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1.
Takuya Uehara Hideshi Naka Shigeru Matsuyama Tetsu Ando Hiroshi Honda 《Applied Entomology and Zoology》2012,47(3):227-232
The sex pheromones of two species of hawk moth, Deilephila elpenor lewisii (Butler) and Theretra oldenlandiae oldenlandiae (Fabricius), were analyzed using gas chromatography–electroantennographic detection (GC–EAD) and GC–mass spectrometry (GC–MS). Two and three EAD-active components were found in D. elpenor lewisii and T. oldenlandiae oldenlandiae, respectively. GC–MS analyses using authentic compounds and extracts derivatized by dimethyl disulfide and 4-methyl-1,2,4-triazoline-3,5-dione identified the two components in D. elpenor lewisii as (E)-11-hexadecenal (E11–16:Ald) and (10E,12E)-10,12-hexadecadienal (E10,E12–16:Ald), and the three in T. oldenlandiae oldenlandiae as E11–16:Ald, E10,E12–16:Ald, and (10E,12Z)-10,12-hexadecadienal (E10,Z12–16:Ald). In field-trap tests, no males of either species were attracted to any single components. Male moths of D. elpenor lewisii were specifically attracted to a binary blend of E11–16:Ald and E10,E12–16:Ald at a ratio of 85:15, whereas males of T. oldenlandiae oldenlandiae were attracted to a ternary blend of E11–16:Ald, E10,Z12–16:Ald and E10,E12–16:Ald at a ratio of 30:40:30. We therefore conclude that the sex pheromone of D. elpenor lewisii is a mixture of E11–16:Ald and E10,E12–16:Ald and that of T. oldenlandiae oldenlandiae is E11–16:Ald, E10,Z12–16:Ald and E10,E12–16:Ald. 相似文献
2.
A bioassay technique was used to select plant species that were able to germinate and grow in a site contaminated with flash
torch and battery manufacturing industrial effluents. Three varieties each of rice, namely Surya-52, Jaya-14 and Pant-10;
three varieties of pulses [Gram (Bahar), Mung (K-851) and Lens (T-9)] and three varieties of oilseeds (Mustard-RS-30, Mustard-B-9
and Mustard T-69) were used for the determination of phytotoxicity by bioassay technique. The average % phytotoxicity for
rice was 18.03% (14.34–22.7%), for pulses was 15.76% (8.75–26.64%) and for oil seed was 11.09% (6.42–15.24%). Accumulation
of metals (Cu, Fe, Mn, Cd, Cr and Pb) was estimated in the root, shoot and edible parts of different crop varieties grown
in pot culture up to maturity and treated with industrial effluent. The concentration of different metal ions in root, shoot
and edible parts were in the range of Cu: 9.25–45.25, 7.25–42.35 and 5.65–35.26; Fe: 60.66–212.25, 45.24–155.62; Mn: 7.12–38.30,
6.25–27.27.23 and 4.25–24.45; Cd: 0.80–2.45, 0.75–2.12 and 0.45–1.95, Cr: 6.54–28.25, 5.36–24.45 and 4.35–16.32; and Pb: 0.95–3.75,
0.78–2.25 μg/g d.w. respectively. A higher concentration of Cd was found in Surya-52 rice variety and in Gram (Bahar) pulse
variety and of Pb was detected in Surya-52 rice variety. Cd and Pb are non-essential metal ions and highly toxic to plants.
Accumulation of toxic metal ions like Pb and Cd in the edible parts of oil a seed variety may not exceed the recommended daily
intake limits. Percentage phytotoxicity and inhibition of root and shoot length was also less in the oil seed variety. Thus
these plant varieties can be considered for cultivation in fields contaminated by waste from the flash-torch and battery-manufacturing
industry. 相似文献
3.
Atsushi Fukui Miyuki Suzuki Yachiyo Suzuki Itsuro Uotani 《Ichthyological Research》2002,49(2):159-164
The early ontogeny of Lophonectes gallus (Bothidae) is described based on 83 specimens (1.9–17.5 mm BL), collected from the Tasman Sea off southeastern Australia.
The larvae are diagnosed by the following array of characters: vertebrae 10 + 30–31 = 40–41; one elongated dorsal fin ray
and several melanophores present on gut in preflexion stage (1.9–4.7 mm BL); and spines on posterior basipterygial process,
and urohyal, cleithrum, and epiotic without spines after postflexion stage (8.0–17.5 mm BL). The larvae are relatively small
at metamorphosis (15–18 mm BL) compared with other bothid larvae.
