XIX.—Photochemical Measurements of Light Intensity in Two Common Vegetation Types in Tropical Africa, by Means of the Improved Eder-Hecht Photometer

1932 ◽  
Vol 51 ◽  
pp. 150-161 ◽  
Author(s):  
John Phillips ◽  
J. D. Scott ◽  
J. Y. Moggridge
Keyword(s):  
Light Intensity ◽  
Ultraviolet Rays ◽  
Portable Instrument ◽  
Vegetation Types ◽  
Tropical Africa ◽  
Central Plateau ◽  
Positive Correlation ◽  
The Hours ◽  
In Virtue Of ◽  
Very High

Summary(1) A year's measurement of the light-intensity in an exposed site (“mbuga”) and in a Berlinia woodland community, Kikori (4° 21' S.), Tanganyika, by means of the Eder-Hecht Graukeilphotometer is described.(2) The Bunsen-Roscoe units per second are shown to be very high, even under canopy of the Berlinia; they are very much greater than measurements recorded by Dorno for Assuan and Rio de Janeiro.(3) While there is a positive correlation between the B.-R. values and the hours of direct sunshine, it is also clear that during cloudy periods (less than 50 per cent, of possible sunshine is experienced at Kikori and on the Central Plateau of East Africa generally) the B.-R. values are also very high.(4) There is a positive correlation between the values of the Eder-Hecht photometer (in terms of blue-violet-ultraviolet rays), and the readings of the Livingston radio-atmometer measuring the total light-intensity of the same stations in terms of cubic centimetres of water.(5) In virtue of the peculiar effects of the light of Tropical Africa upon the European nervous system, it is urged that quantitative and qualitative studies of the light in those regions should be investigated.(6) Field biologists should make greater use of this efficient, cheap, simple, and portable instrument.

The Use of Ecological Tolerances for the Reconstruction of Tertiary Palaeoclimates

1997 ◽  
Vol 45 (3) ◽  
pp. 475 ◽  
Author(s):  
Helene A. Martin
Keyword(s):  
Vegetation Types ◽  
Climatic Parameters ◽  
Salt Tolerant ◽  
Pollen Assemblage ◽  
Pollen Types ◽  
Living Species ◽  
Marine Influence ◽  
Lagarostrobos Franklinii ◽  
Single Living ◽  
Very High

The major vegetation types may be recognised from the pollen assemblage being deposited beneath them, hence the palaeovegetation may be reconstructed from fossil pollen assemblages. The climatic parameters of the vegetation may then be used to reconstruct palaeoclimates. The result, however, is very general. Most pollen types can only be affiliated with a family, a genus or a group of species and the ecological tolerances within these groups may not be uniform. There are, however, some distinctive pollen types that can be identified with a single living species and this paper examines the potential of these types in the reconstruction of palaeoclimates. Lagarostrobos franklinii (J.D.Hook) Quinn, Huon pine, has a long history and the fossil occurrences of it are compatible with the hypothesis that its ecological tolerances have not changed and it has always required very high humidity. Two sclerophyllous taxa,Eucalyptus spathulata Hook. and Dodonaea triquetra Wendl., however, coexisted with rainforest and then other vegetation types as the climate became drier, adapting to the prevailing conditions. The evidence suggests that the salt-tolerant E. spathulata may have evolved in small patches of coastal scrub, subjected to marine influence, within the dominant rainforest vegetation.

Does Astaxanthin Protect Haematococcus against Light Damage?

1998 ◽  
Vol 53 (1-2) ◽  
pp. 93-100 ◽  
Author(s):  
Lu Fan ◽  
Avigad Vonshak ◽  
Aliza Zarka ◽  
Sammy Boussiba
Keyword(s):  
Light Intensity ◽  
Light Stress ◽  
Phosphate Starvation ◽  
High Light Intensity ◽  
High Irradiance ◽  
High Light ◽  
Protective Agent ◽  
Light Damage ◽  
Low Light ◽  
Very High

Abstract The photoprotective function of the ketocarotenoid astaxanthin in Haematococcus was questioned. When exposed to high irradiance and/or nutritional stress, green Haematococcus cells turned red due to accumulation of an immense quantity of the red pigment astaxanthin. Our results demonstrate that: 1) The addition of diphenylamine, an inhibitor of astaxanthin biosynthesis, causes cell death under high light intensity; 2) Red cells are susceptible to high light stress to the same extent or even higher then green ones upon exposure to a very high light intensity (4000 μmol photon m-2 s-1); 3) Addition of 1O2 generators (methylene blue, rose bengal) under noninductive conditions (low light of 100 (μmol photon m-2 s-1) induced astaxanthin accumulation. This can be reversed by an exogenous 1O2 quencher (histidine); 4) Histidine can prevent the accumulation of astaxanthin induced by phosphate starvation. We suggest that: 1) Astaxanthin is the result of the photoprotection process rather than the protective agent; 2) 1O2 is involved indirectly in astaxanthin accumulation process.

