scholarly journals EVIDENCE FOR THERMAL REACTIONS FOLLOWING EXPOSURE OF DIDINIUM TO INTERMITTENT ULTRAVIOLET RADIATIONS

1956 ◽  
Vol 40 (2) ◽  
pp. 311-325 ◽  
Author(s):  
A. C. Giese ◽  
D. C. Shepard ◽  
J. Bennett ◽  
A. Farmanfarmaian ◽  
C. L. Brandt
Keyword(s):  
High Intensity ◽  
Dark Period ◽  
Wave Length ◽  
Reasonable Assumption ◽  
Lower Intensity ◽  
Division Rate ◽  
General Application ◽  
Thermal Reactions ◽  
Wide Range ◽  
Continuous Radiation

1. The nature of ultraviolet injury and its variation with the same dose given at different intensities and wave lengths have been investigated in the protozoan Didinium nasutum, using time to the fourth division as a measure of injury. 2. The injury has been found to consist of a "slowdown" of division rate, which always occurs, and a "stasis," usually at the second division after irradiation, which appears in varying degrees among more severely injured samples. 3. Injury was found to be almost independent of intensity at three wave lengths out of four studied over a wide range of intermediate and high intensities, but was found to rise sharply with lower intensity at all except the longest wave length. 4. Flashed UV of high intensity is much more effective than the same dose of continuous radiation at high intensity and shorter total time of treatment. It is also more effective than the same dose at low intensity and equal time of treatment, though only slightly so. 5. An increase of injury with rise of temperature and with increase of dark period clearly indicates that injury depends on thermochemical reactions following the absorption of UV in Didinium. 6. The most reasonable assumption is that a similar conclusion applies to other organisms as well, and that its general application may be useful in the investigation of UV effects on protoplasm.

scholarly journals The continuous absorption of light in potassium vapour

1928 ◽  
Vol 117 (777) ◽  
pp. 486-508 ◽  
Keyword(s):  
Vapour Pressure ◽  
Alkali Metals ◽  
Wave Length ◽  
Experimental Conditions ◽  
General Application ◽  
Continuous Absorption ◽  
Wide Range ◽  
Absorption Of Light ◽  
Relative Absorption ◽  
Band Absorption

While considerable attention has been paid to the line and band absorption of the alkali metals, very little work has been done on the continuous absorption. R. W. Wood and Holtzmark have observed the existence of this absorption, and Harrison has made some measurements on the continuous absorption of sodium in the region 2500 Å. U. - 2150 Å. U. In the present paper, results are given for potassium over a wide range of wave-length (4000 Å. U. - 2200 Å. U.) and under widely different experimental conditions. The ordinary methods of spectrophotometry have usually been designed to measure the absorption of solutions, etc., and are not suitable for measuring the absorption in a vapour unless the vapour pressure can be kept absolutely constant. A method of spectrophotometry has been developed by which it is possible to obtain measurements of the relative absorption coefficients for different wave-lengths correct to about 2 per cent, without keeping the vapour pressure absolutely constant. While the method is specially suitable for the measurement of an absorption which is not quite steady, it is really of quite general application.

scholarly journals INCREASED PHOTOREVERSAL OF ULTRAVIOLET INJURY BY FLASHING LIGHT

1956 ◽  
Vol 39 (4) ◽  
pp. 513-526 ◽  
Author(s):  
E. Christensen ◽  
A. C. Giese
Keyword(s):  
High Intensity ◽  
Wave Length ◽  
Continuous Light ◽  
Tetrahymena Pyriformis ◽  
Sublethal Dose ◽  
Division Rate ◽  
Intermittent Light ◽  
Reciprocity Law ◽  
Division Pattern ◽  
Living Organisms

