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1.
Capsule?House Sparrow (Passer domesticus) populations in south Swedish farmland are not affected by supplemental winter feeding, irrespective of agricultural landscape type or presence of animal husbandry, although winter populations declined more in mixed farmland and when farms contained animal husbandry.

Aims?To investigate whether food limitation of House Sparrow population size during the winter varied spatially in relation to agricultural landscape intensification and farm management.

Methods?We experimentally increased the winter food supply for populations on farmsteads in replicated landscapes that differed in agricultural intensification (open plains versus mixed farming) and/or farm management (crop farming versus animal husbandry), and estimated possible differences in effects on winter population change.

Results?We found no effect of supplementary winter feeding on changes in House Sparrow population sizes over the winter, irrespective of agricultural landscape type or presence of animal husbandry at the farm. However, we found a significantly larger winter population decline in mixed farmland and when farms contained animal husbandry.

Conclusions?The results suggest that House Sparrow populations in south Swedish farmland are not primarily limited by winter food availability. Alternatively, supplemental winter feeding may augment interspecific competition or attracts predators, offsetting any positive effect on population change. However, the stronger population decline in landscapes in which more breeding resources may be available (animal husbandry farms, mixed farmland), suggests stronger intraspecific competition during the winter in line with the resource separation hypothesis.  相似文献   

2.
Abstract

Green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a valuable bio-control agent that predates over various insect pests with high efficacy. It has developed considerable resistance to different classes of insecticides. This study was planned to investigate resistance level, stability and reversion rate against some new chemical insecticides using a field collected population of C. carnea. Field collected strain of C. carnea showed 313.44-fold, 216.50-fold and 276.83-fold resistance to imidacloprid, indoxacarb and chlorfenapyr compared to susceptible population, respectively. Baseline susceptibility values of C. carnea to imidacloprid, indoxacarb and chlorfenapyr were 2627.31, 502.10 and 581.89?ppm, while the insecticide resistance decrease rate was ?0.039, ?0.048 and ?0.040, respectively. Rotation of these insecticides requires quality measures maintaining survival of C. carnea in an intense environment where repeated applications are required to avoid economic damage by pests.  相似文献   

3.
Abstract

Efforts in improving banana plants that are resistant to the Fusarium wilt-causing Fusarium oxysporum f.sp. cubense tropical race 4 (Foc4) are indispensable. In this study, we developed rapid, space-efficient in vitro bioassay for assessing banana plant resistance to Foc4 using 35?×?150?mm glass test tubes, followed by quantitative and objective analysis of necrosis area and biomass changes as represented by fresh weight changes. Disease resistance screening was conducted based on the necrosis area as quantified using ImageJ software and on biomass gain during in vitro bioassay. In vitro banana plantlets showed age-related resistance during the development of necrosis (p?=?.034, Kruskal–Wallis test in root and shoot system and p?=?.027, one-way ANOVA in shoot system only), in which plantlets that were infected at the youngest age (24 weeks’ post-initiation) showed the largest necrosis area (up to 46.6%). In addition, plant fresh weight gain in this group (0.233?±?0.041?g) was higher compared to the gains in older plantlets (0.079?±?0.117 and 0.009?±?0.069?g, infected at 28 and 38?weeks’ post-initiation, respectively). Overall, for consistent and reliable result, the age of banana plantlet should be taken into consideration in interpreting the result of this in vitro bioassay.  相似文献   

4.
ABSTRACT

Potentiometric measurements in different media and at different temperatures were performed in order to determine protonation constants of glyphosate and formation constants for Ca2+ and Mg2+ complexes, together with their dependence on ionic strength and ?H0 values. Calorimetric measurements were also performed to determine ?H0 of protonation. Potentiometric measurements in mixed Ca2+ and Mg2+ solution allowed us to determine the formation of a mixed metal species. Thermodynamic parameters reported in this work can be used for studying the complete speciation of glp in electrolyte solutions containing the major ionic components of natural fluids.  相似文献   

