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1.
( ? )-Meptazinol is an analgesic with an additional acetylcholinesterase (AChE) inhibitory activity. In order to investigate the formation mechanism of its biological conformation observed in AChE-bis( ? )-meptazinol complex, two different and naturally stable conformers of ( ? )-meptazinol hydrochloride in solution were determined and identified by nuclear magnetic resonance (NMR) and molecular dynamic simulations. Moreover, ab initio calculations and NMR evidence showed the difficulties in conformer interconversion. In combination with the results of conformational comparison, it was proposed that the pharmacophoric conformer of ( ? )-meptazinol might come from the conformer with less favourable energy rather than the conformer with the lowest energy.  相似文献   

2.
The vapor–liquid coexistence curve of the simple point charge heavy-water model (SPC-HW), [J. Chem. Phys., 114, 8064–8067 (2001)] is determined by Gibbs Ensemble Monte-Carlo (GEMC) simulation. The estimated critical conditions of the model based on the Wegner-type expansion for the order parameters and the rectilinear diameter are ρc = 0.300 g/cc, T c = 661 K and P c = 156 bars. The dielectric constant determined by isothermal–isochoric molecular dynamics is underpredicted along the coexistence curve by 29–44% in comparison with the experimental values. The analysis of the orthobaric temperature dependence of the system microstructure, in terms of the three site–site radial distribution functions, indicates that the first coordination numbers for the oxygen–oxygen and the oxygen–deuterium interactions are ~4.3 ± 0.1 and ~1.9 ± 0.1 at T = 300 K, and decrease by 15 and 55%, respectively, at criticality. The dipole–dipole correlation functions show that the orientational order in heavy water is quickly lost beyond the first oxygen–oxygen coordination shell. The model's second virial coefficient is determined by Monte-Carlo integration and used to aid the interpretation of the predicted phase equilibrium results.  相似文献   

3.
Seed dynamics are an important part of the life history of plants and may have strong implications on abundance and spatial distribution of populations. In this study, we explored how seed dynamics (removal, predation, germination) interact with micro-environmental conditions to affect the spatial structure of populations of Brahea aculeata (Arecaceae) in a tropical dry forest. B. aculeata is distributed throughout arroyo basins and attains its highest densities near to arroyos/rivers. We hypothesized that: (i) seed removal, predation and germination vary across topographic positions resulting in greater palm abundances adjacent to arroyos and (ii) seed removers/predators respond to both a seed density-dependent effect and a microclimate effect. To test this, in six arroyos basins, seeds were sown across three topographic positions (stream, mid and top of basins) with two seed abundances (1 and 10), protected and non-protected from potential predators. Predation, removal and germination were then followed. After 107 days, 100 % of the exposed seeds were removed/predated and none germinated. For seed removal, we found differences among topographic positions and seed densities with higher removal (up to 80 %) and lower predation rates for grouped seeds. Germination was only observed for protected seeds with higher germination rates in single (17 % ± 9) than in grouped seeds (4 % ± 1). The highest germination and establishment rates were adjacent to the streams; areas which had the lowest light intensity (mean ± SE = 883 ± 160 lm/ft2) and temperatures (mean ± SE = 20.1 ± 0.6 °C), and highest humidity (mean ± SE = 50.8 ± 1.8 %), especially during the rainy season. Differential seedling establishment rates across the landscape due to spatial patterns of seed predation/removal as well as micro-environmental variables appear to have implications for shaping the spatial structure of B. aculeata population at Sierra de Álamos, Mexico.  相似文献   