Received: March 22, 2001 / Revised: December 12, 2001 / Accepted: December 26, 2001 相似文献
4.
Alma R. Villalobos-Arámbula Rocío Bustos Maricela Casas-Castañeda Esperanza Gutiérrez Francisco J. Perea Swee L. Thein B. Ibarra 《Human genetics》1997,99(4):498-500
β-globin haplotypes of 20 β-thalassemia (β-thal) and 87 βA Mexican mestizo chromosomes were analyzed to ascertain the origin of the β-thal alleles and the frequencies and distribution
of the βA haplotypes among northwestern Mexican mestizos. Sixteen β-thal chromosomes carried six Mediterranean alleles [five codon
39 C→T; two IVS1:1 G→A; two IVS1:5 G→A; three IVS1:110 G(A; one codon 11 (–T) and three (δβ)°-thal]; the remaining four were
linked to three rare alleles (two –28 A→C and one each: –87 C→T and initiation codon ATG→GTG). Among the 87 βA chromosomes, 17 different 5′ haplotypes with frequencies for 1, 3, 2 and 5 of 39.0%, 17. 2%, 9.2% and 6.9%, respectively,
were observed. The β-haplotype analysis showed that 13 out of 16 Mediterranean chromosomes could easily be explained by gene
migration; however, one codon 39 associated with haplotype 4 (– – – – + + –), one IVS1:1 with haplotype 1(+ – – – – + +) and
one IVS1:5 G→A, may represent separate mutational events. Analysis of the rare alleles showed that the –28 A→C mutation was
associated with the commonest βA haplotype in Mexican mestizos, Mediterraneans and the total world population; therefore an independent origin cannot be ruled
out. The –87 C→T and initiation codon ATG→GTG were found with β-haplotypes different from the reported ones, suggesting an
indigenous origin.
Received: 23 April 1996 / Revised: 10 September 1996 相似文献
5.
Govindjee 《Photosynthesis research》2006,87(2):151-158
This Editorial has four goals: (1) to inform the readers of ‘Photosynthesis Research‘ about the past of the ‘Historical corner’; which began 20 years ago; (2) to encourage photosynthesis researchers and historians of science to contact me for publishing papers of historical interest; these include: (a) Obituaries and Tributes; (b) historical papers on current and past discoveries and controversies; (c) history of research in specific laboratories, or in specific countries, or at specific conferences; (d) Personal perspectives (not discussed any further); (3) to encourage researchers not to discard, but to save correspondence and data of their discoveries for the future historians by donating them to their Archives, when appropriate (not discussed any further); and (4) to reinforce to the readers that the concept of two-light reaction and two-pigment system was already there in 1959. I mention here three key papers presented at the IXth International Botanical Congress, held at Montreal Canada (in August, 1959) prior to the famous April 9, 1960 paper by Robert Hill and Fay Bendall on the ‘Z-scheme’ of photosynthesis, that was based on thermodynamic and energetic considerations.
★ This Historical corner Editorial is dedicated to Bessel Kok (1918–1978). 相似文献
6.
Three sex pheromonal components, (Z)-11-hexadecenal (Z11–16:Ald), (Z)-11-hexadecenol (Z11–16:OH), and hexadecanal (16:Ald),
in a ratio of 88.0∶7.2∶4.8, were identified from ovipositor extracts of the fulvous clover moth,Heliothis maritima Grasl. (Lepidoptera: Noctuidae) by gas chromatographymass spectrometry. In addition, trace amounts of (Z)-9-hexadecenal (Z9–16:Ald)
were detected in the extracts by GC. A blend of Z11–16:Ald, Z11–16:OH and 16:Ald in a ratio of 100∶6∶3, as well as in combination
with 0.1 or 1 part Z9–16:Ald was tested at 0.01, 0.1, 1.0 and 10.0 μg doses in a flight tunnel. In flight tunnel tests male
behavioral responses elicited by 0.1 or 1.0 μg doses of the 100∶6∶3∶1 blend were similar to those elicited by an ovipositor
extract at 2 female equivalents. Deletion of Z9–16:Ald from the blend at 0.1 μg dose caused a decrease in the male response.
