bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of level of food intake on the incorporation of acetate into lipids and its distribution among various tissues in sheep
Authors: Broad T. E. , Ulyatt M. J.
Published: May 2005

1. Romney wethers were infused intravenously with [2-14C]acetate for 5 d during which time they were given, three/group, different amounts of lucerne(Medicago sativaL.) chaff. The groups and the amounts fed were: MS, 700 g but starved during the infusion period; M, 700 g throughout; 1.3 M, 950 g throughout; AL,ad lib.throughout.

2. On day 4 of the infusion, the oxygen consumption, and production rate of expired14CO2were measured. At the end of the infusion, the sheep were killed and the amounts of radioactivity in the lipids of various tissues wre determined.

3. Significant differences were present between the specific activities of the tissues. The internal adipose tissues generally had higher specific activities than subcutaneous or intermuscular adipose depots. Although the intramuscular lipid also was highly labelled, the liver had the greatest specific activity.

4. Food intake did not significantly affect this pattern of specific activity of labelling of the tissues.

5. While most of the total lipid radioactivity was present in adipose tissues, the proportion in the liver increased to 40% during starvation.
The response of liver enzymes to feed restriction and subsequent adlib. feeding in the laying hen
Authors: Pearce J.
Published: May 2005

1. The effects of restricted feeding, andad lib.feeding following food restriction, on hepatic carbohydrate and lipid metabolism in the laying hen were studied.

2. The birds were allocated to four groups and given either 92, 84 or 75 g/d or allowedad lib.access to food.

3. Food restriction significantly reduced liver total lipid content compared withad lib.-fed control birds and this was reflected in reduced hepatic lipogenic enzyme activities.

4. When birds from the restricted regimens were allowed free access to food they intially consumed more food than the control group but after 2 weeks ofad lib.feeding the food consumptions of the birds in all the groups were similar.

5. Concomitant with the increase in food intake there were also increases in liver lipid content and hepatic lipogenic enzyme activities. After 18 d ofad lib.feeding these measurements were similar in the previously restricted birds and thead lib.-fed control group.

6. Despite these effects on lipid metabolism, food restriction, and the subsequent release from food restriction, had no significant effects on the specific activities of the glycolytic enzymes examined.

7. Although there were large increases in liver lipid content following release from feed restriction no birds died from, or showed any of the symptoms of, fatty liver-haemorrhagic syndrome. This suggests that, in the absence of any other factor which may be involved in the syndrome, these high liver lipid contents were not, alone, sufficient to cause FLHS. The results also indicate that free access to food following food restriction is unlikely to be a major factor in initiating the syndrome.
The effects of diet on some metabolic enzymes in the small intestinal mucosa during lactation in the rat
Authors: Palmer Maureen F. , Rolls B. A.
Published: May 2005

1. Five groups of rats were investigated: (a) unmated rats allowed free access to a commercial stock rodent diet (NP group); (b) rats in the second week of lactation allowed free access to the stock diet; (c) rats in the second week of lactation allowed only that amount of the stock diet eaten by the NP group; (d) rats in the second week of lactation allowed that amount of the stock diet eaten by the NP group and in addition free access to a high-energy, protein-free supplement; (e) rats in the second week of lactation allowed that amount of the stock diet eaten by the NP group and in addition free access to a protein supplement.

2. The weight and length of the small intestine, the mucosal content of protein and of DNA and the mucosal activities of alkaline phosphatase (EC3.1.3.1), acid phosphatase (EC3.1.3.2), isocitric de- hydrogenase (NADP+)(EC1.1.1.42)and glucose-6-phosphatase (EC3.1.3.9) were measured in individual animals.

3. For the factors investigated it was, with few exceptions, found that: there were markedly higher values in lactating animals allowed unrestricted access to food than in unmated animals; in restricted lactating animals the values were considerably lower than in unrestricted lactating rats and often similar to those in unmated animals; supplements of dietary energy restored none or only a proportion of the in- creases usually found in lactation but a protein supplement restored most or all these increases. Reasons for departure from this general picture on the part of some factors are discussed.

4. The results presented here support the view that changes found in lactation are hormonally induced but governed by nutrient availability, that protein is the important nutrient raw material but that dietary energy can support some changes probably by a ‘protein-sparing’ effect. Some changes appear to be less susceptible to the effects of dietary restriction, whether of protein or total energy. It is suggested that the additional nutrients eaten by unrestricted lactating rats permit the development of more, but less mature, enterocy tes.
The degradation of nucleic acids in, and the removal of breakdown products from the small intestines of steers
Authors: McAllan A. B.
Published: May 2005

1. Nucleic acids and breakdown products were estimated in digesta taken from different sites in the small intestines of slaughtered steers given different diets. Amounts passing different sites were compared using cellulose as a non-digestible marker. The validity of this marker was checked with chromic oxide in some experiments. In other experiments, nucleic acids or derivatives were infused into the proximal duodenum of steers receiving diets of approximately equal proportions of flaked maize and hay. The amounts disappearing during passage through the small intestine were estimated using polyethylene glycol (PEG) as a non- absorbable marker.

