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1.
In a laboratory experiment, we use a public goods game to examine the hypothesis that human subjects use an involuntary eye-detector
mechanism for evaluating the level of privacy. Half of our subjects are “watched” by images of a robot presented on their
computer screen. The robot—named Kismet and invented at MIT—is constructed from objects that are obviously not human with
the exception of its eyes. In our experiment, Kismet produces a significant difference in behavior that is not consistent
with existing economic models of preferences, either self- or other-regarding. Subjects who are “watched” by Kismet contribute
29% more to the public good than do subjects in the same setting without Kismet. 相似文献
2.
Amir Neori 《Journal of applied phycology》2011,23(1):143-149
Freshwater fish culture is generally considered the largest sector in world aquaculture. Several of the leading species consume
“green water” plankton. This plankton—mostly microalgae (phytoplankton) and also bacteria, protozoa and zooplankton—grows
in man-made fertilized water impoundments. The quantity of “green water” microalgae consumed by fish and shrimp is estimated
here at a quarter billion ton fresh weight a year, about three and a half times as much as the entire recognized aquaculture.
This estimate is based on the quantities of the microalgae consumed and the efficiencies of their use for growth by the main
species in aquaculture. The cost of producing “green water” microalgae by the aquaculturists—mostly in SE Asia—is low. The
populations in “green water” are biologically managed by the cultured fish themselves. The fish with their different feeding
habits help “manage” the composition of the plankton and the overall water quality as they grow. The aquaculturists further
manage “green water” through simple means, including water exchange and fertilization. Cost is remunerated partially by the
income from sales of the fish and partially by bio mitigation services that “green water” polyculture ponds provide the aquaculturists
in treating farm and household waste. A comprehension of the scale and importance of the microalgae sector to world aquaculture
should lead to more research to improve understanding of algal population dynamics, growth factors, and efficiency of food
chains. The consequent improved control of the plankton’s interaction with fish and shrimp production in “green water” will
undoubtedly contribute much to the expansion in production of seafood. 相似文献
3.
Abnormal proteins synthesized in the presence of ethionine were degraded more rapidly than the normal ones in cell-free extracts
of ethanol-grown yeast. The denatured proteins, however, were degraded in preference to their native counterparts which were
either normal or abnormal.
Participant of the UNESCO course “On Modern Problems in Biology and Microbial Technology”. 相似文献
4.
Sandra I. Pitta-Alvarez Fabricio Medina-Bolivar María A. Alvarez Agustina A. Scambatto Patricia L. Marconi 《In vitro cellular & developmental biology. Plant》2008,44(6):502-507
Berberis buxifolia Lam., known as “Calafate”, is a plant native to Argentina that exhibits antimicrobial activity. This biological activity
is attributed to the isoquinoline alkaloid berberine. The aim of this research was to test the antimicrobial properties of
different extracts of this species, taking berberine as the reference molecule, and to examine if the expression of bacterial
multidrug resistance (MDR) efflux pumps could be responsible for possible resistance mechanisms. To this end, a wild-type
and a mutant strain of Staphylococcus aureus with a defective MDR efflux pump were used and the minimum inhibitory concentrations of the extracts were determined. The
studies were carried out with infusions of in vivo shoots and “Calafate” commercial tea, as well as with the media derived from shoot cultures incubated with different plant
growth regulators (thidiazuron, picloram, and jasmonic acid). As far as antimicrobial activity is concerned, all the extracts
tested were significantly more effective than berberine standard. “Calafate” commercial tea and shoot tea had inhibitory concentrations
similar to the one observed for ampicillin standard. The media from the shoot cultures, however, were significantly more effective
than all the others, particularly the one derived from jasmonic acid, suggesting the presence of compounds that could be acting
synergistically with berberine. There were no differences in antimicrobial activity against the wild-type and the mutant S. aureus; no definite conclusions could be drawn concerning the relationship between MDR pumps and possible pathogen resistance to
extracts of B. buxifolia. 相似文献
5.
Gilligan’s (1982) refinement of Kohlberg’s theory on moral development operates on two theses: (1) females, more so than males,
reach moral decisions based on the personalities of the relevant individuals; and (2) female behaviors stemming from moral
decisions are based upon “care” and “responsibility for others.” This article accepts the first thesis but argues that the
second is incorrect. That is, self-interest—i.e., aiding “blood” kin and/or carefully monitoring reciprocity—rather than “altruism”
is argued to be the operant dynamic in forging distaff morality and resultant behavior. Six empirical examples are presented
as contraindicative of Gilligan’s second thesis. Finally, it is suggested that selection for the psychological traits of independence
and the mastery of subtle social chess yielded ancestral females who had more descendants—us—than did females with alternative
profiles.
