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111.
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113.
Jenkins SJ Ruckerl D Cook PC Jones LH Finkelman FD van Rooijen N MacDonald AS Allen JE 《Science (New York, N.Y.)》2011,332(6035):1284-1288
A defining feature of inflammation is the accumulation of innate immune cells in the tissue that are thought to be recruited from the blood. We reveal that a distinct process exists in which tissue macrophages undergo rapid in situ proliferation in order to increase population density. This inflammatory mechanism occurred during T helper 2 (T(H)2)-related pathologies under the control of the archetypal T(H)2 cytokine interleukin-4 (IL-4) and was a fundamental component of T(H)2 inflammation because exogenous IL-4 was sufficient to drive accumulation of tissue macrophages through self-renewal. Thus, expansion of innate cells necessary for pathogen control or wound repair can occur without recruitment of potentially tissue-destructive inflammatory cells. 相似文献
114.
Wild herbivore diversity and abundance have declined in African savannas for the past 20 years. Competition for forage resources between wild herbivore and livestock species might contribute to this decline, given habitat and diet overlap under conditions of resource limitation. Development of conservation and management strategies rely on understanding the spatial distribution of resources for livestock and wildlife, especially since the combination of transhumance pastoralism and wildlife conservation is common over Africa. We studied the distribution patterns of wild grazers in relation to cattle abundance, and distance to permanent and seasonal water bodies in semi-arid Kenya between 1983 and 2000. Cattle were abundant far from permanent water bodies during dry and wet years. Wild grazers less dependent on water also concentrated far from water during all years. Only wild grazer species more dependent on water remained concentrated close to water. Hence, wild grazers and cattle show spatial partitioning in the use of permanent and seasonal water bodies, but not in their forage resources. Our study provides no strong evidence of spatial displacement of wild grazers by cattle. We suggest that pastoralist decisions on cattle distribution do not need to negatively affect wildlife distribution and that coexistence can be possible through spatial partitioning. Our results show that pastoralist decisions play an important role in the interactions between livestock and wildlife in African savannas and that herd mobility is a key component in supporting sustainable use of resources for both wildlife and livestock. 相似文献
115.
Several experiments were performed examining the effect of different culture variables on the growth and survival of Argopecten nucleus and Nodipecten nodosus larvae. Higher growth and survival values were obtained at a low density (1 larvae mL?1) than at a high density (5 larvae mL?1), except for N. nodosus's survival, which was not affected by density. Higher growth was obtained when feeding the larvae a diet of Isochrysis galbana, similar results occurred with the diet of Isochrysis galbana+Chaetoceros calcitrans in A. nucleus and with I. galbana combined with the lipid emulsion EmDHA in N. nodosus. Higher survival was obtained when the diet included a mixture of microalgae than when EmDHA was supplemented. Growth and survival of the larvae of A. nucleus were greater when fed continuously, while N. nodosus grew and survived better when food was given discontinuously. Higher growth and survival values were recorded at lower food concentrations ranging from 20 to 40 cells μL?1 of I. galbana. Higher growth was observed with increasing temperature between 22 and 28 °C, although there was a simultaneous decrease in survival. No significant effects on larval production parameters were found when the culture water was changed totally or partially, but higher larval growth of N. nodosus was verified when a partial renewal of water was performed. 相似文献
116.
Isaac K. Mpanga Günter Neumann Judith K. Brown Joseph Blankinship Russell Tronstad Omololu Idowu 《植物养料与土壤学杂志》2023,186(3):276-285
Background
Grape pomace (GP) is a by-product of wineries after filtering the grape juice for wine production. GP contains seeds, pulp, skin, and stalks with acidic properties, and it is normally composted before using as a soil amendment. However, composting GP requires more time, labor, and equipment; furthermore, composting loses some of the desirable organic acids for arid soils. The acidic properties of these organic acids and the plant nutrients in GP make it a desirable amendment for arid soils in both non-composted and composted forms.Aim
This study investigates the potential of directly applying GP as a soil amendment and its impact on arid soil health and plant performance.Methods
To test the potential of non-composted GP as a soil amendment, greenhouse and field studies were conducted by combining GP with existing management practices (manure application for soil used in the greenhouse study and fertigation for the field study) to assess the effects of GP on soil health and crop (maize, wheat, and grape) performance.Results
Adding 5% GP to an alkaline soil significantly increased maize and wheat growth and shoot nutrient concentrations in the greenhouse and grapes in the field (48% yield increase). The significance of GP on maize, wheat, and grapes was associated with soil nutrient enhancements (i.e., nutrients supplied, increase in organic matter and microbial biomass increase, reduction in pH, and better nutrient mobilization).Conclusion
GP has the potential for direct use as a soil amendment for soil and crop health improvement, especially in arid soils with high pH and limited soil organic matter. 相似文献117.
