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1.
We investigated the influence of three factors—diesel oil concentration [2500, 5000, 10,000, 20,000 mg total petroleum hydrocarbons
(TPH) kg−1 soil], biostimulation (unfertilized, inorganic fertilization with NPK nutrients, or oleophilic fertilization with Inipol
EAP22), and incubation time—on hydrocarbon removal, enzyme activity (lipase), and microbial community structure [phospholipid
fatty acids (PLFA)] in a laboratory soil bioremediation treatment. Fertilization enhanced TPH removal and lipase activity
significantly (P ≤ 0.001). The higher the initial contamination, the more marked was the effect of fertilization. Differences between the
two fertilizers were not significant (P > 0.05). Microbial communities, as assessed by PLFA patterns, were primarily influenced by the TPH content, followed by fertilization,
and the interaction of these two factors, whereas incubation time was of minor importance. This was demonstrated by three-factorial
analysis of variance and multidimensional scaling analysis. Low TPH content had no significant effect on soil microbial community,
independent of the treatment. High TPH content generally resulted in increased PLFA concentrations, whereby a significant
increase in microbial biomass with time was only observed with inorganic fertilization, whereas oleophilic fertilization (Inipol
EAP22) tended to inhibit microbial activity and to reduce PLFA contents with time. Among bacteria, PLFA indicative of the
Gram-negative population were significantly (P ≤ 0.05) increased in soil samples containing high amounts of diesel oil and fertilized with NPK after 21–38 days of incubation
at 20°C. The Gram-positive population was not significantly influenced by TPH content or biostimulation treatment. 相似文献
2.
Dmitriev LF 《Neurochemical research》2007,32(8):1278-1291
Polyunsaturated fatty acids (PUFA) and α-tocopherol (α-TOH) are the most oxygen-sensitive constituents of cells. α-TOH is
a member of the vitamin E family that is considered the most important lipophilic antioxidant in cell membranes. Its importance
is emphasized by the involvement of oxidative stress in injury to the central nervous system and neurodegenerative diseases.
Currently, α-TOH transfer protein (TTP), is believed to play a significant role in maintaining the vitamin status but the
presence of α-TOH in membranes is required but not sufficient to protect the membranes against lipid hydroperoxides (LOOH)
formation. The lipid-radical theory presented in this review considers the role of two membrane factors—α-tocopherol and cytochrome
b5; these factors secure the functioning of lipid-radical cycles and the participation of lipid-radical reactions in the key
membrane processes. The prominent intermembrane reaction realized via a protein–lipid interaction, during which electron transport
from cytochrome b5—located in the outer membrane—to peroxyl radical (LOO·)—located in inner membrane—causes reduction of the peroxyl radical: cyt.b5red + LOO· → cyt.b5ox + LOO−. This secures an interaction of α-TOH with other intermediate, LOO− excepting the LOOH formation. The discussion will be focused on the consequences of ineffective electron transfer to LOO· and excessive oxidative pathway of metabolism of the PUFA (LOO· → LOOH). Assuming the operation of cytochrome b5/α-tocopherol-controlled lipid-radical cycles and considering the role of the cycles in membrane bioenergetics we arrive
at a model for effective function of adenine nucleotide translocator and ATP synthesis in mitochondria. This paper summarizes
our experimental evidence that the oxidative and non-oxidative pathways of metabolism of PUFA via their respective intermediates
occur in the cells. While this fact is not widely appreciated it may be relevant to elucidation of new mechanisms of neurodegenerative
diseases. 相似文献
3.
L. M. Fenk T. Hoinkes A. Schmid 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2010,196(12):957-961
Cupiennius salei (Ctenidae) has been extensively studied for many years and is probably the only spider that presently can be considered a
model organism for neuro-ethology. The night-active spiders have been shown to predominantly rely on their excellent mechano-sensory
systems for courtship and prey capture, whereas vision was assumed to play a minor role, if any, in these behavioral contexts.
Using slowly moving discs presented on a computer screen it could be shown for the first time that visual stimuli alone can
elicit attack behavior (abrupt approaching reactions) in these spiders as well. These observations suggest that visual information
could be used by the spiders to elicit and guide predatory behavior. Attack behavior in Cupiennius salei can thus be triggered independently by three sensory modalities—substrate vibrations, airflow stimuli, and visual cues—and
offers an interesting model system to study the interactions of multimodal sensory channels in complex behavior. 相似文献
4.