2. In the slaughter experiments the amounts of nucleic acids entering the small intestine varied with the type of diet. RNA and DNA disappeared on average, to extents of 89% and 80% respectively between the abomasum and the terminal ileum, irrespective of the diet. RNA disappearance occurred almost entirely in the proximal quarter of the small intestine, whereas that of DNA extended further along the tract.

3. Nucleic acid degradation in the upper small intestine was accompanied by the transient appearance of adenosine, guanosine and pyrimidine nucleosides. These products were in greatest concentration in digesta from the first quarter of the small intestine and had generally completely disappeared by the terminal ileum.

4. Of the different substances infused into the small intestine, free nucleic acids were removed to extents greater than 97%, adenine, guanine and uracil had completely disappeared, thymine and xanthine to approximately 80% and 95% and hypoxanthine and cytosine to only 51% and 48% respectively. The nucleosides adenosine and cytidine were also completely removed in the small intestine but were replaced, in part, by the catabolic products inosine plus hypoxanthine or cytosine respectively. Other nucleosides were removed to approximately half the extent of the corresponding bases.

5. Serum and urine allantoin and uric acid levels were related to the amounts of purines entering the small intestines in free or bound form.
Role of vitamin E in the aetiology of phrynoderma (follicular hyperkeratosis) and its interrelationship with B-complex vitamins
Authors: Nadiger H. A.
Published: May 2005

1. A study was undertaken to investigate the role of vitamin E in the aetiology of phrynoderma (follicular hyperkeratosis). Fifty-six children with the disease and twenty-one normal children were investigated for this purpose.

2. Plasma vitamin E levels (mean±SE; mg/l) were found to be low in phrynoderma (3.7±0.19) in contrast with normal children (6.6±0.40) and therapy with a combination of vitamin E and B-complex brought about complete cure.

3. The increase in plasma vitamin E levels after the administration of vitamin E at a dose of 100 mg three times daily for 4 weeks was higher than that obtained when vitamin E at the same dose was administered together with vitamin B-complex for 4 weeks, suggesting an interaction between the two vitamins. Further studies are necessary to find out the exact nature of this interrelationship.
Synthesis of DNA as shown by the deoxyuridine suppression test is normal in the vitamin B12-deficient fruit bat (Rosettus Aegyptiacus)
Authors: Miller Hedva , Fernandes-Costa F. , Metz J.
Published: May 2005

1. DNA synthesis in the bone marrow and lymphocytes of the vitamin B12-deficient fruit bat (Rosettus Aegyptiacus) has been studied via the deoxyuridine (dU) suppression test.

2. In contrast to vitamin B12deficiency in man, the dU suppression test was not abnormal in the vitamin B12-deficient bat, and this correlates with the reported finding that the latter does not develop megaloblastic anaemia.

3. The protection of haemopeiesis from vitamin B12deficiency in the bat is probably related to the presence in the bat of separate pools of methylfolate and tetrahydrofolate, which enables the bat to overcome the trapping of methylfolate attendant on vitamin B12deficiency.

4. These results confirm the central role of the vitamin B12and folate-dependent pathway ofde novosynthesis of DNA in the pathogenesis of vitamin B12-deficient megaloblastic anaemia.
Frequency distributions of mean daily intakes of food energy and selected nutrients obtained during nutrition surveys of Merent groups of people in Great Britain between 1968 and 1971
Authors: Darke Sylvia J. , Disselduff Molly M. , Try G. P.
Published: May 2005

1. Nutrition surveys were made in Great Britain between 1968 and 1971 of 1321 pre-schoolchildren aged 6 months to 4.5 years, 321 primary schoolchildren (10–11 years), 178 secondary schoolchildren (14–15 years), 792 secondary schoolchildren (14–15 years), 435 women in the second trimester of pregnancy, 443 elderly people (65–74 years), 384 elderly people (75 years and over).

2. The studies included a 7 d weighed dietary record and all subjects except some of the pre-schoolchildren were medically assessed for evidence of malnutrition. Among the children there were no clinical signs of undernutrition, 4% of the boys and 7% of the girls were described as obese. In the survey of elderly people 3% were malnourished but in each case malnutrition was associated with clinical disease.

3. Percentage frequency distribution curves of mean daily intakes (averaged for 7 d) were obtained for total food energy, total protein, animal protein, fat, carbohydrate, calcium, iron, retinol, thiamin, riboflavin, nicotinic acid, pyridoxine, vitamin C and vitamin D.

4. Comparison of the distribution of food energy intakes with 1969 recommendations (Department of Health and Social Security, 1969) showed that the mean of the distribution was less than the 1969 recommendation for energy. From the age of 12 months, results indicated that males had larger intakes of food energy than females.

5. Comparison of the distributions for protein, Ca, Fe, retinol, thiamin, riboflavin and vitamin C with the recommendations for these nutrients revealed that appreciable numbers of people had intakes less than the recommendations without signs of malnutrition.
Dietary chromium intake of lactating Finnish mothers: effect on the Cr content of their breast milk
Authors: Kumpulainen Jorma , Vuori Erkki , Mäkinen Seija , Kara Raija
Published: May 2005

1. The chromium in the diets of lactating Finnish mothers and of their breast milk was determined by graphite furnace atomic absorption.

