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1.
Kohji Yamamura 《Researches on Population Ecology》1999,41(3):229-234
Transformation is required to achieve homo-scedasticity when we perform ANOVA to test the effect of factors on population
abundance. The effectiveness of transformations decreases when the data contain zeros. Especially, the logarithmic transformation
or the Box–Cox transformation is not applicable in such a case. For the logarithmic transformation, 1 is traditionally added
to avoid such problems. However, there is no concrete foundation as to why 1 is added rather than other constants, such as
0.5 or 2, although the result of ANOVA is much influenced by the added constant. In this paper, I suggest that 0.5 is preferable
to 1 as an added constant, because a discrete distribution defined in {0, 1, 2, . . .} is approximately described by a corresponding
continuous distribution defined in (0, ≧) if we add 0.5. Numerical investigation confirms this prediction.
Received: October 16, 1998 / Accepted: June 10, 1999 相似文献
2.
Group testing procedures, in which groups containing several units are tested without testing each unit, are widely used as cost-effective procedures in estimating the proportion of defective units in a population. A problem arises when we apply these procedures to the detection of genetically modified organisms (GMOs), because the analytical instrument for detecting GMOs has a threshold of detection. If the group size (i.e., the number of units within a group) is large, the GMOs in a group are not detected due to the dilution even if the group contains one unit of GMOs. Thus, most people conventionally use a small group size (which we call conventional group size) so that they can surely detect the existence of defective units if at least one unit of GMOs is included in the group. However, we show that we can estimate the proportion of defective units for any group size even if a threshold of detection exists; the estimate of the proportion of defective units is easily obtained by using functions implemented in a spreadsheet. Then, we show that the conventional group size is not always optimal in controlling a consumer's risk, because such a group size requires a larger number of groups for testing. 相似文献
3.
Sakura Yamamura 《全球网;跨国事务杂志》2023,23(1):120-131
The global Covid-19 pandemic has strongly impacted social practices, relocating communications and social networks into the digital space. Contextualized in such impact of the Covid-19 pandemic, the local LGBT* activism in Japan achieved a special momentum: both the acceleration of the socio-spatial relocation of LGBT* activism to the digital space and the postponement of the Tokyo Olympics 2020 by 1 year enabled activists to mobilize people domestically and globally. The pandemic was not the actual cause or driver of the local LGBT* activism, yet it has been an important catalyst for the transnationalization of the local movement in Japan, pushing evidently the spatial boundaries to achieve broader public outreach but in turn also receiving stronger support from the global community through transnational networks. This study explores novel dynamics of spatiality and temporality of social transformations through the Covid-19-induced increase in global digital connectedness as well as transnationalization of local actions. 相似文献
4.
5.
Summary A simple evolutionary model of dormancy and dispersal is presented with special reference to phytophagous lady beetles. In
order to investigate spatially heterogeneous environments, we assume the simplest patch structure, that is, there are only
two patches, main and sub. Environments are also assumed to be temporally constant. The main patch is superior to the sub
patch, but density effect at the main patch is higher than at the sub patch. Optimal dormancy and dispersal are obtained at
the same time by the method of evolutionarily stable strategy (ESS). In the univoltine life cycle, dormancy strategy vanishes
because dormant individuals do not reproduce at all but suffer from a certain mortality rate during winter hibernation. In
the bivoltine life cycle, the dormancy and dispersal rates constitute a trade-off: the rates change together with a negative
correlation when the mortality rate during dispersal or during winter hibernation changes. When suitability of the main patch
gradually deteriorates, the optimal strategy changes as follows: neither dormancy nor dispersal is adopted at the most suitable
condition, the dispersal rate is increased without dormancy in the intermediate condition, and then the dormancy rate is increased
with a constant dispersal rate. We discuss the field observation data of lady beetles in the light of results of our model. 相似文献
6.