5.
Abstract

Two series of aminoguanidines containing an alkynyl moiety were designed, synthesised, and screened for antibacterial and anticancer activities. Generally, the series 3a–3j with a 1,2-diphenylethyne exhibited better antibacterial activity than the other series (6a–6k) holding 1,4-diphenylbuta-1,3-diyne moiety antibacterial activity. Most compounds in series 3a–3j showed potent growth inhibition against the tested bacterial strains, with minimum inhibitory concentration (MIC) values in the range 0.25–8?µg/mL. Compound 3g demonstrated rapid and persistent bactericidal activity at 2?×?MIC. The resistance study revealed that resistance of the tested bacteria towards 3g is not easily developed. Molecular docking studies revealed that compounds 3g and 6e bind strongly to the LpxC and FabH enzymes. Moreover, excellent activity of selected compounds against the growth of cancer cell lines A549 and SGC7901 was also observed, with IC50 values in the range 0.30–4.57?µg/mL. These findings indicate that compounds containing the aminoguanidine moiety are promising candidates for the development of new antibacterial and anticancer agents.  相似文献   

6.
Aim: To investigate peripheral blood monocytes/macrophages (Mo/M?) paraoxonase 2 (PON2) in diabetes and the factors modulating its activity.

Methods: One hundred and eighteen patients with newly diagnosed uncomplicated type 2 diabetes mellitus were compared regarding clinical, biochemical and oxidative stress parameters with 80 healthy subjects. The capacity of the peripheral blood mononuclear cells (PBMNC) to release pro-oxidants and to neutralise them was determined by measuring the respiratory burst (RB) and the intracellular antioxidant enzyme PON2. In vitro experiments were conducted on a differentiated monocytes cell line (dU937) that was exposed to serum deprivation followed by addition of isolated lipoproteins (VLDL or LDL).

Results: Paraoxonase 2 activity in Mo/M? was significantly lower in type 2 diabetes patients (0.042?±?0.044 vs 0.165?±?0.133U lactonase activity/mg protein in controls, p?1c) and insulin resistance (HOMA-IR). In multivariate regression models, 15–34% of the PON2 variance was explained by diabetes. The in vitro addition of VLDL normalised the RB of serum deprived dU937 cells, S? (to 82?±?18% of the cells incubated with serum, S+) and PON2 activity (from 0.524?±?0.061 in S???to 0.298?±?0.048?U/mg protein). In contrast, when LDL was added, the RB remained lower (61?±?12% of S+, p?=?.03) and PON2 higher (0.580?±?0.030?U/mg protein, p?=?.003).

Conclusions: The decrease in monocyte/macrophage PON2 enzymatic activity observed in type 2 diabetes cannot be totally explained by abdominal obesity and insulin resistance. The underlying molecular mechanisms need to be identified.  相似文献   

7.
Cholinesterases (ChEs) are enzymes that break down neurotransmitters associated with cognitive function and memory. We isolated cinnamic acids (1 and 2), indolinones (3 and 4), and cycloartane triterpenoid derivatives (519) from the roots of Cimicifuga dahurica (Turcz.) Maxim. by chromatography. These compounds were evaluated for their inhibitory activity toward ChEs. Compound 1 was determined to have an IC50 value of 16.7?±?1.9?μM, and to act as a competitive inhibitor of acetylcholinesterase (AChE). Compounds 3, 4 and 14 were found to be noncompetitive with IC50 values of 13.8?±?1.5 and 6.5?±?2.5?μM, and competitive with an IC50 value of 22.6?±?0.4?μM, respectively, against butyrylcholinesterase (BuChE). Our molecular simulation suggested each key amino acid, Tyr337 of AChE and Asn228 of BuChE, which were corresponded with potential inhibitors 1, and 3 and 4, respectively. Compounds 1 and 4 were revealed to be promising compounds for inhibition of AChEs and BuChEs, respectively.  相似文献   

8.