scholarly journals Responses to climatic factors by foragers of Plebeia pugnax Moure (in litt.) (Apidae, Meliponinae)

2001 ◽  
Vol 61 (2) ◽  
pp. 191-196 ◽  
Author(s):  
S. D. HILÁRIO ◽  
V. L. IMPERATRIZ-FONSECA ◽  
A. de M. P. KLEINERT
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Minimum Temperature ◽  
Climatic Factors ◽  
Flight Activity ◽  
Wide Range ◽  
The Hours ◽  
Recorded Data

Flight activity of Plebeia pugnax Moure (in litt.) was studied in six colonies coming from Cunha, SP, from July to October 1994. Twice a week, from 8:00 a.m. to 6:00 p.m., for 5 minutes every half-hour, all the bees entering and leaving the hives were counted. Six hundred counts were made and the materials that foragers carried were recorded. Data were analysed in relation to temperature, relative humidity, light intensity and day time. Foragers' flight activity was relatively constant in a wide range of temperature, from 22°C to 34°C. The minimum temperature for the beginning of flight activity was 14°C. Effective flight activity (when foragers of all colonies were leaving the hives) occurred at 15°C. These bees also flew within a wide range of relative humidity, from 30% to 100%, decreasing slowly after 50%. Flight activity increased as light intensity rose and it has also increased as the hours passed by, reaching a peak around midday and decreasing gradually afterwards. Pollen was collected all day long, while resin collection was relatively constant and debris transportation was slightly higher after 10:00 h. From all known Plebeia species, this one flew on the lowest temperature ever registered for this genus.

scholarly journals The Tale of a Disappearing Lagoon: A Habitat Mapping and Ecological Assessment of Fosu Lagoon, Ghana

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Bernard Essel ◽  
Justice Kwame Gyesi ◽  
Richmond Kofi Addo ◽  
Wisdom Galley ◽  
Gideon MacCarthy
Keyword(s):  
Vegetation Cover ◽  
Current Trend ◽  
Ecological Assessment ◽  
Remote Sensing And Gis ◽  
Vegetation Types ◽  
Marsh Vegetation ◽  
Gis Technique ◽  
If Current ◽  
Gradual Disappearance ◽  
Very High

Coastal regions of Ghana are primarily engaged in sea and lagoon fishing. Like many lagoons in Ghana, Fosu lagoon is a major source of livelihood for its surrounding communities. However, the lagoon and its associated marsh vegetation is under serious threat from human-induced interference. Due to this, the lagoon is considered as one of the most polluted lagoons in Ghana. Also, studies reveal that a major conservation challenge is the lack of inventory for the lagoon’s associated vegetation. Hence, the research was to map and assess the lagoon’s habitat and identify threats to the lagoon. In achieving the research objectives, remote sensing and GIS technique were used to effectively map the lagoon and the catchment area. The result indicated that the Fosu lagoon is characterized by a massive decline in lagoon size and the vegetation cover. Thus, the standing water has declined by 50.2 acres from 1970 to 2017 to physical development and weeds. Also, it was evident in the result that the lagoon’s vegetation is now fragmented into six various vegetation types and the weeds in the lagoon make approximately one-third of the lagoon’s vegetation cover. Also, adding to the threat of the lagoon were high levels of plastic waste and metal pollution. Hence, if current trend continues, the possibility of further degradation is very high. The main impact of this research was to provide evidence to the gradual disappearance of the Fosu lagoon.

Enteric Bacteria Survival Factors

1992 ◽  
Vol 25 (12) ◽  
pp. 93-103 ◽  
Author(s):  
M. Pommepuy ◽  
J. F. Guillaud ◽  
E. Dupray ◽  
A. Derrien ◽  
F. Le Guyader ◽  
...  
Keyword(s):  
Water Quality ◽  
Light Intensity ◽  
Sewage Treatment ◽  
Enteric Bacteria ◽  
Bactericidal Effect ◽  
Mediterranean Coast ◽  
Shellfish Farming ◽  
Two Parameters ◽  
Very High