In the field test, however, presence or absence of Z9–16:Ald did not significantly influence the number of males trapped in
sticky traps with rubber septa containing 100 μg of the respective blends. 相似文献
7.
Arik Colakoglu F Ormanci HB Berik N Kunili IE Colakoglu S 《Biological trace element research》2011,143(2):983-991
The venerid clam Chamelea gallina is a popular and economic foodstuff around the Mediterranean countries especially in Italy, Spain, and France. The aim of
this study is to evaluate the nutritional quality of striped venus of Southern Marmara. Samples were harvested seasonally
at five stations and analyzed to determine meat yield, proximate, and elemental composition. According to the results, meat
yield ranged from 20.24% to 29.94%. Means of water, protein, lipid, and ash content were 67%, 10.12%, 2.57%, and 1.66%, respectively.
The mean concentrations (mg/kg wet weight) of elements in tissues are as follows: B: 2.37–4.24; Cr: 0–0.76; Co: 0–0.43; Cu:
0.71–5.30; Mn: 0.30–5.94; Zn: 13.08–77.76; Ni: 0–1.22; Fe: 2.46–114.22; Al: 1.23–75.49; Pb: 0.18–3.24; Ba: 0.66–15.97; Cd:
0.04–0.69. Among the reported metal levels, only Pb and Zn in two stations exceeded the maximum critical concentrations enforced
by Turkish legislation and European Commission. Therefore, we report that striped venus from Southern Marmara Sea, in general,
are safe for human consumption; nonetheless, Pb and Zn levels should be closely monitored in the future. 相似文献
8.
Jelena Arsenijević Slavica Ražić Zoran Maksimović Svetlana Đogo 《Central European Journal of Biology》2011,6(4):616-623
This paper brings out the results of the study on the levels of selected trace elements (Cu, Fe, Mn, Zn and Cr) in aerial
parts of Thymus pannonicus All. (Lamiaceae) and rhizosphere soil from twelve locations in Serbia. Prior to assays by flame and flameless atomic absorption
spectrometry, samples were subjected to microwave-assisted acid digestion. Real and potential acidity of soil samples were
also measured. Obtained results for soil samples, although slightly higher for some elements (Cu: 12.38–45.18 mg/kg; Fe: 22102–46193
mg/kg; Mn: 776.95–4901.27 mg/kg; Zn: 62.27–214.02 mg/kg; Cr: 48.86–69.13 mg/kg), were found to fit into biogeochemical background.
Element contents in plant samples differed depending on collecting site (Cu: 5.26–14.07 mg/kg; Fe: 25.92–1454.07 mg/kg; Mn:
89.29–278.25 mg/kg; Zn: 1.81–10.64 mg/kg; Cr: 1.11–3.51 mg/kg), which can be partly explainable by different nutrient availability
influenced by soil acidity. Zinc levels in T. pannonicus were below expected and seem to be strongly influenced by plant physiological properties. 相似文献
9.
Published data on the association of vascular endothelial growth factor (VEGF) −1154G>A polymorphism with cancer risk is inconclusive.
To derive a more precise estimation of association between VEGF −1154G>A polymorphism and the risk of cancer, we performed
a meta-analysis of 7,071 cancer cases and 7,693 controls from 16 published case–control studies. Our meta-analysis didn’t
reveal an association between VEGF −1154G>A polymorphism and overall cancer risk (GG vs. AA: OR: 1.08, 95% CI: 0.96–1.20;
GA vs. AA: OR: 1.04, 95% CI: 0.93–1.17; recessive model: GG+GA vs. AA: OR: 1.06, 95% CI: 0.95–1.18; dominant model: GG vs.
GA+AA, OR: 1.11, 95% CI: 1.00–1.24). Nevertheless, for non-Caucasians, GG homozygote may have higher cancer risk compared
with either A carriers (OR: 1.58, 95% CI: 1.12–2.23) or AA homozygote (OR: 1.43, 95% CI: 1.17–1.76). No significant heterogeneity
was detected except in the dominant model and “prostate cancer” subgroup analysis. More studies with larger samples are warranted
to confirm these findings. 相似文献
10.
