bluuebunny/crossref_metadata_2025 huggingface dataset:
Postcranial adaptations for climbing in Loridae (Primates)
Authors: Runestad Jacqueline A.
Published: September 2010

The Loridae are an arboreal family of small primates that are specialized for slow and quiet climbing. This paper examines the relationship between lorid locomotory behaviour and postcranial skeletal morphology. Lorid humeral and femoral diaphyseal geometric cross‐sectional properties, articular surface areas, and lengths are compared to those properties in other small primates with less specialized locomotory behaviour. The comparative sample includes both closely related prosimians and more distantly related platyrrhines.

Results indicate that lorids have greater humeral and femoral diaphyseal rigidity than other quadrupedal primates of similar body size, suggesting that lorid limbs are subjected to greater forces. Lorids also have relatively larger humeral and femoral articulations, corresponding to field and laboratory observations which indicate that lorid joints are highly mobilc. In addition, lorids have long humeri relative to femoral length, and compared to humeral length in less specialized prosimians of similar body mass. Long humeral length relative to femoral length is interpreted as a climbing adaptation because similar limb proportions are also seen in many non‐primate climbers. Altogether, humeral and femoral diaphyseal cross‐sectional properties, articular surface areas, and lengths comprise a suite of characters which have potential for identifying climbing specialists in the fossil record.
Breeding and juvenile survival among slender‐tailed meerkats (Suricatu suricatta) in the south‐western Kalahari: ecological and social influences
Authors: Doolan S.P. , Macdonald D.W.
Published: September 2010

Reproductive success of co‐operatively‐breeding slender‐tailed meerkats (Suricata suricatta) in the Kalahari was monitored over four breeding seasons and 26 band years, concentrating on three focal bands. Breeding was strongly seasonal, with peak numbers of births coinciding with maximum rainfall between January and March. Breeding seasons were extended, and more litters were produced, during the years with above average rainfall. For dominant females, the mean annual rate of litter production was 1.9 ± 0.8 litters per year and short interbirth intervals (mean = 90 %pL 18 days) indicated that females came into oestrus within three weeks of giving birth. Births were synchronous within but not between bands. Major known causes of kitten mortality were cold weather and predation, and losses mainly occurred between three and five weeks of age. Sixty‐seven percent of juveniles survived between emergence from the den at three or four weeks old and attainment of effective foraging independence at 12 weeks. There were no significant effects of birth date within the season upon litter size or survival. Several incidents of apparent infanticide were recorded. These meerkats were highly co‐operative and adult band members assiduously guarded and provisioned the kittens. Nevertheless, regression analysis showed that neither rainfall (an index of prey availability) nor band size variables accounted for much variance in juvenile survival to 12 weeks, which appeared to be heavily influenced by chance events such as flash floods. In contrast, rainfall between January and March had a significantly positive effect on the total number of juveniles produced during the breeding year.
Roosting and foraging behaviour of Natterer's bats (Myotis nattereri) close to the northern border of their distribution
Authors: Swift Susan M.
Published: September 2010

Seven nursery roosts and four roosts of male Myotis nattereri, Kuhl 1818 were found in central Scotland at latitude 56–57 d̀N. Most were in crevices in the stonework of man‐made structures other than occupied houses. Emergence occurred late in the evening, at an average light intensity of 3.5 lux and emerging bats circled in dark, sheltered areas outside roosts before departing along flyways towards foraging areas. Individuals departed from, and returned to, roosts in groups of 2‐6, and circling behaviour was repeated on returning to the roost. During pregnancy, bats from anursery roost made one flight each per night. This increased to an average maximum of 1.84 early in lactation and then decreased again to one around weaning. Night roosts were situated in foraging areas and were used by M. nattereri for resting and grooming, for suckling volant but incompletely weaned young and also, possibly, for information transfer. Important foraging habitats were woodland edges, parkland, roadside vegetation and sheltered areas of water. Arthropod prey was captured both on the wing and by gleaning from foliage, and the bats were able to vary their diet according to arthropod availability. Overall, important prey included Diptera (both Nematocera and higher flies), Trichoptera, Coleoptera and non‐flying groups such as Hemiptera, Dermaptera, Arachnida and Opiliones.
Patterns of multiple paternity within and between annual reproduction cycles of the fire salamander (Salamandra salamandra) under natural conditions
Authors: Steinfartz S. , Stemshorn K. , Kuesters D. , Tautz D.
Published: September 2010

We have investigated patterns of paternity in a population of the fire salamander Salamandra salamandra in Germany under fully natural conditions. Pregnant females were caught after hibernation in their natural habitat and their offspring were genotyped with different sets of microsatellite loci to assess paternity. Each female was marked with a transponder and released at the same place where it had been caught. We were able to recapture several marked females in the following years and to analyse the offspring arrays of six females for different reproductive years between 2000 and 2001 for possible long‐term sperm storage and repeated sperm usage. The reconstruction of paternal genotypes for 21 female offspring arrays with the GERUD 1.0 program showed that multiple paternity is frequent under natural conditions with more than half of the females showing two or three fathers for their offspring cohorts. Despite the fact that S. salamandra is capable of long‐term sperm storage under captive conditions, under natural conditions we did not find evidence for long‐term sperm storage and repeated sperm usage for the six analysed female offspring arrays from consecutive years. This might be an indication for possible cryptic female choice owing to differences of sperm quality between stored and freshly uptaken sperm or degradation of sperm after fertilization. Furthermore, we found that males in nature do not contribute equally to a female's clutch when it is sired from multiple fathers. Currently, it is not clear whether such a paternity pattern reflects a simple ‘topping off’ mechanism of sperm in the spermathecae of the female as described for the newt species Taricha granulosa or whether this is the result of intensive sperm competition.
First observations on South America's largely insectivorous canid: the hoary fox (Pseudalopex vetulus)
Authors: Courtenay O. , Macdonald D.W. , Gillingham S. , Almeida G. , Dias R.
Published: September 2010