In order to improve bacterial water quality of shellfish farming areas, studies were conducted in the English Channel (Morlaix) and on the Mediterranean coast (Toulon). These two areas were chosen in order to compare behaviour of fecal bacteria in two different ecosystems. In the estuary of Morlaix sediments are polluted by way of settlement, but most of the bacteria are mixed with turbid waters and are able to survive a very long time (T90 are in a range of several hours to several days). By measuring the increase in salt tolerance of the strains grown in natural organic matter, it was demonstrated that Salmonella can tolerate coastal water salinities. Moreover, because light penetration is prevented by suspended matter, the solar bactericidal effect is very low. On the contrary, through lack of nutrients and very high sunlight intensity, die-off rates in Mediterranean waters are very high (at the surface T90 are less than 2 hours, and several hours in deep waters). A close relationship was found between the light intensity received by bacteria and the T90. Predicted T90 must be found using these two parameters(including turbidity and deep effect on light intensity). The authors suggest that precautions must be taken to carry out impact studies depending on water quality of the area, especially in turbid areas. The knowledge of these mechanisms is very important to evaluate waste water impact on the quality of shellfish farming areas, and to improve elimination of fccal bacteria in sewage treatment plants.

Effect of Light Intensity on Adaptation ofDunaliellato Very High Salt Concentrations

1993 ◽  
Vol 44 (10) ◽  
pp. 1561-1567 ◽  
Author(s):  
MARGARET GINZBURG ◽  
BEN-ZION GINZBURG
Keyword(s):  
Light Intensity ◽  
High Salt ◽  
Very High ◽  
Effect Of Light

The Reactions of the Desert Locust, Schistocerca gregaria (Forsk.), (Orthoptera, Acrididae) to Physical Factors, with special Reference to Relative Humidity

1957 ◽  
Vol 48 (3) ◽  
pp. 515-531 ◽  
Author(s):  
S. A. Aziz
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Schistocerca Gregaria ◽  
Fourth Instar ◽  
The Other ◽  
Physical Factors ◽  
Desert Locust ◽  
Level Of Activity ◽  
Enclosed Space ◽  
Very High

Reactions of 3-day-old first- and fourth-instar hoppers of Schistocerca gregaria (Forsk.) of phase gregaria, to three physical factors, namely to relative humidity, temperature and light have been studied in an alternative chamber apparatus designed to give an enclosed space with gradients of humidity. The responses to each factor independent of the others, and to the interactions of these factors, were considered.It was found that both the first- and the fourth-instar hoppers respond strongly to humidity. They are agitated by low, and even more by very high, humidities, but become more quiescent within a zone of 60–70 per cent. R.H., where they spend more time. Within this zone they hop and turn less and this decrease in activity appears to be a response which is independent of both temperature and of light intensity. This zone of decreased agitation has been called “the zone of minimum activity”. However, the speed of walking in contrast to the other types of activity, increased progressively with humidity.Increase in light intensity raises the level of activity at all humidities, i.e., it increases the duration of activity within the limits of experimental time and the speed of walking. With rise in temperature there is an increase in hopping, in klinokinesis and orthokinesis.

scholarly journals Effect of Incubation Temperature, Light Intensity and Salinity on Growth, Lipid Content and Composition of Two Egyptian Race a of Botryococcus Braunii

2019 ◽  
pp. 1-9
Author(s):  
Mohammad I Abdel-Hamid ◽  
◽  
Yehia A Azab ◽  
Eman I Abdel-Aal ◽  
◽  
...  
Keyword(s):  
Light Intensity ◽  
Lipid Content ◽  
Incubation Temperature ◽  
Dark Period ◽  
Dry Weight ◽  
Botryococcus Braunii ◽  
Nacl Salinity ◽  
Potential Source ◽  
Chain Compounds ◽  
Very High

Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considerable numbers of short C6-C15 chain compounds were detected in biomass of cultures grown under light intensity of 48.6 μ mol photons m-2s-1 and in cultures supplemented with 17mM NaCl. These results may indicate that the Egyptian isolates of Botryococcus are potential source of hydrocarbon biofuel.

scholarly journals HUBUNGAN KECERDASAN EMOSIONAL, KEDISIPLINAN BELAJAR DAN MOTIVASI BELAJAR DENGAN HASIL BELAJAR PESERTA DIDIK KELAS XI IPA SMA DI KECAMATAN TERNATE TENGAH

2018 ◽  
pp. 10
Author(s):  
Herawati HM ◽  
Sudding . ◽  
Muhammad Syahrir
Keyword(s):  
Emotional Intelligence ◽  
Random Sampling ◽  
Learning Motivation ◽  
Positive Correlation ◽  
High Category ◽  
Ex Post ◽  
Ex Post Facto ◽  
Academic Year ◽  
Very High ◽  
Cluster Random Sampling

