Search Results - (Author, Cooperation:T. Day)
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1M. Mougeot, D. Atanasov, K. Blaum, K. Chrysalidis, T. Day Goodacre, D. Fedorov, V. Fedosseev, S. George, F. Herfurth, J. D. Holt, D. Lunney, V. Manea, B. Marsh, D. Neidherr, M. Rosenbusch, S. Rothe, L. Schweikhard, A. Schwenk, C. Seiffert, J. Simonis, S. R. Stroberg, A. Welker, F. Wienholtz, R. N. Wolf, and K. Zuber
American Physical Society (APS)
Published 2018Staff ViewPublication Date: 2018-06-08Publisher: American Physical Society (APS)Print ISSN: 0031-9007Electronic ISSN: 1079-7114Topics: PhysicsKeywords: Nuclear PhysicsPublished by: -
2P. Abbot ; J. Abe ; J. Alcock ; S. Alizon ; J. A. Alpedrinha ; M. Andersson ; J. B. Andre ; M. van Baalen ; F. Balloux ; S. Balshine ; N. Barton ; L. W. Beukeboom ; J. M. Biernaskie ; T. Bilde ; G. Borgia ; M. Breed ; S. Brown ; R. Bshary ; A. Buckling ; N. T. Burley ; M. N. Burton-Chellew ; M. A. Cant ; M. Chapuisat ; E. L. Charnov ; T. Clutton-Brock ; A. Cockburn ; B. J. Cole ; N. Colegrave ; L. Cosmides ; I. D. Couzin ; J. A. Coyne ; S. Creel ; B. Crespi ; R. L. Curry ; S. R. Dall ; T. Day ; J. L. Dickinson ; L. A. Dugatkin ; C. El Mouden ; S. T. Emlen ; J. Evans ; R. Ferriere ; J. Field ; S. Foitzik ; K. Foster ; W. A. Foster ; C. W. Fox ; J. Gadau ; S. Gandon ; A. Gardner ; M. G. Gardner ; T. Getty ; M. A. Goodisman ; A. Grafen ; R. Grosberg ; C. M. Grozinger ; P. H. Gouyon ; D. Gwynne ; P. H. Harvey ; B. J. Hatchwell ; J. Heinze ; H. Helantera ; K. R. Helms ; K. Hill ; N. Jiricny ; R. A. Johnstone ; A. Kacelnik ; E. T. Kiers ; H. Kokko ; J. Komdeur ; J. Korb ; D. Kronauer ; R. Kummerli ; L. Lehmann ; T. A. Linksvayer ; S. Lion ; B. Lyon ; J. A. Marshall ; R. McElreath ; Y. Michalakis ; R. E. Michod ; D. Mock ; T. Monnin ; R. Montgomerie ; A. J. Moore ; U. G. Mueller ; R. Noe ; S. Okasha ; P. Pamilo ; G. A. Parker ; J. S. Pedersen ; I. Pen ; D. Pfennig ; D. C. Queller ; D. J. Rankin ; S. E. Reece ; H. K. Reeve ; M. Reuter ; G. Roberts ; S. K. Robson ; D. Roze ; F. Rousset ; O. Rueppell ; J. L. Sachs ; L. Santorelli ; P. Schmid-Hempel ; M. P. Schwarz ; T. Scott-Phillips ; J. Shellmann-Sherman ; P. W. Sherman ; D. M. Shuker ; J. Smith ; J. C. Spagna ; B. Strassmann ; A. V. Suarez ; L. Sundstrom ; M. Taborsky ; P. Taylor ; G. Thompson ; J. Tooby ; N. D. Tsutsui ; K. Tsuji ; S. Turillazzi ; F. Ubeda ; E. L. Vargo ; B. Voelkl ; T. Wenseleers ; S. A. West ; M. J. West-Eberhard ; D. F. Westneat ; D. C. Wiernasz ; G. Wild ; R. Wrangham ; A. J. Young ; D. W. Zeh ; J. A. Zeh ; A. Zink
Nature Publishing Group (NPG)
Published 2011Staff ViewPublication Date: 2011-03-25Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: *Altruism ; Animals ; *Biological Evolution ; Cooperative Behavior ; Female ; Game Theory ; *Genetic Fitness ; Genetics, Population ; Heredity ; Humans ; Male ; *Models, Biological ; Phenotype ; Reproducibility of Results ; *Selection, Genetic ; Sex RatioPublished by: -
3S. Leslie ; B. Winney ; G. Hellenthal ; D. Davison ; A. Boumertit ; T. Day ; K. Hutnik ; E. C. Royrvik ; B. Cunliffe ; D. J. Lawson ; D. Falush ; C. Freeman ; M. Pirinen ; S. Myers ; M. Robinson ; P. Donnelly ; W. Bodmer
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-03-20Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Algorithms ; European Continental Ancestry Group/genetics ; *Genetics, Population ; Great Britain/ethnology ; Haplotypes/*genetics ; Humans ; Polymorphism, Single Nucleotide/*genetics ; Principal Component AnalysisPublished by: -
4Staff View
ISSN: 1477-9730Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Architecture, Civil Engineering, SurveyingNotes: A number of published steromatching algorithms have been implemented and tested on SPOT images of areas for which gridded digital elevation models (DEMs) are available with spacings of 80 m or less, as well as ground control checkpoints.Results are presented for comparison of stereomatched output with the DEMs as well as an analysis of the errors arising and their causes. Results are discussed for planimetrically geocoded and epipolar resampled data. An error budget describing effects due to orientation, feature localisation and matching are discussed and conclusions drawn for future work in this area.Type of Medium: Electronic ResourceURL: -
5Wang, Weizhi ; Fejer, M. M. ; Hammond, R. H. ; Beasley, M. R. ; Ahn, C. H. ; Bortz, M. L. ; Day, T.
Woodbury, NY : American Institute of Physics (AIP)