Katja N. Adamik Rafael Obrador Judith Howard 《Veterinary anaesthesia and analgesia》2018,45(3):260-268
Objective
To evaluate the effects of a 6% hydroxyethyl starch (130/0.42) in either a buffered, electrolyte-balanced (HES-BAL) or saline (HES-SAL) carrier solution on electrolyte concentrations and acid–base parameters in healthy anaesthetized dogs.Study design
Prospective randomised clinical study.Animals
A group of 40 client-owned dogs undergoing general anaesthesia for elective surgical procedures or diagnostic imaging.Methods
During anaesthesia, dogs were intravenously administered 15 mL kg?1 of either HES-SAL (n = 20) or HES-BAL (n = 20) over 30–40 minutes. Jugular blood samples were analysed before (T0) and 5 minutes (T5), 1 hour (T60) and 3 hours (T180) after fluid administration. Sodium, potassium, chloride, ionised calcium, phosphate, albumin, pH, venous pCO2, base excess (BE), bicarbonate and anion gap were determined and strong ion difference (SID) and total quantity of weak nonvolatile acids were calculated for each time point.Results
Chloride was significantly increased at T5, T60 and T180 compared with T0 after HES-SAL, and was significantly greater after HES-SAL than after HES-BAL at T5 (p = 0.042). Ionised calcium was significantly decreased at T5 compared with T0 after HES-SAL, and was significantly lower after HES-SAL than after HES-BAL at T5 (p < 0.001). Bicarbonate was significantly lower after HES-SAL than after HES-BAL at T5 (p = 0.004) and T60 (p = 0.032). BE was significantly lower after HES-SAL than after HES-BAL at T5 (p < 0.001) and T60 (p = 0.007). SID was significantly decreased after HES-SAL at T5 and T60 compared with T0, and was significantly lower after HES-SAL than after HES-BAL at T5 (p = 0.027). Mean electrolyte and acid–base parameters remained within or marginally outside of reference intervals.Conclusions and clinical relevance
Changes in both groups were minor and short-lived with either fluid in healthy individuals, but might become clinically relevant with higher fluid doses or in critically ill dogs. 相似文献118.
Hilbert A Reith P Brockmann SO Tyczka J Fischer SF Piechotowski I Wagner-Wiening C Winter CH Bendak J Meier C Spengler D Miller T Kleine-Albers C Renner C Koepsel U Hensler E Henning K Fröhlich A Conraths FJ Kramer M 《Berliner und Münchener tier?rztliche Wochenschrift》2011,124(7-8):295-302
In 2008 and 2009, two consecutive outbreaks of Q fever in humans were recorded in the district of Freudenstadt, northern Black Forrest, Baden-Württemberg, Germany. In 2008, a total of 41 persons from a single local community fell ill and were found infected with Coxiella burnetii. Although comprehensive diagnostic and epidemiological outbreak investigations were conducted and control measures taken which included vaccination of ruminants at risk in three parts of the affected community, re-occurrence of the disease in 2009 with further 29 confirmed human Q fever cases could not be prevented. While the origin of infection of the first outbreak was probably a flock of 550 sheep moved in the surrounding of the affected villages, the source of infection for the consecutive outbreak in 2009 could not be identified. It seems possible that meadows contaminated with infectious placenta or birth fluids represented the sources of infection. 相似文献
119.
Ainsworth DM Appleton JA Eicker SW Luce R Julia Flaminio M Antczak DF 《Veterinary immunology and immunopathology》2003,91(1):61-71
The effect of strenuous exercise on the mRNA concentrations of interleukin-12p35 subunit (IL-12p35), interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in equine pulmonary and peripheral blood mononuclear cells (PBMCs) was investigated. We hypothesized that strenuous exercise would suppress the expression of IL-12p35, IFN-gamma and augment the expression of IL-4. Eleven horses were randomly divided into two groups, a stall-confined control group (n=5) and an exercise-conditioned treatment group (n=6). Bronchoalveolar and PBMCs were obtained from horses in the treatment group prior to the commencement of a 9-week conditioning program and 24h after the completion of a maximum exercise test conducted in week 12. Samples were obtained simultaneously from control horses. Differential counts were performed on the bronchoalveolar lavage cells. Real-time PCR was performed on the pulmonary and PBMCs to quantitate cytokine expression using equine-specific primers and Taqman probes. Target gene expression was normalized to 18s rRNA expression. With the exception of IL-4 in the BALF cells, mRNA for the three cytokines was detected in the mononuclear cells from all horses at both sampling times. There were no significant differences in the cytokine mRNA concentrations between the two groups of horses at either of the sampling times. These findings demonstrate that strenuous treadmill exercise does not exert a deleterious effect on gene expression for IL-12p35, IFN-gamma or IL-4 when assessed in horses 24h following the intense physical activity. 相似文献
120.
Judith L. Fisher William A. Loneragan Kingsley Dixon Julie Delaney Erik J. Veneklaas 《Biological conservation》2009,142(10):2270-2281
Relationships between fire history, vegetation structure and composition, and invasion by introduced plant species have received limited attention in Australian woodlands. A study in a Mediterranean, fire adapted urban Banksia woodland remnant in the biodiversity hotspot of southwest Australia investigated: (1) Have significant changes occurred in the woodland tree canopy between 1963 and 2000? (2) Do correlations exist between fire frequency and canopy cover? (3) If there is a difference in the vegetation composition of Banksia woodland invaded by the South African Ehrharta calycina (PCe) and Pelargonium capitatum (PCp) compared to largely intact remnants (GC)? and (4) Do correlations exist between vegetation condition, composition, fire frequency and invasion? Aerial photography, processed in a Geographical Information System, was used to establish fire history and changes in canopy cover over time (1963–2000). PCe and PCp sites experienced the greatest number of fires, with a net reduction in canopy cover in all areas experiencing four or more fires (60% of all woodlands). Frequent fire corresponded with a decline in native cover, richness and diversity, a shift from native to introduced species, changes in the relative importance of fire response categories, and loss of native resprouting shrub cover. Life forms of introduced species, which included no trees, shrubs and perennial sedges, contrasted strongly with those of native species, which had poor representation of annual and perennial grasses. Clear ecological and conservation consequences due to the loss of species diversity, changes in fire ecology and invasion have occurred in the Banksia woodlands. This study provides an understanding of the invasion process, enhancing conservation knowledge to improve the adaptive management of the key threatening process of invasion in biodiverse communities. 相似文献