1. Photoreversal of ultraviolet (UV) injury was studied in the ciliate protozoan Tetrahymena pyriformis (geleii) strain W, cultured in the absence of other living organisms. The division pattern of progeny of single animals was followed in hanging drop preparations. 2. A sublethal dose of 450 ergs/mm.2 of monochromatic UV of wave length 2654 A produces a lag before the first division followed by a period of cessation of fission after the second division. This cessation sometimes lasts as long as 6 weeks, during which time the animals become smaller and rounder and more opaque. Organisms about to resume division increase in size and transparency; after a few divisions the animals regain their normal division rate. 3. The effect of UV ranging in intensity from 5 to 15 ergs/mm.2/sec. was found to obey the reciprocity law quite well for the UV effect on the division pattern of T. pyriformis. However, the same dose at lower and at higher intensities was less effective. 4. The effect of a dose of UV delivered at high intensity (19 ergs/mm.2/sec.) could be increased by flashing the light, indicating that the system became saturated in the continuous light. 5. A photoreversing dose of monochromatic blue light of wave length 4350 A was found to be more effective when delivered as continuous light at a low intensity, or as intermittent light at a high intensity, rather than as continuous light at the high intensity—indicating that a dark mechanism participates in photoreversal. 6. The time for the dark reaction was determined to be of the order of a few hundredths of a second in experiments in which different lengths of dark period were used while maintaining a constant light period of 0.0025 second. 7. For Colpidium colpoda the efficiency of a given dose of photoreversing light was increased by flashing the light. 8. The present experiments are interpreted in terms of data available in the literature.

scholarly journals Non-Coding RNAs in the Transcriptional Network That Differentiates Skeletal Muscles of Sedentary from Long-Term Endurance- and Resistance-Trained Elderly

2021 ◽  
Vol 22 (4) ◽  
pp. 1539
Author(s):  
Paola De Sanctis ◽  
Giuseppe Filardo ◽  
Provvidenza Maria Abruzzo ◽  
Annalisa Astolfi ◽  
Alessandra Bolotta ◽  
...  
Keyword(s):  
Exercise Training ◽  
High Intensity ◽  
Vastus Lateralis ◽  
Mammalian Target Of Rapamycin ◽  
Differentially Expressed ◽  
Transcriptional Networks ◽  
Vastus Lateralis Muscle ◽  
Age Related ◽  
Wide Range ◽  
Non Coding Rnas

In a previous study, the whole transcriptome of the vastus lateralis muscle from sedentary elderly and from age-matched athletes with an exceptional record of high-intensity, life-long exercise training was compared—the two groups representing the two extremes on a physical activity scale. Exercise training enabled the skeletal muscle to counteract age-related sarcopenia by inducing a wide range of adaptations, sustained by the expression of protein-coding genes involved in energy handling, proteostasis, cytoskeletal organization, inflammation control, and cellular senescence. Building on the previous study, we examined here the network of non-coding RNAs participating in the orchestration of gene expression and identified differentially expressed micro- and long-non-coding RNAs and some of their possible targets and roles. Unsupervised hierarchical clustering analyses of all non-coding RNAs were able to discriminate between sedentary and trained individuals, regardless of the exercise typology. Validated targets of differentially expressed miRNA were grouped by KEGG analysis, which pointed to functional areas involved in cell cycle, cytoskeletal control, longevity, and many signaling pathways, including AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR), which had been shown to be pivotal in the modulation of the effects of high-intensity, life-long exercise training. The analysis of differentially expressed long-non-coding RNAs identified transcriptional networks, involving lncRNAs, miRNAs and mRNAs, affecting processes in line with the beneficial role of exercise training.

scholarly journals Effects of Two Workload-Matched High-Intensity Interval Training Protocols on Regional Body Composition and Fat Oxidation in Obese Men

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1096
Author(s):  
Spyridon Tsirigkakis ◽  
George Mastorakos ◽  
Yiannis Koutedakis ◽  
Vassilis Mougios ◽  
Alan M. Nevill ◽  
...  
Keyword(s):  
Body Composition ◽  
High Intensity ◽  
Interval Training ◽  
Fat Oxidation ◽  
Peak Oxygen Uptake ◽  
High Intensity Interval Training ◽  
Randomized Design ◽  
Wide Range ◽  
Regional Body Composition ◽  
High Intensity Interval