4.
To provide an in-depth insight into the molecular basis of spontaneous tautomerism in DNA and RNA base pairs, a hybrid Monte Carlo (MC)–quantum chemical (QC) methodology is implemented to map two-dimensional potential energy surfaces along the reaction coordinates of solvent-assisted proton transfer processes in guanosine and its analog acyclovir in aqueous solution. The solvent effects were simulated by explicit inclusion of water molecules that model the relevant part of the first hydration shell around the solute. The position of these water molecules was estimated by carrying out a classical Metropolis Monte Carlo simulation of dilute water solutions of the guanosine (Gs) and acyclovir (ACV) and subsequently analyzing solute–solvent intermolecular interactions in the statistically-independent MC-generated configurations. The solvent-assisted proton transfer processes were further investigated using two different ab initio MP2 quantum chemical approaches. In the first one, potential energy surfaces of the ‘bare’ finite solute–solvent clusters containing Gs/ACV and four water molecules (MP2/6-31+G(d,p) level) were explored, while within the second approach, these clusters were embedded in ‘bulk’ solvent treated as polarizable continuum (C-PCM/MP2/6-31+G(d,p) level of theory). It was found that in the gas phase and in water solution, the most stable tautomer for guanosine and acyclovir is the 1H-2-amino-6-oxo form followed by the 2-amino-6-(sZ)-hydroxy form. The energy barriers of the water-assisted proton transfer reaction in guanosine and in acyclovir are found to be very similar – 11.74 kcal mol?1 for guanosine and 11.16 kcal mol?1 for acyclovir, and the respective rate constants (k = 1.5?×?101 s?1, guanosine and k = 4.09?×?101 s?1, acyclovir), are sufficiently large to generate the 2-amino-6-(sZ)-hydroxy tautomer. The analysis of the reaction profiles in both compounds shows that the proton transfer processes occur through the asynchronous concerted mechanism.  相似文献   

5.
Invasive species frequently degrade habitats, disturb ecosystem processes, and can increase the likelihood of extinction of imperiled populations. However, novel or enhanced functions provided by invading species may reduce the impact of processes that limit populations. It is important to recognize how invasive species benefit endangered species to determine overall effects on sensitive ecosystems. For example, since the 1990s, hybrid Spartina (Spartina foliosa × alterniflora) has expanded throughout South San Francisco Bay, USA, supplanting native vegetation and invading mudflats. The endangered California clapper rail (Rallus longirostris obsoletus) uses the tall, dense hybrid Spartina for cover and nesting, but the effects of hybrid Spartina on clapper rail survival was unknown. We estimated survival rates of 108 radio-marked California clapper rails in South San Francisco Bay from January 2007 to March 2010, a period of extensive hybrid Spartina eradication, with Kaplan–Meier product limit estimators. Clapper rail survival patterns were consistent with hybrid Spartina providing increased refuge cover from predators during tidal extremes which flood native vegetation, particularly during the winter when the vegetation senesces. Model averaged annual survival rates within hybrid Spartina dominated marshes before eradication (? = 0.466) were greater than the same marshes posttreatment (? = 0.275) and a marsh dominated by native vegetation (? = 0.272). However, models with and without marsh treatment as explanatory factor for survival rates had nearly equivalent support in the observed data, lending ambiguity as to whether hybrid Spartina facilitated greater survival rates than native marshland. Conservation actions to aid in recovery of this endangered species should recognize the importance of available of high tide refugia, particularly in light of invasive species eradication programs and projections of future sea-level rise.  相似文献   

6.
Although spiny rock lobster (Jasus edwardsii) is a wholly sub-littoral species, they show a considerable ability to survive prolonged emersion, a fact exploited during the commercial export of this species. Yet, despite this remarkable hardiness, basic information on how this species responds physiologically to emersion is somewhat lacking. Using flow-through respirometry and electrophysiological techniques, we identified that J. edwardsii undergoes marked physiological changes during rest, emersion and recovery over a broad range of temperatures (3.7–17.8 °C). Under resting conditions, routine metabolic rates (RMR) were 22.57 ± 2.39, 9.69 ± 0.55 and 8.09 ± 0.27 mL O2 h?1, average heart rates (Hr) were 54.72 ± 4.46, 37.68 ± 2.86 and 29.67 ± 0.59 BPM, and ventilation frequencies were 83.71 ± 5.86, 45.34 ± 2.91 and 41.62 ± 0.65 BPM at 15.0, 7.5 and 3.7 °C, respectively. Notably, the surgical implantation of electrodes elevated RMR compared with non-surgical treatments. In surgery and non-surgery groups, Q 10 was calculated to be ca. 3.0. Upon emersion, rate of oxygen consumption and Hr decreased below resting rates in a temperature-dependent manner, but, along with rate of CO2 production, increased steadily during 24-h emersion. Ventilation frequencies upon emersion showed a contrasting response and increased significantly above resting rates. When returned to flow-through sea water for recovery, elevated respiration rates provided clear evidence of an O2 debt, and near-complete recovery was observed after 17 h at both 15.0 and 7.5 °C, but close to no debt was recovered at 3.7 °C. In addition, J. edwardsii was observed to undergo marked diurnal and periodic ventilation cycles, characterised by synchronous changes in RMR, Hr and ventilation frequency.  相似文献   