Published 1996Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: A monitor for Al vapor density based on atomic absorption (AA) using a frequency-doubled external-cavity-diode-laser source at 394 nm has been demonstrated in both evaporation and sputtering processes. Closed loop operation was achieved for electron-beam evaporated aluminum in a vacuum chamber using the AA signal for feedback. A series of runs in a dc sputtering chamber at the deposition rate of 900 A(ring)/min illustrates the system reproducibility and the possibility of controlling the sputtering process and measuring the spatial distribution of the sputtered atoms with the AA monitor. Coherent light in the blue-UV region (380–430 nm) using quasi-phase-matched lithium niobate waveguides was demonstrated with efficiencies of 25–150%/W, a range of wavelengths that covers many technologically important elements in physical vapor deposition processes. © 1996 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
6Staff View
ISSN: 1365-3040Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: We assessed whether growth of garden pea (Pisum sativum mutant Argenteum) was reduced under ecologically relevant enhancements of ultraviolet-B radiation (UV-B, 280–320 nm) by employing modulated field lampbanks which simulated 0, 16 or 24% ozone depiction. In addition, we determined whether enhanced UV-B altered the concentration and distribution of chlorophyll and UV-B-absorbing compounds in leaves, and whether this was dependent on leaf age. There were no significant UV-B effects on the four whole-plant parameters we examined (height, above-ground biomass, total leaflet area or average leaflet area). Of the 12 leaf-level parameters we examined, UV-B had a significant effect (P 〈 0.05) on only one parameter: the ratio of UV-B-absorbing compounds to chlorophyll, which was greatest at the highest UV-B level. Total chlorophyll concentrations tended to be lower under enhanced UV-B (P= 0.11), while the proportion of UV-B-absorbing compounds in the adaxial epidermis tended to be higher (P= 0.11). Total leaf concentrations of UV-B-absorbing compounds were unaffected by UV-B level. Cooler, suboptimal growing conditions during this late summer/early autumn experiment may have masked some potential UV-B effects. In contrast to the UV-B effects, we found strong leaf-age effects on nearly all parameters that we assessed. On an area basis, concentrations of total chlorophyll and UV-B-absorbing compounds increased with leaf age, while Chlorophyll a/b) ratios decreased. One of the few parameters unaffected by leaf age was the ratio of UV-B-absorbing compounds to total chlorophyll, which remained constant within a given UV-B treatment. Pea was much less sensitive to enhanced UV-B than in previous growth-chamber and greenhouse studies, and in nearly all cases UV-B treatment effects were overshadowed by leaf-age effects. In view of the large effect leaf age had on concentrations of UV-B-absorbing compounds, as well as their distribution within leaves, researchers may need to consider leaf age in UV-B experimental designs.Type of Medium: Electronic ResourceURL: -
7Staff View
ISSN: 1365-3040Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: The depth of penetration of Ultraviolet-B (UV-B, 300 and 320 nm) and visible (680 nm) light was measured in foliage of Abies lasiocarpa and Picea engelmannii using a fibre-optic microprobe. Measurements were made on foliage at four times during development: needles were sampled from within expanding buds (in bud); within 72 h of emergence from the bud scales (emergent); from elongating branches (elongating); and from foliage that emerged the previous summer (mature). Light attenuation in pre-emergent needles of both species was steep and showed strong wavelength dependence. Short wavelength 300-nm light was attenuated strongly in the developing epidermal layer, but a significant proportion of this potentially damaging UV-B radiation penetrated into the mesophyll. For A. lasiocarpa and P. engelmannii, 99% attenuation of 300-nm light occurred at 51 and 96 μm, respectively, well within the mesophyll. At this stage, however, the bud scales were opaque to light below 400nm. As the epidermal cell walls and cuticle continued to develop and chlorophyll accumulated following emergence from the bud scales, light attenuation, particularly of UV-B radiation, increased. Although no UV-B is transmitted through the epidermis-hypodermis of mature needles, small but measurable quantities of 300- and 320-nm light were measured in the photosynthetic mesophyll of post-emergent and elongating needles. Thus, shortly after emergence from the bud scales in mid-June to mid-July, when incident UV doses are highest, absorption of UV-B radiation by potentially sensitive chromophores in the mesophyll may disrupt physiological and developmental processes in these species. Soluble UV-absorbing pigments accumulated during needle maturation for P. engelmannii but not A. lasiocarpa, suggesting that, for A. lasiocarpa at least, the development of effective UV screening properties in the epidermis may not be related to the induction of soluble flavonoids.Type of Medium: Electronic ResourceURL: -