A real-time PCR assay was used to quantify the relationship in alfalfa and pea between disease severity and the amount of Aphanomyces euteiches detected in roots. The study included isolates of race 1 and race 2 of the alfalfa pathovar of A. euteiches and an isolate obtained from diseased pea. Spearman rank correlations between pathogen DNA content and disease severity index (DSI) ratings were positive ( ? 0.57) and significant (P  0.0007) for individual alfalfa plants, bulked alfalfa plant samples, and individual pea plants. In all experiments, significantly more pathogen was detected in susceptible populations than in resistant populations. The results clearly demonstrate that resistance to A. euteiches in both alfalfa and pea is characterized by a reduction in pathogen colonization relative to levels observed for susceptible reactions. The assay was very specific for A. euteiches, producing very linear assays with DNA extracted from pathogen isolates obtained from alfalfa, pea, and bean. Possible applications of the assay in conjunction with other real-time PCR assays specific to other legume pathogens are discussed in relation to simultaneous disease screening for multiple plant pathogens and the study of microbial population dynamics in mixed plant infections.  相似文献   

9.
Abstract

How should race be categorized? This article investigates the usefulness of having three categories to describe a black‐white racial continuum, focusing on Brazil and the functional ability of elderly (60+) people there. Ironically, even as the U.S. census has started to acknowledge mixed race again, much social research in Brazil has begun not to. Using 1998 national household survey microdata (PNAD) for Brazil, we find it advantageous to use a three‐category scheme that separates a mixed black‐white (pardo) status from black or white when examining the functional ability of elders. We also find the tantalizing possibility of a crossover in which browns actually have more functional ability than white counterparts after controlling for many demographic, geographic, and socioeconomic factors.  相似文献   

10.
Protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase are important targets to treat obesity and diabetes, due to their deep correlation with insulin and leptin signalling, and glucose regulation. The methanol extract of Paulownia tomentosa fruits showed potent inhibition against both enzymes. Purification of this extract led to eight geranylated flavonoids (1–8) displaying dual inhibition of PTP1B and α-glucosidase. The isolated compounds were identified as flavanones (1–5) and dihydroflavonols (6–8). Inhibitory potencies of these compounds varied accordingly, but most of the compounds were highly effective against PTP1B (IC50?=?1.9–8.2?μM) than α-glucosidase (IC50?=?2.2–78.9?μM). Mimulone (1) was the most effective against PTP1B with IC50?=?1.9?μM, whereas 6-geranyl-3,3′,5,5′,7-pentahydroxy-4′-methoxyflavane (8) displayed potent inhibition against α-glucosidase (IC50?=?2.2?μM). All inhibitors showed mixed type Ι inhibition toward PTP1B, and were noncompetitive inhibitors of α-glucosidase. This mixed type behavior against PTP1B was fully demonstrated by showing a decrease in Vmax, an increase of Km, and Kik/Kiv ratio ranging between 2.66 and 3.69.  相似文献   

11.
A series of 2-amino-5-nitrothiazole derived semicarbazones were designed, synthesised and investigated for MAO and ChE inhibition properties. Most of the compounds showed preferential inhibition towards MAO-B. Compound 4, (1-(1-(4-Bromophenyl)ethylidene)-4-(5-nitrothiazol-2-yl)semicarbazide) emerged as lead candidate (IC50?=?0.212?µM, SI?=?331.04) against MAO-B; whereas compounds 21 1-(5-Bromo-2-oxoindolin-3-ylidene)-4-(5-nitrothiazol-2-yl)semicarbazide (IC50?=?0.264?µM) and 17 1-((4-Chlorophenyl) (phenyl)methylene)-4-(5-nitrothiazol-2-yl)semicarbazide (IC50?=?0.024?µM) emerged as lead AChE and BuChE inhibitors respectively; with activity of compound 21 almost equivalent to tacrine. Kinetic studies indicated that compound 4 exhibited competitive and reversible MAO-B inhibition while compounds 21 and 17 showed mixed-type of AChE and BuChE inhibition respectively. Docking studies revealed that these compounds were well-accommodated within MAO-B and ChE active sites through stable hydrogen bonding and/or hydrophobic interactions. This study revealed the requirement of small heteroaryl ring at amino terminal of semicarbazone template for preferential inhibition and selectivity towards MAO-B. Our results suggest that 5-nitrothiazole derived semicarbazones could be further exploited for its multi-targeted role in development of anti-neurodegenerative agents.

A library of 2-amino-5-nitrothiazole derived semicarbazones (421) was designed, synthesised and evaluated for in vitro MAO and ChE inhibitory activity. Compounds 4, 21 and 17 (shown) have emerged as lead MAO-B (IC50:0.212?µM, competitive and reversible), AChE (IC50:0.264?µM, mixed and reversible) and BuChE (IC50:0.024?µM, mixed and reversible) inhibitor respectively. SAR studies disclosed several structural aspects significant for potency and selectivity and indicated the role of size of aryl binding site in potency and selectivity towards MAO-B. Antioxidant activity and neurotoxicity screening results further suggested their multifunctional potential for the therapy of neurodegenerative diseases.  相似文献   

12.
《Bird Study》2012,59(3):329-341
ABSTRACT

Capsule: In Egyptian Vultures Neophron percnopterus, both sexes invested similar parental effort throughout the breeding period. However, there was variation in the degree of intensity of parental care during some stages of the breeding period, suggesting that sex-role specialization exists for some activities.

Aims: To quantify parental care behaviour of Egyptian Vultures for the first time and to examine the role of sex, weather conditions, and stage of nesting cycle on breeding ecology.

Methods: We monitored 15 nests of Egyptian Vultures to analyse parental care investment. We collected data on nine different behavioural parameters/activities per sex, which were recorded throughout the entire breeding period. Variation in parental investment was analysed using generalized linear mixed models.

Results: Females invested more effort in incubation/brooding (61.45% for females and 31.54% for males) and egg turning (0.45?events/h for females and 0.37?events/h for males) while males contributed more to nest material delivery to the nest (0.67?deliveries/h for males and 0.14?deliveries/h for females). Conversely, both sexes invested the same effort in nestling attendance (21.89% for females and 21.21% for males) and food provisioning (0.28?items/h for females and 0.25?items/h for males). Furthermore, parental investment was not affected by weather, especially during critical moments such as incubation/brooding, however, changeover rate was positively related to temperature.

Conclusion: Our results suggest that, in the Egyptian Vulture, one sex is not entirely responsible for a particular task and the compensatory effort of the other mate is required. Finally, our findings indicate that major events such as incubation onset and hatching caused important shifts in the patterns of parental investment.  相似文献   

13.
Background and objective: Toenail is an advantageous biomarker to assess exposure to metals such as manganese and mercury. Toenail Mn and Hg are in general analyzed by chemical methods such as inductively coupled plasma mass spectrometry and atomic absorption spectrophotometry. In this project, a practical and convenient technology—portable X-ray florescence (XRF)—is studied for the noninvasive in vivo quantification of manganese and mercury in toenail.

Material and methods: The portable XRF method has advantages in that it does not require toenail clipping and it can be done in 3?min, which will greatly benefit human studies involving the assessment of manganese and mercury exposures. This study mainly focused on the methodology development and validation which includes spectral analysis, system calibration, the effect of toenail thickness, and the detection limit of the system. Manganese- and mercury-doped toenail phantoms were made. Calibration lines were established for these measurements.

Results: The results show that the detection limit for manganese is 3.65?μg/g (ppm) and for mercury is 0.55?μg/g (ppm) using 1?mm thick nail phantoms with 10?mm soft tissue underneath.

Discussion and conclusion: We conclude that portable XRF is a valuable and sensitive technology to quantify toenail manganese and mercury in vivo.  相似文献   

14.
Abstract

The present study is envisaged to develop nanoethosomal formulation for enhanced topical delivery of amphotericin B (AmB) for the treatment of cutaneous fungal infections. AmB encapsulated nanoethosomes were prepared using mechanical dispersion method in a strength of 0.1% w/w similar to the strength of marketed topical formulation. Vesicle size of nanoethosomal formulations was found to be in the range of 186?±?2 to 298?±?4?nm. The optimized nanoethosomal formulation was further incorporated in gel base to form AmB nanoethogel formulation. Rheological characterization study of nanoethogel demonstrated its viscoelastic nature with high elasticity and resistance to deformation at 37?°C. The yield stress value was found to be 108.05?±?2.4 and 52.15?±?0.9?Pa for nanoethogel and marketed gel formulation, respectively. The nanoethogel formulation exhibited 2.7- and 3.5-fold higher steady state transdermal flux and skin deposition of AmB, respectively, in comparison to marketed formulation. Confocal laser scanning microscopy (CLSM) study also revealed enhanced skin permeation and deposition with nanoethogel formulation. In vivo study showed that topical application of nanoethogel does not exhibit any skin irritation as tested by Draize test. The developed formulation, in comparison to the marketed gel, demonstrated a remarkable increase in the antifungal activity against Candida albicans. It is thus corroborated from the above results that nanoethosomal formulation represents an efficacious carrier for effective topical delivery of AmB.  相似文献   

15.
Microbial resistance to the available drugs poses a serious threat in modern medicine. We report the design, synthesis and in vitro antimicrobial evaluation of new functionalized 2,3-dihydrothiazoles and 4-thiazolidinones tagged with sulfisoxazole moiety. Compound 8d was most active against Bacillis subtilis (MIC, 0.007?µg/mL). Moreover, compounds 7cd and 8c displayed significant activities against B. subtilis and Streptococcus pneumoniae (MIC, 0.03–0.06?µg/mL and 0.06–0.12?µg/mL versus ampicillin 0.24?µg/mL and 0.12?µg/mL; respectively). Compounds 7a and 7cd were highly potent against Escherichia coli (MIC, 0.49–0.98?µg/mL versus gentamycin 1.95?µg/mL). On the other hand, compounds 7e and 9c were fourfolds more active than amphotericin B against Syncephalastrum racemosum. Molecular docking studies showed that the synthesized compounds could act as inhibitors for the dihydropteroate synthase enzyme (DHPS). This study is a platform for the future design of more potent antimicrobial agents.  相似文献   

16.
Abstract

Drugs used for the treatment and prevention of malaria are often plagued by the problem of development of resistance. This has hampered their therapeutic efficiency and rendered them ineffective for monotherapy. However, if re-packaged and combined properly, many of these neglected anti-malarial drugs can possibly find their way back into the treatment regime. The present study evaluates the use of curcumin (CC) and primaquine (PRI) as an anti-malarial combination, packaged within niosomes, in comparison to their respective monotherapy options. It was observed that in Plasmodium berghei-infected mice, mice treated with a combination of 35?mg/kg of CC along with either 5?mg/kg or 1?mg/kg body weight of PRI demonstrated 100% anti-malarial activity and survivability beyond 20 days. The niosome-based PRI–CC combination therapy provided increased protection and survival rate that was associated with prevention in recrudescence. The findings of the study suggest that niosome-based PRI–CC combination therapy may be a promising approach in the treatment of malaria.  相似文献   

17.
Abstract

Purpose: Retinol binding protein 4 (RBP4) has recently been identified as an adipokine possibly involved in the development of impaired glucose metabolism. We aimed to test serum RBP4 in healthy non-obese individuals and in patients with well-characterized phenotype: obesity without confounding effects of diabetes, metabolic syndrome or dyslipidaemia. Additionally, we examined whether serum RBP4 is associated with anthropometric parameters, insulin resistance and blood lipid parameters.