7.
Hybridization between introduced and related native species has been suggested to be a key driving force of evolutionary processes in invasions that may be accelerated by increasing nitrogen (N) deposition. We carried out two experiments to compare the competitive ability of a newly-reported putative hybrid (Sphagneticola calendulacea × Sphagneticola trilobata) to that of its invasive paternal parent and investigate its response to different N additions. Growth of the hybrid increased by 39.62 ± 15.69 % when grown with the native parent but showed no significant changes when grown with the invasive parent. Growth of invasive S. trilobata showed no significant changes when grown with the other two taxa. The hybrid and invasive parent inhibited the growth of the native parent by 33.27 ± 15.26 % and 78.56 ± 3.13 %, respectively. Low level N addition (50 kg N ha?1) enhanced the growth of both the hybrid and native parent, whereas medium and high levels of N additions (150, 300 kg N ha?1) had no effects on hybrid growth but decreased native parent growth. However, all N treatments had no significant effects on the growth of the invasive parent. Our results suggest that the hybrid is an equal competitor to its invasive parent and is more susceptible to N deposition. Therefore, this hybrid could be a threat to native diversity but may decline more than the invasive parent under high N conditions.  相似文献   

8.
ABSTRACT

All eight stereoisomers of conidendrin were synthesized from (1 R,2 S,3 S)-1-(4-benzyloxy-3-methoxyphenyl)-3-(4-benzyloxy-3-methoxybenzyl)-2- hydroxymethyl-1,4-butanediol ((+)-4) and its enantiomer with high optical purity. The configurations at 4-positions of the conidendrin stereoisomers were constructed by intramolecular Friedel-Crafts reaction of protected 4. After conversion to tetrahydronaphthalene intermediate 7a, the 2- and 3-position of tetrahydronaphthalene structure 7a were converted to 3a- and 9a-position of (+)-α-conidendrin (3a), respectively. By the epimerization process of 2- or 3-position of 7a, the other diastereomers were obtained. All enantiomers were also synthesized from (?)-4.  相似文献   

9.
Increased sea level is the climate change effect expected to have the greatest impact on mangrove forest survival. Mangroves have survived extreme fluctuations in sea level in the past through sedimentation and belowground carbon (C) accumulation, yet it is unclear what factors may influence these two parameters. We measured sedimentation, vertical accretion, and belowground C accumulation rates in mangrove forests from the Republic of Palau and Vietnam to examine how diversity (high-Vietnam vs. low-Palau), land use, and location (fringe vs. interior) might influence these parameters. Land use in this study was identified as disturbance and restoration for all mangrove forests sampled in Palau and Vietnam, respectively. Vertical accretion rates were significantly greater in Vietnam (2.44 ± 1.38 cm/year) than Palau mangrove forests (0.47 ± 0.08 cm/year; p < 0.001, F1,17 = 24.96). Vertical accretion rates were positively correlated to diversity (R = 0.43, p < 0.05). However, stronger correlations of accretion to bulk density (R = 0.64, p < 0.01) and significantly higher bulk densities in Vietnamese (0.67 ± 0.04 g/cm3) than Palau mangroves (0.30 ± 0.03 g/cm3; p < 0.001, F1,17 = 54.4) suggests that suspended sediments played a greater role in mangrove forest floor maintenance relative to sea level rise. Average vertical accretion rates were similar between naturally colonized (1.01 ± 0.10 cm/year) and outplanted sites (1.06 ± 0.05 cm/year) and between fringe (1.06 ± 0.12 cm/year) and interior mangrove (0.99 ± 0.09 cm/year) in Vietnam. In Palau, vertical accretion rates did not differ between disturbed (0.42 ± 0.11 cm/year) and undisturbed (0.51 ± 0.13 cm/year) mangrove forests and were higher in fringe (0.61 ± 0.15 cm/year) than interior sites (0.33 ± 0.09 cm/year; p = 0.1, F1,7 = 3.45). Belowground C accumulation rates did not differ between any factors examined. C accumulation rates (69–602 gC/m2/year) were similar to those reported elsewhere in the literature and suggest that intact coastal ecosystems play an important role in the global C cycle, sequestering C at rates that are 10–20× greater than upland forests. Assuming vertical accretion rates measured using 210Pb are an effective proxy for surface elevation, the Vietnamese and Palauan mangroves appear to be keeping up with current rates of sea level rise.  相似文献   