Hilde Eggermont James M. Russell Georg Schettler Kay Van Damme Ilse Bessems Dirk Verschuren 《Hydrobiologia》2007,592(1):151-173
This study describes the physical and chemical properties of 17 Afroalpine lakes (>2 m deep) and 11 pools (<2 m deep) in the
Rwenzori mountains, Uganda-DR Congo, with the aim to establish the baseline conditions against which to evaluate future environmental
and biological changes in these unique tropical ecosystems, and to provide the foundation for lake-based paleoenvironmental
studies. Most Rwenzori lakes are located above 3,500 m elevation, and dilute (5–52 μS/cm specific conductance at 25°C) open
systems with surface in- and outflow. Multivariate ordination and pairwise correlations between environmental variables mainly
differentiate between (1) lakes located near or above 4,000 m (3,890–4,487 m), with at least some direct input of glacial
meltwater and surrounded by rocky catchments or alpine vegetation; and (2) lakes located mostly below 4,000 m (2,990–4,054
m), remote from glaciers and surrounded by Ericaceous vegetation and/or bogs. The former group are mildly acidic to neutral
clear-water lakes (surface pH: 5.80–7.82; Secchi depth: 120–280 cm) with often above-average dissolved ion concentrations
(18–52 μS/cm). These lakes are (ultra-) oligotrophic to mesotrophic (TP: 3.1–12.4 μg/l; Chl-a: 0.3–10.9 μg/l) and phosphorus-limited (mass TN/TP: 22.9–81.4). The latter group are mildly to strongly acidic (pH: 4.30–6.69)
waters stained by dissolved organic carbon (DOC: 6.8–13.6 mg/l) and more modest transparency (Secchi-disk depth: 60–132 cm).
Ratios of particulate carbon, particulate nitrogen and chlorophyll a in these lakes indicate that organic matter in suspension is primarily derived from the lakes’ catchments rather than aquatic
primary productivity. Since key features in the Rwenzori lakes’ abiotic environment are strongly tied to temperature and catchment
hydrology, these Afroalpine lake ecosystems can be expected to respond sensitively to climate change and glacier melting.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
11.
A new epigonid fish, Epigonus cavaticus, is described on the basis of eight specimens (59.2–69.5 in standard length: SL) collected from a cave at depth 20 m, southern
fringing reef of Ngemelis Island, Palau. The species differs from other congeners by having minute teeth on both jaws, no
opercular spine, pyloric caeca 7–8, gill rakers 25–27, total pored lateral line scales 48–50, dorsal fin rays VII-I, 10–11
(mode VII-I, 10), pectoral fin rays 16, vertebrae 10 + 15, body depth 21.4–25.0% SL, pectoral fin length 22.7–24.6% SL, eye
diameter 44.4–47.5% head length: HL, upper jaw length 40.2–42.5% HL. Four paratypes (63.7–66.8 mm SL) of the new species are
female with mature gonads, it is the smallest in size at sexual maturity among the congeners. 相似文献
12.
A new righteye flounder, Poecilopsetta pectoralis, is described from 4 specimens (2 males, 2 females) collected from deep waters (510–580 m) around New Caledonia. The species
is easily distinguished from 13 congeners by having 99–105 lateral line scales, a narrow interorbit [male: 37.00–40.25 in
head length (HL); female: 47.33–50.71], long pectoral fin on ocular side (male: 0.89–0.91 in HL; female: 1.04–1.20), no scales
from snout to anterior interorbital region, and 4 spots on caudal fin. Sexual dimorphism is evident in this species, showing
males bearing the ocular-side pectoral fin longer than females, and it is the first example in Poecilopsetta. 相似文献
13.
A Closer Look at Amphetamine-Induced Reverse Transport and Trafficking of the Dopamine and Norepinephrine Transporters 总被引:1,自引:0,他引:1
Amphetamine (AMPH) and its derivatives are regularly used in the treatment of a wide array of disorders such as attention-deficit
hyperactivity disorder (ADHD), obesity, traumatic brain injury, and narcolepsy (Prog Neurobiol 75:406–433, 2005; J Am Med Assoc 105:2051–2054, 1935; J Am Acad Child Adolesc Psychiatry 41:514–521, 2002; Neuron 43:261–269, 2004; Annu Rev Pharmacol Toxicol 47:681–698, 2007; Drugs Aging 21:67–79, 2004). Despite the important medicinal role for AMPH, it is more widely known for its psychostimulant and addictive properties
as a drug of abuse. The primary molecular targets of AMPH are both the vesicular monoamine transporters (VMATs) and plasma
membrane monoamine—dopamine (DA), norepinephrine (NE), and serotonin (5-HT)—transporters. The rewarding and addicting properties
of AMPH rely on its ability to act as a substrate for these transporters and ultimately increase extracellular levels of monoamines.