8Staff View
ISSN: 1365-3040Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: We examined how ultraviolet-B radiation (UV-B; 300 nm) screening effectiveness changes with leaf age in Rhododendron maximum growing in a shaded understory by measuring depth of penetration and epidermal transmittance with a fibre-optic microprobe. Depth of penetration (and epidermal transmittance) of UV-B decreased with leaf age in 1- to 4-year-old leaves, averaging 62 (32), 52 (22), 45 (16) and 48 μm (13%), respectively. Epidermal thickness increased with age in 1- to 4-year-old leaves due to a thickening of the cuticle from an average of 20 to 29μm. Ultraviolet-B-absorbing compound concentrations increased with age from 1–3 to 1–5 A300 cm−2 leaf area. Concentrations of UV-B-absorbing compounds (area basis) were a strong predictor of depth of penetration (r2= 0.82) and epidermal transmittance (r2= 0.95) of UV-B in mature (1–4 year-old) foliage. Chlorophyll concentrations (area basis) increased in leaves up to 3 years of age. Current-year leaves (30 d old) were exceptional in that while they were particularly effective at screening UV-B (depth of penetration and epidermal transmittance averaged 39μm and 5%, respectively) they had relatively low concentrations of UV-B-absorbing compounds (1.3 A300 cm−2). Our findings show that UV-B-screening effectiveness is not necessarily related to absorbing compound concentrations on a whole-leaf basis, possibly due to anatomical changes within the epidermis that occur with leaf age.Type of Medium: Electronic ResourceURL: -
9Staff View
ISSN: 1365-3040Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: In some plants, particularly herbaceous species, a considerable proportion of incident ultraviolet-B radiation (UV-B, 280-320 nm) penetrates into the leaf mesophyll where it is potentially damaging to nucleic acids and the photosyn-thetic machinery. We used optical techniques to look at the spatial variation in UV-B penetration through the epidermis of foliage of two herbaceous species (Chenopodium album and Smilacina stellata)and a conifer (Picea pun-gens). Measurements of UV-B penetration in intact foliage with a fibre-optic microprobe revealed that 300 nm radiation reached 161±36μm (mean±SD) into leaves of C. album, 154±40μm in S. stellata and 17±2μm in P. pungens, with epidermal transmittance being 39±14%, 55±19% and 0%, respectively. A thin polymer film was developed which fluoresced blue when irradiated by UV-B. Fresh epidermal leaf peels were placed over the film and irradiated with UV-B, and microscopic examination of the film from below allowed us to determine the spatial pattern of UV-B penetration through the epidermis. In herbaceous species, film fluorescence below cell walls, but not epidermal and guard cell protoplasts indicated that UV-B transmittance was much greater through anticlinal cell wall regions than protoplasts. Ultraviolet-B transmittance through large areas of epidermal cells could be induced by plasmolysis. Epidermal transmittance was also relatively high through stomal pores (and what appear to be nuclei in Smilacina), but relatively low through stomatal guard cells. Results from the fluorescing film technique were substantiated by direct measurements of UV-B transmittance through epidermal peels with a fibre-optic microprobe run paradermally along the bottom or inner side of irradiated peels. In Smilacina, we estimate that UV-B epidermal transmittance was up to 90% through anticlinal cell wall regions, but 〈10% through protoplast areas. In contrast to herbaceous species, we did not detect any UV-B transmittance through the epidermis of P. pungens with either the fluorescing film or the fibre-optic microprobe technique. The epidermis appears to be a much more spatially uniform UV-B filter in conifers than in these herbaceous species.Type of Medium: Electronic ResourceURL: -
10Dayas, C. V. ; Xu, Y. ; Buller, K. M. ; Day, T. A.