Relevance of Rheological Properties of Sodium Alginate in Solution to Calcium Alginate Gel Properties 总被引:2,自引:0,他引:2
Fu S Thacker A Sperger DM Boni RL Buckner IS Velankar S Munson EJ Block LH 《AAPS PharmSciTech》2011,12(2):453-460
The purpose of this study is to determine whether sodium alginate solutions’ rheological parameters are meaningful relative
to sodium alginate’s use in the formulation of calcium alginate gels. Calcium alginate gels were prepared from six different
grades of sodium alginate (FMC Biopolymer), one of which was available in ten batches. Cylindrical gel samples were prepared
from each of the gels and subjected to compression to fracture on an Instron Universal Testing Machine, equipped with a 1-kN
load cell, at a cross-head speed of 120 mm/min. Among the grades with similar % G, (grades 1, 3, and 4), there is a significant correlation between deformation work (L
E) and apparent viscosity (η
app). However, the results for the partial correlation analysis for all six grades of sodium alginate show that L
E is significantly correlated with % G, but not with the rheological properties of the sodium alginate solutions. Studies of the ten batches of one grade of sodium
alginate show that η
app of their solutions did not correlate with L
E while tan δ was significantly, but minimally, correlated to L
E. These results suggest that other factors—polydispersity and the randomness of guluronic acid sequencing—are likely to influence
the mechanical properties of the resultant gels. In summary, the rheological properties of solutions for different grades
of sodium alginate are not indicative of the resultant gel properties. Inter-batch differences in the rheological behavior
for one specific grade of sodium alginate were insufficient to predict the corresponding calcium alginate gel’s mechanical
properties. 相似文献
5.
In visual operant conditioning ofDrosophila at the flight simulator, only motor output of flies—yaw torque—is recorded, which is involved in the conditioning process.
The current study used a newly-designed data analysis method to study the torque distribution ofDrosophila. Modification of torque distribution represents the effects of operant conditioning on flies’ behavioral mode. Earlier works[10] showed that, when facing contradictory visual cues, flies could make choices based upon the relative weightiness of different
cues, and it was demonstrated that mushroom bodies might play an important role in such choice behavior. The new “torque-position
map” method was used to explore the CS-US associative learning and choice behavior inDrosophila from the aspect of its behavioral mode. Finally, this work also discussed various possible neural bases involved in visual
associative learning, choice processing and modification processing of the behavioral mode in the visual operant conditioning
ofDrosophila. 相似文献
6.
E. P. Voronina 《Journal of Ichthyology》2009,49(10):940-961
Structure of nonmodified scales and lateral-line scales (Sll) is compared in 179 species of 105 genera of 13 families of the order Pleuronectiformes. Morphological diversity of Sll depends on the level of development and of interaction of two component parts—the scale plate and the tubular part. Of the
considered characters, the most individually variable character is whether the tubular part is complete or incomplete. The
interspecies differences may manifest themselves in structure of the scale plate, the level of unification of opening of the
tubular part and of the cutaneous canaliculus, or in completeness or incompleteness of the tubular part. As a rule, Sll in species of the same genus is similar in structure. In some cases, special traits of this structure may be diagnostic characters
of genera and contribute to the solution of controversial issues of generic position of species. The families of Pleuronectiformes
are characterized by a different ratio of taxa with certain involved characters of nonmodified scales and Sll. However, their distribution in this order does not give a simple idea on their relationships and on the direction of evolutionary
transformations. This follows from the fact that the structure of Sll depends on a wide complex of factors—morphogenesis of nonmodified scales, level of ossification of trunk canal, time of anlage,
and mutual influence of these structures at early stages of ontogenesis. 相似文献
7.
Rufino RD Sarubbo LA Neto BB Campos-Takaki GM 《Journal of industrial microbiology & biotechnology》2008,35(8):907-914
The strategy of optimization using sequential factorial design was employed to enhance the tensio-active emulsifying agent
produced by Candida lipolytica using soybean oil refinery residue as substrate. A full factorial design was used to evaluate the impact of three fermentation
factors—amounts of refinery residue, glutamic acid and yeast extract. This allowed exclusion of the yeast extract. Full factorials
designs were then sequentially used to optimize the levels of the residue and glutamic acid. The surface tension value was
finally reduced to 25.29 mN/m. The maximum emulsifier activity using different substrates was within 40 h of cultivation.
The surface tension of the cell-free broth containing the biosurfactant remained very stable during exposure to a wide range
of pH (2–12), temperatures (0–120°C) and salinity (2–10% NaCl). The combination of an industrial waste and a cheap substrate
therefore seems to be very promising for the low-cost production of potent biosurfactant. 相似文献
8.
