Differences in energy partition between crowded and uncrowded individual barnacles (Balanus glandula Darwin)

1977 ◽  
Vol 55 (4) ◽  
pp. 643-647 ◽  
Author(s):  
R. S. S. Wu ◽  
C. D. Levings ◽  
D. J. Randall
Keyword(s):  
Population Density ◽  
Reproductive Output ◽  
Population Regulation ◽  
The Other ◽  
Body Tissue ◽  
Balanus Glandula ◽  
Energy Partition ◽  
Adequate Amount ◽  
Other Hand ◽  
Feeding Area

The egg: body tissue ratio and shell: tissue ratio, when expressed in terms of energy, may serve as a good indication of the energy partition of individual barnacles. When comparing these two ratios between crowded and uncrowded individual barnacles, a decrease in degree of crowding was associated with: (1) an increase in the egg: body tissue ratio and (2) a decrease in shell: tissue ratio of the individuals. This appears to suggest a difference in energy partition in the barnacles with different degrees of crowding. Uncrowded individuals, which acquire an adequate amount of energy, could channel more energy into egg output and hence produce more progeny. On the other hand, crowded individuals acquire a limited amount of energy and apparently use a larger proportion of their assimilated energy in (1) building body tissue rather than egg and (2) building a taller shell so as to increase the general feeding area of the population. The reduction in reproductive output when population density is high (and vice versa) could be an important mechanism in population regulation of the species.

Effects of population density on female and male burrow characteristics in the fiddler crab, Uca bengali Crane, 1975

Crustaceana ◽  
2015 ◽  
Vol 88 (12-14) ◽  
pp. 1283-1299 ◽  
Author(s):  
Fahmida Wazed Tina ◽  
Mullica Jaroensutasinee ◽  
Krisanadej Jaroensutasinee
Keyword(s):  
Body Size ◽  
Population Density ◽  
Fiddler Crab ◽  
High Density ◽  
The Other ◽  
Low Density ◽  
Density Effects ◽  
Egg Incubation ◽  
Other Hand ◽  
Males And Females

We examined the effects of population density on body size and burrow characteristics ofUca bengaliCrane, 1975. We predicted that (1) males in high-density areas (HD) should be larger in size and build higher quality burrows than males in low-density areas (LD), and (2) HD females should be larger in size, but build lower quality burrows than LD females, as HD females can find higher numbers of good quality male burrows around them for breeding and egg incubation. Our results showed that males and females in HD were larger in size than those in LD. Since HD males were larger in size, they built higher quality burrows than males in LD. On the other hand, even though LD females were smaller in size than HD ones, they built higher quality burrows than HD females. Our results thus indicate that density effects both body size and burrow characteristics.

Big Houses in Kano Emirate

Africa ◽  
1974 ◽  
Vol 44 (2) ◽  
pp. 117-135 ◽  
Author(s):  
Polly Hill
Keyword(s):  
Population Density ◽  
Special Reference ◽  
The Other ◽  
Economic Conditions ◽  
Economic Organization ◽  
Other Hand ◽  
Opening Paragraph ◽  
The Village ◽  
Compare And Contrast

Opening ParagraphIn 1971–2 I undertook research in part of the very densely populated farming zone around Kano city (often called the Kano close-settled zone) in order to compare it with a Hausa village, Batagarawa, some 100 miles further north in Katsina Emirate, where I had lived and worked in 1967. At Batagarawa farmland is not scarce and members of the community are free to establish farms on uncultivated (bush) land, some of which is no further than a mile or so from the village. For some 30 to 40 miles or more around Kano city, on the other hand, there is little or no uncultivated bush and farmers with insufficient land are obliged to buy or to ‘borrow’ (aro) farmland from others. My purpose was to compare and contrast the socio-economic organization and economic conditions of farmers in the two localities, with special reference, in so far as this variable could be isolated, to population density.

Expression of autogeny in relation to larval population density of Sarcophaga bullata Parker (Diptera: Sarcophagidae)

1973 ◽  
Vol 51 (11) ◽  
pp. 1189-1193 ◽  
Author(s):  
J. A. Baxter ◽  
A. M. Mjeni ◽  
P. E. Morrison
Keyword(s):  
Population Density ◽  
The Other ◽  
Larval Rearing ◽  
Population Densities ◽  
Larval Population ◽  
Sarcophaga Bullata ◽  
Other Hand ◽  
Rearing Conditions

The expression of autogeny in S. bullata was influenced by the larval rearing conditions. Low larval population densities resulted in large flies that were autogenous. On the other hand, high larval population densities produced small flies that were anautogenous, In anautogenous females the size and stage to which the follicles developed varied with the size of the fly. When reared on a sucrose–water diet, the females from an intermediate larval population density possessed larvae, mature eggs, degenerate follicles, or undeveloped follicles.

scholarly journals Factors Affecting the Cases and Deaths of COVID-19 Victims

2021 ◽  
Vol 18 (2) ◽  
pp. 674
Author(s):  
Jerald M. Velasco ◽  
Wei-Chun Tseng ◽  
Chia-Lin Chang
Keyword(s):  
Population Density ◽  
Least Squares ◽  
Ordinary Least Squares ◽  
The Other ◽  
Least Squares Regression ◽  
Ordinary Least Squares Regression ◽  
Factors Affecting ◽  
Average Temperature ◽  
Other Hand ◽  
Preliminary Study

This paper attempts to find the factors that affect the number of cases and deaths of coronavirus disease 2019 (COVID-19) patients a year after the first outbreak in Wuhan, China. There were 141 countries affected with COVID-19 involved in the study. Countries were grouped based on population. Using ordinary least squares regression, it was found that the total number of cases and deaths were significantly related with the levels of population of the different countries. On the overall, median age of the country, and average temperature are positively related with the number of deaths from the virus. On the other hand, population density is positively related with the deaths due to COVID for low populated countries. The result of this preliminary study can be used as a benchmark for authorities in the formulation of policies with regards to treating COVID-19 related issues.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

Can the Academic Self-Concept be Positive and Realistic?

2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann
Keyword(s):  
Academic Performance ◽  
Opposite Effect ◽  
Self Esteem ◽  
Point Of View ◽  
The Other ◽  
Self Concept ◽  
High Ability ◽  
Self Image ◽  
Other Hand

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Don’t Put Me in This Group

2019 ◽  
Vol 50 (2) ◽  
pp. 80-93
Author(s):  
Jort de Vreeze ◽  
Christina Matschke
Keyword(s):  
Positive Emotions ◽  
Negative Emotions ◽  
Negative Information ◽  
The Self ◽  
The Other ◽  
Other Hand ◽  
Group Memberships

Abstract. Not all group memberships are self-chosen. The current research examines whether assignments to non-preferred groups influence our relationship with the group and our preference for information about the ingroup. It was expected and found that, when people are assigned to non-preferred groups, they perceive the group as different to the self, experience negative emotions about the assignment and in turn disidentify with the group. On the other hand, when people are assigned to preferred groups, they perceive the group as similar to the self, experience positive emotions about the assignment and in turn identify with the group. Finally, disidentification increases a preference for negative information about the ingroup.

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