AMPH achieves this elevation in extracellular levels of neurotransmitter by inducing synaptic vesicle depletion, which increases
intracellular monoamine levels, and also by promoting reverse transport (efflux) through plasma membrane monoamine transporters
(J Biol Chem 237:2311–2317, 1962; Med Exp Int J Exp Med 6:47–53, 1962; Neuron 19:1271–1283, 1997; J Physiol 144:314–336, 1958; J Neurosci 18:1979–1986, 1998; Science 237:1219–1223, 1987; J Neurosc 15:4102–4108, 1995). This review will focus on two important aspects of AMPH-induced regulation of the plasma membrane monoamine transporters—transporter
mediated monoamine efflux and transporter trafficking. 相似文献
14.
The transmembrane transport of anticancer drugs is mainly regulated by P-glycoprotein encoded by the human multidrug resistance
gene 1 gene (MDR1). Since there were controversies regarding the association between MDR1 C3435T polymorphism and response to chemotherapy among patients with advanced breast cancer, a meta-analysis of the link
was conducted. A total of 7 studies consist of 464 advanced breast cancer patients relating MDR1 C3435T polymorphism to the response of chemotherapy were included in this meta-analysis. The main analysis revealed a lack
of association between the MDR1 C3435T and response to chemotherapy, with odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) of 1.37
(95% CI: 0.78–2.40), 1.17 (95% CI: 0.69–2.01), 1.18 (95% CI: 0.76–1.84) and 1.61 (95% CI: 0.70–3.68) for homozygous comparison,
heterozygous comparison, dominant model and recessive model, respectively. The subgroup analysis by ethnicity did not change
the pattern of results, with ORs of 0.99 (95% CI: 0.11–9.07), 0.68 (95% CI: 0.29–1.60), 0.81 (95% CI: 0.36–1.85) and 1.51
(95% CI: 0.77–2.96), in homozygous comparison, heterozygous comparison, dominant model and recessive model, respectively in
Caucasian, and 1.50 (95% CI: 0.75–3.03), 1.72 (95% CI: 0.85–3.47), 1.59 (95% CI: 0.90–2.80) and 2.29 (95% CI: 0.51–10.35),
respectively in Asian. The available evidence indicates that MDR1 C3435T polymorphism cannot be considered as a reliable predictor of response to chemotherapy in patients with advanced breast
cancer. 相似文献
15.
Minimal inhibitory concentrations (MICs) of 14 first and second-line antituberculous drugs against drug-susceptible and drug-resistant
clinical isolates of Mycobacterium tuberculosis (including the multiple drug-resistant or MDR-TB isolates), as well as the type strain H37Rv, were determined radiometrically
by the Bactec 460-TB methodols. MICs (μg/ml) of all the fourteen drugs were within an extremely narrow range in case of susceptible
strains; isoniazid (0.02–0.04), rifampin (0.2–0.4), ethambutol and streptomycin (0.5–2.0), ethionamide (0.25–0.5), D-cycloserine
(25–75), capreomycin (1–2), kanamycin (2–4), amikacin (0.5–1.0), clofazimine (0.1–0.4), ofloxacin (0.5–1.0), ciprofloxacin
(0.25–1.0), and sparfloxacin (0.1–0.4). The activity of second-line drugs remained unaltered against MDR-TB isolates resistant
to routine first-line drugs. With peak serum level concentrations (Cmax), the intracellular killing of the virulent H37Rv
strain was studied in detail in cultured human macrophages. Based on an decreasing order of bactericidal activity, our results
showed the following spectrum of intracellular drug action: among the first-line drugs, rifampin > ethionamide = isoniazid
> ethambutol > streptomycin > D-cycloserine; among second-line drugs, clofazimine = amikacin > kanamycin = capreomycin; among
fluoroquinolones, sparfloxacin > ofloxacin > ciprofloxacin. On the other hand, contrary to atypical mycobacteria, the macrolide
drug clarithromycin was inactive against both extracellular and intracellular M. tuberculosis.
Received: 23 January 1996 / Accepted: 5 April 1996 相似文献
16.