The breeding behaviour and social dynamics of a free‐ranging group of hoary foxesPseudalopex vetuluswere studied in the central cerrado (savannah) region of Brazil. The average adult size was 3.42 kg [95% confidence limits (CL): 2.92–3.91 kg]. The breeding pair occupied overlapping home ranges of 420–456 ha, where they reared a single litter of five offspring (M:F: 3:2) in 12 months. There were no additional adult group members and all offspring dispersed whenc. 10 months old, at least three of which (both sexes) established a home range adjacent to the natal territory. The proportion of time invested in rearing offspring by the breeding female declined significantly (33–2%) with increasing offspring age (pre‐weaning to offspring independence), in contrast to that of the breeding male, which was relatively constant (17–29%); the male acted as a chaperone to foraging offspring, mostly in the absence of the breeding female. Hoary fox diet comprised predominantly of insects, particularly termites and dung beetles, none of which was sufficiently bulky to make carriage to the cubs energetically efficient.
Morphological consequences of range fragmentation and population decline on the endangered Iberian lynx (Lynx pardinus)
Authors: Pertoldi C. , García‐Perea R. , Godoy J. A. , Delibes M. , Loeschcke V.
Published: September 2010

The Iberian lynx Lynx pardinus is one of the world's most endangered felids and is vulnerable to human‐induced mortality and habitat loss, which reduce population size and accelerate the loss of genetic variation. Twenty‐five metric traits of Iberian lynx skulls have been measured on 95 skulls collected between 1872 and 2003. The skulls belong to three geographically distinct areas/populations, which have recently diverged from each other as a consequence of increased habitat fragmentation: Doñana area, Sierra Morena mountains and Montes de Toledo area. The morphometric study was undertaken using univariate, multivariate and admixture analysis approaches, and all three techniques provided evidence for morphometric differentiation, both in skull size and shape, among the three populations for both males and females. Environmental and genetic forces that may have shaped these patterns are discussed. The males of the population of the Doñana area showed a different degree of reduction in size in nine of the skull traits with time, which has been suggested to be partly because of worsened habitat conditions. However, the heterogeneity of the degree of mean size reduction and the relatively high degree of reduction of some of the skull traits investigated (>4%), which have altered the original proportions between the skull variables, could also partly be attributed to inbreeding depression in the Doñana population. The phenotypic variability of the skull traits showed significant increases (two traits) or decreases (nine traits) with time, and this different pattern of change with time has been suggested to be because of a different number of genes controlling the traits with different degrees of dominance and epistatic interactions. The increased phenotypic variability of two of the traits has also been attributed to a possible decreased level of developmental stability, which can be produced by environmental and/or genetic stress. The findings of this investigation contribute to the discussion about the utility and the limits of quantitative genetics techniques for conservation purposes.
What is the taxonomic status of the Cambodian banteng and does it have close genetic links with the kouprey?
Authors: Hassanin A. , Ropiquet A.
Published: September 2010

In a recent paper, Galbreath, Mordacq & Weiler (2006) concluded that the kouprey Bos sauveli was not a natural species, but rather a feral animal derived from hybridization between banteng Bos javanicus and zebu Bos taurus indicus. Here, we analyze two mitochondrial genes (cytochrome b and subunit II of the cytochrome c oxidase) for all the seven species of the subtribe Bovina, including new sequences for several specimens of banteng, zebu and gaur of Cambodia. Our analyses indicate that mitochondrial sequences of Cambodian banteng are divergent from those of Javan banteng (mean difference =4.27%), but similar to those of kouprey (1.25%). We propose two conflicting hypotheses to interpret these results: (1) the Cambodian and Indonesian banteng belong to two distinct species, and the kouprey derived from Cambodian banteng; (2) all subspecies of banteng belong to Bo. javanicus, but the mitochondrial genome of kouprey was transferred by natural hybridization into the ancestor of Cambodian banteng. Morphological, ecological and ethological characteristics of banteng and kouprey rather support the second hypothesis. However, we need to sequence nuclear markers, and to analyze banteng from Lao, Myanmar, Thailand and Vietnam, to give a definitive conclusion on the taxonomic status of banteng and kouprey.
MINERAL NUTRITION IN TIME AND SPACE
Authors: RORISON I. H.
Published: September 2010

Summary

Interest in mineral nutrition during the last 20 years has centred increasingly on its dynamic aspects. This has led to a consideration of temporal variation, both diurnal and seasonal, and of spatial patterns as they affect nutrient supply. The response of plants to such variations are reviewed in the light of distribution and survival. Although all plants require the same small number of mineral elements, there is evidence of fine tuning in relation to soil heterogeneity. This allows a large number of nutritional options which in turn may influence coexistence and change. Selected examples for nitrogen and phosphorus are given and attention drawn to the need for further study, not only of nutrient interactions, of the energy costs of different nutrient pathways and of messenger functions of key nutrients (e.g. N and P linking activities of both root and shoot), but also of activities around the root surface; the micro‐environment produced and the involvement of microflora and fauna.
THE COMPARATIVE ECOLOGY OF FLOWERING
Authors: KAY Q. O. N.
Published: September 2010