Oxford, UK : Blackwell Science Ltd
Published 2000Staff ViewISSN: 1365-2826Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: Oestrogen replacement therapy reportedly suppresses hypothalamic-pituitary-adrenal (HPA) axis responses to an emotional stressor in postmenopausal women. However, most studies in the rat suggest a facilitatory role for oestrogen in the control of HPA axis function. One explanation for this difference may be the regimen of oestrogen replacement: during oestrogen replacement therapy, oestrogen levels are low and constant whereas most animal studies examined the HPA axis response when oestrogen levels are rising. In the present study, we assessed HPA axis stress responses in mature ovariectomized rats after plasma oestrogen levels had been maintained at physiological levels for a prolonged period (25 or 100 pg/ml for 7 days). In the case of both an emotional stressor (noise) and a physical stressor (immune challenge by systemic interleukin-1β administration), oestrogen replacement suppressed stress-related Fos-like immunolabelling, in hypothalamic neuroendocrine cells and plasma adrenocorticotropin hormone responses. From the present data, and past reports, it appears unlikely that these effects of oestrogen are due to a direct action on corticotropin-releasing factor or oxytocin cells. Therefore, to obtain some indication of oestrogen's possible site(s) of action, Fos-like immunolabelling was mapped in the amygdala and in brainstem catecholamine groups, which are neuronal populations demonstrating substantial evidence of involvement in the generation of HPA axis stress responses. In the amygdala, oestrogen replacement suppressed central nucleus responses to immune challenge, but not to noise. Amongst catecholamine cells, oestrogen replacement was more effective against responses to noise than immune challenge, suppressing A1 and A2 (noradrenergic) and C2 (adrenergic) responses to noise, but only A1 responses to immune challenge. These data suggest that, as in postmenopausal women on oestrogen replacement therapy, chronic low-level oestrogen replacement can suppress HPA axis stress responses in the rat. Moreover, oestrogen appears to exert effects at multiple sites within putative HPA axis control pathways, even though most of the relevant neuronal populations do not contain genomic receptors for this gonadal steroid and the pattern of oestrogen action differs for an emotional vs a physical stressor.Type of Medium: Electronic ResourceURL: -
11Staff View
ISSN: 1460-9568Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: Previous studies have shown that the medial prefrontal cortex can suppress the hypothalamic–pituitary–adrenal axis response to stress. However, this effect appears to vary with the type of stressor. Furthermore, the absence of direct projections between the medial prefrontal cortex and corticotropin-releasing factor cells at the apex of the hypothalamic–pituitary–adrenal axis suggest that other brain regions must act as a relay when this inhibitory mechanism is activated. In the present study, we first established that electrolytic lesions involving the prelimbic and infralimbic medial prefrontal cortex increased plasma adrenocorticotropic hormone levels seen in response to a physical stressor, the systemic delivery of interleukin-1β. However, medial prefrontal cortex lesions did not alter plasma adrenocorticotropic hormone levels seen in response to a psychological stressor, noise. To identify brain regions that might mediate the effect of medial prefrontal cortex lesions on hypothalamic–pituitary–adrenal axis responses to systemic interleukin-1β, we next mapped the effects of similar lesions on interleukin-1β-induced Fos expression in regions previously shown to regulate the hypothalamic–pituitary–adrenal axis response to this stressor. It was found that medial prefrontal cortex lesions reduced the number of Fos-positive cells in the ventral aspect of the bed nucleus of the stria terminalis. However, the final experiment, which involved combining retrograde tracing with Fos immunolabelling, revealed that bed nucleus of the stria terminalis-projecting medial prefrontal cortex neurons were largely separate from medial prefrontal cortex neurons recruited by systemic interleukin-1β, an outcome that is difficult to reconcile with a simple medial prefrontal cortex–bed nucleus of the stria terminalis–corticotropin-releasing factor cell control circuit.Type of Medium: Electronic ResourceURL: -
12Staff View