10.
Abstract

The molecular dynamics simulation has been performed to investigate the charge distribution, structural and dynamical properties of liquid ammonia at 273 K using a polarisable force field of the atom-bond electronegativity equalisation method (ABEEMσπ). One ammonia molecule in this model has eight charge sites, one N atomic site, three H atomic sites, three N–H bond sites and one lone-pair electron site. ABEEMσπ model can present the quantitative site charges of molecular ammonias in liquid and their changing in response to their surroundings. The radial distribution functions and dynamical properties are in fair agreement with the available experimental data. The first peak of gNN(r) appears at N–N distance of ~3.50 ± 0.05 Å where most hydrogen bonds are formed. The average coordination number of the first shell is 13.0 ± 0.1 among which a central ammonia molecule intimately connects 3 ~ 4 ammonia molecules by hydrogen bonds. The power spectrum shows the vibrations of hydrogen bonds. For a reference, a simple estimation of the average hydrogen bonding energy in liquid ammonia is 6.5 ± 0.1 kcal/mol larger than 3.8 ± 0.3 kcal/mol in dimer ammonia. Our simulation results provide more detailed information about liquid ammonia.  相似文献   

11.
Muchimangins are benzophenone-xanthone hybrid polyketides produced by Securidaca longepedunculata. However, their biological activities have not been fully investigated, since they are minor constituents in this plant. To evaluate the possibility of muchimangins as antibacterial agent candidates, five muchimangin analogs were synthesized from 2,4,5-trimethoxydiphenyl methanol and the corresponding xanthones, by utilizing p-toluenesulfonic acid monohydrate for the Brønsted acid-catalysis. The antibacterial assays against Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, and Gram-negative bacteria, Klebsiella pneumoniae and Escherichia coli, revealed that the muchimangin analogs (±)-1,3,6,8-tetrahydroxy-4-(phenyl-(2′,4′,5′-trimethoxyphenyl)methyl)-xanthone (1), (±)-1,3,6-trihydroxy-4-(phenyl-(2′,4′,5′-trimethoxyphenyl)methyl)-xanthone (2), and (±)-1,3-dihydroxy-4-(phenyl-(2′,4′,5′-trimethoxyphenyl)methyl)-xanthone (3) showed significant activities against S. aureus, with MIC values of 10.0, 10.0, and 25.0 μM, respectively. Analogs (±)-1 and (±)-2 also exhibited antibacterial activities against B. subtilis, with MIC values of 50.0 and 12.5 μM, respectively. Furthermore, (+)-3 enhanced the antibacterial activity against S. aureus, with a MIC value of 10 μM.  相似文献   