2. The average maternal diet was estimated to provide approximately 30 μg Cr/d. Breast milk samples had a mean Cr content of 0.4 ng/ml, with a range of 0.1g-06g ng/ml.

3. Cr intake of the lactating mothers did not correlate with the corresponding breast milk Cr concentration.

4. The diets and the breast milk of these Finnish mothers were lower in Cr than those of any other population studied in the world.
Chronic cardiac beriberi in a former prisoner of the Japanese
Authors: Gill G. V. , Henry L. , Reid H. A.
Published: May 2005

1. A case is described of an Englishman who suffered severe ‘wet beriberi’ whilst a prisoner of war (POW) of the Japanese in World War II.

2. Following release he developed a congestive cardiomyopathy which increased in severity until his death 31 years after repatriation.

3. Autopsy findings were consistent with chronic cardiac damage due to beriberi.
Factors influencing the composition of the weight lost by obese patients on a reducing diet
Authors: Durrant Merril L. , Garrow J. S. , Royston P. , Stalley Susan F. , Sunkin Shirley , Warwick Penelope M.
Published: May 2005

1.Weight loss, resting metabolic rate and nitrogen loss were measured in forty obese inpatients on reducing diets.

2. Five subjects ate 3·55 MJ/d for 6 weeks (Expt I). Twenty-one subjects ate 4.2 MJ/d for the first week, 2·0 MJ/d for the second week and 4 2 MJ/d for the third week (Expt 2). Fourteen subjects ate 3·4 MJ/d for the first week and then 0.87 MJ protein or carbohydrate for the second or third weeks, using a cross-over design for alternate patients (Expt 3).

3. Patients in Expt I had highest weight loss and N loss in the first 2 weeks, but adapted to the energy restriction over the remaining weeks. On average subjects were in N balance at the end of the study.

4. In Expt 2 patients eating 2·0 MJ/d in week 2 showed increased weight loss compared with week I.N loss was not raised but it failed to decrease as it had in Expt I. Weight loss and N loss were reduced on return to 4.2 MJ/d for a third week.

5. In Expt 3 patients eating 0·87 MJ protein showed significantly more weight loss and less N loss than patients eating 0·87 MJ carbohydrate.

6. Resting metabolic rate decreased with time on the low-energy diet, but the manipulations of energy or protein content did not significantly affect the pattern of decrease.

7. Both weight loss and N loss were greater the lower the energy intake, and both decreased with time. Diets with a high protein:energy value give a favourable value for N:weight loss at each level of energy intake.
The appearance of re-cycled urea in the digestive tract of goats during the final third of a once daily feeding of a low-protein ration
Authors: Obara Y. , Shimbayashi K.
Published: May 2005

1. An experiment was carried out with goats fed on a low-protein ration to clarify the importance of the rumen and significance of saliva in the appearance of re-cycled urea in the digestive tract during the final third of a once daily feeding regimen. The isotope-dilution method with [15N]urea and15NH4Cl was used.

2. When the serum urea level was 58 mg N/l, the amount of urea transferred from the blood urea pool to the rumen ammonia pool was 48.6 mg N/l, which was estimated to be approximately 43% of the total amount of urea having appeared in the NH3pool of the digestive tract. When the serum urea level was 106 mg N/l, the corresponding amount of NH3was 77.7 mg N/h, which was estimated to be approximately 46% of this total amount.

3. The amount of saliva secreted was measured directly by the oesophageal fistula method. Salivary secretion serves as a mode of transfer of blood urea to the rumen NH3pool. Then the ratio, salivary secretion:diffusion through the rumen wall during the final third of the cycle was calculated to be 1:4–1:6.

4. In goats fed on a low-protein diet, the rumen is an important site of appearance of blood urea in the digestive tract. It was verified that the principal mode of transfer of blood urea to the rumen was the direct diffusion through the wall of the rumen.
Effect of protein on abomasal secretion of acid in sheep
Authors: Van Bruchem J. , Van 'T Klooster A. Th.
Published: May 2005

1. The relationship between protein content of abomasal digesta and abomasal secretion of acid was studied in sheep fitted with re-entrant cannulas in the proximal duodenum.

2. A close relationship was found between the rate of passage of protein through the abomasum and acid secretion, both after varying the protein content of the rations supplied, and after direct introduction of proteins into the abomasum (infusion tube).

3. It is concluded that proteins stimulate abomasal secretion of acid.
The effects of soya-bean oil and type of forage in the diet on the plasma lipid composition of sheep
Authors: Steele W.
Published: May 2005

1. Sheep were given four different diets which contained two types of forage and two types of concentrate. The forage portion of the diet consisted of either hay or silage, while the low-oil concentrate had high levels of starch and in the high-oil concentrate this starch was replaced by an isoenergetic amount of soya-bean oil.