Crayfish establish social dominance hierarchies through agonistic interactions, and these hierarchies are maintained through
assessment of social status. Chemical signals influence several aspects of fighting behavior, but the specific chemosensory
sensilla involved in detecting these signals in crayfish are unknown. The goal of our study was to examine the importance
of aesthetasc sensilla—olfactory sensors on the antennules of decapod crustaceans—in regulating changes in fighting behavior
in crayfish, Procambarus clarkii, over the course of repeated pairings. We selectively ablated aesthetascs from pairs of crayfish after the first day of trials
and compared the behavior of these ablated animals to that of pairs of intact controls. Results show that unablated crayfish
significantly decreased the number and duration of fights over repeated pairings, whereas crayfish lacking aesthetascs continued
to engage in similar amounts of fighting across all three trial days. This difference shows that aesthetascs regulate fighting
behavior in P. clarkii. 相似文献
9.
Evolutionary radiations, times of profound diversification of species against a broader background of more muted evolutionary
change, have long been considered one of the fundamental patterns in the fossil record. Further, given the important role
geological, environmental, and climatic processes play in causing speciation, analyzing the biogeographic context of radiations
can yield important insight into their evolutionary mechanisms. In this study we examine biogeographic patterns and quantify
rates of speciation in a diverse group of Devonian trilobites, the calmoniids, that has been hailed as a classic paleontological
example of an evolutionary radiation. In particular, a phylogenetic biogeographic analysis—modified Brooks Parsimony Analysis—was
used to examine the processes and geographic setting of speciation within the group. Results indicate that the Malvinokaffric
Realm was a geographically complex area, and this geographic complexity created various opportunities for speciation via geodispersal
and vicariance that created the fuel that fed the speciation in these taxa. Part of the geographic complexity was created
not only by the inherent geologic backdrop of the region, but the overlying changes of sea level rise and fall. Rates of speciation
were highest when sea level was lowest. Low sea level encouraged isolation of faunas in different tectonic basins. By contrast,
sea level rise facilitated range expansion and geodispersal to other distinct tectonic basins, and speciation rates concomitantly
fell; however, the taxa with the expanded ranges were later fodder for diversification when sea level fell again. Here we
present a view of evolutionary radiations driven fundamentally by external abiotic factors—geology and climate—that cause
range expansion and opportunities for geographic isolation with resultant rapid speciation. 相似文献
10.
An original behavioral test was used to study the effect of opioid substances on the thresholds of nociceptive responses to
pain stimuli—a series of electric impulses applied to nerve endings of the caudal fin—in the common carp (Cyprinus carpio). The substances tested included tramadol (μ-agonist of opioid receptors), DADLE (δ-agonist), and U-50488 (κ-agonist) injected
intramuscularly in concentrations 10–100 nmol/g of body weight. Raised thresholds of sensitivity to the pain stimulus were
observed in the studied fish 5 to 15 min after the injection. The degree of analgesia and the rate of its increase varied
depending on the dose. The total duration of analgesia was 40 to 90 min and depended on the concentration of the injected
substance. It was observed in some experiments that the analgesic effect of tramadol (the most efficient of the analgesics
used) could last longer than 4 h. The analgesic effect of opioids was not detected in experiments where they were applied
together with naloxone, an antagonist of opioids. Decreased motor response to pain stimuli after injections of analgesics
was not caused by the immobilization of the animal, because the tested fish individuals released into an aquarium demonstrated
normal swimming and their usual behavior. We concluded that the systems of opioid nociceptive regulation function similarly
in fish and land vertebrates. This regulation can play an important role in defense behavior and in other behaviors in fish. 相似文献
11.
Burkholderia cepacia is an opportunistic pathogen that causes serious pulmonary infections in cystic fibrosis patients. Although several potential
virulence factors—a protease, lipase, and two phospholipases C (one hemolytic and one nonhemolytic)—have been identified,
only two, the protease and the lipase, have been described in detail. The goal of this study was to purify and characterize
a nonhemolytic phospholipase C secreted by B. cepacia strain Pc224c. The enzyme was concentrated from culture supernatants and purified by polyacrylamide gel electrophoresis.
The 54-kDa protein was stable in the presence of sodium dodecyl sulfate (up to 10%) and at 4°, 22°, and 37°C; it was, however,
inactivated at 100°C. The enzyme bound to glass, chromatography matrices, and polyvinylidene difluoride and cellulose membranes,
suggesting that it is hydrophobic. In a genetic approach, primers based on conserved sequences of a B. cepacia Pc69 hemolytic phospholipase C and both the Pseudomonas aeruginosa hemolytic and nonhemolytic proteins were designed to identify the Pc224c nonhemolytic phospholipase C gene. One polymerase
chain reaction product was identified; it was sequenced and the sequence compared with sequences in the BLAST database. The
best match was the Pseudomonas aeruginosa hemolytic phospholipase C. Ten additional B. cepacia strains were screened for the gene by Southern hybridization; five had the 4-kb band, suggesting that these strains have
a similar form of the PLC gene. Nine of the ten strains reacted with the probe, suggesting that similar sequences were present,
but in another form.
Received: 13 October 1998 / Accepted: 6 November 1998 相似文献
12.
The high prevalence of meiotic recombination—an important element of sexual reproduction—represents one of the greatest puzzles
in biology. The influence of either selection by a co-evolving parasite alone or in combination with genetic drift on recombination
rates was tested in the host-parasite system Tribolium castaneum and Nosema whitei. After eight generations, populations with smaller genetic drift had a lower recombination rate than those with high drift
whereas parasites had no effect. Interestingly, changes in recombination rate at one site of the chromosome negatively correlated
with changes at the adjacent site on the same chromosome indicating an occurrence of crossover interference. The occurrence
of spontaneous or plastic changes in recombination rates could be excluded with a separate experiment. 相似文献
13.
The influence of experimental temperature on the permeability of model diffusants across porcine buccal mucosa was investigated
in vitro. The permeability increased significantly as the experimental temperature was increased in increments of approximately 7°C.
It was observed that the apparent permeability and temperature were related by an exponential relationship that conformed
to the Arrhenius equation. Diffusants with higher lipophilicities—buspirone and bupivacaine—had lower activation energies
for diffusion when compared to hydrophilic diffusants—antipyrine and caffeine. The activation energy for diffusion of the
model diffusants decreased linearly with increasing distribution coefficients across porcine buccal mucosa. The results suggested
that the buccal mucosa acts as a stronger barrier to the diffusion of hydrophilic diffusants than the lipophilic ones. The
log-linear relationship between permeability and temperature indicates that temperature should be carefully controlled in
diffusion experiments. These results also point to the possibility of developing heat-generating buccal delivery devices,
especially for hydrophobic diffusants. 相似文献
14.
Paul H. Rubin 《Human nature (Hawthorne, N.Y.)》2000,11(3):259-279
Dominance hierarchies (sometimes called “pecking orders”) are virtually universal in social species, including humans. In
most species and in ancestral and early human societies, these hierarchies allocate scarce resources, including food and often
access to females. Humans sometimes use hierarchies for these allocational purposes, but humans use hierarchies for productive
purposes as well—as in firms, universities, and governments. Productive hierarchies and dominance hierarchies share many features.
As a result, people, including students of human behavior, often confuse types of hierarchies. For example, the Communist Manifesto attributes features to productive hierarchies that are actually characteristic of dominance hierarchies. Government hierarchies
are particularly confusing, as they have many features of both types. In modern societies with socially mandated monogamy
and voluntary attachment to hierarchies in the form of competitive labor markets, productive hierarchies are generally useful
for all members, and it is important not to confuse the two types, either in policy or in scientific analysis. 相似文献
15.
Satishkumar P. Jain Pirthi Pal Singh Sharad Javeer Purnima D. Amin 《AAPS PharmSciTech》2010,11(2):936-944
The present paper was focused on exploiting Plackett–Burman design to screen the effect of nine factors—poly (ethylene oxide)
molecular weight (X
1), poly (ethylene oxide) amount (X
2), ethylcellulose amount (X
4), drug solubility (X
5), drug amount (X
6), sodium chloride amount (X
7), citric acid amount (X
8), polyethylene glycol amount (X
9), and glycerin amount (X
11) on the release of drugs from the extended release extrudates, i.e., release rate and release mechanism. The experiments
were carried out according to a nine-factor 12-run statistical model and subjected to an 8-h dissolution study in phosphate
buffer pH 6.8. The significance of the model was indicated by the ANOVA and the residual analysis. Poly (ethylene oxide) amount,
ethylcellulose amount and drug solubility had significant effect on the T90 values whereas poly (ethylene oxide) amount and
ethylcellulose amount had significant effect on the n value. 相似文献
16.
Ranunculus kadzusensis is an endangered aquatic plant species that commonly reproduces in the rice paddies of Korea and Japan during winter and
early spring. Here, we investigated the effects of main aquatic environmental factors—light, temperature, and water depth—on
its growth, with the goal of seeking information that will contribute to its in situ conservation. As the amount of shading
increased, biomass, maximum shoot length, number of branches, flowers, and fruits, main stem diameter, and maximum leaf length
decreased. Although seed germination occurred under a 12-h photoperiod and at either 30/20°C (day/night) or 20/15°C, most
plants died at the higher temperature. Survival was 0% for surface-grown plant sets when tested in a wintertime pond experiment.
