共查询到20条相似文献,搜索用时 46 毫秒
1.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid. 相似文献
2.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl− (0.19), glutamate− (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius. 相似文献
3.
2-Dimethylaminomethylene-1-benzosuberone 1 was coupled with diazotized aniline derivatives to afford a series of the hitherto unreported 2-arylazo-1-benzosuberones 3a–i. The tautomeric structure and the effect of substituents on the tautomeric form (s) of the products 3a–i were discussed. Similar coupling of the enaminone 1 with diazonium salts of heterocyclic amines gave the respective fused azolotriazino-benzosuberones. Some of the newly synthesized compounds showed potent antimicrobial, anti-HCV, antioxidant, antitumor (as topoisomerase I inhibitors), and antimicrobial activities. 相似文献
4.
Nine blood group systems of goats were identified using 12 caprine reagents produced by absorption of alloimmune antisera.
The caprine C blood group system, possibly homologous to the ovine C blood group system, was characterized by two reagents
and shown to be controlled by three alleles,C
12,C
25, andC
−. A more complex blood group system of goats, designated G, was identified using three reagents and shown to be controlled
by six codominant alleles (G
10.19.20,G
10.19,G
10.20,G
10,G
19,G
20) and a recessive allele (G
−). A further seven one-factor two-allelic systems were identified by seven reagents. The nine genetic systems provided exclusion
probabilities of 0.479, 0.492, 0.548, and 0.572 in Australian Angora, Dairy, Cashmere, and Texan Angora goat breeds, respectively.
This work was supported by a grant from the Australian Stud Book, Alison Road, Randwick, New South Wales 2031, Australia. 相似文献
5.
Stanislava Vondráčková Michal Hejcman Jiřina Száková Vladimíra Müllerová Pavel Tlustoš 《Plant and Soil》2014,379(1-2):231-245
Background and aims
The ionome (elemental composition) of grassland species has rarely been studied at the level of individual organs and little is known about effects of soil chemical properties on the ionome. Using the model oxalate plant Rumex obtusifolius, we asked how its biomass production and the distribution of elements between its organs is affected by soil chemical properties.Methods
We established a pot experiment with R. obtusifolius planted in acidic non-contaminated control and in slightly acidic and alkaline soils anthropogenically contaminated by the risk elements As, Cd, Pb, and Zn. Both contaminated soils were untreated and treated by lime and superphosphate. We determined biomass production and the concentrations of elements in its organs.Results
Biomass production was negatively related to the mobility of micro- and risk elements. Restricted transport of micro- and risk elements from belowground organs into leaves was recorded in untreated contaminated soils. In both lime-treated soils and in superphosphate-treated alkaline soil, elevated transport of micro- and risk elements from belowground organs into leaves was recorded in comparison to untreated contaminated soils. The lowest concentrations of micro- and risk elements were recorded in stems and seeds, followed by belowground organs and leaves.Conclusions
R. obtusifolius is an As-, Cd-, Pb-, and Zn-excluder and is sensitive to high availability of micro- and risk elements in the soil. Soil chemical properties affect the distribution of essential elements within the plant greatly. 相似文献6.
Pan Yuerong 《Human Evolution》1990,5(3):239-240
The paper deals with a new form ofSinoadapis from the Lufeng hominoid Locality, assigned toSinoadapis shihuibaensis sp. nov. Holotype PA 882 A fragment of right mandible with C,−M3. Other materials. PA 903 A fragment of left maxilla with P3−M3. PA 959 Left lower tooth row with I1−P2, P4. PA 902 Right upper tooth row with C′−P3. PA 964 An isolated left I1. PA 907 An isolated right I3. PA 972 An isolated right M3. 相似文献
7.
Salmonella enterica subsp. enterica poses a threat to both human and animal health, with more than 2500 serovars having been reported to date. Salmonella serovars are identified by slide and tube agglutination tests using O and H antigen-specific anti-sera, although this procedure is both labor intensive and time consuming. Establishment of a method for rapid screening of the major Salmonella serovars is therefore required. We have established multiplex polymerase chain reaction (m-PCR) assays for identification of seven serovars of Salmonella, i.e., Typhimurium, Choleraesuis, Infantis, Hadar, Enteritidis, Dublin and Gallinarum. Three serovar-specific genomic regions (SSGRs) of each serovar were selected using an approach in comparative genomics. The Salmonella-specific invA gene was used to confirm the genetic background of the organisms. The isolates tested were identified as a target serovar when the three selected SSGRs and invA were all positive for amplification. The specificity of each m-PCR assay was investigated using 118 serovars of Salmonella and 12 species of non-Salmonella strains. Although a small number of false-positive results were observed in the m-PCR assays used to identify Typhimurium, Choleraesuis, Enteritidis and Dublin for closely related serovars, false-negative results were not observed in any assays. These assays had sufficient specificity to identify the seven Salmonella serovars, and therefore, have the potential for use as rapid screening methods. 相似文献
8.