Summary

The major roles of flowering are in sexual reproduction and in fruit and seed production. Flowering competes with vegetative growth and vegetative reproduction for resources, and involves heavy resource costs which are often much greater than those required for seed production alone. Interactions between plants dependent upon flowering may be competitive or mutualistic. Theoretical models suggest that these interactions may often be of primary importance in determining whether different species or genotypes coexist, or displace or mutually exclude one another, and may thus be responsible for the heavy investment in flowering, but very few cases have been analyzed satisfactorily. The existence of simultaneously or sequentially flowering guilds of species with similar floral characteristics may be a consequence of mutualistic interactions. Flowering strategies and the range of possible interactions dependent upon flowering are potentially very diverse but are constrained by the physical and biotic environment, sometimes very severely.
BOTANICAL CONTRIBUTIONS TO CONTEMPORARY ECOLOGICAL THEORY
Authors: GRIME J. P. , HODGSON J. G.
Published: September 2010

Summary

In the search for general principles in ecology, the role of botany has often been subordinate to those of mathematics, genetics and zoology. This paper identifies three important areas of ecological research (competition, coexistence, and relationships between anti‐herbivore defence and decomposition processes) where comparative studies of autotrophic plants can play a leading part in analyses of the structure of communities and the functioning of ecosystems. With respect to a fourth research topic (ecological constraints arising from evolutionary histories), a stronger botanical response to the zoological lead is advocated.
Nitrate inhibition of N2 fixation in Phaseolus vulgar is L. cv. OAC Rico and a supernodulating mutant
Authors: Hansen Alexander P. , Martin Peter , Buttery Brian R. , Park Soon J.
Published: September 2010

summary

Time‐integrated, 15N–based determinations of N2 fixation were undertaken on common bean (Phaseolus vulgaris L.) cv. Rico and its supernodulating mutant RBS15. Plants were cultured in pots filled with quartz sand and experienced three different (0.5, 3.0, 6.0 mol m3) constantly maintained levels of nitrate for a total period of 65 d. Irrespective of nitrate treatment, biomass production of RBS15 was consistently lower compared to Rico. Nodule numbers of the wild type were only slightly elevated in response to a rise in nitrate concentration from 05 to 30 mol m3, while nodule numbers of RBS15 increased substantially, indicating that nodulation of the mutant was N limited in the 0.5 mol m 3 treatment. A further rise in nitrate concentration failed to induce any more change in the mutant, but caused earlier senescence in Rico nodules. Both genotypes decreased their dependency on atmospheric N2 in the presence of increasing quantities of nitrate in the rooting medium, with relatively small differences between genotypes. Calculated in absolute terms, total N2 fixation was mostly lower in the mutant despite its higher nodule numbers. Much larger differences appeared when the amount of N., fixed per unit nitrogen invested into nodules was compared. Here the mutant exhibited significantly lower values. The data suggest that nodulation of the supernodulating mutant is tolerant to nitrate, while N, fixation in both genotypes is detrimentally affected.
Chronology and mechanisms of P uptake by mycorrhizal sweet potato plants
Authors: Oapos;KEEFE D. M. , SYLVIA D. M.
Published: September 2010

summary

Vesicular‐arbuscular (VA) mycorrhizal and non‐mycorrhizal sweet potato plants [Ipomoea batatas (L.S) Lam. cv. White Star] were grown in a glasshouse in a phosphorus (P)‐fixing soil in order to (i) establish the chronology of mycorrhiza‐mediated P uptake, (ii) document the distribution of total and metabolically active external hyphae in relation to roots, root hairs and P‐depletion zones at the time when the P‐uptake response first becomes apparent, (iii) evaluate the pore‐size distribution of the soil relative to the radii of roots, root hairs and hyphae of mycorrhizal fungi, and (iv) determine if sweet potato mycorrhiza alter the organic acid composition of the rhizosphere. Phosphorus inflow, VA mycorrhizal root colonization, and active hyphae increased during the first half of an 8 wk experiment. During the latter half of the experiment, however, colonization and active hyphae increased while P inflow decreased. Roots colonized by mycorrhizal fungi supported a higher proportion of active hyphae in the soil than non‐colonized roots. In a second experiment, hyphal distribution around individual roots colonized by mycorrhizal fungi was not consistently different from hyphal distribution around non‐colonized roots. Hyphae of mycorrhizal fungi were of a diameter that would allow them to penetrate pores that hold water at water contents less than field capacity while roots, and to a large extent root hairs, would be excluded from these pores. We found no evidence that sweet potato roots, whether or not they were colonized by mycorrhizal fungi, altered the organic acid composition of the rhizosphere. We conclude that mycorrhiza mediated P uptake commenced with the onset of colonization by the fungi and was due to a change in the ability of the root to come into contact with the soil solution.
Mycorrhizas and drought resistance of Picea sitchensis (Bong.) Carr
Authors: LEHTO TARJA
Published: September 2010