2. The effects of these diets on various factors in the blood was measured.

3. The erythrocytes were more fragile in hypotonic solutions (6.0–8.5 g sodium chloride/l) of saline when they were eating a diet of hay and high-oil concentrates.

4. The levels of calcium, magnesium, phosphorus, glucose and β-hydroxybutyrate in the plasma were unaffected by dietary treatments.

5. Substitution of silage for hay in the diet increased the intake of all fatty acids, especially that of C18:3.

6. When the sheep had low intakes of oil, the change from hay to silage led to increases in the amounts of triglyceride (TG) and total lipid (TL) in their plasma, whereas with high intakes of oil this change of forage increased the plasma TG content by an even greater amount but did not alter the concentration of TL.

7. Increasing the intake of dietary oil raised the levels of both TG and TL in the plasma, irrespective of the type of dietary forage.

8. On silage diets the sheep had much greater amounts of 18:0 and 18:1 fatty acids but smaller quantities of 18:2 fatty acid in their plasma than on hay diets.

9. Changing the dietary forage from hay to silage or the concentrate from low- to high-oil enhanced the levels of all the trans isomers of C18 fatty acids in the blood of the animals.

10. These results imply that unsaturated fatty acids in silage-based diets are hydrogenated to a greater extent in the rumen than those in hay diets which results in an elevation in blood TG levels and that this in turn could profoundly alter such functions as milk fat synthesis and fat deposition in ruminants.
Preparation of an experimental low-fluoride diet from single-cell organisms for rats and mice
Authors: Khalawan S. A. , Elliott J. C. , Fearnhead R. W.
Published: May 2005

1. A method for producing a standard low-fluoride diet from a green alga and yeast is described.Chlorella pyrenoidosawas grown in a culture medium prepared with distilled water and analytical grade chemical salts. The spent culture medium from the alga culture was reclaimed and replenished with salts and sucrose for the production of yeast,Saccharomyces cerevisiae.

2. The single-cell organisms were separated by centrifugation from their culture media and the dried cells were blended with sucrose, maize oil, cellulose and a salt mix to produce diet pellets for rats and mice.

3. The diet was readily accepted as food by rats and mice and it was found to contain 100–300 μg fluoride/kg dry weight. Two generations of rats and four generations of mice were bred on this diet.

4. The use of hydroxyapatite to reduce the fluoride content of the chemicals used in the production of the alga and yeast biomass was investigated. Diet pellets prepared with this biomass contained 45–60 μg fluoride/kg dry weight.
On the Kazhdan-Lusztig basis of a spherical Hecke algebra
Authors: Knop Friedrich
Published: May 2005

Lusztig proved that the Kazhdan-Lusztig basis of a spherical algebra can be essentially identified with the Weyl characters of the Langlands dual group. We generalize this result to the unequal parameter case. Our new proof is simple and quite different from Lusztig’s.
Discovering patterns to extract protein–protein interactions from the literature: Part II
Authors: Hao Yu , Zhu Xiaoyan , Huang Minlie , Li Ming
Published: May 2005

Motivation: An enormous number of protein–protein interaction relationships are buried in millions of research articles published over the years, and the number is growing. Rediscovering them automatically is a challenging bioinformatics task. Solutions to this problem also reach far beyond bioinformatics.

Results: We study a new approach that involves automatically discovering English expression patterns, optimizing them and using them to extract protein–protein interactions. In a sister paper, we described how to generate English expression patterns related to protein–protein interactions, and this approach alone has already achieved precision and recall rates significantly higher than those of other automatic systems. This paper continues to present our theory, focusing on how to improve the patterns. A minimum description length (MDL)-based pattern-optimization algorithm is designed to reduce and merge patterns. This has significantly increased generalization power, and hence the recall and precision rates, as confirmed by ourexperiments.

Availability:  http://spies.cs.tsinghua.edu.cn

Contact:  zxy-dcs@tsinghua.edu.cn
Coyote prey selection and community stability during a decline in food supply
Authors: Prugh Laura R.
Published: May 2005

The foraging behavior of predators can have a large influence on community dynamics and has been shown to increase stability in some cases and decrease stability in others. I studied the foraging behavior of coyotes (Canis latrans) in the Alaska Range during the peak and decline of a snowshoe hare (Lepus americanus) population cycle (1999–2002). Coyote diet was compared with prey availability to test for changes in prey selection and to examine the effect of coyote predation on the vertebrate prey community. Coyotes responded to the hare decline by increasing selection for hares and porcupines, whereas selection for voles, ground squirrels and Dall sheep did not change. Although the study area was characterized by considerable habitat heterogeneity, coyotes utilized the area as a fine‐grained environment. Coyote foraging behavior was driven primarily by changes in snowshoe hare abundance, and their sensitivity to change in alternative prey density was low. Predation by coyotes may therefore decrease the stability of alternative prey populations rather than dampening fluctuations. In order for predation to enhance the stability of prey populations, I hypothesize that prey profitability must be determined primarily by abundance.
Deleting species from model food webs
Authors: Quince Christopher , Higgs Paul G. , McKane Alan J.
Published: May 2005