Chun-Guang Zhang Prachya Musikasinthorn Katsutoshi Watanabe 《Ichthyological Research》2002,49(2):140-146
A new species of channid fish, genus Channa, is described from 7 specimens collected from the vicinity of Hepu, Guangxi Province, southern China. The new species, Channa nox, is distinguished from all other channid species by the following combination of characters: absence of pelvic fins, small
rounded head (22.1%–26.8% SL), narrow interorbital width (19.6%–26.7% HL), short snout length (3.6%–5.1% SL), predorsal and
prepectoral lengths (26.9%–28.4% SL and 24.8%–28.3% SL, respectively), 47–51 dorsal fin rays, 31–33 anal fin rays, 55–63 lateral
line scales, 5.5–6.5 scales above lateral line, 9–13 cheek scales, 53–55 total vertebrae, 1 or 2 scale(s) on each side of
lower jaw undersurface, the black upper half of body with 8–11 irregular (often anteriorly pointed V-shaped) bands or blotches,
a large white-rimmed black ocellus on caudal peduncle and sparse white spots on the dark brown body and dorsal and caudal
fins, as well as the shape of the hyomandibular process of the suprabranchial organs. Channa nox is sympatrically distributed with its morphologically most similar congener, C. asiatica.
Received: January 18, 2001 / Revised: November 2, 2001 / Accepted: December 12, 2001 相似文献
17.
Meiotic prophase serves as an arena for the interplay of two important cellular activities, meiotic recombination and synapsis of homologous chromosomes. Synapsis is mediated by the synaptonemal complex (SC), originally characterized as a structure linked to pairing of meiotic chromosomes (Moses (1958) J Biophys Biochem Cytol 4:633–638). In 1975, the first electron micrographs of human pachytene stage SCs were presented (Moses et al. (1975) Science 187:363–365) and over the next 15 years the importance of the SC to normal meiotic progression in human males and females was established (Jhanwar and Chaganti (1980) Hum Genet 54:405–408; Pathak and Elder (1980) Hum Genet 54:171–175; Solari (1980) Chromosoma 81:315–337; Speed (1984) Hum Genet 66:176–180; Wallace and Hulten (1985) Ann Hum Genet 49(Pt 3):215–226). Further, these studies made it clear that abnormalities in the assembly or maintenance of the SC were an important contributor to human infertility (Chaganti et al. (1980) Am J Hum Genet 32:833–848; Vidal et al. (1982) Hum Genet 60:301–304; Bojko (1983) Carlsberg Res Commun 48:285–305; Bojko (1985) Carlsberg Res Commun 50:43–72; Templado et al. (1984) Hum Genet 67:162–165; Navarro et al. (1986) Hum Reprod 1:523–527; Garcia et al. (1989) Hum Genet 2:147–53). However, the utility of these early studies was limited by lack of information on the structural composition of the SC and the identity of other SC-associated proteins. Fortunately, studies of the past 15 years have gone a long way toward remedying this problem. In this minireview, we highlight the most important of these advances as they pertain to human meiosis, focusing on temporal aspects of SC assembly, the relationship between the SC and meiotic recombination, and the contribution of SC abnormalities to human infertility.The synaptonemal complex–50 years 相似文献
18.
Progression age enhanced backward bifurcation in an epidemic model with super-infection 总被引:10,自引:0,他引:10
We consider a model for a disease with a progressing and a quiescent exposed class and variable susceptibility to super-infection.
The model exhibits backward bifurcations under certain conditions, which allow for both stable and unstable endemic states
when the basic reproduction number is smaller than one.
Received: 11 October 2001 / Revised version: 17 September 2002 /
Published online: 17 January 2003
Present address: Department of Biological Statistics and Computational Biology, 434 Warren Hall, Cornell University, Ithaca, NY 14853-7801
This author was visiting Arizona State University when most of the research was done.
Research partially supported by NSF grant DMS-0137687.
This author's research was partially supported by NSF grant DMS-9706787.
Key words or phrases: Backward bifurcation – Multiple endemic equilibria – Alternating stability – Break-point density – Super-infection – Dose-dependent
latent period – Progressive and quiescent latent stages – Progression age structure – Threshold type disease activation –
Operator semigroups – Hille-Yosida operators – Dynamical systems – Persistence – Global compact attractor 相似文献
19.