We have determined and compared trace metals concentration in saliva taken from chemical warfare injures who were under the exposure of mustard gas and healthy subjects by means of inductively coupled plasma optical emission spectroscopy (ICP-OES) for the first time. The influence of preliminary operations on the accuracy of ICP-OES analysis, blood contamination, the number of restored teeth in the mouth, salivary flow rate, and daily variations in trace metals concentration in saliva were also considered. Unstimulated saliva was collected at 10:00–11:00 a.m. from 45 subjects in three equal groups. The first group was composed of 15 healthy subjects (group 1); the second group consisted of 15 subjects who, upon chemical warfare injuries, did not use Salbutamol spray, which they would have normally used on a regular basis (group 2); and the third group contained the same number of patients as the second group, but they had taken their regular medicine (Salbutamol spray; group 3). Our results showed that the concentration of Cu in saliva was significantly increased in the chemical warfare injures compared to healthy subjects, as follows: healthy subjects 15.3± 5.45(p.p.b.), patients (group 2) 45.77±13.65, and patients (Salbutamol spray; group 3) 29 ±8.51 (P <0.02). In contrast, zinc was significantly decreased in the patients, as follows: healthy subjects 37 ± 9.03(p.p.b.), patients (group 2) 12.2 ± 3.56, and patients (Salbutamol spray; group 3) 20.6 ±10.01 (P < 0.01). It is important to note that direct dilution of saliva samples with ultrapure nitric acid showed the optimum ICP-OES outputs. 相似文献
9.
Vladimir Zaichick Sofia Zaichick Vasilii Karandashev Sergey Nosenko 《Biological trace element research》2009,129(1-3):107-115
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs. 相似文献
10.
Bat ectoparasites (Nycteribiidae,Streblidae, Siphonaptera,Heteroptera, Mesostigmata,Argasidae, and Ixodidae) from Algeria
下载免费PDF全文
![点击此处可从《Journal of vector ecology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mohammed Lamine Bendjeddou Hibat Allah Loumassine Ingo Scheffler Zihad Bouslama Zuhair Amr 《Journal of vector ecology》2017,42(1):13-23
Twenty two species of ectoparasites (Family Nycteribiidae: Nycteribia (Listropoda) schmidlii schmidlii, Nycteribia (Nycteribia) latreillii, Nycteribia (Nycteribia) pedicularia, Penicillidia (Penicillidia) dufourii, and Phthiridium biarticulatum; Family Streblidae: Brachytarsina (Brachytarsina) flavipennis and Raymondia huberi; Order Siphonaptera: Rhinolophopsylla unipectinata arabs, Nycteridopsylla longiceps, Araeopsylla gestroi, Ischnopsyllus intermedius, and Ischnopsyllus octactenus; Order Heteroptera: Cimex pipistrelli, Cimex lectularius, and Cacodmus vicinus; Class Arachnida: Order Mesostigmata: Spinturnix myoti and Eyndhovenia euryalis; Order Ixodida: Family Argasidae: Argas transgariepinus and Argas vespertilionis; Family Ixodidae: Hyalomma dromedarii, Ixodes ricinus, and Ixodes vespertilionis) were recovered from 19 bat species in Algeria. New host records for bats are recorded for the first time: N. schmidlii from Rh. clivosus and R. cystops; N. latreillii from Rh. blasii and P. gaisleri; R. huberi from Rh. clivosus; C. pipistrelli from E. isabellinus and H. savii; C. vicinus from E. isabellinus; S. myoti from P. gaisleri; E. euryalis from P. gaisleri and Rh. blasii; A. vespertilionis from P. gaisleri; I. ricinus from T. teniotis and Rh. hipposideros and H. dromedarii from P. kuhlii. Raymondia huberi is recorded for the first time from Algeria. 相似文献
11.