In natural biological communities the disappearance of one species can have knock‐on effects causing extinction of further species from the food web. To investigate these effects we used an evolutionary model to assemble many independent simulated food webs, and studied their dynamical behaviour when one species was deleted. On average, only 2.1% of the remaining species went extinct as a result of the deletion. However, the probability of extinction of predators and indirect predators (more than one link up the chain) of the deleted species was several times larger than for an average species. The model allows predators to adapt their choice of prey in response to changing frequencies of the prey. It was found that the larger the proportion of the deleted species in the predator's diet, the greater its probability of extinction. The probability of extinction of prey of the deleted species was also significantly higher than for an average species. This is due to increased competition between prey species after removal of their predator. The effect was largest for prey species that formed an intermediate fraction of the diet of the deleted species. The number of further extinctions increased significantly with the number of links in the food web to the deleted species prior to deletion, and was also correlated with the bottom‐up and top‐down keystone species indices. We also considered which properties of the web as a whole influenced its robustness to species deletion. This revealed a significant correlation between ecosystem redundancy and deletion stability, but no clear relationship with complexity.
Bird‐made fruit orchards in northern Europe: nestedness and network properties
Authors: Lázaro Amparo , Mark Susanne , Olesen Jens M.
Published: May 2005

Frugivorous birds are involved in the distribution of fleshy‐fruited plants. In a temperate forest in northern Europe, we investigated how fruit‐eating birds and habitat variation affect the local distribution of these plants and what the consequences are to the species composition of the fruit‐bearing plant community. We subdivided the forest into 25×25 quadrates and mapped the distribution of all fleshy‐fruited plant species (18 species) expected to have their seeds dispersed by birds. Our specific aims were (i) to test if the distribution of the fleshy‐fruited species in the forest was clumped, (ii) nested, and (iii) to describe the set of species as an interacting network. Our results show that bird‐dispersed fleshy‐fruited species in a temperate forest constitute a set of orchards with a strong spatial structure. The distributions of species were highly correlated and nested. We suggest that factors involved in dispersal and colonization are mainly responsible of a nested structure, where rare species are only found together with more widespread species and species‐poor sites only contain widespread species. Besides, the community had small‐world topology with high clustering and short path length between species. This makes the network robust against random perturbations.
The frequency spectrum of structured discrete time population models: its properties and their ecological implications
Authors: Greenman J. V. , Benton T. G.
Published: May 2005

Much research effort has been devoted to the study of the interaction between environmental noise and discrete time nonlinear dynamical systems. A large part of this effort has involved numerical simulation of simple unstructured models for particular ranges of parameter values. While such research is important in encouraging discussion of important ecological issues it is often unclear how general are the conclusions reached. However, by restricting attention to weak noise it is possible to obtain analytical results that hold for essentially all discrete time models and still provide considerable insight into the properties of the noise‐dynamics interface. We follow this approach, focusing on the autocorrelation properties of the population fluctuations using the power (frequency) spectrum matrix as the analytic framework. We study the relationship between the spectral peak structure and the dynamical behaviour of the system and the modulation of this relationship by its internal structure, acting as an “intrinsic” filter and by colour in the noise acting as an “extrinsic” filter. These filters redistribute “power” between frequency components in the spectrum. The analysis emphasises the importance of eigenvalues in the identification of resonance, both in the system itself and in its subsystems, and the importance of noise configuration in defining which paths are followed on the network. The analysis highlights the complexity of the inverse problem (in finding, for example, the source of long term fluctuations) and the role of factors other than colour in the persistence of populations.
A test of the coevolution theory of autumn colours: colour preference of Rhopalosiphum padi on Prunus padus
Authors: Archetti Marco , R. Leather Simon
Published: May 2005

According to the coevolution theory of autumn colours, the bright colours of trees evolved as a warning signal towards parasites colonizing the plant in autumn. We monitored colonization of the aphid Rhopalosiphum padi on individual tress of Prunus padus in autumn and observed a strong preference of aphids for trees with green leaves. This is the first direct observation of a key assumption of the theory, that parasites avoid bright colours. Moreover our observations, compared with previous data gathered on the same species, suggest that aphids colonizing trees with green leaves develop better in spring than aphids colonizing trees with bright autumn colours, which is consistent with the second main assumption of the coevolution theory.
Evolution of allometries in the worker caste ofDorylusarmy ants
Authors: Schöning Caspar , Kinuthia Wanja , Franks Nigel R.
Published: May 2005

The worker caste of polymorphic ant species consists of individuals of strikingly different morphologies. Most studies of polymorphic species have focused on intracolonial allometries and their association with division of labour and task performance of workers of different physical subcastes. However, the factors driving the evolution of these allometries are poorly understood. Here, we analyse the importance of life‐style (hypogaeic vs intermediate vs epigaeic) as a factor in the evolution of allometries of functionally important body traits inDorylusarmy ants in the context of an evolutionary scenario according to which a hypogaeic life‐style is the ancestral state in this group. To this end, we conducted a detailed comparative analysis of the allometries of nine characters for ten species belonging to all six currently recognized subgenera and showing different life‐styles. Eight of the nine traits under consideration show a clear increase in relative size from hypogaeic to intermediate to epigaeic life‐style. These results strongly suggest that shifts in ecological niche are linked with adaptations in these traits. The degree of overall differentiation among species is more pronounced in larger than in smaller workers. The pattern of division of labour in the epigaeicD.molestusindicates that two factors that may have caused this phenomenon are new food habits and an increased need for colony defence.
Inorganic soil nitrogen under grassland plant communities of different species composition and diversity
Authors: Palmborg Cecilia , Scherer‐Lorenzen Michael , Jumpponen Ari , Carlsson Georg , Huss‐Danell Kerstin , Högberg Peter
Published: May 2005