12.
We constructed nitrogen (N) budgets for the lawns of three simulated residences built to test the environmental impacts of three different residential landscape designs in southern California. The three designs included: a “Typical” lawn planted with cool season tall fescue (Schedonorus phoenix), fertilized at the recommended rate for this species (192 kg?1 ha?1 year?1) and irrigated with an automatic timer; a design intended to lower N and water requirements (“Low Input”) with the warm season seashore paspalum (Paspalum vaginatum) fertilized at 123 kg?1 ha?1 year?1 and irrigated with a soil moisture-based system; and a design incorporating local best practices (“Low Impact” lawn) that included the native sedge species Carex, fertilized at 48 kg?1 ha?1 year?1 and irrigated by a weather station-based system. Plant N uptake accounted for 33.2 ± 0.5 (tall fescue), 53.7 ± 0.7 (seashore paspalum), and 12.2 ± 1.3 % (Carex) of annual N inputs, while estimated N retention in soil was relatively large and similar in the three lawns (41–46 %). At lower N and water inputs than Typical, Low Input showed the highest annual clipping yield and N uptake, although it also had higher denitrification rates. Leaching inorganic N losses remained low even from the Typical lawn (2 %), while gaseous N losses were highly variable. The Low Input lawn was most efficient in retaining N with relatively low water and N costs, although its fertilization rates could be further reduced to lower gaseous N losses. Our results suggest that the choice of a warm-season, C4 turf species with reduced rates of irrigation and fertilization is effective in this semi-arid region to maintain high productivity and N retention in plants and soils at low N and water inputs.  相似文献   

13.
The aim of the present experiment was to investigate an experimental brown midrib (Bm) maize hybrid in comparison with a control (Con) non-Bm maize hybrid on ruminal and total tract digestibility, ruminal fermentation, ruminal ingesta kinetics, nitrogen (N) utilisation and microbial efficiency. A total of six ruminally and duodenally cannulated German Holstein cows were used. Animals were fed diets of either 11.5 kg dry matter (DM) of a Con or a Bm maize silage plus 4.1 kg DM of concentrate. Ruminal and total tract digestibility of organic matter, neutral detergent fibre and acid detergent fibre did not differ between hybrids. Short-chain fatty acid concentrations and pH in the rumen were not affected, but ruminal mean retention time was lower for Diet Bm (Con: 45.4 ± 2.39 h; Bm: 40.6 ± 2.39 h; least squares means ± standard error). Cows fed Diet Bm had greater efficiency of N utilisation (Con: 30.1 ± 1.37%; Bm: 33.1 ± 1.37%) and increased flow of microbial crude protein at the duodenum (MCPF) (Con: 7.0 ± 0.37 g/MJ metabolisable energy (ME); Bm: 8.1 ± 0.37 g/MJ ME). Thus, MCPF and utilisable crude protein at the duodenum (uCP) were greater for Diet Bm (MCPF – Con: 1117 ± 52.1 g/d; Bm: 1306 ± 52.1 g/d; uCP – Con: 1594 ± 57.9 g/d; Bm: 1807 ± 57.9 g/d) and ruminal N balance was lower for Diet Bm (Con: 98.7 ± 8.92 g/d; Bm: 65.6 ± 8.92 g/d). The present results show that the Bm maize hybrid might be advantageous for dairy cow nutrition with regard to N utilisation and MCPF. However, further research is necessary to draw more precise conclusions on the potential of Bm maize hybrids in general.  相似文献   

14.
Demographic parameters of Diuraphis noxia (Mordvilko) and its parasitoid, Diaeretiella rapae (McIntosh) were investigated under laboratory conditions at temperatures of 20 ± 1°C, 60 ± 5% relative humidity of 60 ± 5% and a photoperiod of 16: 8 (light: dark) hours. The survival rates (lx ) and the life expectancy (ex ) at the beginning of adult emergence were 86% and 25.81 days for D. noxia and 100% and 7.36 days for D. rapae, respectively. Based on the Weibull distribution parameters, the survival curves were type I for both D. noxia and D. rapae, which indicates that mortality mostly occurred in older stages. The r m-values in aphid and parasitoid were obtained as 0.22 ± 0.002 and 0.19 ± 0.003 day?1, respectively. Mean generation time (T) and doubling time (DT) were 15.93 ± 0.202 and 3.15 ± 0.031 days for the aphid and 15.33 ± 0.071 and 3.67 ± 0.054 days for the parasitoid, respectively. The R0 -values of D. noxia and D. rapae were evaluated 33.19 ± 0.961 and 18.07 ± 0.761 females/female/generation, respectively. The gross and net fecundity rates were 59.21 ± 1.94 and 32.825 ± 0.972 nymphs/female/day for the aphid and 37.59 ± 1.46, and 33.8 ± 1.51 eggs/female/day for the parasitoid, respectively. The results of this research indicated that D. rapae is an adequate parasitoid for control of Russian wheat aphid.  相似文献   