summary

Mycorrhizal [Paxillus involutus (Batsch) Fr.] and non–mycorrhizal Sitka spruce [Picea sitchensis (Bong.) Carr.] seedlings were grown to comparable size and with comparable shoot N, P and K concentrations in a perlite nutrient solution culture. Shoot water potentials of mycorrhizal and non–mycorrhizal seedlings were related to the moisture content of the substrate during a drying cycle. At any given substrate moisture content, mycorrhizal plants had significantly lower water potentials than non–mycorrhizal plants, the difference being about O.l MPa. In a factorial experiment there was no effect of mycorrhizal infection on stomatal conductance or net photosynthetic rate in either well–watered or droughted seedlings.
Effects of ambient air pollution in open‐top chambers on bean (Phaseolus vulgaris L.)
Authors: SCHENONE G. , BOTTESCHI G. , FUMAGALLI I. , MONTINARO F.
Published: September 2010

summary

Field‐grown bean crops (Phaseolus vulgaris L.) were exposed to either ambient non‐filtered or filtered air in open‐top chambers at two sites in the Po plain (Northern Italy) in 1988 and 1989. Three cultivars were utilized in 1988 (Taylor's Horticultural, Lingua di Fuoco, Saluggia), one in 1989 (Taylor's Horticultural). The crops grown in ambient non‐filtered air showed significant reductions in yield compared with those in filtered air at both sites for the two years. Yield decrement of the most sensitive cultivar (Taylor's Horticultural) reached 31 % at the urban site in 1988 and 31% at the rural site in 1989. Severe foliar injury attributable to oxidants was observed on plants kept in non‐filtered air or grown in non‐chambered control plots. The instrumental monitoring of air pollutants showed 7 h means of O3 up to 50 nl I−1 during the experiments; it is known that these values can cause yield losses to sensitive crops. The concentrations of other pollutants (SO2 and NO2) were on the contrary below the known thresholds for yield losses to plants. We can argue that ambient ozone is the major air contaminant responsible for the observed yield losses of bean; the negative effects can occur both at rural and urban sites because of the widespread presence of photooxidants in the Po plain.
An in vitro assay for incompatibility between Triticum aestivum L. and Secale cereale L.
Authors: OSTASH M. , FAUTRIER A. G. , FIELD R. J.
Published: September 2010

summary

A liquid medium was developed for in vitro germination and growth of rye (Secale cereale L.) pollen. Addition of style extracts from ‘Otane’ wheat which were incompatible with rye selectively inhibited pollen tube growth, compared with compatible ‘Chinese Spring’ wheat. Dialysed extracts were most suitable for incompatibility assays. Rye pollen was also selectively inhibited by extracts from self–compatible styles. Intergeneric incompatibility in wheat appears to be controlled by inhibitory style proteins.
The alder [Alnus glutinosa (L.) Gaertn.] problem in the British Isles: a third approach to its palaeohistory
Authors: TALLANTIRE P. A.
Published: September 2010

summary

The previous approaches (rational and empirical limits for the alder pollen curve) are discussed in relation to the immigration/establishment and spread/expansion phases. For the former, consistent ‘tail’ values for alder pollen of over 3 % (total land pollen) are considered requisite, lower values being ascribed to long–distance transport. For the latter, a mapped plot of the radiocarbon dates for the initial marked rise in the alder pollen curve, to over 10 %, is presented, using only those diagrams from sites considered stratigraphically reliable and for which the dated samples derive from specific points on the curve (start, mid–rise or finish). Certain ecological considerations, which appear to have been either overlooked or neglected, are dealt with in relation to the thermoclimatic and hygroclimatic demands of alder. Alder establishment seems highly probable by 8000 BP for at least two sites in southeastern England. This supports the view that alder immigrated from Western Germany or Holland. The spread of alder shows a clear regionalism, with a major increase after about 7500 BP, mainly after 7000 BP. The failure of alder to spread north and west from its initial footholds is ascribed to the seasonal, prolonged periods of drought during the Boreal chronozone (c. 7800—‐75 00 BP), i.e. the hygroclimatic conditions were unfavourable. The initial establishment was restricted to the south east of England on account of the thermoclimatic demand and the source areas for seed.

The delays shown in its eventual spread north and west are ascribed to unfulfilled thermoclimatic demands, possibly due to low air and sea temperatures. A plea is made for the use of primary sources only, not computer‐stored data, when plotting these phenomena, and for future investigations to create a denser network of reliably dated sites, with unequivocal stratigraphic conditions, continuous pollen diagrams, and with macrofossil investigations when appropriate (excluding wood), at all altitudes.
Novel effects of phytochrome status on reproductive shoot growth in Triticum aestivum L.
Authors: CASAL JORGE J.
Published: September 2010

The effects of supplementary far‐red light (FR), provided either (bring or at the end of the photoperiod, on reproductive shoot growth were investigated in Triticum aestivam L. plants grown under natural radiation. Natural photoperiods were inductive per se and supplementary FR had no obvious effects on the date of floral initation, as indicated by the lack of differences in both the final number of leaves and the rate of leaf appearance. The first internode to elongate was longer, and the first visible node appeared earlier in FR‐treated plants. However, the rate of extension growth of the peduncle (i.e. the uppermost internode, that bears the ear) was temporarily delayed by FR. Therefore, the period between the appearance of the first visible node and ear emergence was extended by FR. Neither the final length of the flag‐leaf sheath nor the final length of the stem were significantly affected by the treatments. The responses to FR provided during twilight were fully reversed by red light, indicating the involvement of phytochrome. The potential significance of stem‐growth responses mediated by phytochrome for wheat crop performance is discussed.
The Azolla–Anabaena symbiosis: endophyte continuity in the Azolla life‐cycle is facilitated by epidermal trichomes †
Authors: PERKINS S. K. , PETERS G. A.
Published: September 2010