We measured aboveground plant biomass and soil inorganic nitrogen pools in a biodiversity experiment in northern Sweden, with plant species richness ranging from 1 to 12 species. In general, biomass increased and nitrate pools decreased with increasing species richness. Transgressive overyielding of mixed plant communities compared to the most productive of the corresponding monocultures occurred in communities with and without legumes. N2‐fixing legumes had a fertilizing function, while non‐legumes had a N retaining function. Plant communities with only legumes had a positive correlation between biomass and soil nitrate content, whereas in plant communities without legumes they were negatively correlated. Both nitrate and ammonium soil pools in mixed non‐legume communities were approximately equal to the lowest observed in the corresponding monocultures. In mixed legume/non‐legume communities, no correlation was found for soil nitrate with either biomass or legume biomass as percentage of total biomass. The idea of complementarity among species in nitrogen acquisition was supported in both pure non‐legume and mixed non‐legume/legume communities. In the latter, however, facilitation through increased nitrogen availability and retention, was probably dominating. Our results suggest that diversity effects on biomass and soil N pools through resource use complementarity depend on the functional traits of species, especially N2fixation or high productivity.
Egg predation and predator‐induced hatching plasticity in the African reed frog,Hyperolius spinigularis
Authors: Vonesh James R.
Published: May 2005

Predators can reduce prey density through consumption and induce changes in the phenotypes of surviving prey (e.g. their behavior, morphology, life history). Recent reviews have highlighted the importance of both types of effects for understanding species interactions in food webs. However, most studies focus on only density or trait effects‐few have examined both within a single predator–prey system. Here I examine both the density and trait effects of egg‐stage predators of the East African reed frog,Hyperolius spinigularis,a species with arboreal clutches and aquatic larvae. To quantify the density effects of egg predators, I monitored seasonal clutch production and survivorship over two breeding seasons and thus estimated the effects of different predators on larval input into the aquatic habitat. I also quantified the effects of egg predators on the timing of hatching and hatchling phenotype. The reed frog,Afrixalus fornasini, and the ephydrid fly,Typopsilopasp., caused most of the mortality ofH. spinigulariseggs, so I focused on these two predators. Egg predation reduced larval densities from 18 to 82% depending upon the time of the season. Predation byAfrixalusandTypopsilopacaused surviving embryos to hatch 3–4 days earlier, at an earlier developmental stage, and at sizes that were 20–30% smaller compared to hatchlings from undisturbed clutches. Recent experimental studies in this system have demonstrated that reductions in larval density and size due to egg‐stage predators facilitate larval survival in the presence of aquatic predators. Reductions in larval density increase larval survival by reducing larval competition and increasing growth through vulnerable size classes. Predator‐induced early‐hatched tadpoles exhibited higher larval growth rates than tadpoles from undisturbed clutches, and thus realized higher survival by growing more rapidly though vulnerable size classes. Thus both the density and trait effects of egg‐stage predators have important, sometimes unexpected, consequences for survival in subsequent life‐stages.
Are systems with strong underlying abiotic regimes more likely to exhibit alternative stable states?
Authors: Didham Raphael K. , Watts Corinne H. , Norton David A.
Published: May 2005

Suding et al. (2004) demonstrate how conceptual advances in alternative ecosystem states theory have led to a greater understanding of why degraded systems are often resilient to restoration management. In their review they pose one (of several) ‘outstanding’ questions (Box 3 in Suding et al. 2004): “Are there predictable characteristics that indicate when a system will follow a successional pathway and/or that indicate the presence or absence of alternative ecosystem states?” We suggest that the persistence of alternative stable states might be predicted from simple consideration of assembly rules for systems structured along a gradient of environmental adversity. We raise the hypothesis that strongly abiotically‐ or disturbance‐structured assemblages, with nonrandom trait under‐dispersion (Weiher and Keddy 1995), are more likely to exhibit catastrophic phase shifts in community structure than assemblages which are weakly structured by environmental adversity.
Effects of nectar robbing on nectar dynamics and bumblebee foraging strategies in Linaria vulgaris (Scrophulariaceae)
Authors: Newman Daniel A. , Thomson James D.
Published: May 2005