The rate of maximum shoot extension was greatest for plants grown at depths of 50 and 100 cm versus those at 20 cm. Thus,
we demonstrated that R. kadzusensis is intolerant of high temperatures and shade, which may explain why its growth is limited to paddies with no shading and
where temperatures are low early in the year, before rice cultivation begins. 相似文献
17.
Francesca Garbarini Riccardo Boero Federico D'Agata Giangiacomo Bravo Cristina Mosso Franco Cauda Sergio Duca Giuliano Geminiani Katiuscia Sacco 《PloS one》2014,9(9)
Gender differences in cooperative choices and their neural correlates were investigated in a situation where reputation represented a crucial issue. Males and females were involved in an economic exchange (trust game) where economic and reputational payoffs had to be balanced in order to increase personal welfare. At the behavioral level, females showed a stronger reaction to negative reputation judgments that led to higher cooperation than males, measured by back transfers in the game. The neuroanatomical counterpart of this gender difference was found within the reward network (engaged in producing expectations of positive results) and reputation-related brain networks, such as the self-control network (engaged in strategically resisting the temptation to defect) and the mentalizing network (engaged in thinking about how one is viewed by others), in which the dorsolateral prefrontal cortex (DLPFC) and the medial (M)PFC respectively play a crucial role. Furthermore, both DLPFC and MPFC activity correlated with the amount of back transfer, as well as with the personality dimensions assessed with the Big-Five Questionnaire (BFQ-2). Males, according to their greater DLPFC recruitment and their higher level of the BFQ-2 subscale of Dominance, were more focused on implementing a profit-maximizing strategy, pursuing this target irrespectively of others'' judgments. On the contrary, females, according to their greater MPFC activity and their lower level of Dominance, were more focused on the reputation per se and not on the strategic component of reputation building. These findings shed light on the sexual dimorphism related to cooperative behavior and its neural correlates. 相似文献
18.
Maaike Bruinsma Sarah van Broekhoven Erik H. Poelman Maarten A. Posthumus Martin J. Müller Joop J. A. van Loon Marcel Dicke 《Oecologia》2010,162(2):393-404
Herbivore-induced plant defences influence the behaviour of insects associated with the plant. For biting–chewing herbivores
the octadecanoid signal-transduction pathway has been suggested to play a key role in induced plant defence. To test this
hypothesis in our plant—herbivore—parasitoid tritrophic system, we used phenidone, an inhibitor of the enzyme lipoxygenase
(LOX), that catalyses the initial step in the octadecanoid pathway. Phenidone treatment of Brussels sprouts plants reduced
the accumulation of internal signalling compounds in the octadecanoid pathway downstream of the step catalysed by LOX, i.e.
12-oxo-phytodienoic acid (OPDA) and jasmonic acid. The attraction of Cotesia glomerata parasitoids to host-infested plants was significantly reduced by phenidone treatment. The three herbivores investigated,
i.e. the specialists Plutella xylostella, Pieris brassicae and Pieris rapae, showed different oviposition preferences for intact and infested plants, and for two species their preference for either
intact or infested plants was shown to be LOX dependent. Our results show that phenidone inhibits the LOX-dependent defence
response of the plant and that this inhibition can influence the behaviour of members of the associated insect community. 相似文献
19.
The concept of cooperative communities that enforce norm conformity through reward, as well as shaming, ridicule, and ostracism,
has been central to anthropology since the work of Durkheim. Prevailing approaches from evolutionary theory explain the willingness
to exert sanctions to enforce norms as self-interested behavior, while recent experimental studies suggest that altruistic
rewarding and punishing—“strong reciprocity”—play an important role in promoting cooperation. This paper will use data from
308 conversations among the Ju/’hoansi (!Kung) Bushmen (a) to examine the dynamics of norm enforcement, (b) to evaluate the costs of punishment in a forager society and understand how they are reduced, and (c) to determine whether hypotheses that center on individual self-interest provide sufficient explanations for bearing the
costs of norm enforcement, or whether there is evidence for strong reciprocity.
Polly Wiessner is a professor of anthropology at the University of Utah. She has carried out fieldwork with the Ju/’hoansi
of the Kalahari for the past 30 years on social networks, style in artifacts, economy, population, nutrition, and social change.
She has also worked among the Enga of Papua New Guinea since 1985 on the oral history of exchange, ritual, and warfare. 相似文献