The effects of two high-intensity interval training (HIIT) protocols on regional body composition and fat oxidation in men with obesity were compared using a parallel randomized design. Sixteen inactive males (age, 38.9 ± 7.3 years; body fat, 31.8 ± 3.9%; peak oxygen uptake, VO2peak, 30.9 ± 4.1 mL/kg/min; all mean ± SD) were randomly assigned to either HIIT10 (48 × 10 s bouts at 100% of peak power [Wpeak] with 15 s of recovery) or HIIT60 group (8 × 60 s bouts at 100% Wpeak with 90 s of recovery), and subsequently completed eight weeks of training, while maintaining the same diet. Analyses of variance (ANOVA) showed only a main effect of time (p < 0.01) and no group or interaction effects (p > 0.05) in the examined parameters. Total and trunk fat mass decreased by 1.81 kg (90%CI: −2.63 to −0.99 kg; p = 0.002) and 1.45 kg (90%CI: −1.95 to −0.94 kg; p < 0.001), respectively, while leg lean mass increased by 0.86 kg (90%CI: 0.63 to 1.08 kg; p < 0.001), following both HIIT protocols. HIIT increased peak fat oxidation (PFO) (from 0.20 ± 0.05 to 0.33 ± 0.08 g/min, p = 0.001), as well as fat oxidation over a wide range of submaximal exercise intensities, and shifted PFO to higher intensity (from 33.6 ± 4.6 to 37.6 ± 6.7% VO2peak, p = 0.039). HIIT, irrespective of protocol, improved VO2peak by 20.0 ± 7.2% (p < 0.001), while blood lactate at various submaximal intensities decreased by 20.6% (p = 0.001). In conclusion, both HIIT protocols were equally effective in improving regional body composition and fat oxidation during exercise in obese men.

Improvement of the Detection Sensitivity of Edxrf Trace Element Analysis by Means of Efficient X-Ray Focusing Based on Strongly Curved Hopg Crystals

1995 ◽  
Vol 39 ◽  
pp. 109-117
Author(s):  
Burkhard Beckhoff ◽  
Birgit Kanngießer
Keyword(s):  
High Intensity ◽  
Focal Plane ◽  
Bragg Reflection ◽  
Pyrolytic Graphite ◽  
Trace Element Analysis ◽  
Detection Sensitivity ◽  
Element Analysis ◽  
X Ray ◽  
Wide Range ◽  
Very High

X-ray focusing based on Bragg reflection at curved crystals allows collection of a large solid angle of incident radiation, monochromatization of this radiation, and condensation of the beam reflected at the crystal into a small spatial cross-section in a pre-selected focal plane. Thus, for the Bragg reflected radiation, one can achieve higher intensities than for the radiation passing directly to the same small area in the focal plane. In that case one can profit considerably from X-ray focusing in an EDXRF arrangement. The 00 2 reflection at Highly Oriented Pyrolytic Graphite (HOPG) crystals offers a very high intensity of the Bragg reflected beam for a wide range of photon energies. Furthermore, curvature radii smaller than 10 mm can be achieved for HOPG crystals ensuring efficient X-ray focusing in EDXRF applications. For the trace analysis of very small amounts of specimen material deposited on small areas of thin-filter backings, HOPG based X-ray focusing may be used to achieve a very high intensity of monochromatic excitation radiation.

scholarly journals The Role of Methyl Groups in the Early Stage of Thermal Polymerization of Polycyclic Aromatic Hydrocarbons Revealed by Molecular Imaging

2020 ◽  
Author(s):  
Pengcheng Chen ◽  
Shadi Fatayer ◽  
Bruno Schuler ◽  
Jordan N. Metz ◽  
Leo Gross ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Early Stage ◽  
Complex Mixture ◽  
Thermal Polymerization ◽  
Industrial Applications ◽  
Thermal Reactions ◽  
Force Microscopy ◽  
Wide Range ◽  
Polycyclic Aromatic

The initial thermal reactions of aromatic hydrocarbons are relevant to many industrial applications. However, tracking the growing number of heavy polycyclic aromatic hydrocarbon (PAH) products is extremely challenging because many reactions are unfolding in parallel from a mixture of molecules. Herein, we studied the reactions of 2,7-dimethylpyrene (DMPY) to decipher the roles of methyl substituents during mild thermal treatment. We found that the presence of methyl substituents is key for reducing the thermal severity required to initiate chemical reactions in natural molecular mixtures. A complex mixture of thermal products including monomers, dimers, and trimers were characterized by NMR, mass spectrometry and non-contact atomic force microscopy (nc-AFM). A wide range of structural transformations including methyl transfer and polymerization reactions were identified. A detailed mechanistic understanding was obtained on the roles of H radicals during the polymerization of polycyclic aromatic hydrocarbons.