Light, scanning electron, and transmission electron microscopy were used to follow sporocarp development in Azolla mexicana and the mechanism by which sporocarps become inoculated with symbiotic Anabaena. Packaging of the Anabaena into sporocarps is facilitated by branched epidermal trichomes, termed sporangial pair hairs. Sporocarps arc borne in pairs and arise from the ventral lobe initial of the first leaf of a lateral branch. Four sporangial fours ore associated with each sporangial pair from the onset of their development. These hairs differentiate rapidly and exhibit transfer cull ultrastructure. They protrude into the mass of undifferentiated Anabaena filaments which comprise the apical colony. Subsequently, the sporangial primordia and the sporangial hairs with in ten wined Anabaena filaments are displaced ventrally and covered by the developing involucre. A reservoir of Anabaena filaments is thus entrapped between the developing sporocarp pair and the lower surface of the involucre, A cup‐shaped indusium forms around the base of each sporangium, separating it from the sporangial hairs while entrapping the Anabaena filaments. As development continues, the indusia completely encapsulate the individual sporangia and engulf the Anabaena which is differentiating into akinetes. In mature megasporocarps the Anabaena cells are packaged into a chamber near the indusial pore and a cluster of simple trichomes occur external to the indusium around their base.

The partner tabes of the developing sporangia form modified leaf cavities. These cavities are smaller than those in dorsal lobes not partnered with sporangia and they have a diminished complement of berth simple cavity trichomes and Anabaena. The Anabaena filaments in these modified cavities rapidly begin to differentiate akinetes rather than heterocysts. Factors which may contribute to akinete formation in the sporocarps and modified leaf cavities are discussed.
Mediation of competition between two colonizing VA mycorrhizal fungi by the host plant
Authors: PEARSON J. N. , ABBOTT L. K. , JASPER D. A.
Published: September 2010

In two experiments, we investigated the effect of Scutellospora calosopora (Nicol. & Gerd.) Walker & Sanders on mycorrhiza formation between subterranean clover and Glossip. (WUM 10). The rate and extent of colonization by Glomus sp. in the first expt was negatively correlated with increasing quantities of inoculum of S. calospora. A split‐root system was used to deter mine whether the declive in mycorrhiza formation was likely to be due to(1) a direct interaction (and/or an effect of‘prior occupancy'related to a higher number of infective hyphae present at higher inoculum levels) or (2) an indirect effect mediated by an effect of S. calospora on the plain itself. In this experiment, S. Cfralospora present on one side of the spllit‐roor markedly reduced colonization (total, arbuscular and vesicular) by Glomus sp. on the other side. However, this effect was compounded by a difference between the length of roots formed in association with each fungus. These results indicate that, for these two fungi in association with subterranean clover, the mechanism of competition during mycorrhiza formation has a physiological basis and may involve the carbohydrate supply of the host.
The occurrence of SO2‐related foliar symptoms on Scots pine (Pinus sylvestris L.) in an open‐air forest fumigation experiment
Authors: SHAW P. J. A. , HOLLAND M R. , DARRALL N. M. , McLEOD A. R.
Published: September 2010

As part of a long‐team open‐air fumigation experiment, Scots pine was exposed continuously to SO2 pollution following a predetermined pattern of hourly mean values based upon monitoring data from a site in central England. Although annual mean concentrations did not exceed 22 ppb, up to 20% of trees developed foliar necrosis in threw consecutive growing seasons similar to published descriptions of acute K(X damage, The number of trees affected increased with SO2 concentration, mid there‐ wan H significant tendency for the same trees to be affected in consecutive years, implying that sensitivity lo these levels was genetically bused. As a group, trees showing necrotic symptoms were not significantly retarded in their growth, although their 1990 budburst was significantly delayed and the few trees which lost over 50% of their foliage were visibly stunted. Fumigation of potted trees for short periods in chambers with up to 1000 ppb SO2 failed to produce any comparable effects. Regression analyses between the number of plants affected each year and a range of gas concentration parameters showed mean concentrations during a critical period in May to be most closely related to the development of symptoms, although no effects became visible until approximately 5 wk later. The start date for the critical period differed between years, and for the two years of which budburst data were available it coincided with the start of needle elongation. The duration of the critical period lay in the range 6–14 d. Linear extrapolation from the data suggested the threshold mean SO2 concentration for visible injury to be in the range 6–8 ppb (measured during the critical period during needle expansion) although this could underestimate the true value.
Strip‐cankering of beech (Fagus sylvatica): Pathology and distribution of symptomatic trees
Authors: HENDRY S. J. , LONSDALE D. , BODDY LYNNE
Published: September 2010