Anya Plutynski 《Biology & philosophy》2008,23(3):363-381
There have been two different schools of thought on the evolution of dominance. On the one hand, followers of Wright [Wright
S. 1929. Am. Nat. 63: 274–279, Evolution: Selected Papers by Sewall Wright, University of Chicago Press, Chicago; 1934. Am.
Nat. 68: 25–53, Evolution: Selected Papers by Sewall Wright, University of Chicago Press, Chicago; Haldane J.B.S. 1930. Am.
Nat. 64: 87–90; 1939. J. Genet. 37: 365–374; Kacser H. and Burns J.A. 1981. Genetics 97: 639–666] have defended the view that
dominance is a product of non-linearities in gene expression. On the other hand, followers of Fisher [Fisher R.A. 1928a. Am.
Nat. 62: 15–126; 1928b. Am. Nat. 62: 571–574; Bürger R. 1983a. Math. Biosci. 67: 125–143; 1983b. J. Math. Biol. 16: 269–280;
Wagner G. and Burger R. 1985. J. Theor. Biol. 113: 475–500; Mayo O. and Reinhard B. 1997. Biol. Rev. 72: 97–110] have argued
that dominance evolved via selection on modifier genes. Some have called these “physiological” versus “selectionist,” or more
recently [Falk R. 2001. Biol. Philos. 16: 285–323], “functional,” versus “structural” explanations of dominance. This paper
argues, however, that one need not treat these explanations as exclusive. While one can disagree about the most likely evolutionary
explanation of dominance, as Wright and Fisher did, offering a “physiological” or developmental explanation of dominance does
not render dominance “epiphenomenal,” nor show that evolutionary considerations are irrelevant to the maintenance of dominance,
as some [Kacser H. and Burns J.A. 1981. Genetics 97: 639–666] have argued. Recent work [Gilchrist M.A. and Nijhout H.F. 2001.
Genetics 159: 423–432] illustrates how biological explanation is a multi-level task, requiring both a “top-down” approach
to understanding how a pattern of inheritance or trait might be maintained in populations, as well as “bottom-up” modeling
of the dynamics of gene expression. 相似文献
20.
Dynamic calibration of mechanically, air- and electromagnetically braked cycle ergometers 总被引:2,自引:0,他引:2
B. F. Maxwell R. T. Withers A. H. Ilsley M. J. Wakim G. F. Woods L. Day 《European journal of applied physiology and occupational physiology》1998,78(4):346-352
In this study we measured the accuracy of the following types of cycle ergometer against the criterion of a dynamic calibration
rig (DCR): 35 friction-braked (Monark), 5 research-grade air-braked (Repco) and 5 electromagnetically braked (2 Siemens, 1
Elema-Schonander, 1 Ergoline, l Warren E. Collins). Monark ergometer power outputs over the range 58.9–353.2 W significantly
(P < 0.001) underestimated those registered by the DCR with mean accuracies of 91.7–97.8%. The least accurate individual reading
for each of the six up-scale (0–353.2 W) power outputs ranged from 81.6␣to␣91.6%; corresponding down-scale (353.2–0 W) accuracies
were 85.1–92.5%. A hysteresis effect was furthermore evident for this ergometer in that up-scale measurements were significantly
(P < 0.05) greater than down-scale ones. In addition, when the oldest [mean (SD): 11.3 (2.3) years old] and newest [1.4 (0.8)
years old] eight ergometers were compared, the latter were significantly (P < 0.05) more accurate over the range 117.7–294.3 W. Apart from the two lowest power outputs of 47␣W (62.2–96.0% accuracy)
and 127 W (88.0–97.7% accuracy), the individual up-scale and down-scale accuracies of the Repco ergometers ranged from 98.0
to 104.2% for power outputs of 272.7–1137.8 W and the means were not significantly different from those of the DCR. There
was also no evidence of hysteresis. Except for the initial power output of 50 W (40 rev/min: 83.8–99.2% accuracy; 60 rev/min:
93.2–122.6% accuracy), the␣individual accuracies of the electromagnetically braked ergometers ranged from 89.3 to 101.4% over
the up-scale range of 100–400 W, and none of the means were significantly different from those of the DCR. The variability
of individual errors for the preceding data emphasises that all cycle ergometers should be validated against the criterion
of a DCR if accurate power outputs are required.
Accepted: 19 February 1998 相似文献