Mechanical effect of an electric field on nanostructure elements

2021 ◽  
Vol 3 ◽  
pp. 79-82
Author(s):  
V. P. Babaev ◽  
◽  
S. V. Zaitsev ◽  
K. A. Inshakova ◽  
A. N. Shaykin ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Potential ◽  
High Intensity ◽  
Structural Damage ◽  
High Surface ◽  
Mechanical Effect ◽  
Surface Curvature ◽  
Electrical Discharges ◽  
Experimental Estimation ◽  
Wide Range

A computational and experimental estimation of the magnitude of forces acting in a high-intensity electric field on elements of nanoconstructions with a high surface curvature is made. Depending on the magnitude of the electric potential and vacuum conditions, these forces can vary both in magnitude and direction over a wide range. They can cause structural damage, as well as provoke unwanted electrical discharges. The possibilities of useful application of these effects are analyzed.

whom one would like to have as a friend, a member vertu, and publick civility’ (1953–82:1.816). of the family, or a guest, or whom one would call a The sources of the virtue may be found in Renais-gentleman. (The praise given him at i3.1–5 would sance moral manuals, such as Elyot’s Gouernour not apply to any other knight.) According to Colin, (1531) with its first book treating ‘the best fourme those who possess the virtue may be recognized by of education or bringing up of noble children’ and the gifts given them by the Graces: ‘comely carriage, the planned second volume aiming to cover ‘all the entertainement kynde, | Sweete semblaunt, friendly reminant . . . apt to the perfection of a iuste publike offices that bynde’ (x 23.4–5) – or rather, according weale’ (1.2); or in Seneca’s De Beneficiis (tr. Arthur to the proem, given them by Elizabeth from whom Golding in 1578), as Archer 1987 argues; or in all virtues well ‘Into the rest, which round about you such courtesy books as Castiglione’s Courtier (1528, ring, | Faire Lords and Ladies, which about you tr. 1561) in which ‘The Count with golden vertue dwell, | And doe adorne your Court, where courtes-deckes’ the court, as Sackville wrote in its praise; and ies excell’ (7.7–9). especially Guazzo’s Civile Conversation (1574, tr. It follows, as Spenser acknowledges in the opening 1581/1586; see VI i 1.6n), for sections of it were line of canto i, ‘Of Court it seemes, men Courtesie included in Bryskett’s Discourse of Civill Life, which doe call’. In its wide range of meanings, the simplest claims to report his conversation with Spenser on is courtly etiquette and good manners. In this sense, moral philosophy. The full title of this last work, A it is more a social than a moral virtue, and therefore discourse, containing the ethicke part of morall philo-open to being feigned, as evident in the ‘faire dis-sophie: fit to instruct a gentleman in the course of a sembling curtesie’ seen by Colin at Elizabeth’s court vertuous life, could serve as a subtitle of Spenser’s (Colin Clout 700), which is ‘nought but forgerie’ poem, especially since Bryskett tells Lord Grey that (VI proem 5.3). While it is the virtue most closely his end is ‘to discourse upon the morall vertues, yet associated with the Elizabethan court and Elizabe-not omitting the intellectuall, to the end to frame a than culture generally, Spenser’s treatment of it goes gentleman fit for civill conversation, and to set him far beyond his own culture. As Chang 1955:202–20 in the direct way that leadeth him to his civill felicitie’ shows, it has an illuminating counterpart in the (6). See ‘courtesy books’ in the SEnc. Confucian concept of ritual. Spenser fashions a virtue As the final book of the 1596 edition, appropri-that may best be called civility, which is the basis ately Book VI raises larger questions about the whole of civilization; see VI proem 4.5n. Yet civility in poem. One such question is the relation of Spenser’s its political expression could legitimize violence in art to nature, and, for a generation of critics, the Ireland, as P. Stevens 1995 notes, and it is not sur-seminal essay has been ‘A Secret Discipline’ by Harry prising to see the patron of courtesy slaughtering the Berger, Jr, in which he concludes that ‘the secret (Irish) brigands at VI xi 46. Accordingly, its link with discipline of imagination is a double burden, discord-Machiavelli’s virtù has been rightly noted by Neuse ant and harmonious: first, its delight in the power 1968 and Danner 1998. On its general application and freedom of art; second, the controlled surrender to the uncertain human condition, see Northrop whereby it acknowledges the limits of artifice’ 2000. Ideally, though, it is the culminating moral (1988:242; first pub. 1961). As chastity is to Brito-virtue of The Faerie Queene, and, as such, has the mart, courtesy is to Calidore: the virtue is natural religious sense expressed by Peter in addressing those to him. He is courteous ‘by kind’ (ii 2.2): ‘gentle-whose faith, according to the Geneva gloss, is con-nesse of spright | And manners mylde were planted firmed ‘by holines of life’: ‘be ye all of one minde: naturall’ (i 2.3–4). It is natural also to Tristram one suffre with another: loue as brethren: be pitiful: because of his noble birth (ii 24) and proper nurtur-be courteous’ (1 Peter 3.8); see, for example, ing, as shown by his defence of the lady abused by Morgan 1981, and Tratner 1990:147–57. Without her discourteous knight. Its powers are shown in the courtesy’s ‘civility’ there would be no civilization; three opening cantos: Calidore may reform both without its ‘friendly offices that bynde’ (x 23.5), Crudor when he is threatened with death, and his there would be no Christian community. By includ-lady, Briana, who is ‘wondrously now chaung’d, ing courtesy among the virtues, Spenser fulfils from that she was afore’ (i 46.9) when she sees the Milton’s claim in Reason of Church Government that change in him (41–43). Also, he may restore Aldus