Differences in morphology among bumblebee species sharing a nectar resource may lead to variation in foraging behaviour and efficiency. Less efficient bumblebees might opportunistically switch foraging strategies from legitimate visitation to secondary robbing when hole‐biting primary robbers are present. We observed various aspects of pollination and nectar robbing ecology of Linaria vulgaris in the Colorado Rocky Mountains, with emphasis on the role of bumblebee proboscis length. Bees can extract nectar from a nectar spur legitimately, by entering the front of the flower, or illegitimately, by biting or reusing holes in the spur. Although L. vulgaris flowers are apparently adapted for pollination by long‐tongued bees, short‐tongued bees visited them legitimately for trace amounts of nectar but switched to secondary robbing in the presence of primary robbers. Longer‐tongued bees removed more nectar in less time than did shorter‐tongued bees, and were less likely to switch to secondary robbing even when ∼100% of flowers had been pierced. As the proportion of robbed flowers in the population increased, the relative number of legitimate visits decreased while the relative number of robbing visits increased. Robbing decreased nectar standing crop and increased the proportion of empty flowers per inflorescence. Despite these potentially detrimental effects of robbers, differences in inflorescence use among robbers and pollinators, and the placement of holes made by primary robbers, may mitigate negative effects of nectar robbing in L. vulgaris. We discuss some of the reasons that L. vulgaris pollination ecology and growth form might temper the potentially negative effect of nectar robbing.
Phylogenetic methodologies for studying specialization
Authors: Irschick D. , Dyer L. , Sherry T.W.
Published: May 2005

Although the concept of specialization has played a central role in the development of ecological and evolutionary theory, important questions about specialization remain largely unanswered. We argue that the traditional division of specialization into evolutionary and ecological factors may be less useful than considering specialization as three components, which may not be mutually exclusive: ecological, behavioral, and functional. Many ecologists assume that these different aspects of specialization are necessarily correlated. However, this assumption has rarely been tested, but could be examined by using a phylogenetic approach. We argue that (1) ecologists should measure these different aspects of specialization within their respective organisms by placing measures of specialization on a standardized scale, and (2) should employ phylogenetic approaches for understanding how these components evolve. We argue that this approach will provide a more coordinated understanding of how specialization evolves.
The anarchist's guide to ecological theory. Or, we don't need no stinkin’ laws
Authors: O'Hara R. B.
Published: May 2005

Several ecologists have recently suggested that ecology has several laws. This conclusion contrasts with the views of some philosophers of science, who have suggested that biology cannot have laws. I argue that the debate has been confused because two very different types of law can be recognised: correlative and causal laws. Once we recognise that there is a difference, the argument against causal laws becomes stronger, and instead I suggest that ecologists should recognise that they can and do produce generalisations that are used to build models – nomological machines – that describe the ecological systems they are studying.
Ecological laws: what would they be and why would they matter?
Authors: Lange Marc
Published: May 2005

There remains considerable debate over the existence of ecological laws. However, this debate has not made use of an adequate account of what a relationship would have to be like in order for it to qualify as an ecological law. As a result, confusions have persisted not only over how to show that ecological laws do (or do not) exist, but also regarding why their existence would matter – other than to whether ecology looks like physics. I argue that ecological laws would have to possess collectively a distinctive kind of invariance under counterfactual perturbations. I call this invariance “stability.” A law of physics, such as the law that all bodies travel no faster than the speed of light, is not only true, but also necessary in a physically significant sense. (A bodymusttravel no faster than light; itcouldn'tdo otherwise, even if it were subjected to a greater force.) Likewise, the stability of ecological laws would render them necessary in an ecologically relevant sense. Furthermore, ecological laws would differ from fundamental laws of physics in the range of counterfactual perturbations under which they are invariant. Therefore, I argue, the existence of ecological laws would make ecological explanations irreducible to even the most complete possible physical explanations of the same phenomena. Ecological laws would make ecology genuinely autonomous from physics.
DECORATING KNOWLEDGE: THE ORNAMENTAL BOOK, THE PHILOSOPHIC IMAGE AND THE NAKED TRUTH
Authors: Sheriff Mary
Published: May 2005

This essay examines the relations between decoration and knowledge, reason and imagination, truth and fable in eighteenth‐century France. Focusing on the Encyclopédie, ou Dictionnaire raisonné des sciences, des arts et des métiers, par une société de gens de lettres edited by Denis Diderot and Jean Le Rond d'Alembert, it explores the complicated and contradictory relations of these concepts developed not only in the Encyclopédie's entries, but especially in its Frontispiece designed by C.N. Cochin, fils. Using Maurice Quentin de La Tour's monumental pastel portrait of the marquise de Pompadour sitting beside the Encyclopédie as a central example, the essay also suggests that tensions between decoration/knowledge, reason/imagination, truth/fable still shape current interpretation.
THE ENCYCLOPÉDIE AND THE IDEA OF THE DECORATIVE ARTS
Authors: Lavezzi Élisabeth
Published: May 2005