ISSN: 1460-9568Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: The amygdala plays a pivotal role in the generation of appropriate responses to emotional stimuli. In the case of emotional stressors, these responses include activation of the hypothalamic–pituitary–adrenal (HPA) axis. This effect is generally held to depend upon the central nucleus of the amygdala, but recent evidence suggests a role for the medial nucleus. In the present study, c-fos expression, amygdala lesion and retrograde tracing experiments were performed on adult rats in order to re-evaluate the role of the central as opposed to the medial amygdala in generating neuroendocrine responses to an emotional stressor. Brief restraint (15 min) was used as a representative emotional stressor and was found to elicit c-fos expression much more strongly in the medial than central nucleus of the amygdala; relatively few Fos-positive cells were seen in other amygdala nuclei. Subsequent experiments showed that ibotenic acid lesions of the medial amygdala, but not the central amygdala, greatly reduced restraint-induced activation of cells of the medial paraventricular nucleus, the site of the tuberoinfundibular corticotropin-releasing factor cells that constitute the apex of the HPA axis. Medial amygdala lesions also reduced the activation of supraoptic and paraventricular nucleus oxytocinergic neurosecretory cells that commonly accompanies stress-induced HPA axis activation in rodents. To assess whether the role of the medial amygdala in the control of neuroendocrine cell responses to emotional stress might involve a direct projection to such cells, retrograde tracing of amygdala projections to the paraventricular nucleus was performed in combination with Fos immunolabelling. This showed that although some medial amygdala cells activated by exposure to an emotional stressor project directly to the paraventricular nucleus, the number is very small. These findings provide the first direct evidence that it is the medial rather than the central amygdala that is critical to hypothalamic neuroendocrine cell responses during an emotional response, and also provide the first evidence that the amygdala governs oxytocin as well as HPA axis responses to an emotional stressor.Type of Medium: Electronic ResourceURL: -
13Staff View
ISSN: 1460-9568Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: Psychological stressors trigger the activation of medullary noradrenergic cells, an effect that has been shown to depend upon yet-to-be-identified structures located higher in the brain. To test whether the amygdala is important in this regard, we examined the effects of amygdala lesions on noradrenergic cell responses to restraint, and also looked at whether any amygdala cells that respond to restraint project directly to the medulla. Ibotenic acid lesions of the medial amygdala completely abolished restraint-induced Fos expression in A1 and A2 noradrenergic cells. In contrast, lesions of the central amygdala actually facilitated noradrenergic cell responses to restraint. Tracer deposits in the dorsomedial (but not ventrolateral) medulla retrogradely labelled many cells in the central nucleus of the amygdala, but none of these cells expressed Fos in response to restraint. These data suggest for the first time that the medial amygdala is critical to the activation of medullary noradrenergic cells by a psychological stressor whereas the central nucleus exerts an opposing, inhibitory influence upon noradrenergic cell recruitment. The initiation of noradrenergic cell responses by the medial amygdala does not involve a direct projection to the medulla. Accordingly, a relay through some other structure, such as the hypothalamic paraventricular nucleus, warrants careful consideration.Type of Medium: Electronic ResourceURL: -
14Staff View
ISSN: 1460-9568Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: Recent investigations have implicated the medial prefrontal cortex (mPFC) in modulation of subcortical pathways that contribute to the generation of behavioural, autonomic and endocrine responses to stress. However, little is known of the mechanisms involved. One of the key neurotransmitters involved in mPFC function is dopamine, and we therefore aimed, in this investigation, to examine the role of mPFC dopamine in response to stress in Wistar rats. In this regard, we infused dopamine antagonists SCH23390 or sulpiride into the mPFC via retrodialysis. We then examined changes in numbers of cells expressing the c-fos immediate-early gene protein product, Fos, in subcortical neuronal populations associated with regulation of hypothalamic-pituitary-adrenal (HPA) axis stress responses in response to either of two stressors; systemic injection of interleukin-1β, or air puff. The D1 antagonist, SCH23390, and the D2 antagonist, sulpiride, both attenuated expression of Fos in the medial parvocellular hypothalamic paraventricular nucleus (mpPVN) corticotropin-releasing factor cells at the apex of the HPA axis, as well as in most extra-hypothalamic brain regions examined in response to interleukin-1β. By contrast, SCH23390 failed to affect Fos expression in response to air puff in any brain region examined, while sulpiride resulted in an attenuation of the air puff-induced response in only the mpPVN and the bed nucleus of the stria terminalis. These results indicate that the mPFC differentially processes the response to different stressors and that the two types of dopamine receptor may have different roles.Type of Medium: Electronic ResourceURL: -
15Boulton, G. S. ; Baldwin, C. T. ; Peacock, J. D. ; McCabe, A. M. ; Miller, G. ; Jarvis, J. ; Horsefield, B. ; Worsley, P. ; Eyles, N. ; Chroston, P. N. ; Day, T. E. ; Gibbard, P. ; Hare, P. E. ; von Brunn, V.
