmhagen B, Dalén L, Meijer T, Angerbjörn A. From monogamy to complexity: social organization of arctic foxes (Vulpes lagopus) in contrasting ecosystems. CAN J ZOOL 2012. [DOI: 10.1139/z2012-077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Canids display pronounced intraspecific variation in social organization, ranging from single breeding females to large and complex groups. Despite several hypotheses in this matter, little is understood about the ecological factors underlying this flexibility. We have used the arctic fox ( Vulpes lagopus (L., 1758)) to investigate how contrasting ecosystem conditions concerning resources and predation influence group formation. We predicted that complex groups are more common in resource-rich ecosystems with predators, whereas simple groups occur in more marginal ecosystems without predators. Samples from 54 groups were collected from four populations of arctic foxes with contrasting prey resources and predation and these samples were genotyped in 10 microsatellite loci. We found considerable variation between ecosystems and a significant relationship between resources and formation of complex groups. We conclude that sufficient amounts of food is a prerequisite for forming complex groups, but that defense against predation further increases the benefits of living in larger groups. We present a conceptual model suggesting that a trade-off between the cost of resource depletion and the benefits obtained for guarding against predators explain the differences in social organization. The variable ecology of the arctic foxes makes it is a plausible model species for understanding the connection between ecology and social organization also in other species.
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Affiliation(s)
- K. Norén
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - P. Hersteinsson
- Institute of Biology, University of Iceland, Sturlugata 7, IS-101 Reykjavik, Iceland
| | - G. Samelius
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, SE-730 91 Riddarhyttan, Sweden
| | - N.E. Eide
- Norwegian Institute for Nature Research, N-7485 Trondheim, Norway
| | - E. Fuglei
- Norwegian Polar Institute, FRAM Centre, N-9296 Tromsø, Norway
| | - B. Elmhagen
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - L. Dalén
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - T. Meijer
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - A. Angerbjörn
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
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Groot M, Lasaroms J, van Bennekom E, Meijer T, Vinyeta E, van der Klis J, Nielen M. Illegal treatment of barrows with nandrolone ester: effect on growth, histology and residue levels in urine and hair. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2012; 29:727-35. [DOI: 10.1080/19440049.2011.647097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Meijer T, Norén K, Hellström P, Dalén L, Angerbjörn A. Estimating population parameters in a threatened arctic fox population using molecular tracking and traditional field methods. Anim Conserv 2008. [DOI: 10.1111/j.1469-1795.2008.00188.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nielen MWF, Lasaroms JJP, Essers ML, Oosterink JE, Meijer T, Sanders MB, Zuidema T, Stolker AAM. Multiresidue analysis of beta-agonists in bovine and porcine urine, feed and hair using liquid chromatography electrospray ionisation tandem mass spectrometry. Anal Bioanal Chem 2008; 391:199-210. [DOI: 10.1007/s00216-007-1760-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 11/14/2007] [Accepted: 11/19/2007] [Indexed: 11/28/2022]
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Abstract
We demonstrate production of continuous coherent blue laser light by using a five-level system in rubidium vapor. Two low-power lasers, at 780 and 776 nm, induce strong atomic coherence in the 5S-5P-5D states. The atoms decay to the 6P excited state, from which stimulated emission produces a coherent blue (420 nm) beam. We have coupled both ground-state hyperfine levels, effecting coherence between four levels. The coherent blue output is enhanced by several mechanisms, including stronger coupling to a larger fraction of the atomic population, operation at a detuning such that the vapor is nominally transparent to the 780 nm pump field, reduced losses owing to optical pumping, and optimal phase matching. We report experimental findings and compare them with results from a semiclassical Maxwell-Bloch model.
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Affiliation(s)
- T Meijer
- School of Physics, University of Melbourne, Victoria 3010, Australia
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van Vegchel N, de Jonge J, Meijer T, Hamers JP. Different effort constructs and effort-reward imbalance: effects on employee well-being in ancillary health care workers. J Adv Nurs 2001; 34:128-36. [PMID: 11430600 DOI: 10.1046/j.1365-2648.2001.3411726.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS OF THE STUDY The present study investigates the relationship between Effort-Reward Imbalance (ERI) and employee well-being, using three different concepts of efforts (i.e. psychological demands, physical demands and emotional demands). BACKGROUND The ERI model had been used as a theoretical framework, indicating that work stress is related to high efforts (i.e. job demands) and low occupational rewards (e.g. money, esteem and security/career opportunities). The ERI model also predicts that, in overcommitted workers, effects of ERI on employee well-being are stronger compared with their less committed counterparts. METHODS A cross-sectional survey among 167 ancillary health care workers of two nursing homes was conducted. Multiple univariate logistic regression analyses were used to test the relationship between ERI and employee well-being. RESULTS Results of the logistic regression analyses showed that employees with both high (psychological, physical and emotional) efforts and low rewards had higher risks of psychosomatic health complaints, physical health symptoms and job dissatisfaction (odds ratios (ORs) ranged from 5.09 to 18.55). Moreover, employees who reported both high efforts and high rewards had elevated risks of physical symptoms and exhaustion (ORs ranged from 6.17 to 9.39). No support was found for the hypothesis on the moderating effect of overcommitment. CONCLUSION Results show some support for the ERI model; ancillary health care workers with high effort/low reward imbalance had elevated risks of poor employee well-being. In addition, results show that the combination of high efforts and high rewards is important for employee well-being. Finally, some practical implications are discussed to combat work stress in health care work.
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Affiliation(s)
- N van Vegchel
- Department of Social and Organizational Psychology, Utrecht University, The Netherlands
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Meijer T, Rozman J, Schulte M, Stach-Dreesmann C. New findings in body mass regulation in zebra finches (Taeniopygia guttata) in response to photoperiod and temperature. J Zool (1987) 1996. [DOI: 10.1111/j.1469-7998.1996.tb05317.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Abstract
In gallinaceous birds and other nidifugous species, it is thought that
effective incubation does not start before the last egg is laid, and young
hatch synchronously (LACK, 1968). We investigated the egg-laying and
nest-attendance pattern of the precocial nidifugous red Burmese Junglefowl
Gallus gallus spadiceus, and its consequences for the asynchrony of embryo
development and of hatching. Eggs were laid in sequences, followed by pause
days. Egg-weight in these sequences decreased by 0.6 g/egg. When laying,
females sat in the nest for 1-3 h/day, and attended the nest overnight on
days on which the last eggs of a clutch were laid. At the moment the last
egg was laid, first eggs were already attended for 40 h (range 16-84 h),
which resulted in extreme developmental asynchrony at the end of laying
(measured as the diameter of the area vasculosa). Last eggs of clutches
decreased markedly in weight (by more than 1 g/egg) and had shorter
incubation times than the heavier first eggs. Eggs hatched asynchronously
over a period of 15 h (range 7-33 h) and in the order of laying. The
development of incubation behaviour, asynchrony of embryo development and of
hatching of the precocial nidifugous Junglefowl, corresponded to a high
degree to what is known of altricial species.
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Affiliation(s)
- T. Meijer
- 2(Dep. of Ethology, Univ. of Bielefeld, P.O. Box 10 01 31, 33501 Bielefeld, Germany
| | - I. Siemers
- 1(Dep. of Ethology, Univ. of Bielefeld, P.O. Box 10 01 31, 33501 Bielefeld, Germany
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Meijer T, Deerenberg C, Daan S, Dijkstra C. Egg-Laying and Photorefractoriness in the European Kestrel Falco tinnunculus. ACTA ACUST UNITED AC 1992. [DOI: 10.2307/3676667] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Dijkstra C, Bult A, Bijlsma S, Daan S, Meijer T, Zijlstra M. Brood Size Manipulations in the Kestrel (Falco tinnunculus): Effects on Offspring and Parent Survival. J Anim Ecol 1990. [DOI: 10.2307/5172] [Citation(s) in RCA: 310] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
An adaptive decline in average clutch size with progressive date of laying is characteristic of most bird species with a single clutch of variable size per year. The effect of photoperiod on timing of laying, clutch size, and subsequent molt was investigated in kestrel pairs breeding and raising their young in captivity. In natural daylight (nLD), clutch size, under ad libitum feeding, showed the same decline with date as in nature. Birds breeding later also started molt later and molted faster (more feathers simultaneously), so that all birds completed molt more or less at the same time. Constant long days (LD 17.5:6.5 and LD 13:11) from December 1 onward advanced both reproduction and molt. The LD 17.5:6.5 group developed the reproductive system faster, had a shorter courtship period, and laid eggs earlier than the LD 13:11 group. In both photoperiods there was a decrease in clutch size with progressive laying date, similar to that in nLD. Molt started in both groups at about the end of the laying period and slowed down in the longer photoperiod, especially in males. Plasma luteinizing hormone (LH) changes in the two photoperiods were different for males and females. Males showed the expected slower LH response in the shorter photoperiod, but the initial LH response by females was the same in both photoperiods. Data on LH, reproductive behavior, and body mass suggest that females have a wider annual reproductive window than males. Data on time of laying and number of eggs suggest that clutch size in the kestrel is determined by laying date itself, following an endogenous rhythm that is phase-locked to the reproductive cycle.
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Affiliation(s)
- T Meijer
- Zoological Laboratory, University of Groningen, Haren, The Netherlands
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Abstract
Plasma levels of luteinizing hormone (LH), androgens, and corticosterone (B) were measured in breeding and nonbreeding kestrels, both in the field and in captivity under different food conditions. LH levels in breeding males were elevated from courtship through incubation and androgen concentration peaked during courtship and laying. Seasonal changes in LH and androgens were similar in breeding and nonbreeding males, although androgens declined sharply after laying in breeding males. Egg laying was characterized by marked increases in both female body mass and plasma concentrations of LH and B. In both breeding and nonbreeding females LH and B increased during pair formation and courtship (March-April), although maximum levels were lower in nonbreeders. Two marked differences were found between free-living and captive (paired) birds. First, during winter plasma levels of LH were basal in free-living birds, while significantly elevated in both captive males and females. Second, during courtship androgen levels in breeding males were three-fold higher in the field than in captivity, probably as a result of intermale aggression under natural conditions. Females breeding early, late, or not at all had similar LH concentrations on arrival and during early courtship. Before breeding there were also no differences in LH (males and females) or in androgen levels (males) between pairs fed ad libitum and pairs temporary food rationed. However, captive females with experimentally reduced food intake showed low levels of B until their rations were increased. Nonbreeders showed hormonal changes similar to breeders, except for those changes in females that were associated with laying. These results suggest that at the start of the breeding season both nonbreeding and breeding kestrels have functional reproductive systems. That some breed early, late, or not at all is primarily an effect of food availability and is not due to hormonal modulation of the reproductive cycle.
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Affiliation(s)
- T Meijer
- Zoological Laboratory, University of Groningen, The Netherlands
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Dieleman J, de Jong JW, Meijer T. Acceptor Action of Alkali Metals in II—VI Compounds as Detected by Electron Spin Resonance Techniques. J Chem Phys 1966. [DOI: 10.1063/1.1728091] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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