15.
The effects of two common West African farm-made feeds on postprandial metabolism were assessed in adult Nile tilapia (Oreochromis niloticus) by quantifying the oxygen consumption rates (MO2) and total ammonia-nitrogen (TAN) excretion over a 24-h period. Measurements followed the ingestion of a single meal of a fishmeal-based control diet and two diets containing 30% copra (CM) or palm kernel meal (PKM) inclusions by groups of 15 adult O. niloticus per tank. The mean net MO2 (postprandial oxygen consumption corrected for routine metabolic rate) during digestion for the different tilapia groups varied narrowly between 112.2 ± 9.9 and 129.9 ± 20.4 mg O2 kg?1 h?1 with the fish fed the CM diet recording a significantly lower (p = 0.04) net MO2 response relative to the other two diets. Net TAN excretion rates of the different dietary groups varied between 3.4 ± 1.4 and 4.4 ± 1.6 mg TAN kg?1 h?1. Under the standardized experimental conditions, copra and PKMs appeared to be promising candidates as partial replacements to fishmeal in tilapia diets as far as rates of oxygen consumption and ammonia-nitrogen excretion are concerned.  相似文献   

16.
The antidepressant drug tetramezine [1,2‐bis‐(3,3‐dimethyldiaziridin‐1‐yl)ethane] consists of two bridged diaziridine moieties with four stereogenic nitrogen centers, which are stereolabile and, therefore, are prone to interconversion. The adjacent substituents at the nitrogen atoms of the diaziridines moieties exist only in an antiperiplanar conformation, which results in a coupled interconversion. Therefore, three stereoisomers exist (meso form and two enantiomeric forms), which epimerize when the diaziridine moieties are regarded as stereogenic units due to the coupled interconversion. Here, we have investigated the epimerization between the meso and enantiomeric forms by dynamic gas chromatography. Temperature‐dependent measurements were performed, and reaction rate constants were determined using the unified equation of chromatography implemented in the software DCXplorer. The activation barriers of the epimerization were found to be ΔG = 100.7 kJ mol?1 at 25°C and ΔG = 104.5 kJ mol?1 at 37°C, respectively. The activation enthalpy and entropy were determined to be ΔH = 70.3 ± 0.4 kJ mol?1 and ΔS = ?102 ± 2 J mol?1 K?1. Chirality, 2011. © 2010 Wiley‐Liss, Inc.  相似文献   

17.
In the treatment of lifestyle diseases, including metabolic syndrome and type 2 diabetes, it is important to lower body mass and fat tissue, and consequently, to increase insulin-sensitivity. Unfortunately, it often happens that low-energy diet which would lower overweight is not observed and, thus, it does not bring the expected effects. This paper discusses the influence of three diets—control, high-fructose, and high-fatty diet—on absorption of energy from food in order to transform it into body mass. The kJ/g ratio which describes this process has been calculated. In the tested diets, the addition of fructose (79.13?±?2.47 kJ/g) or fat (82.48?±?2.28 kJ/g) results in higher transformation of energy into body mass than in the case of control diet (89.60?±?1.86 kJ/g). The addition of Na[VO(O2)2(4,4′-Me2-2,2′-bpy)]?8H2O (where 4,4′-Me2-2,2′-bpy?=?4,4′-dimethyl-2,2′-bipyridine) results in statistical increase of that ratio: fructose diet (86.88?±?0.44 kJ/g), fat diet (104.68?±?3.01 kJ/g), and control diet (115.98?±?0.56 kJ/g), respectively. Fat diet statistically influences the decrease of kidney mass in comparison to the other diets. The application of the tested vanadium compound results also in the statistical decrease of the fatty liver caused by fructose and fat diet.  相似文献   