[s.l.] : Nature Publishing Group
Published 1982Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] Strong early Holocene crustal uplift over the Spitsbergen archipelago reflects disappearance of an ice mass centred just north-east of the archipelago and which decayed rapidly just after 10,000 BP after a maximum extension between 12,600 and 10,000 BP. From the lithofacies distributions associated ...Type of Medium: Electronic ResourceURL: -
16Staff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] IN 1876, W. Flemming1 described a cementing substance associated with the fibrils of loose connective tissue. This finding is of considerable importance in relation to modern conceptions of the chemical structure of collagen and other fibrous proteins. There is reason to ...Type of Medium: Electronic ResourceURL: -
17Staff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] A true comparable incidence can be obtained from the figures for the three doses of stored smoke condensate (Table 1). Table 1 Dose Date of Initial start of No. of experiment animals Tumour-bearing animals Total Carcinoma Small (75 mg/week) "1 ^ October 660 5-8% 1-1% Medium (150 ...Type of Medium: Electronic ResourceURL: -
18Murray, J.B. ; Rothery, D.A. ; Thornhill, G.D. ; Muller, J.-P. ; Iliffe, J.C. ; Day, T. ; Cook, A.C.
Amsterdam : ElsevierStaff ViewISSN: 0032-0633Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: GeosciencesPhysicsType of Medium: Electronic ResourceURL: -
19Staff View
ISSN: 0168-1605Keywords: Bacillus cereus ; Enterotoxin ; Germination ; Heat resistance ; PsychrotrophicSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Process Engineering, Biotechnology, Nutrition TechnologyType of Medium: Electronic ResourceURL: -
20Staff View
ISSN: 1399-3054Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: We compared photosynthetic and UV-B-absorbing pigment concentrations, gas-exchange rates and photosystem II (PSII) electron transport rates in leaves of pea (Pisum sativum mutant Argenteum) grown without UV-B or under an enhanced UV-B treatment (18 kJ m−2 biologically effective daily dose) in a greenhouse. We also compared the distribution of chlorophyll by depth within leaves of each treatment by using image analysis of chlorophyll autofluorescence. Ultraviolet-B treatment elicited putative protective responses such as an 80% increase in UV-B-absorbing compound concentrations (leaf-area basis), and a slight increase in mesophyll thickness (178 in controls compared to 191 μm in UV-B-treated leaves). However, photosynthetic rates of UV-B-treated leaves were only 80% of those of controls. This was paralleled by reductions in leaf conductance to water vapor (50% of controls) and intercellular CO2 concentrations, suggesting that stomatal limitations were at least partly responsible for lower photosynthetic rates under the UV-B treatment. Total chlorophyll concentrations (leaf-area basis) in UV-B-treated leaves were only 70% of controls, and there was a shift in the relative distribution of chlorophyll with depth in UV-B-treated leaves. In control leaves chlorophyll concentrations were highest near the adaxial surface of the upper palisade, dropped with depth and then increased slightly in the bottom of the spongy mesophyll nearest the abaxial surface. In contrast, in UV-B-treated leaves chlorophyll concentrations were lowest at the adaxial surface of the upper palisade and increased with depth through the leaf. The most notable treatment difference in chlorophyll concentrations was in the upper palisade near the adaxial surface of leaves, where we estimate that chlorophyll concentrations in each 1-μm-thick paradermal layer were about 50% lower in UV-B-treated leaves than in controls. We found reduced electron transport capacity in UV-B-treated leaves, based on lower maximum fluorescence (Fm), variable to maximum fluorescence ratios (F,/Fm) and quantum yield of PSII electron transport (Y). However, the above were assessed from fluorometer measurements on the adaxial leaf surface and may reflect the markedly lower chlorophyll concentrations in the upper palisade of UV-B-treated leaves.Type of Medium: Electronic ResourceURL: