首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 531 毫秒
1.
It is becoming more common now to use atmospheric dispersion models to predict where odour nuisance is likely to occur near pig units. An odour threshold concentration of 1 OuE m(-3) is the level at which an odour is detectable by 50% of screened panellists. A new odour annoyance criterion (C(98,1-h) (98%-ile, 1-h average odour concentration) < or = 4.3 OuE m(-3)) was developed in this study and compared to the Environmental Protection Agency (EPA) (Ireland) recommendation (C(98,1-h)< or = 6 OuE m(-3)) using the ISCST3 model with data from three meteorological stations. Abatement techniques such as exhaust vent modification, feed manipulation, and biofiltration were assessed. Based on current limits (C(98,1-h)< or = 6 OuE m(-3)) for existing facilities, predicted setback distances can be up to 780 m for a 1000-sow unit, depending on which meteorological data set is used. However, if using the suggested odour impact criterion in this research (C(98,1-h)< or = 4.3 OuE m(-3)), setback distances could reach a maximum of 1000 m. Biofilters on second stage weaning and finishing pig buildings offer the greatest single reduction (up to 650 m) in odour impact. When combined with feed manipulation and increased exhaust air velocity, the figure can be as high as 920 m. Due to the critical requirement for local meteorological data, it is recommended that a meteorological station be installed on large pig units to facilitate more accurate predictions. Site measurements of odour emissions should be made in each case because emissions are influenced by a range of local factors including feed, manure management, building design and operation.  相似文献   

2.
Odour and ammonia emissions from intensive poultry units in Ireland   总被引:3,自引:0,他引:3  
Odour and ammonia emissions were measured from three broiler, two layer and two turkey houses in Ireland. The broiler units gave a large range of odour and ammonia emission rates depending on the age of the birds and the season. A considerable variation between the odour and ammonia emission rates was evident for the two layer units which may have been due to the different manure handling systems utilised in the houses. There was relatively little difference in the odour and ammonia emissions from the two turkey houses. As a precautionary principle, odour emission rates utilised in atmospheric dispersion models should use the maximum values for broilers and turkeys (1.22 and 10.5 ou(E) s(-1) bird(-1) respectively) and the mean value for the layers depending on the manure handling system used (0.47 or 1.35 ou(E) s(-1) bird(-1)).  相似文献   

3.
Odour and ammonia emissions from intensive pig units in Ireland   总被引:3,自引:0,他引:3  
Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples were collected on-site and analysed for odour concentration using an olfactometer. Ammonia concentrations in the exhaust ventilation air were measured using a portable sensor. The geomean odour emission rates over the four pig units were 17.2, 44.4, 4.3, 9.9 and 16.8 ou(E) s(-1) animal(-1) for dry sows, farrowing sows, first stage weaners, second stage weaners and finishers, respectively. The mean ammonia emission rates, measured at two of the units, were 12.1, 17.1, 1.4, 2.9 and 10.0 g d(-1) animal(-1) for dry sows, farrowing sows, first stage weaners, second stage weaners and finishers, respectively. In general, the odour and ammonia emission rates were comparable to those reported in literature, although some odour emission rate figures were noticeably lower for finishing pigs in this study. The variability in the data highlights the need for individual site assessment.  相似文献   

4.
Feed trials were carried out to assess the influence of crude protein content in finishing pig diets on odour and ammonia emissions. Eight pigs (4 boars and 4 gilts), average initial weight 70.8 kg (s.e. 3.167) were housed in two pens that were isolated from the rest of a pig house at University College Dublin Research Farm, Newcastle, Dublin, Ireland. Four diets containing 130, 160, 190 and 220 g x kg(-1) crude protein were fed during six four-week feeding periods (one treatment per room). The first week of the feeding periods served to allow odour build up in the pens and as a dietary adjustment period. The pens had partially slatted floors that were cleaned and had all the manure removed after each four-week period. Odour and ammonia concentrations were measured on days 9, 14, 16, 21 and 23 of each trial period. Odour samples were collected in Nalophan bags and analysed for odour concentration using an ECOMA Yes/No olfactometer. The odour threshold concentration was calculated according to the response of the olfactometry panel members and was displayed in Ou(E)m(-3), which referred to the physiological response from the panel equivalent to that elicited by 40 ppbv(-1) n-butanol evaporated in 1 m(3) of neutral gas. Ammonia concentrations in the ventilation air were measured using Dr?ger tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou(E)s(-1)animal(-1), respectively (P<0.01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou(E)s(-1)LU(-1), respectively (P<0.01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 3.11, 3.89, 5.89 and 8.27 g x d(-1)animal(-1), respectively (P0.05). Manipulation of dietary crude protein levels would appear to offer a low cost alternative, in relation to end-of-pipe treatments, for the abatement of odour and ammonia emissions from finishing pig houses.  相似文献   

5.
Eighteen domestic turkeys naturally infected with Leucocytozoon smithi Laveran & Lucet were maintained on restricted feeding schedules under conditions of either continuous light or natural light (light 13 h:darkness 11 h) photoperiods. Peripheral gametocyte numbers of L. smithi in all turkeys were determined every 2 h over a 36-h period. Peripheral gametocyte numbers of turkeys maintained under continuous light and restricted to either a 10-h feeding period (9:30 p.m. to 7:30 a.m.) once a day or a 2-h feeding period twice a day (7:30 a.m. to 9:30 p.m. and 7:30 p.m. to 9:30 p.m.) increased at or near the time of feed availability. Under natural photoperiod, gametocyte periodicity was not affected by restricting feed availability to the dark phase of the light-dark cycle. Mean parasite numbers were highest during the light phase when feed was not available, and lowest during the dark period when feed was accessible.  相似文献   

6.
Bovine jugular venous blood was collected, with and without heparin, and aliquoted into 140 12-ml tubes. Four subsamples (two heparinized and two coagulated) were centrifuged immediately (time zero) and plasma or serum was aspirated and stored at -20 degrees C. One-half of the remaining subsamples were stored at 4 degrees C and the other one-half at 25 degrees C (room temperature). At 1-h intervals (0 to 24 h), 6-h intervals (24 to 72 h) and at 96 and 120 h, four subsamples (heparinized and coagulated at both 4 degrees C and 25 degrees C) were centrifuged, plasma or serum was aspirated and stored at -20 degrees C. Whole blood incubation for 1 h at 25 degrees C reduced mean plasma and serum progesterone (P(4)) concentration (P<0.05). Similarly, whole blood incubation at 4 degrees C for 2 and 3 h, respectively, reduced mean plasma and serum P(4) concentration (P<0.05). No difference was found in mean P(4) concentration between plasma and serum samples harvested from whole blood incubated at 4 degrees C or 25 degrees C. Concentration of estradiol-17beta (E(2)) and estrone (E(1)) fluctuated over time, irrespective of holding temperature. There was a blood type, heparinized or coagulated, by time interaction (P<0.01) for both E(2) and E(1) concentrations It was concluded that incubation time and temperature between collection and centrifugation of bovine blood samples influenced the assayable P(4) concentration in both plasma and serum. In contrast, incubation temperature had no effect on assayable E(2) and E(1) concentrations, but assayable E(2) and E(1) over time were differentially affected, depending on whether plasma or serum was assayed.  相似文献   

7.
We investigated the validity of employing a fuzzy piecewise prediction equation (PW) [Gonzalez et al. J Appl Physiol 107: 379-388, 2009] defined by sweat rate (m(sw), g·m(-2)·h(-1)) = 147 + 1.527·(E(req)) - 0.87·(E(max)), which integrates evaporation required (E(req)) and the maximum evaporative capacity of the environment (E(max)). Heat exchange and physiological responses were determined throughout the trials. Environmental conditions were ambient temperature (T(a)) = 16-26°C, relative humidity (RH) = 51-55%, and wind speed (V) = 0.5-1.5 m/s. Volunteers wore military fatigues [clothing evaporative potential (i(m)/clo) = 0.33] and carried loads (15-31 kg) while marching 14-37 km over variable terrains either at night (N = 77, trials 1-5) or night with increasing daylight (N = 33, trials 6 and 7). PW was modified (Pw,sol) for transient solar radiation (R(sol), W) determined from measured solar loads and verified in trials 6 and 7. PW provided a valid m(sw) prediction during night trials (1-5) matching previous laboratory values and verified by bootstrap correlation (r(bs) of 0.81, SE ± 0.014, SEE = ± 69.2 g·m(-2)·h(-1)). For trials 6 and 7, E(req) and E(max) components included R(sol) applying a modified equation Pw,sol, in which m(sw) = 147 + 1.527·(E(req,sol)) - 0.87·(E(max)). Linear prediction of m(sw) = 0.72·Pw,sol + 135 (N = 33) was validated (R(2) = 0.92; SEE = ±33.8 g·m(-2)·h(-1)) with PW β-coefficients unaltered during field marches between 16°C and 26°C T(a) for m(sw) ≤ 700 g·m(-2)·h(-1). PW was additionally derived for cool laboratory/night conditions (T(a) < 20°C) in which E(req) is low but E(max) is high, as: PW,cool (g·m(-2)·h(-1)) = 350 + 1.527·E(req) - 0.87·E(max). These sweat prediction equations allow valid tools for civilian, sports, and military medicine communities to predict water needs during a variety of heat stress/exercise conditions.  相似文献   

8.
利用开顶箱薰气室,设置正常大气CO2浓度(350 μmol·mol-1)、高CO2浓度(700 μmol·mol-1)2个CO2水平和不施氮(0 g N·m-2)、中氮(5 g N·m-2)和高氮(15 g N·m-2)3个氮素水平,研究CO2浓度升高和氮肥施用对三江平原草甸小叶章生长的影响.结果表明:随着CO2浓度升高,小叶章物候期提前,其中抽穗期提前1~2 d,成熟期提前3 d;不施氮、中氮和高氮水平下, CO2浓度升高使小叶章的分蘖分别增加8.2%(P<0.05)、8.4%(P<0.05)和5.5%(P>0.05);在小叶章生长初期,CO2浓度升高对其生物量的增加有促进作用,拔节期和抽穗期小叶章地上生物量分别增加12.4%和20.9%(P<0.05);生长后期则对小叶章地下生物量的促进作用增大,腊熟期和成熟期的地下生物量分别增加20.5%和20.9% (P<0.05).小叶章生物量对高浓度CO2的响应与供氮水平有关,供氮充足条件下, 高浓度CO2对生物量的促进效应更大.  相似文献   

9.
Inhibition by light potentially influences the distribution of ammonia oxidizers in aquatic environments and is one explanation for nitrite maxima near the base of the euphotic zone of oceanic waters. Previous studies of photoinhibition have been restricted to bacterial ammonia oxidizers, rather than archaeal ammonia oxidizers, which dominate in marine environments. To compare the photoinhibition of bacterial and archaeal ammonia oxidizers, specific growth rates of two ammonia-oxidizing archaea (Nitrosopumilus maritimus and Nitrosotalea devanaterra) and bacteria (Nitrosomonas europaea and Nitrosospira multiformis) were determined at different light intensities under continuous illumination and light/dark cycles. All strains were inhibited by continuous illumination at the highest intensity (500 μE m(-2) s(-1)). At lower light intensities, archaeal growth was much more photosensitive than bacterial growth, with greater inhibition at 60 μE m(-2) s(-1) than at 15 μE m(-2) s(-1), where bacteria were unaffected. Archaeal ammonia oxidizers were also more sensitive to cycles of 8-h light/16-h darkness at two light intensities (60 and 15 μE m(-2) s(-1)) and, unlike bacterial strains, showed no evidence of recovery during dark phases. The findings provide evidence for niche differentiation in aquatic environments and reduce support for photoinhibition as an explanation of nitrite maxima in the ocean.  相似文献   

10.
An electronic-topological approach has been used to define an active ambergris fragment (AAF) which correctly describes the presence (or absence) of the ambergris odour of all 181 compounds investigated. The AAF consists of one oxygen atom and three carbon atoms (alpha, beta, gamma) which are separated by certain key distances and which possess certain atomic charges. The C(alpha) atom must bear at least one hydrogen atom (H(alpha)) which is located at a certain distance from one of the unshared electronic pairs of the oxygen atom.  相似文献   

11.
Latent heat loss of dairy cows in an equatorial semi-arid environment   总被引:1,自引:0,他引:1  
The present study aimed to evaluate evaporative heat transfer of dairy cows bred in a hot semi-arid environment. Cutaneous (E(S)) and respiratory (E(R)) evaporation were measured (810 observations) in 177 purebred and crossbred Holstein cows from five herds located in the equatorial semi-arid region, and one herd in the subtropical region of Brazil. Rectal temperature (T(R)), hair coat surface temperature (T(S)) and respiratory rate (F(R)) were also measured. Observations were made in the subtropical region from August to December, and in the semi-arid region from April to July. Measurements were done from 1100 to 1600 hours, after cows remained in a pen exposed to the sun. Environmental variables measured in the same locations as the animals were black globe temperature (T(G)), air temperature (T(A)), wind speed (U), and partial air vapour pressure (P(V)). Data were analysed by mixed models, using the least squares method. Results showed that average E(S) and E(R) were higher in the semi-arid region (117.2 W m(-2) and 44.0 W m(-2), respectively) than in the subtropical region (85.2 W m(-2) and 30.2 W m(-2), respectively). Herds and individual cows were significant effects (P < 0.01) for all traits in the semi-arid region. Body parts did not affect T(S) and E(S) in the subtropical region, but was a significant effect (P < 0.01) in the semi-arid region. The average flank T(S) (42.8°C) was higher than that of the neck and hindquarters (39.8°C and 41.6°C, respectively). Average E(S) was higher in the neck (133.3 W m(-2)) than in the flank (116.2 W m(-2)) and hindquarters (98.6 W m(-2)). Coat colour affected significantly both T(S) and E(S) (P < 0.01). Black coats had higher T(S) and E(S) in the semi-arid region (41.7°C and 117.2 W m(-2), respectively) than white coats (37.2°C and 106.7 W m(-2), respectively). Rectal temperatures were almost the same in both subtropical and semi-arid regions. The results highlight the need for improved management methods specific for semi-arid regions.  相似文献   

12.
徐建雄  王晶  王恬 《应用生态学报》2007,18(8):1789-1793
选用200羽14日龄健康AA肉鸡,以电子自旋共振(ESR)捕集法和生物化学法对肉仔鸡血液和组织器官的不同自由基进行直接或间接测定,探讨VE和Se对肉鸡不同自由基代谢的作用及其动态变化.结果表明:组织一氧化氮(NO)自由基水平随日粮VE含量升高而降低,二者呈负相关关系,日粮高水平Se有诱导产生NO自由基的倾向;高VE和Se日粮显著提高血清和肝脏中SOD和GSH-Px的活性,但随处理时间的延长,组织SOD活性逐渐降低,而GSH-Px活性逐渐升高,说明日粮VE和/或Se不足均会诱导机体产生O.2-、H2O2自由基,且O2.-自由基会持续大量产生,而H2O2自由基仅在缺乏初期大量产生,而后趋于缓和;低VE和/或低Se均显著提高组织MDA含量,且低Se比低VE更为显著.VE和Se对肉鸡NO、O.2-和H2O2自由基代谢的作用存在协同效应.  相似文献   

13.
AIMS: To apply the real-time Polymerase chain reaction (PCR) method to detect and quantify Escherichia coli O157:H7 in soil, manure, faeces and dairy waste washwater. METHODS AND RESULTS: Soil samples were spiked with E. coli O157:H7 and subjected to a single enrichment step prior to multiplex PCR. Other environmental samples suspected of harbouring E.coli O157:H7 were also analysed. The sensitivity of the primers was confirmed with DNA from E.coli O157:H7 strain 3081 spiked into soil by multiplex PCR assay. A linear relationship was measured between the fluorescence threshold cycle (C T ) value and colony counts (CFU ml(-1)) in spiked soil and other environmental samples. The detection limit for E.coli O157:H7 in the real-time PCR assay was 3.5 x 10(3) CFU ml(-1) in pure culture and 2.6 x 10(4) CFU g(-1) in the environmental samples. Use of a 16-h enrichment step for spiked samples enabled detection of <10 CFU g(-1) soil. E. coli colony counts as determined by the real-time PCR assay, were in the range of 2.0 x 10(2) to 6.0 x 10(5) CFU PCR (-1) in manure, faeces and waste washwater. CONCLUSIONS: The real-time PCR-based assay enabled sensitive and rapid quantification of E. coli O157:H7 in soil and other environmental samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The ability to quantitatively determine cell counts of E.coli O157:H7 in large numbers of environmental samples, represents considerable advancement in the area of pathogen quantification for risk assessment and transport studies.  相似文献   

14.
Biofiltration of n-butyric acid for the control of odour   总被引:3,自引:0,他引:3  
Odour control from pig production facilities is a significant concern due to increased public awareness and the development of more stringent legislation to control production. Although many technologies exist, biofiltration is still the most attractive due to its low maintenance and operating costs. One of the key odour components, n-butyric acid, was selected for a laboratory scale biofilter study. It was examined as a sole carbon substrate in order to investigate the effectiveness of biofiltration in reducing n-butyric acid concentration under different operating conditions using a moist enriched woodchip medium. Three superficial gas velocities; 38.2, 76.4, and 114.6 m x h(-1) were tested for n-butyric acid concentrations ranging from 0.13 to 3.1 g [n-butyric acid] m(-3) [air]. For superficial gas velocities 38.2, 76.4, and 114.6 m x h(-1), maximum elimination capacities (100% removal) of 148, 113 and 34.4 g x m(3) x h(-1), respectively, were achieved. Upon investigation of effective bed height, true elimination capacities (100% removal) of 230, 233 and 103 g x m(-3) x h(-1), respectively, were achieved at these superficial gas velocities. Averaged pressure drops for superficial gas velocities 38.2, 76.4, and 114.6 m x h(-1) were 30, 78 and 120 Pa, respectively. It was concluded that biofiltration is a viable technology for the removal of n-butyric acid from waste exhaust air, but near 100% removal efficiency is required due to the low odour detection threshold for this gaseous compound.  相似文献   

15.
The present study was initiated to gain insight into the way in which tsetse flies ( Glossina spp.) sense odours at different locations in odour plumes in both an open field and a wooded area.
We recorded the antennal responses (EAGs) from stationary living female G. pallidipes 15 m upwind and at various (60, 40, 20, 10, 5 and 1 m) distances downwind from a synthetic host odour source (containing 1-octen-3-ol, acetone and two phenols), in the natural habitat of the fly (Zimbabwe) using a portable electrophysiological device. Experiments were performed in a flat open area (an airstrip) and in riverine woodland. Differences between responses in different environments were determined by comparing various parameters of the EAGs (intermittency, frequency, amplitude, duration and rate of depolarization).
We found that a fly senses odours as puffs that, further downwind, contain less odour and pass less frequently. In an open field downwind from the source, tsetse perceive more olfactory information than upwind for only 10–20 m, whereas in woodland, olfactory responses remain higher and more frequent than upwind up to at least 60 m. In an open field, olfactory information rapidly increases when approaching the odour source from 20 m and in woodland from 5 m onwards.
It is proposed that averaging odour information over time may be of minor importance in long-range location of odour sources. The results suggest that tsetse may smell odour-baited targets from at least 60 m downwind and that the number of flies responding to and being caught by these baits may be higher in woodland than in an open field.  相似文献   