Nancy S. Coney is a professor at Western Illinois University and is interested in both clinical and nonclinical aspects of
women’s psychology.
Wade C. Mackey is interested in biocultural anthropology and has authored two books on fathering:Fathering Behaviors (Plenum, 1995) andThe American Father (Plenum, 1996). 相似文献
6.
Summary The shallow marine subtropical Northern Bay of Safaga is composed of a complex pattern of sedimentary facies that are generally
rich in molluscs. Thirteen divertaken bulk-samples from various sites (reef slopes, sand between coral patches, muddy sand,
mud, sandy seagrass, muddy seagrass, mangrove channel) at water depths ranging from shallow subtidal to 40m were investigated
with regard to their mollusc fauna >1mm, which was separated into fragments and whole individuals.
Fragments make up more than 88% of the total mollusc remains of the samples, and their proportions correspond to characteristics
of the sedimentary facies. The whole individuals were differentiated into 622 taxa. The most common taxon,Rissoina cerithiiformis, represented more than 5% of the total mollusc content in the samples. The main part of the fauna consists of micromolluscs,
including both small adults and juveniles. Based on the results of cluster-, correspondence-, and factor analyses the fauna
was grouped into several associations, each characterizing a sedimentary facies: (1) “Rhinoclavis sordidula—Corbula erythraeensis-Pseudominolia nedyma association” characterizes mud. (2) “Microcirce sp.—Leptomyaria sp. association” characterizes muddy sand. (3)”Smaragdia spp.-Perrinia stellata—Anachis exilis—assemblage” characterizes sandy seagrass. (4) “Crenella striatissima—Rastafaria calypso—Cardiates-assemblage” characterizes muddy seagrass. (5) “Glycymeris spp.-Parvicardium sueziensis-Diala spp.-assemblage” characterizes sand between coral patches. (6) “Rissoina spp.-Triphoridae —Ostreoidea-assemblage” characterizes reef slopes. (7) “Potamides conicus—Siphonaria sp. 2—assemblage” characterizes the mangrove.
The seagrass fauna is related to those of sand between coral patches and reef slopes with respect to gastropod assemblages,
numbers of taxa and diversity indices, and to the muddy sand fauna on the basis of bivalve assemblages and feeding strategies
of bivalves. The mangrove assemblage is related to those of sand between coral patches and the reef slope with respect to
taxonomic composition and feeding strategies of bivalves, but has a strong relationship to those of the fine-grained sediments
when considering diversity indices. Reef slope assemblages are closely related to that of sand between coral patches in all
respects, except life habits of bivalves, which distincly separates the reef slope facies from all others. 相似文献
7.
The effects (and interaction) of two solution concentrations of Mg (50, 500, μM) and two of K (250, 4250 μM) on the growth of micropropagated plants of “F. 12/1” and “Colt” were investigated using a flowing solution culture system.
Magnesium inflow and growth of “Colt” and “F. 12/1” were inhibited to a similar extent by an increased concentration of K
in the nutrient solution. However, the consequences of this inhibition were different. Reduced inflow of Mg in “F. 12/1” caused
Mg deficiency symptoms at high and low concentrations of K, whereas this only occurred with a combination of high K concentration
and low Mg concentration in “Colt”. The distribution of dry matter within the plant was significant in determining susceptibility
to Mg deficiency. Since “F. 12/1” has a smaller root:shoot ratio than Colt it is unable to sustain the same concentration
of Mg in leaves as “Colt” irrespective of external K concentration. The molar ratio of K:Mg in soil solutions should remain
<8.5:1 in order to ensure maximum growth of “F. 12/1” and “Colt”.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
8.
This paper examines a statistics debate among African American caregivers raising children with disabilities for insights
into the work of “African American mothering.” Using ethnographic, narrative and discourse analyses, we delineate the work
that African American mothers do—in and beyond this conversation—to cross ideological and epistemological boundaries around
race and disability. Their work entails choosing to be an “I” and, in some cases, actively resisting being seen as a “they”
and/or part of a collective “we” in order to chart alternative futures for themselves and their children. 相似文献
9.