Eiji Yamamura 《Social indicators research》2014,118(3):1229-1247
Smokers tend to be more impatient and prefer immediate benefits compared with non-smokers. If people follow their primitive instincts they will engage in sexual behavior. Impatient people are more likely to have sex. However, for married people, having sex with a spouse is considered to be an investment in family life. Based on individual level data of Japan General Social Surveys, this paper investigated how sexual behavior differs between smokers and non-smokers. In addition to it, determinants of life satisfaction are also investigated. The important findings through the interval regression model and the ordered probit model are: (1) frequency of sex is positively associated with family satisfaction; (2) unmarried smokers are more likely to have sex than unmarried non-smokers; (3) married smokers are less likely to have sex than married non-smokers. It follows from estimation results that smoking behavior alerts us to his unobserved characteristics before marriage, thus reducing information asymmetry. 相似文献
7.
Kohji Yamamura 《Researches on Population Ecology》1999,41(2):177-182
The relationship between plant density and the abundance of arthropods was examined by planting cabbages in four densities
(0.25, 1, 4, or 8 plants per square meter). Four herbivorous species were examined: the small white butterfly Pieris rapae crucivora Boisduval, the diamondback moth Plutella xylostella (Linnaeus), the beet semi-looper Autographa nigrisigna (Walker), and the green peach aphid Myzus persicae (Sulzer). The number of spiders and the number of eggs of syrphid flies were also examined. The number of individuals per
unit ground area increased curvilinearly with increasing plant density for most arthropods. To clarify the mechanism causing
such a curvilinear increase, the oviposition behavior of Pieris rapae crucivora was examined. The oviposition process of a female was divided into three components: (1) entering the field, (2) alighting
on a plant to bend her abdomen, and (3) attaching an egg on the leaf. The first and the second components curvilinearly increased
with increasing plant density, while the third component was not influenced by the plant density. The analysis of the flight
path of P. rapae crucivora indicated that the curvilinear increase in the frequency of abdominal bending behaviors occurs since a female flies at least
about 1.3 m between successive abdominal bending behaviors, irrespective of the plant density, when the plant density is sufficiently
high.
Received: October 23, 1998 / Accepted: February 15, 1999 相似文献
8.
Tomoyuki Kameyama Rhett Harrison Norio Yamamura 《Researches on Population Ecology》1999,41(3):243-252
The relationship between fig trees and their pollinator wasps is a well-known example of species-specific obligate mutualism.
In this article we present a stochastic model of this mutualistic system, referring to data on a dioecious fig (Ficus schwarzii) in Borneo, and examine the conditions for the persistence of a wasp population for a given period. (1) When the average
duration of the flowering interval of fig trees is short, even a small fig population can sustain a wasp population successfully.
A population whose average period of flowering cycle is half that of another population can sustain a wasp population with
a number of trees less than half of the other population. (2) The wasp survival rate (WSR) is higher when (a) the variation
of the interval periods of fig flowering is smaller, (b) the fig population size is larger, and (c) figs can prolong their
receptivity to wait for a wasp if no wasps are available. (3) WSR is predictable from the average proportion of the fig's
receptive phases, in which wasps are available, to their total receptive phases. (4) The persistence period of a wasp population
increases exponentially with the number of fig trees. Based on these results we propose a new hypothesis, as a possible scenario,
on the evolution of dioecy from monoecy in Ficus.
Received: November 13, 1998 / Accepted: July 14, 1999 相似文献
9.
Japan has the highest suicide rates among the OECD countries and this public health problem seems to be accelerating in over the recent decades. Investigating and understanding the suicidal behaviour is of crucial importance to society and health policy makers. Such an investigation could provide with useful information for those responsible in formulating the national policies on suicide prevention. This study estimates dynamic econometric models for total, male and female suicides in Japan for the period of 1957–2009. Using the ARDL approach to cointegration, we find that the associations of suicide with sociological factors (divorce and fertility rates) were stronger than those with economic factors (per capita GDP and unemployment) for females. 相似文献
10.
Impact of formal and informal deterrents on driving behavior 总被引:1,自引:0,他引:1
This paper explores, using panel data of traffic accidents in Japan, how formal and informal deterrence affect driving manners. I found through fixed effects and fixed effects 2SLS estimations that formal deterrents, such as police, cause drivers to drive attentively but that this effect is not inversely associated with dangerous driving. Informal deterrents, on the other hand, impede dangerous driving but do not induce drivers to drive more attentively. 相似文献