Eight biocides were chosen to determine whether they had any effects on nontarget organisms in soil and to what extent they would reduce their target populations under laboratory experimental conditions. A simplified microcosm system was utilized in which reduced species arrays that included field populations of either only bacteria and fungi, or bacteria, fungi, and protozoa (no nematodes, arthropods, or plants) were inoculated into sterilized soil. In a second set of experiments, plants were grown in sterilized soil. A bactericide-streptomycin-four fungicides-cycloheximide, Fungizone (amphotericin B), captan, and PCNB (quintozene)-an acaricide-cygon-an insecticide-nematicide-carbofuran-and an insecticide-diazinon-were used. Each biocide had effects on nontarget organisms although the increases or decreases, with respect to the control, were of only limited duration. Reductions in target groups were typically of longer duration. Streptomycin, applied at 1 mg·g–1 soil, did not decrease bacterial populations during the experimental incubation. At 3 mg·g–1 soil, streptomycin decreased the numbers of bacteria that grew on tryptone agar, but also reduced active hyphae. Fungizone was the most effective of the 4 fungicides tested in reducing active hyphae. Increased bacterial populations were usually observed following fungal reductions. Carbofuran had the fewest effects on the test organisms (bacteria, fungi, and protozoa). Only an initial stimulation of bacterial and fungal populations was observed with cygon although it also increased NH4
+-N concentrations in soil during most of the incubation, as did streptomycin and cycloheximide. A transitory increase in fungal populations following a decrease in ciliate numbers was observed in the cygon with grazers treatments. Diazinon reduced all microbial populations and inorganic nitrogen concentrations measured. Cygon and PCNB decreased growth of blue grama plants, while streptomycin reduced shoot weights of blue grama. These results should be useful in assessing the effects of these biocides when applied to more complex systems. 相似文献
12.
Douglas E. Soltis 《American journal of botany》1982,69(1):108-115
Karyotypic differences were sought among species of Boykinia, Heuchera, Mitella, Sullivantia, Tiarella, and Tolmiea utilizing a modification of the Hy-banding technique. Prominent centromeric and some telomeric heterochromatin banding was observed. Boykinia aconitifolia and species of Sullivantia possess an identical banded karyotype, while four species of Heuchera, Mitella diphylla, Tiarella cordifolia, and Tolmiea menziesii (the latter at the tetraploid level) are characterized by a second, slightly different banded karyotype. In Sullivantia, Giemsa C-banding stains the same chromosomal regions revealed by Hy-banding. Larger amounts of heterochromatin are present in chromosomes of species of Heuchera, Mitella, Tiarella, and Tolmiea than in chromosomes of Sullivantia species and Boykinia aconitifolia. These karyological observations confirm generic relationships and demonstrate the systematic applicability of chromosome banding techniques to plants with very small chromosomes. 相似文献
13.
Leif I Solberg 《Implementation science : IS》2006,1(1):1-7
Background
In order to conduct good implementation science research, it will be necessary to recruit and obtain good cooperation and comprehensive information from complete medical practice organizations. The goal of this paper is to report an effective example of such a recruitment effort for a study of the organizational aspects of depression care quality.Methods
There were 41 medical groups in the Minnesota region that were eligible for participation in the study because they had sufficient numbers of patients with depression. We documented the steps required to both recruit their participation in this study and obtain their completion of two questionnaire surveys and two telephone interviews.Results
All 41 medical groups agreed to participate and consented to our use of confidential data about their care quality. In addition, all 82 medical directors and quality improvement coordinators completed the necessary questionnaires and interviews. The key factors explaining this success can be summarized as the seven R's: Relationships, Reputation, Requirements, Rewards, Reciprocity, Resolution, and Respect.Conclusion
While all studies will not have all of these factors in such good alignment, attention to them may be important to other efforts to add to our knowledge of implementation science. 相似文献14.
Age, growth, and reproductive characteristics of blacktail snapper, Lutjanus fulvus, which is a commercial fish species, were investigated using 322 specimens (40–332 mm in fork length) caught around the Yaeyama Islands, Okinawa, Japan. Spawning season was estimated to be from April to October, and spawning was confirmed around the full moon and the last quarter moon. Age determination using sectioned otoliths revealed that ages ranged from 0 to 34 years and the majority was ≥ 3 years. Parameters of the von Bertalanffy growth function were estimated to be L ∞ = 270 mm, k = 0.40, and t 0 = ?0.48 years for females, and 257 mm, 0.44, and ?0.42 years for males. Initial growth was rapid during the first 3 years, attaining over 200 mm for both sexes, and then females grew larger than males. Sizes (ages) at the first sexual maturity were 225 mm (4 years) for females and 207 mm (3 years) for males. The wide range of age composition in catch with majority of ≥3 years old implied that the current fishing effort to harvest was not sufficiently large enough to collapse the stock immediately. 相似文献
15.