10.
Victoria N. Alexander 《Biosemiotics》2009,2(1):77-100
Hackles have been raised in biosemiotic circles by T. L. Short’s assertion that semiosis, as defined by Peirce, entails “acting
for purposes” and therefore is not found below the level of the organism (2007a:174–177). This paper examines Short’s teleology and theory of purposeful behavior and offers a remedy to the disagreement.
Remediation becomes possible when the issue is reframed in the terms of the complexity sciences, which allows intentionality
to be understood as the interplay between local and global aspects of a system within a system. What is called “acting for
purposes” is not itself a type of behavior so much as a relationship between a dynamic system that “exists for a purpose”
and its microprocesses that “serve purposes.” The “intentional object” of philosophy is recast here as the holistic self-organized
dynamics of a system, which exists for the purpose of self-maintenance, and that constrains the parts’ behaviors, which serve
the purpose of forming the system. (A “system” can be any emergent, e.g. an abiotic form, an adapted species, a self, a conditioned response, thought, or a set of ideas.) The self-organized whole,
which is represented to the parts in their own constrained behaviors, assumes the guiding function so long attributed to the
mysterious “intentional object.” If emergent self-causation is not disallowed, creative originality, as well as directionality, becomes part of the definition of purposeful behavior. Thus, key tools used here, required for understanding emergence, come
from poetics rather than semoitics. In the microprocesses of self-organization, I find what I call “accidental” indices and
icons — which are poetic in the sense that they involve mere metonymic contiguity and metaphoric similarity — and which are
preferentially selected under constrained conditions allowing radically new connections to habituate into an “intentional”
self-organized system that, not coincidentally, has some of the emergent characteristics of a conventional symbolic system.
相似文献
Victoria N. AlexanderEmail: |
11.
Evolutionary biology owes much to Charles Darwin, whose discussions of common descent and natural selection provide the foundations
of the discipline. But evolutionary biology has expanded well beyond its foundations to encompass many theories and concepts
unknown in the 19th century. The term “Darwinism” is, therefore, ambiguous and misleading. Compounding the problem of “Darwinism”
is the hijacking of the term by creationists to portray evolution as a dangerous ideology—an “ism”—that has no place in the
science classroom. When scientists and teachers use “Darwinism” as synonymous with evolutionary biology, it reinforces such
a misleading portrayal and hinders efforts to present the scientific standing of evolution accurately. Accordingly, the term
“Darwinism” should be abandoned as a synonym for evolutionary biology. 相似文献
12.
Andrew M. Weiss 《Evolutionary biology》2011,38(1):42-51
Evolutionary Science has, at least since the publication of Origin, been less concerned with the continuation of species in stable forms, than with the reconfiguration of forms into a host
of varieties. So influential has this emphasis been that, over the years, “variation” has become a cardinal desideratum, even
taking precedence over the macroevolutionary landscape. This orientation has made it much more difficult to objectively assess
the meaning of non-change patterns such as periods of stasis, which appear to be widespread in most species. Yet, if stasis
is an expectable outcome of evolutionary activity, this raises the possibility that there may be mechanisms and processes
at many causal levels, acting on its behalf, without reference to the impetus toward persistent variation. Researchers have
been reluctant to attribute stasis to a macroevolutionary tendency toward ‘stability’ despite the commonality of stasis in
many species, and notwithstanding the many biological/behavioral processes that seem inclined to produce and maintain conformance,
regulation and consistency. Speciation, paradoxically, is the best evidence for an overriding influence toward stability in
that stability would seem to be a necessary condition prior to the development of isolating mechanisms. An alternative macroevolutionary
model of biological activity is offered consisting of two tendencies, “variety” counterpoised with “stability” both acting
in the service of the persistence of life. 相似文献
13.
Richard Huxtable 《Journal of bioethical inquiry》2009,6(3):327-336
Amongst the latest, and ever-changing, pathways of death and dying, “suicide tourism” presents distinctive ethical, legal
and practical challenges. The international media report that citizens from across the world are travelling or seeking to
travel to Switzerland, where they hope to be helped to die. In this paper I aim to explore three issues associated with this
phenomenon: how to define “suicide tourism” and “assisted suicide tourism”, in which the suicidal individual is helped to
travel to take up the option of assisted dying; the (il)legality of assisted suicide tourism, particularly in the English
legal system where there has been considerable recent activity; and the ethical dimensions of the practice. I will suggest
that the suicide tourist—and specifically any accomplice thereof—risks springing a legal trap, but that there is good reason
to prefer a more tolerant policy, premised on compromise and ethical pluralism. 相似文献
14.