The pathology and distribution of European beech trees bearing elongated bark lesions (strip‐cankers) were investigated. Two types of canker were recognized: those on small trees (<40 cm diameter at breast height (dbh): 1·4 m above ground level) which bore fruit bodies of the xylariaceous ascomycete Biscogniauxia nummularia (Bull.) O. Kuntze, and those on larger specimens (>40 cm dbh) which were consistently associated with the diatrypaceous ascomycete Eutypa spinosa (Pers.) Tul. & C. Tul. All cankers were strictly annual, having formed during single growing seasons following periods of low water availability. The regional and local distribution of trees bearing lesions also appeared to be correlated with environmental conditions, being most severe where low rainfall or high temperatures had occurred. Population studies of the associated fungi, generally considered as saprotrophs, indicated the presence of unique genotypes within individual cankered trees and provided no evidence for the existence of pathotypes within either species. Within the decay columns which underlay canker surfaces, both B. nummularia and E. spinosa formed longitudinally extensive genets, implying non‐mycelial spread in colonization. Suppression of both inter‐ and intraspecific incompatibility between fungi occurred in regions of canker decay columns with elevated water contents. The possible significance of coexistence between the ascomycetes B. nummularia and ‘Hypoxylon purpureum’ (sensu Sharland & Rayner, 1989b) and of the formation of heterokaryons by E. spinosa is discussed.
Relative growth rate and biomass allocation in 20 Aegilops (Poaceae) species
Authors: VILLAR RAFAEL , VENEKLAAS ERIK J. , JORDANO PEDRO , LAMBERS HANS
Published: September 2010

This paper analyses relationships between relative growth rate (rgr), seed mass, biomass allocation, photosynthetic rate and other plant traits as well as habitat factors (rainfall and altitude) in 20 wild species of Aegilops L. and one closely related species of Amblyopyrum (Jaub. & Spach) Eig., which differ in ploidy level (diploid, tetraploid and hexaploid). The plants were grown hydroponically for 20 d in a growth chamber. The relationships between parameters were calculated either using the phylogenetic information (phylogenetically independent contrasts, PIC) or without using the phylogenetic information (trait values of taxa, TIP). The results using the two approaches were very similar, but there were a few exceptions in which the results were different (e.g. rgr vs. seed mass). Specific leaf area (sla) was positively correlated with leaf area ratio (lar) and negatively correlated with net assimilation rate (nar), which together resulted in the absence of a correlation between sla and rgr. Leaf photosynthetic rates (expressed on a mass or area basis) showed no correlation with rgr. rgr was positively correlated with the stem mass ratio and negatively with root mass ratio. Species with a lower d. wt percentage have a higher rgr. Aegilops species from locations with higher annual rainfall invested less biomass in roots and more in shoots (leaves and stems) and had a higher rgr. Diploid species had a lower seed mass and initial mass than the hybrids (tetraploid and hexaploid species), but there was no correlation of rgr with ploidy level. Polyploid species, which have higher seed mass, occur at a higher altitude than diploid species. Our results show that variation in rgr in Aegilops and Amblyopyrum spp. is associated mainly with variation in biomass allocation (proportion of biomass in stems and roots) and d. wt percentage, and not with variation in sla, leaf photosynthetic rates or seed mass.
Survival and recovery of perennial forage grasses under prolonged Mediterranean drought: II. Water status, solute accumulation, abscisic acid concentration and accumulation of dehydrin transcripts in bases of immature leaves
Authors: VOLAIRE FLORENCE , THOMAS HENRY , BERTAGNE NADIA , BOURGEOIS EMMANUELLE , GAUTIER MARIE‐FRANÇOISE , LELIÈVRE FRANÇOIS
Published: September 2010

Swards of cocksfoot (cvs KM2, Lutetia) and perennial ryegrass (cvs Aurora, Vigor) were grown under full irrigation or severe (80 d) drought in a field experiment in the South of France. Responses of the bases of immature leaves plus enclosed tissues were made during the drought period and after rewatering.

By the end of the drought, water content had fallen from 3·0 to 0·8 gwater g−1dm, and osmotic potential from −1·0
to −4·5 MPa in all cvs. Measured minerals and water‐soluble carbohydrates contributed, respectively, c 19 and 44% to osmotic potential in droughted leaf bases. The drought‐sensitive cocksfoot cv. Lutetia was characterized by a large proportion of fructans having a low degree of polymerization (DP=3, 4). As drought progressed, accumulation of dehydrin transcripts and ABA were higher in leaf bases of the sensitive cv. Lutetia than in the resistant cv. KM2.

After rewatering, the water status of immature leaf bases returned to control levels in 1–2 d, and then increased further as leaves began to grow and new tissue was produced. High‐DP‐fructans remained unchanged in leaf bases of ‘Lutetia’ but were depleted by over 55%, and therefore remobilized, in leaf bases of other cvs after 8 d.