《Cryptogamie Bryologie ☆》1999,20(3):167-179
Twenty-seven names are newly placed in synonymy, Plagiochila blepharophora (Nees) Lindenb. var. δ major Schiffn. (= P. sandei Dozy), P.boninensis Inoue (= P. fordiana Steph.), P. cadens Inoue (= P. sciophila Nees), P. cameronensis Inoue (= P. hampeana Gottsche), P. ceramica Inoue (= P. pulvinata Steph.), P. decidua Inoue & Grolle (= P. sciophila Nees), P. didyma Inoue (= P. parvifolia Lindenb.), P. euryphyllon Herzog (= P. sciophila Nees), P. flavovirens Steph. (= P. sciophila Nees), P. fraseri Steph. (= P. teysmannii Sande Lac), P. gedeana Schiffn. (= P. hampeana Gottsche), P. kaernbachii Steph. (= P. sandei Dozy), P. lagunensis Inoue (= P. junghuhniana Sande Lac), P. massalongoana Sande Lac. (= P. junghuhniana Sande Lac), P. minor Horik. (= P. fordiana Steph.), P. nilgherriensis Steph. (= P. semidecurrens (Lehm. & Lindenb.) Lindenb.), P. nubila Steph. (= P. sandei Dozy), P. nymanii Steph. (= P. sandei Dozy), P. orientalis Taylor (= P. sciophila Nees), P. seemannii Mitt. (= P. sandei Dozy), P. sepikensis Inoue (= P. inflata Steph.), P. spinosissima Steph. (= P. semidecurrens (Lehm. & Lindenb.) Lindenb.), P. subplanata Inoue (= P. sciophila Nees), P. trabeculata var. bifida S. Hatt. (= P. fordiana Steph.), P. trochantha Steph. (= P. sciophila Nees), P. tsutomui Inoue (= P. ungarangana Sande Lac), and P. wichurae Steph. (= P. renitens (Nees) Lindenb). Lectotypes are designated for P. junghuhniana, P. semidecurrens, and P. ungarangana. Plagiochila inflata Steph. is reinstated as a species of sect. Annotinae Carl. 相似文献
16.
J. Alan Holman 《Historical Biology》2013,25(4):263-279
Triturus vulgaris (smooth newt), Triturus helveticus or T. vulgaris (palmate or smooth newt), Triturus sp. (newt), Pelobates fuscus (common spadefoot), Bufo bufo (common toad), Bufo calamita (natterjack toad), Bufo sp. (toad), Rana arvalis (moor frog), Rana temporaria (common frog), Rana sp. (frog), Anguis fragilis (slow worm), Lacerta cf. L. vivipara (common lizard), Natrix natrix (grass snake), and Natrix sp. (grass, viperine, or dice snake) were identified at the Middle Pleistocene Boxgrove Site, West Sussex, England. This is the first British fossil record of Pelobates fuscus and the earliest fossil record in Britain for the endangered species Bufo calamita. All of these herpetological species are extant and all of them occur in Britain today with the exception of Pelobates fuscus and Rana arvalis that presently live on the European continent. The Boxgrove, Westbury, and West Runton British pre‐Anglian Middle Pleistocene herpetofaunas show no apparent differences among themselves in patterns of species composition, diversity, or number of exotics. But these three herpetofaunas together have [1] less species diversity and [2] fewer exotic continental species than in the Cudmore Grove British post‐Anglian Middle Pleistocene herpetofauna. Only the Terrestral Sequence Unit at Boxgrove yielded enough herpetological species for paleoecological interpretation. These taxa indicate a quiet pool surrounded by a somewhat humid vegetated area that gave way to a more xerophytic sandy area, and a paleoclimate at least as warm and perhaps somewhat warmer than occurs in the area today. 相似文献
17.