ABSTRAKPenelitian ini merupakan penelitian ex-post facto yang bertujuan untuk mengungkapkan seberapa besar hubungan kecerdasan emoisonal, kedisiplinan belajar dan motivasi belajar dengan hasil belajar peserta didik kelas XI IPA SMA di Kecamatan Ternate Tengah tahun pelajaran 2017/2018. Total populasi penelitian sebanyak 322 peserta didik dengan ukuran sampel sebanyak 181 peserta didik. Teknik penentuan sampel dilakukan dengan menggunakan disproportionate stratified cluster random sampling. Pengambilan data penelitian menggunakan instrumen berupa angket dan tes. Data penelitian dianalisis menggunakan Software SPSS. Hasil penelitian menunjukkan bahwa (1) sebagian besar peserta didik kelas XI IPA SMA di  Kecamatan Ternate Tengah memiliki kecerdasan emosional dan kedisiplinan belajar pada kategori sangat tinggi, motivasi belajar berada pada kategori tinggi dan sangat tinggi, sedangkan hasil belajar berada pada kategori sangat rendah, (2) kecerdasan emosional, kedisiplinan belajar, dan motivasi belajar masing–masing  memiliki hubungan positif dengan hasil belajar peserta didik, (3) terdapat hubungan postif antara kecerdasan emosional dan kedisiplinan belajar dengan hasil belajar peserta didik, kecerdasan emosional dan motivasi belajar dengan hasil belajar peserta didik, serta kedisiplinan belajar dan motivasi belajar dengan hasil belajar peserta didik, dan (4) terdapat hubungan linear antara kecerdasan emosional, kedisiplinan belajar dan motivasi belajar secara bersama–sama dengan hasil belajar peserta didik.Kata Kunci: kecerdasan emosional, kedisiplinan belajar, motivasi belajar, hasil belajar.ABSTRACTThe study is ex-post factor which aims at discovering the extent of correlation of emotional intelligence, learning discipline, and learning motivation on learning result of Grade XI IPA students at SMA (senior high school) in Ternate Tengah subsdistrict of academic year 2017/2018. The total population was 322 students with 181 samples. Samples were obtained by employing disproportionate stratified cluster random sampling. Data were obtained by employing instruments of questionnaire and test. Data were analyzed by using SPSS software. The result of the study reveal that (1) most of the students of grade XI IPA at SMA in Ternate Tengah subdistrict had emotional intelligence and learning discipline in very high category, learning motivation in high and very high category; whereas, the learning result is in very low category, (2) the emotional intelligence, learning discipline, and learning motivation each had positive correlation with students learning result, (3) there is positive correlation between emotional intelligence and learning discipline; emotional intelligence and learning motivation on learning result; and learning discipline and learning motivation on learning result, (4) there is linear correlation between emotional intelligence, learning discipline, and learning motivation collaboratively on syudents learning result. Keywords: Emotional Intelligence, Learning Discipline, Learning Motivation, Learning Achievement.

RELATIONSHIP BETWEEN WEIGHT AND PHYSICO-MECHANICAL PROPERTIES OF COFFEE GRAINS PRODUCED FROM DIFFERENT HARVEST RIPENING

2014 ◽  
Vol 4 (1) ◽  
pp. 21-30
Author(s):  
Yuwana Yuwana ◽  
Evanila Silvia ◽  
Bosman Sidebang
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Static Friction ◽  
Linear Analysis ◽  
Angle Of Repose ◽  
True Density ◽  
Experiment Research ◽  
Positive Correlation ◽  
Length Width ◽  
Very High

This research aimed to determine relationships between weight and several physic-mechanical properties of coffee grains. Grains having 12.2% (wet basis) moisture content in average, originated from cherries of different ripening levels identified by green, yellow, red and deep red in colors were used for experiment. Research used regresi linear analysis. Results of experiment indicated that weight of grains positively correlated to length, width, thickness and frontal area with very high values of determination coefficient. Weight of grains correlated positively to sphericity and negatively to porosity. Weight of grains originated from green and red cherries had positive correlation with density whereas weight of grains originated from yellow and deep red cherries possessed no correlation with density. Weight of grains from yellow, red and deep red cherries had negative correlation with true density in contrast weight of grains from green cherries had positive correlation with true density. There were no reliable trend concerning the relationships between weight of grains and coefficient of static friction and angle of repose.

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