2014 ◽  
pp. 37-37
Keyword(s):  
Moral Virtue ◽  
Human Condition ◽  
Faerie Queene ◽  
Double Burden ◽  
Christian Community ◽  
General Application ◽  
1 Peter ◽  
Wide Range ◽  
The Family ◽  
The Faerie Queene

Variability in photoperiod and the inhibition of flowering in a high latitude population of Saxifraga rivularis

1981 ◽  
Vol 59 (3) ◽  
pp. 388-391 ◽  
Author(s):  
J. A. Teeri ◽  
S. J. Tonsor
Keyword(s):  
High Latitude ◽  
High Intensity ◽  
Dark Period ◽  
Controlled Environment ◽  
Photoperiodic Control ◽  
Incandescent Light ◽  
Devon Island ◽  
Low Intensity ◽  
Long Day ◽  
Long Day Plants

A population of Saxifraga rivularis L. collected at Truelove Lowland, Devon Island, N.W.T., Canada (75°41′ N) exhibits a photoperiodic control of flowering in controlled environment chambers. The plants respond in a manner typical of long-day plants with flowering inhibited by either a 6-h daily dark period, or by a 6-h daily low intensity irradiance regime of incandescent light. The inhibition of flowering by 6 h day−1 of incandescent light does not occur if the incandescent light is given in twelve 0.5-h doses, each followed by 1 h of red-rich high intensity irradiance.

Breaking of shoaling internal solitary waves

2010 ◽  
Vol 659 ◽  
pp. 289-317 ◽  
Author(s):  
PAYAM AGHSAEE ◽  
LEON BOEGMAN ◽  
KEVIN G. LAMB
Keyword(s):  
Boundary Layer ◽  
Solitary Waves ◽  
Wave Length ◽  
Boundary Layer Separation ◽  
Developmental Time ◽  
Internal Solitary Waves ◽  
Global Instability ◽  
Layer Separation ◽  
Wide Range ◽  
High Reynolds

The breaking of fully nonlinear internal solitary waves of depression shoaling upon a uniformly sloping boundary in a smoothed two-layer density field was investigated using high-resolution two-dimensional simulations. Our simulations were limited to narrow-crested waves, which are more common than broad-crested waves in geophysical flows. The simulations were performed for a wide range of boundary slopes S ∈ [0.01, 0.3] and wave slopes extending the parameter range to weaker slopes than considered in previous laboratory and numerical studies. Over steep slopes (S ≥ 0.1), three distinct breaking processes were observed: surging, plunging and collapsing breakers which are associated with reflection, convective instability and boundary-layer separation, respectively. Over mild slopes (S ≤ 0.05), nonlinearity varies gradually and the wave fissions into a train of waves of elevation as it passes through the turning point where solitary waves reverse polarity. The dynamics of each breaker type were investigated and the predominance of a particular mechanism was associated with a relative developmental time scale. The breaking location was modelled as a function of wave amplitude (a), characteristic wave length and the isopycnal length along the slope. The breaker type was characterized in wave slope (Sw = a/Lw, where Lw is a measure of half of the wavelength) versus S space, and the reflection coefficient (R), modelled as a function of the internal Iribarren number, was in agreement with other studies. The effects of grid resolution and wave Reynolds number (Rew) on R, boundary-layer separation and the evolution of global instability were studied. High Reynolds numbers (Rew ~ 104) were found to trigger a global instability, which modifies the breaking process relative to the lower Rew case, but not necessarily the breaking location, and results in a ~ 10 % increase in R, relative to the Rew ~ 103 case.

Sign in / Sign up

Export Citation Format

Share Document