Patients and methods: Twenty-eight patients with obesity and no co-morbidities and twenty-five age-matched lean controls were recruited. Anthropometric parameters, body composition, fasting blood lipid profile, RBP4, glucose and insulin were assessed and HOMA-IR was calculated.

Results: Mean concentration of RBP4 did not differ between studied groups (in obese patients was 33.93?±?4.46?µg/ml and 32.53?±?2.53?µg/ml in non-obese controls). RBP4 positively correlated with serum triglycerides in obese and non-obese individuals (r?=?0.74, p?=?0.03 and r?=?0.62, p?=?0.02, respectively) and did not show any significant associations with HOMA-IR, anthropometric and body composition parameters.

Conclusions: Excessive adiposity without co-morbidities is not associated with higher levels of circulating RBP4. Serum RBP4 cannot be considered as a direct predictive marker for impaired glucose metabolism. RBP4 possibly contributes to lipid metabolism.  相似文献   

18.
ABSTRACT

Penicillium marneffei is a thermally dimorphic fungus that causes penicilliosis, and become the third-most-common opportunistic fungal infection in immunocompromised patients in Southeast Asia. Azoles and amphotericin B have been introduced for the treatment, however, it is important to investigate possible mechanisms of azole resistance for future treatment failure. We identified 177 putative MFS transporters and classified into 17 subfamilies. Among those, members of the Drug:H+ antiporter 1 subfamily are known to confer resistance to antifungals. Out of 39 paralogs, three (encoded by PmMDR1, PmMDR2, and PmMDR3) were heterologously overexpressed in S. cerevisiae AD? conferred resistance to various drugs and compounds including azoles, albeit to different degrees. PmMDR1-expressing strain showed resistance to the broadest range of drugs, followed by the PmMDR3, and PmMDR2 conferred weak resistance to a limited range of drugs. We conclude that PmMDR1 and PmMDR3, may be able to serve as multidrug efflux pumps.  相似文献   

19.
Abstract

New affinity reagents for ATP-dependent enzymes are described. Optimal conditions are evolved for the synthesis of mixed anhydrides of AMP, ADP, ATP with mesitoic acid (MsCOpnA, n = 1?3) and for their 1, N6-etheno, 2′, 3′-dialdehyde and photoactive analogues. UV, CD and fluorescence spectra of the compounds have been analyzed. Hydrolysis of MsCOpnA (n = 1?3) and their etheno analogues over a wide pH range has been carried out.  相似文献   

20.
ABSTRACT

The possible functional significance of sclerophylly (hard and coriaceous leaves) is discussed on the basis of different interpretations reported in old and recent literature. These, have been schematically divided into four groups of hypotheses, i.e. the “water conservation?d hypothesis, the “resistance to negative turgour pressures?d hypothesis, the “nutritional?d hypothesis and the “protective?d hypothesis. In particular, a section is devoted to discussing the first and second hypotheses in terms of relationships of sclerophylly to drought resistance strategies. Data reported in the literature lead to the conclusion that the sclerophyllous habitus per se seems not to be related to drought resistance of plants as previously thought. Nor do clear-cut relationships appear to exist between leaf sclerification and living leaf cells with thicker walls, leading to a high modulus of elasticity (ε), the latter known to be of importance for generating low leaf water potentials, i.e. higher driving forces for water uptake. Because leaf sclerification has proved to be related to soil nutrient deficiency, this leaf habitus can be considered as a mere epiphenomenon of nutrient stress. On the other hand, the selective advantage of sclerophylly as protection against herbivore attacks, though not demonstrated in different environments, seems to be of great interest and deserves further studies.  相似文献   

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