18.
We compared the cytotoxic activities of dietary epoxylignans and their stereoisomers and found (?)-verrucosin, which is (7S,7′R,8R,8′R)-7,7′-epoxylignan, to be the most cytotoxic epoxylignan against HeLa cells (IC50 = 6.6 μM). On the other hand, the activity was about a factor of 10 less against HL-60. In this research on the relationship between the structure and cytotoxic activity of (?)-verrucosin 13, the 7-(4-methoxyphenyl)-7′-(3,4-dimethoxyphenyl) derivative 60, for which the activity (IC50 = 2.4 μM) is three times greater than (?)-verrucosin 13, was discovered. The induction of apoptosis by caspase 3/7 was observed upon treatment with the (?)-verrucosin derivative.  相似文献   

19.
Chrysoperla carnea (Steph.) is a general predator reared in industrial scale. Different eggs of moth were used to rear C. carnea, but stabled moth colony needed expensive equipment and is costly. In this research, we surveyed appropriate diet to mass rearing. For this purpose, 100 same old (24H) eggs of C. carnea, separately, were selected randomly from the mass culture of C. carnea which was reared on the egg of flour moth Anagasta kuehniella (Zeller), artificial diet and semi-artificial diet under laboratory conditions (25 ± 5°C, 65 ± 5% RH and L–D: 16–8). These results showed reduction process ex (expectation of life table at age X) and the survival curve was convex (K-Strategy). Also Lx in appearing of adults that fed on egg of flour moth, artificial diet and semi-artificial diet were 0.76, 0.4 and 0.9 which implied that 24, 60 and 10% of cohort were dead before reaching adult stage. Eggs produced by each female were recorded daily until all females died. The parameters were estimated using Carey’s (1993) method. Gross (GRR) and net (R0) reproductive rates of predator on A. kuehniella, artificial diet and semi artificial diets were 225.5 ± 3.45, 72.4 ± 3.5, 267.8 ± 4.8 and 180.12 ± 2.3, 24.33 ± 4.3, 254.05+3.3 (female/female/generation), respectively. Mean generation time (T), Doubling time (DT), Intrinsic rate of increase (rm ) and Finite rate of increase (λ) of predator on A. kuehniella, artificial diet and semi artificial diet were 31.9 ± 0.71, 42.87 ± 0.45, 29.79 ± 0.57 (days); 4.27 ± 0.03, 9.36 ± 0.06, 3.74 ± 0.05 (days); 0.162 ± 0.001, 0.074 ± 0.003, 1.185 ± 0.002; and 1.175 ± 0.001, 1.076 ± 0.002, 1.203 ± 0.002 (female/female/day), respectively. This research indicated that semi-artificial diet is a suitable prey for the predator.  相似文献   

20.
The aim of this study was to determine the effects of a caffeine-containing energy drink on physical performance during a rugby sevens competition. A second purpose was to investigate the post-competition urinary caffeine concentration derived from the energy drink intake. On two non-consecutive days of a friendly tournament, 16 women from the Spanish National rugby sevens Team (mean age and body mass = 23 ± 2 years and 66 ± 7 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink (Fure®, ProEnergetics) or the same drink without caffeine (placebo). After 60 min for caffeine absorption, participants performed a 15-s maximal jump test, a 6 × 30 m sprint test, and then played three rugby sevens games against another national team. Individual running pace and instantaneous speed during the games were assessed using global positioning satellite (GPS) devices. Urine samples were obtained pre and post-competition. In comparison to the placebo, the ingestion of the energy drink increased muscle power output during the jump series (23.5 ± 10.1 vs. 25.6 ± 11.8 kW, P = 0.05), running pace during the games (87.5 ± 8.3 vs. 95.4 ± 12.7 m/min, P < 0.05), and pace at sprint velocity (4.6 ± 3.3 vs. 6.1 ± 3.4 m/min, P < 0.05). However, the energy drink did not affect maximal running speed during the repeated sprint test (25.0 ± 1.5 vs. 25.0 ± 1.7 km/h). The ingestion of the energy drink resulted in a higher post-competition urine caffeine concentration than the placebo (3.3 ± 0.7 vs. 0.2 ± 0.1 μg/mL; P < 0.05). In summary, 3 mg/kg of caffeine in the form of a commercially available energy drink considerably enhanced physical performance during a women’s rugby sevens competition.  相似文献   

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