16.
The aim of this study was to establish validity of a 5-m multiple shuttle test (5-m MST) using indirect (criterion and construct) and direct measures of performance. For criterion validity, comparisons were made between data from established fitness tests and a 5-m MST. Construct validity was determined by comparing results from a 5-m MST with subjects of different playing abilities. Direct validity was determined by comparing values attained from a 5-m MST with data from a time-motion study of field hockey. For criterion validity, the strongest relationship existed between the 20-m MST (42.7 +/- 7.1 ml.kg(-1).min(-1)) and total distance from the 5-m MST (650.9 +/- 59.2 m; r = 0.92). For construct validity, regional representative players covered more distance than club-level players (689.9 +/- 46.6 m vs. 661.1 +/- 31.0 m; p < 0.01). For direct validity, the highest correlation was found between total distance from the 5-m MST (706.0 +/- 37.5 m) and mean displacement during matches (61.0 +/- 6.0 m; r = 0.74). It was concluded that the 5-m MST had both indirect and direct validity for the fitness assessment of field hockey players. The data obtained from the 5-m MST directly relates to the physical fitness of the players during competition.  相似文献   

17.
Electricity generation integrated with xylose degradation was investigated in a two-chamber mediator-less microbial fuel cell (MFC). Voltage output followed saturation kinetics as a function of xylose concentration for concentration below 9.7 mM, with a predicted maximum of 86 mV (6.3 mW m(-2) or 116 mW m(-3)) and half-saturation constant (K(s)) of 0.29 mM. Xylose concentrations from 0.5 mM to 1.5 mM resulted in coulombic efficiencies and maximum voltage ranging from 41+/-1.6% to 36+/-1.2% and 55+/-2.0 mV to 70+/-3.0 mV respectively. Xylose degradation rate increased with increasing xylose concentration up to 9.7 mM and the predicted maximum degradation rate was 0.13 mM h(-1) and K(s) of 3.0 mM. Stirring by nitrogen in the anode chamber led to 99+/-2.3 mV maximum voltage (8.4+/-0.4 mW m(-2) or 153+/-7.1 mW m(-3)) and 5.9+/-0.3% coulombic efficiency at MFC running time 180 h, which were respectively 17+/-1.2% and 37+/-1.8%, higher than those without stirring. The COD removal under stirring was 22.1+/-0.3%, which was slightly lower than that of 23.7+/-0.4% under no stirring. However, stirring resulted in 59% lower xylose degradation rate. This work demonstrates that xylose can be used in the MFC for electricity production. Comparatively higher electricity generation and coulombic efficiency can be obtained by adjusting initial xylose concentration and applying stirring in the anode chamber.  相似文献   

18.
The kinetic constants for an alkaline protease from Bacillus mojavensis were determined using a central composite circumscribed design (CCCD) where concentration of substrate (casein) and the assay temperature were varied around their center point. The K(m),V(max), K(cat), activation energy (E(a)) and temperature coefficient (q(10)) were determined and the values of these kinetic constants obtained were found comparable to that obtained with conventional methods. The Michaelis-Menten constant (K(m)) for casein decreased with corresponding increase in V(max), as reaction temperature was raised from 45-60 degrees C. The protease exhibited K(m) of 0.0357 mg/ml, 0.0270 mg/ml, 0.0259 mg/ml, and 0.0250 mg/ml at 45, 50, 55, and 60 degrees C, respectively, whereas V(max) values at these temperatures were 74.07, 99.01, 116.28, and 120.48 microg/ml/min, respectively, as determined by response surface methodology. The Arrhenius plot suggested that the enzyme undergoes thermal activation above 45 degrees C until 60-65 degrees C followed by thermal inactivation. Likewise, the energy of activation (E(a)) was more between 45-55 degrees C (9747 cal/mol) compared to E(a) between 50-60 degrees C (4162 cal/mol).  相似文献   