Regarding the arts as something peopledo — as behaviors, rather than the residue or artifacts of behavior — makes possible a theoretical grounding about their nature
and importance, an endeavor that current anthropology of art has largely abandoned. A reconsideration of the suspect and largely
discarded terms “functionalism” and “evolutionism” is presented in light of current evolutionary thinking. It is suggested
that a contemporary reformulation of these concepts, illustrated by the author's Darwinian or “adaptationist” perspective
on art, supports aims and claims of current anthropology of art, and contributes new focus and direction to its endeavors. 相似文献
15.
16.
V. G. Zalesski 《Plasma Physics Reports》2011,37(13):1196-1201
Electron emission influence from gas-discharge plasma on plasma emitter energy parameters is considered. It is shown, that
electron emission from plasma is accompanied by energy contribution redistribution in the gas-discharge from plasma emitter
supplies sources—the gas-discharge power supply and the accelerating voltage power supply. Some modes of electron emission
as a result can be realized: “a probe measurements mode,” “a transitive mode,” and “a full switching mode.” 相似文献
17.
This paper deals with information transfer from the environment and “self”-organization in open, nonlinear systems far from
thermodynamic equilibrium — in the presence of either non-stationary phase jitter noise, or amplitude stationary noise. By
“self”-organization we mean here the progressive formation within the system of sequential, ordered (coherent) relationships
between appropriate dynamical variables-like for example, the phase differences between the oscillating components of the
system. We take up (in Section II) the classical Laser as a specific example and examine in detail the influence of phase
jitter noise in the mode (phase) locking process. We find—as expected—that phase fluctuations in the cavity cause degradation
of the coherent behaviour (i.e. increase the entropy) of the system — which, however, levels off, or saturates with time.
Further (in Section III) we examine systems where the number of self-sustained oscillating components may vary with time in
such a way that the maximum entropy of the system increases faster than the overall instantaneous entropy. We put forth the
hypothesis that in such cases — because of the increase of the redundancy — the system gets organized not just in spite of,
but merely because of the presence of Noise. Possible applications in biological systems (especially concerning a model of
cerebral organization) are briefly discussed. It is understood here, that the system has to display some preliminary dynamical
structure before the organizing procedure takes over. What happens afterwards is the subject of this paper. 相似文献
18.
Mackay AL 《Journal of biosciences》2003,28(5):539-546
Conclusion We must conclude that the sub-title of Bernal’s “The Social Function of Science” — “What science does: what science could
do” is still the relevant challenge and indicates Bernal’s chief contribution, besides the foundation of molecular biology
to our civilization. It is manifest that resources spent on armaments are a monstrous pathological symptom of our social structure.
The ancient problem of “what is property” and what may be “owned” and by whom or by what organs of society is awakening. 相似文献
19.
20.
Parasites often confront conflicting demands when evaluating and distributing themselves among host individuals, in order to attain maximum reproductive success. We tested two alternative hypotheses about host preference by fleas in relation to the age of their rodent host. The first hypothesis suggests that fleas select adult over juvenile rodents because the latter represent a better nutritional resource (the “well-fed host” hypothesis), whereas the second hypothesis suggests that fleas prefer the weaker and less resistant juveniles because they are easier to colonise and exploit (“poorly fed host” hypothesis). We sampled fleas (Synosternus cleopatrae) on the gerbil (Gerbillus andersoni) in 23 different plots in the Negev desert and found an unequal distribution of fleas between adult and juvenile hosts. Furthermore, flea distribution changed as a function of flea density—from juvenile-biased flea parasitism (the “poorly fed host” hypothesis) at low densities to adult-biased flea parasitism (the “well-fed host” hypothesis) at high densities. Other factors that influenced flea preference were soil temperature and the presence of ticks. These results suggest that host selection is not an explicit alternative choice between adults and juveniles (“well-fed host” versus “poorly fed host” hypotheses), but rather a continuum where the distribution between adults and juveniles depends on host, parasite, and environmentally related factors. 相似文献