It is concluded that enclosed immature leaf bases survive drought by tolerating a low water status and that changes conventionally associated with desiccation tolerance are expressed most strongly in susceptible plants least able to maintain their water supply.
Antioxidative systems, pigment and protein contents in leaves of adult mediterranean oak species (Quercus pubescens and Q. ilex) with lifetime exposure to elevated CO2
Authors: SCHWANZ P. , POLLE A.
Published: September 2010

The aim of the present study was to investigate the effects of elevated CO2 on the antioxidative systems and the contents of pigments, soluble protein and lipid peroxidation in leaves of adult oaks, Quercus pubescens and Quercus ilex, grown at naturally enriched CO2 concentrations. For this purpose, a field study was conducted at two CO2 springs in Central Italy. Measurements of the pre‐dawn water potentials indicated less drought stress in trees close to CO2 springs than in those grown at ambient CO2 concentrations. Most leaf constituents investigated showed significant variability between sampling dates, species and sites. The foliar contents of protein and chlorophylls were not affected in trees grown close to the CO2 vents compared with those in ambient conditions. Increases in glutathione and other soluble thiols were observed, but these responses might have been caused by a low pollution of the vents with sulphurous gases. At CO2 vents, glutathione reductase was unaffected, and superoxide dismutase activity was significantly diminished, in both species. Generally, the activities of catalase, guaiacol peroxidase and ascorbate peroxidase as well as the sum of dehydroascorbate and ascorbate were decreased in leaves from trees grown in naturally CO2‐enriched environments compared with those grown at ambient CO2 concentrations. The reduction in protective enzymes did not result in increased lipid peroxidation, but increased monodehydroascorbate radical reductase and dehydroascorbate reductase activities found in leaves of Q. pubescens suggest that the smaller pool of ascorbate was subjected to higher turnover rates. These data show that changes in leaf physiology persist, even after lifetime exposure to enhanced atmospheric CO2. The results suggest that the down‐regulation of protective systems, which has also previously been found in young trees or seedlings under controlled exposure to elevated CO2 concentrations, might reflect a realistic response of antioxidative defences in mature trees in a future high‐CO2 world.
The effects of stress on plant cuticular waxes
Authors: Shepherd Tom , Wynne Griffiths D.
Published: September 2010

Plants are subject to a wide range of abiotic stresses, and their cuticular wax layer provides a protective barrier, which consists predominantly of long‐chain hydrocarbon compounds, including alkanes, primary alcohols, aldehydes, secondary alcohols, ketones, esters and other derived compounds. This article discusses current knowledge relating to the effects of stress on cuticular waxes and the ways in which the wax provides protection against the deleterious effects of light, temperature, osmotic stress, physical damage, altitude and pollution. Topics covered here include biosynthesis, morphology, composition and function of cuticular waxes in relation to the effects of stress, and some recent findings concerning the effects of stress on regulation of wax biosynthesis are described.

Contents

Summary
469

I
Introduction
470

II
Biosynthesis of cuticular wax
470

III
Deposition and crystalline morphology of cuticular wax
474

IV
Cuticular wax as a photoprotective layer
475

V
Effects of irradiation and temperature on cuticular wax composition
478

VI
Contact angles and wettability
481

VII
Humidity effects
482

VIII
Water, salinity and cold stress
482

IX
Mechanical stress
485

X
Altitude
486

XI
Pollution
486

XII
Genetic and environmental control of cuticular wax production
488

XIII
Conclusions
493

Acknowledgements
493

References
493
Globalized Horticulture: The Formation and Global Integration of Export Grape Production in North East Brazil
Authors: SELWYN BEN
Published: September 2010

In horticulture contemporary globalization is associated with (at least) two connected processes – the concentration, centralization and expanding reach of global retailers and the emergence of numerous new sites of export horticulture specializing in fresh fruit and vegetable production aimed at metropolitan markets. Whilst there have been numerous studies about developmental impacts, conditions of labour, and producers' upgrading strategies within this new context, few studies give much, if any, space to explaining and analyzing the processes through which these new regions have come into being. This article provides a detailed account of the emergence and global integration of one of these new sites – the São Francisco valley grape branch in North East Brazil, within the context of the wider regional fruiticulture sector. It focuses on state activities and incentives, the provenance of grape producers and their organizations, and grape branch composition.
Review Essay: Land, Labour and Agrarian Transition in Vietnam
Authors: AKRAM‐LODHI A. HAROON
Published: September 2010

Martin Ravallion and Dominique van de Walle argue that growing landlessness in Vietnam is a function of people capitalizing on the higher returns to education witnessed in wage labour when compared with farming. So, growing landlessness is a sign of economic success. This review argues that Ravallion and van de Walle misconstrue landlessness, misinterpret the associated data and downplay the constraints facing rural Vietnamese. In so doing, they fail to capture the complex realities of Vietnam's agrarian transition.
Signaling pathways of isoproterenol‐induced ERK1/2 phosphorylation in primary cultures of astrocytes are concentration‐dependent
Authors: Du Ting , Li Baoman , Li Hongmei , Li Min , Hertz Leif , Peng Liang
Published: September 2010