19.
Abstract The wing-fanning activation response of male Oriental fruit moths (OFM), Grapholita molesta (Busck), in the field to the three-component pheromone containing the female-produced ratio of components (Z8-12:OAc + 6% E8-12:OAc + 3% Z8-12:OH) was compared with the response to blends containing 2,10 and 20% E with 3% OH, and the 6% E blend containing 30 and 100% OH. Comparisons were made over three temperature ranges: 15–17, 20–21 and 26–28oC. Both the maximum response distance and male response specificity were significantly altered by changes in odour quality as well as temperature. For blends containing different Z/E ratios the maximum response distance increased significantly with temperature. Response specificity was most pronounced at the 20–21oC range, with males displaying a lower threshold for the natural 6% E ratio, evidenced by the fact that fewer males responded and at closer distances to the source with off-ratios. At 26–28oC response specificity for the Z/E ratios was much reduced, primarily due to more males activating to off-ratios. With blends containing different proportions of Z8-12:OH in the 6% E blend, increasing temperature increased the maximum response distance for all treatments, but in addition increasing the proportion of OH alone from 3% to 30% significantly increased the maximum response distance over the three temperature ranges tested. This increase occurred without affecting the proportion of responders or the distribution of response distances around the mean value. However, with 100% OH added to the blend, whereas male response was high at 20–21oC, the distribution of response distances was significantly more variable than with 3% or 30%, and male response was eliminated or very low at 15–17oC and 26–28oC. Our results support previous studies showing that peak response levels in this species are dependent on male perception of the natural blend of components, and that males have a high degree of specificity for the qualitative properties of the pheromone. However, the present results also extend those of previous flight tunnel tests in which response specificity was most pronounced in the upwind flight phase of the sequence, by showing that male OFM also display a  相似文献   

20.
Kertesz N  Samson J  Debacker C  Wu H  Labastie MC 《Gene》2002,292(1-2):13-24
Topography of three genetic elements--dystrophin (dmd) exons 5-7 (E(1)), 46-47 (E(2)), and centromere of chromosome X (N(X)) were studied relative to cell nuclei and to chromosome X territories of spatially fixed human lymphocytes. Repeated three-dimensional (3D) dual color fluorescence in situ hybridization combined with high-resolution cytometry was used. In addition, the nuclear location of fluorescence weight centers (FWC), spatial volume, and maximal area per one section of chromosome-X territories were investigated. The larger (X(L)) and smaller (X(S)) homologous X-chromosomes were distinguished for each nucleus according to the 3D volume of their territories. The distributions of the [center of nucleus]-to-[genetic element] distances (radial distributions) of dmd exons E(1), E(2), centromere N(X) and FWC were very similar for both homologous X-chromosomes of female lymphocytes as well as for the chromosome X of the human male. On the other hand, larger average mutual distances between all pairs of signals (E(1), E(2), N(X), FWC) and larger average maximal area were observed for the larger chromosome (X(L)) in comparison with the smaller one (X(S)). The territory of the larger homologue showed also more irregular surface. The most significant differences between homologous X-chromosomes were found for N(X)-E(1), N(X)-E(2) and E(1)-E(2) distances that were in average about twice longer for X(L) as compared with X(S). These parameters correlate to each other and can be used for the reliable determination of more (de)condensed X-chromosome territory. The longer E(1)-E(2) distances for X(L) indicate more open chromatin structure of the dystrophin gene on this chromosome in contrary to closed structure on X(S). Substantially shorter distances of the dystrophin exons from the centromeric heterochromatin in X(S) as compared to X(L) can be explained by silencing effect of centromeres as described in Nature 1 (2000) 137.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号