In this work, the distribution of nine metals in two types of cultivated mushroom had been investigated. For Agaricus bisporus, the biomass was separated into caps and stalks, and for Pleurotus ostreatus, the entire mushrooms were taken for analysis. Electrothermal atomic absorption spectrometry was used for total element determination
in acid digests. For accuracy checking, the certified reference material (NIST 1571, citrus leaves) was analyzed. The results
obtained for the two fungi species were within the ranges of concentration reported previously by other authors. Subcellular
fractionation was accomplished by centrifugation of cell homogenates, which has been suspended in Tris-HCl buffer. In the
first centrifugation (7300g, 4°C, 10 min), cell walls were separated (pellet I), and the second centrifugation (147,000g, 4°C, 60 min) yielded mixed membrane fraction (pellet II) and cytosol (supernatant II). Recoveries of the fractionation procedure
were in the range 70–100% (with the exception of Fe). For all elements studied, the highest relative contributions were found
in cytosol fractions of the fruiting bodies (63–72%, 49–76%, 44–93%, 26–87pc, 55–85%, 50–68%, 41–78%, 39–78%, 54–67% respectively
for Al, Bi, Cd, Cr, Cu, Fe, Mn, Ni, and Pb. Lower contributions were found in cell walls (respectively 22–32%, 24–44%, 6.1–47%,
12–52%, 7.3–37%, 7.9–32%, 19–52%, 20–42%, and 25–38%) and only minute amounts in the mixed membrane fraction (3.0–5.8%, 0.7–7.0%,
0.7–8.3%, 1.0–22%, 7.5–14%, 16–24%, 1.1–19%, and 5.1–7.7%). The results obtained indicate that small water-soluble molecules
were the primary forms of nine elements in two mushroom species studied. On the other hand, the evidence has been provided
on elements binding to larger, water-insoluble molecules contained in the structures of cell wall and membranes. The relative
distribution was both element and fungi dependent. Thus, in P. ostreatus, total element levels were higher than in A. bisporus, with the preference for their accumulation in cytosol. On the contrary, total element content in the latter fungi was lower;
however, a clear tendency toward more efficient element incorporation to the water-insoluble structures was observed (no apparent
differences between stalks and caps). These findings might contribute in a better understanding of the accumulation of metals
in mushrooms. 相似文献
18.
Wineries,drosophila, alcohol,and Adh 总被引:1,自引:0,他引:1
R. William Marks John G. Brittnacher John F. McDonald T. Prout F. J. Ayala 《Oecologia》1980,47(1):141-144
Summary Previous workers (McKenzie and Parsons, 1972, 1974; McKenzie, 1974; Briscoe et al., 1975) have found anomalous distributions of species of Drosophila, of sexes of D. melanogaster, and of Adh alleles in and around wineries in Australia and Spain. Field studies in California's Sonoma Valley provide evidence that the explanations advanced for these distributions may incorrect. The anomalous distribution of species was attributed to alcohol, either as a selective agent or as a behavioral stimulus. We find a virtually identical species distribution in the absence of environmental alcohol. The anomalous sex ratio was attributedd to differential survivall of the sexes when raised on alcohol. We present crude evidence thatehe difference may simply be a behavioral response to some product of fermentation, which need not be alcohol. Finally, the allele frequency difference reported from Spain was attributed to differential adult mortality on alcohol. We do not find an allele frequency difference even when alcohol is exposed, and therefore suggest that selection is occurring in pre-adult stages. 相似文献
19.
Summary A technique for multi-element analysis of brain tissue by proton induced X-ray emission spectroscopy (PIXE) is described and data from analysis of fixed and unfixed samples from rat hippocampus, neocortex, amygdala, and spinal cord is presented and commented on. The atoms present in the tissue are bombarded with protons which causes the ejection of electrons from the inner shells. When the holes are refilled with electrons from outer shells, X-ray quanta characteristic for each element are emitted. Using a high resolution energy dispersive detector a complete X-ray spectrum of the specimen can be recorded in a single measurement. Detection limits 5 p.p.m. of dry matter are obtained for most elements with atomic number >14 (silicon). Around 13 elements were found in concentrations above the detection limits. The grand means for non-fixed hippocampi were e.g. for Zn–120 p.p.m.; Rb–20 p.p.m.; Fe–150 p.p.m.; Pb–3 p.p.m.; Ni–5 p.p.m. 相似文献
20.
Mark Deakin 《The International Journal of Life Cycle Assessment》1999,4(2):87-93
Previous editions of this Journal have drawn attention to the critical role valuation plays in life cycle analysis and environmental impact assessment (see for exampleVolkwkin andKlöpffer |1|). In particular, the critical role of valuation has heen highlighed in a number of discussions on ‘valuation step’ within life cycle costing, ‘hedonic and contingency’ assessments of environmental impact and both the utility and welfare of ‘pathway’ analysis/assessment (Krkwitt, Mayerhofer, Trukenmüller andFriedrich, 1998;Powell, Pearce andCraighill, 1997;Volkwein, On in andKlöpffer, 1996 |2-4|). Focusing on the utility of market valuation, this paper examines the critique of discounting environmentalists have made in relation to property valuation, investment appraisal and the application of the principle in the income based net annual return model of land use time-horizons and the spatial configuration of building programmes-a criticism implict in ‘valuation step’, ‘hedonic, contingency’ and ‘pathway’ analysis/assessments. It examines the argument put forward regarding the link between the selection of a discount rate, the valuation of property, appraisal of investment and inter-generational downloading of costs associated with the use of land, repair, maintenance and refurbishment of buildings: the downloading of costs, seen by some, to have an adverse impact and work against the introduction of experimental designs aimed at energy saving, clean air environments. 相似文献