The decorative arts do not appear as a category of useful knowledge in Diderot's and d'Alembert's Encyclopédie but those arts now called decorative arts, such as cabinet‐making, were central to the eighteenth‐century Parisian economy and a defining feature of a publication which set itself the task of raising the status of the useful arts. This essay explores the antecedents of the notion of the decorative arts in the history of ideas. By comparing Renaissance, baroque and enlightened art theory, it charts the faltering emergence of a definition of arts such as marquetry that no longer sees them as either materially or procedurally dependent on the finer arts of painting or architecture. In the subtle shifts of meaning the object gives way to the maker as principal element upon which the definition of an art turns.
THE MARRIAGE OF ART AND COMMERCE: PHILIPPE DE LASALLE'S SUCCESS IN SILK
Authors: Miller Lesley Ellis
Published: May 2005

Since the eighteenth century Philippe Lasalle (1723–1804) has enjoyed a reputation as the most successful designer–manufacturer–inventor in the world‐renowned silk manufacturing centre of Lyons during the ancien régime. This essay proposes that it was through the conscious marriage of art and commerce that Lasalle made his fortune and arrived at his technological inventions, that his efforts at turning painterly drawings into textiles acted as the springboard for his major commercial commissions and afforded him access to the taste leaders of eighteenth‐century Europe. Armed with a clear understanding of contemporary institutions and practices in academic art and textile manufacture – the Académie Royale, the Manufacture Royale des Gobelins, and the Grande Fabrique at Lyons – Lasalle drew fully on state incentives to expand upon and market ranges of French luxury goods. This proposal problematizes existing views of Lasalle who has remained largely a local hero, nicely contextualized relative to Lyons and Lyonnais activities but somewhat underestimated relative to his manipulation of other worlds. The thesis derives from detailed examination of Lasalle's known textile output from when he formed his first partnership in 1751 until he fled from Lyons at the beginning of the French Revolution.
REGENERATION THROUGH THE EVERYDAY? CLOTHING, ARCHITECTURE AND FURNITURE IN REVOLUTIONARY PARIS
Authors: Auslander Leora
Published: May 2005

Throughout the decade of the French Revolution, those involved in the events argued that the aesthetic and the rhythms of everyday life needed to be transformed. Contemporaries justified the rather counter‐intuitive idea that a change in the political ordering of society required changes in clothing, language, calendars, weights and measures, theatre and street names, by arguing for the extraordinary power of signs and symbols. Political discourse reached the mind; signs and material things reached the heart. Armand‐Guy Kersaint made this point eloquently in his argument for republican architecture: ‘If I were to speak to men chosen at random and in need of education … I would focus on … the need to strike the spirit of the multitude with the help of buildings and monuments, at the same time as I attempted to convince them by reason.’ This essay focuses on one domain of revolutionary transformation of the everyday – furniture (in comparison with clothing and architecture) – to explain and demonstrate revolutionaries' vision of change, the constraints they faced in their projects, and the aesthetic outcomes.
FRAMING AMBITION: THE INTERIOR POLITICS OF MME DE POMPADOUR
Authors: Scott Katie
Published: May 2005

The scope and scale of Mme de Pompadour's patronage of the arts is infamous. Focusing on just three of her residences – at Versailles, Bellevue and at the hôtel d'Evreux in Paris – this essay attempts to show not what she bought, but what it meant. Exploiting both textual and visual sources, the essay explores the different ways in which Pompadour was manifest in her interiors: as intimacy and movement at Versailles, as spectacle at Bellevue, and finally as spectator at the hôtel d'Evreux. Tracing a path through her patronage from her arrival at Versailles in 1745 until her death in 1764, an argument is made for understanding her purchases and commissions as constituting a sustained effort to achieve a legitimate cultural and political identity in the face of often bitter criticism.
Life history and production of Agapetus quadratus (Trichoptera: Glossosomatidae) in a temporary, spring‐fed stream
Authors: ÁLVAREZ MARUXA , PARDO ISABEL
Published: May 2005

1. The life history and trophic basis of production of the caddisfly grazer Agapetus quadratus were studied in the torrent Gorg Blau, a spring‐fed stream on the island of Majorca that dries annually during summer.

2. Quantitative random samples were taken every 2–3 weeks during an annual surficial flow period, from November 2000 to mid‐July 2001. Instars of field‐collected larvae were determined by measurements of head width and pronotum length, and the sex of all pupae was determined to study sexual dimorphism and sex ratio.

3. Stage‐frequency histograms suggested a trivoltine population, with an average cohort time of 4 months. Larval development was asynchronous, with continuous growth and overlapping generations. Recruitment peaks were identified in mid‐November, early March and late June, indicative of winter, spring and summer generations. On average, females were larger than males and the mean sex ratio was 2 : 3 (females : males). Population densities and biomasses derived from the field data were used to calculate production and turnover rate.

4. Annual production of A. quadratus in the torrent Gorg Blau (4.80 g dry mass m−2 year−1) was the highest ever reported for the genus, being comparable with that estimated for some insects with rapid development and multiple cohorts.

5. Estimates of production of A. quadratus were combined with foregut content analysis to estimate the fraction of total production derived from the principal food sources: algae and organic detritus. Algae supported a major proportion of the production of this grazer.

6. The low density of predators characteristic of many temporary streams, and the small amplitudes in discharge and temperature during most of the wet period that characterise the spring habitats might allow high levels of grazer production in this particular Mediterranean stream.