J. Neurochem. (2010) 115, 1007–1023.

Stimulation of β‐adrenoceptors activates the canonical adenylate cyclase pathway (via Gs protein) but can also evoke phosphorylation of extracellular‐regulated kinases 1 and 2 (ERK1/2) via Gs/Gi switching or β‐arrestin‐mediated recruitment of Src. In primary cultures of mouse astrocytes, activation of the former of these pathways required micromolar concentrations of the β1/β2‐adrenergic agonist isoproterenol, that acted on β1‐adrenoceptors, whereas the latter was activated already by nanomolar concentrations, acting on β2 receptors. Protein kinase A activity was required for Gs/Gi switching, which was followed by Ca2+ release from intracellular stores and Giα‐ and metalloproteinase‐dependent transactivation of the epidermal growth factor receptor (EGFR; at its Y1173 phophorylation site), via its receptor‐tyrosine kinase, β‐arrestin 1/2 recruitment, and MAPK/ERK kinase‐dependent ERK1/2 phosphorylation. ERK1/2 phosphorylation by Src activation depended on β‐arrestin 2, but not β‐arrestin 1, was accompanied by Src/EGFR co‐precipitation and phosphorylation of the EGFR at the Src‐phosphorylated Y845 site and the Y1045 autophosphorylation site; it was independent of transactivation but dependent on MAPK/ERK kinase activity, suggesting EGFR phosphorylation independently of the receptor‐tyrosine kinase or activation of Ras or Raf directly from Src. Most astrocytic consequences of activating either pathway (or both) are unknown, but morphological differentiation and increase in glial fibrillary acidic protein in response to dibutyryl cAMP‐mediated increase in cAMP depend on Gs/Gi switching and transactivation.
Macrophage‐colony stimulating factor as an inducer of microglial proliferation in axotomized rat facial nucleus
Authors: Yamamoto Shinichi , Nakajima Kazuyuki , Kohsaka Shinichi
Published: September 2010

J. Neurochem. (2010) 115, 1057–1067.

We analyzed the mechanism of microglial proliferation in rat axotomized facial nucleus (axotFN). In immunoblotting analysis for possible mitogens, we noticed that the amounts of macrophage‐colony stimulating factor (M‐CSF) increased in the axotFN for 3–7 days after transection. In contrast, the amounts of granulocyte macrophage‐CSF and interleukin‐3 did not significantly increase. A potential source for M‐CSF was immunohistochemically verified to be microglia. Immunoblotting showed that the amounts of receptor for M‐CSF (cFms) increased in the axotFN for 3–14 days after injury, and immunohistochemical staining showed that cFms is expressed in microglia. Proliferating cell nuclear antigen as a marker of proliferation was immunohistochemically identified in microglia in axotFN, and the level was found to peak 3 days after transection in immunoblotting. Hypothesizing that up‐regulated M‐CSF triggers the above phenomena, we investigated the effects of M‐CSF on cFms and proliferating cell nuclear antigen levels in primary microglia. The biochemical experiments revealed that M‐CSF induces cFms and drives the cell cycle in microglia. The neutralization of M‐CSF in microglia derived from axotFN significantly reduced the proliferation. These results demonstrate that up‐regulated M‐CSF triggers the induction of cFms in microglia and causes the microglia to proliferate in the axotFN.
Ganglioside‐mediated aggregation of amyloid β‐proteins (Aβ): comparison between Aβ‐(1–42) and Aβ‐(1–40)
Authors: Ogawa Mariko , Tsukuda Miho , Yamaguchi Takahiro , Ikeda Keisuke , Okada Takuma , Yano Yoshiaki , Hoshino Masaru , Matsuzaki Katsumi
Published: September 2010

J. Neurochem. (2011) 116, 851–857.

Conversion of the soluble, non‐toxic amyloid β‐protein (Aβ) into an aggregated, toxic form rich in β‐sheets is considered a key step in the development of Alzheimer’s disease. Accumulating evidence suggests that lipid rafts in membranes play a pivotal role in this process. We have proposed that Aβ‐(1–40) specifically bound to a ganglioside cluster forms cytotoxic fibrils via a conformational transition from an α‐helix‐rich structure to a β‐sheet‐rich one. In the present study, we compared the interaction of Aβ‐(1–40) and Aβ‐(1–42) with both model and living cell membranes. Aβ‐(1–42) exhibited lipid specificity and affinity similar to Aβ‐(1–40), though its amyloidogenic activity was more than 10‐fold that of Aβ‐(1–40). Antibody staining experiments, using the A11 antibody specific to Aβ oligomers, demonstrated that oligomers were not detected during the aggregation process, and cell death was observed only after significant accumulation of the proteins, suggesting that the fibril‐induced disruption of cell membranes leads to the cytotoxicity. Furthermore, we succeeded in visualizing fibrils formed on cell membranes using total internal reflection fluorescence microscopy. Aβ‐(1–40) formed long fibrils extruding to the aqueous phase, whereas Aβ‐(1–42) fibrils appeared to be laterally co‐assembled and short.
Iranian nursing students’ comprehension and experiences regarding evaluation process: a thematic analysis study
Authors: Vaismoradi Mojtaba , Parsa‐Yekta Zohreh
Published: September 2010

Scand J Caring Sci; 2011; 25; 151–159
 
Iranian nursing students’ comprehension and experiences regarding evaluation process: a thematic analysis study

In this study, a qualitative design based on a thematic analysis approach was employed to explore the comprehension and experiences of Iranian nursing students regarding evaluation process in both classroom and clinical setting. After utilising purposeful sampling to choose 13 bachelor’s degree nursing students, semi‐structured interviews were held for data gathering. During the data analysis, three main themes emerged: ‘definition of evaluation process’, ‘unfair evaluation’ and ‘ideal evaluation’. The second theme consisted of two sub‐themes: ‘problematic process’ and ‘unexpected outcome’. Our study findings showed a gap between what Iranian nursing students depicted as a fair and equitable evaluation and what they experienced during their academic career. There is a need to bring a change to process of evaluation to increase the feeling of fairness and justice regarding evaluation among nursing students. The findings can be helpful for international nurse instructors to be exposed to the unheard perspectives of nursing students and reconsider the weaknesses of evaluation process conducted by them.