bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of free intracellular Ca2+ during synaptic and spike activity of cricket tibial motoneurons
Authors: Baden Tom , Hedwig Berthold
Published: March 2009

For all nervous systems, motoneurons are the main output pathway. They are involved in generating episodic motor activity as well as enduring motor rhythms. To determine whether changes in cytosolic Ca2+ correlate with motor performance, we studied the spatiotemporal dynamics, mode of entry and role of free intracellular Ca2+ in cricket (Gryllus bimaculatus) front leg tibial extensor and flexor motoneurons. Synaptic activation or intracellular depolarising current injection uniformly increased Ca2+ with the same dynamics throughout the primary and secondary branches of the dendritic tree of all motoneurons. Ca2+ rise times (mean τrise, 233–295 ms) were lower than decay times (mean τdecay, 1927–1965 ms), and resulted in a Ca2+ plateau during repetitive activation, such as during walking. The neurons therefore operate with a different Ca2+ level during walking than during episodic leg movements. Ca2+ enters the dendritic processes of motoneurons via a voltage‐activated mechanism. Entry is driven by subthreshold excitation, and is largely independent of the neurons’ spiking activity. To what extent ligand‐activated mechanisms of Ca2+ entry operate remains uncertain. We found no evidence for any prominent Ca2+‐activated secondary currents in these motoneurons. Excitatory postsynaptic potentials evoked by extracellular stimulation of descending neurons were unaffected by the level of free intracellular Ca2+. The activity of tibial motoneurons therefore appears to be only weakly dependent on the level of free intracellular Ca2+ in dendrites. This is different to what has been found for many other neurons studied, and may represent an essential prerequisite for insect motoneurons to support a wide range of both episodic and rhythmic motor sequences underlying behaviour.
Dynamic Capabilities, Government Policies, and Performance in Firms from Emerging Economies: Evidence from India and Pakistan
Authors: Malik Omar R. , Kotabe Masaaki
Published: March 2009

abstract

In this study we developed a model of the dynamic capability development mechanisms in Emerging Market manufacturing Firms (EMF). We identified three dynamic capability development mechanisms: organizational learning, reverse engineering, and manufacturing flexibility. We generated hypotheses based on this framework, linking these mechanisms with firm performance. We also modelled the roles played by managerial use of two types of government policies: input supporting policies and marketing supporting policies. We tested our hypotheses on a sample of Indian and Pakistani manufacturing firms. Results showed that organizational learning, reverse engineering and manufacturing flexibility had significant impacts on EMF performance. Additionally, organizational learning combined with input supporting government policies enhanced performance, and the combination of manufacturing flexibility and marketing supporting government policies had an insignificant influence on performance.
Governance, Negotiations, and Alliance Dynamics: Explaining the Evolution of Relational Practice
Authors: Ness Håvard
Published: March 2009

abstract

This paper explores relational practice in strategic alliances. Focusing on how governance mechanisms and negotiation strategies evolve and form patterns of interaction that are under influence of both recursive and adaptive forces, four modes of relational practice are discussed: recursively integrative, recursively distributive, adaptive toward integrative, and adaptive toward distributive. Three longitudinal cases are examined. I find that different contractual conditions enable (or restrain) interaction patterns. Negotiation behaviour, in turn, affects future contractual conditions and their combination and recombination form the evolution of relational practice. As relationships progress, initial governance mechanisms are complemented and negotiation behaviours change. I explain how perceptions of both process and relational outcomes influence relational practice. In addition, I explicate why relational practices have both recursive and adaptive characteristics, and identify conditions that cause relational practices to move towards more integrative or distributive modes.
Bridging the Rigour–Relevance Gap in Management Research: It's Already Happening!
Authors: Hodgkinson Gerard P. , Rousseau Denise M.
Published: March 2009

abstract

Kieser and Leiner (2009) maintain that the rigour–relevance gap in management research is fundamentally unbridgeable because researchers and the researched inhabit separate social systems. They argue that it is impossible to assess the relevance of research outputs within the system of science and that neither action research nor related approaches to collaborative research can succeed in producing research that is rigorous as well as relevant. In reply, we show how their analysis is inconsistent with available evidence. Drawing on a diversity of management research domains, we provide counter‐illustrations of work where researchers, in a number of cases in collaboration with practitioners, have generated knowledge that is both socially useful and academically rigorous.
The Read-Recite-Review Study Strategy
Authors: McDaniel Mark A. , Howard Daniel C. , Einstein Gilles O.
Published: March 2009

Two experiments with college students investigated the effectiveness of the 3R (read-recite-review) strategy for learning from educational texts. The 3R strategy was compared with rereading and note-taking study strategies using free-recall, multiple-choice, and short-answer inference tests immediately after study and after a 1-week delay. In Experiments 1 and 2, 3R improved immediate and delayed free recall of fact-based passages, relative to the rereading and note-taking strategies. In Experiment 2 , which used longer, more complex passages on engineering topics, performance on multiple-choice and problem-solving items was better in the 3R than in the rereading condition, and was equivalent in the 3R and note-taking conditions, though 3R took less study time than note taking. An inherent advantage of 3R relative to other testing methods for improving learning is that 3R is under the learner's control. These results indicate that it is also an efficacious study technique that capitalizes on the mnemonic potency of retrieval and feedback.
Trade, Tariffs and Total Factor Productivity: The Case of Spanish Firms
Authors: Dovis Marion , Milgram‐Baleix Juliette
Published: March 2009

The aim of this paper is to examine the sensitivity of total factor productivity (TFP) to foreign competition in the case of a European country. Using the Olley and Pakes method, we calculate the TFP of Spanish manufacturing firms and study the impact of EU tariffs and the presence of foreign products and imports on TFP at the firm level. Applying the System‐GMM method, we find that TFP is negatively impacted by European tariffs, whereas competition in the form of the increased presence of foreign products in the domestic market and firm imports leads to improvements in the TFP. Moreover, these two effects are complementary. We also find evidence of important asymmetries among firms depending on their involvement in foreign markets.
Predatory versatility in a larval dragonfly, Hemianax papuensis (Odonata: Aeshnidae)
Authors: ROWE R. J.
Published: March 2009

Larvae of the large dragonfly Hemianax papuensis used four disparate, prey‐specific predatory behaviours. Arthropod prey moving on a substratum were stalked and then attacked from a distance. Arthropod prey moving in the water column or at the water surface were approached using ‘jet’ propulsion and then attacked from a distance. Snails, an unusual prey for an arthropod, were stalked; then the larva manoeuvred about them until a specific orientation was achieved before an attack was made from close range. Dead snails were scavenged, using tactics very similar to those used with live snails, but non‐snail carrion was rarely taken. There was no evidence that the possession, by H. papuensis, of specialized behaviours for an atypical prey‐snails‐lowered its success when attacking other types of ‘typical’ prey.
The impact of locomotor energetics on mammalian foraging
Authors: ALTMANN S. A.
Published: March 2009

The ecological impact of energy expended on an activity stems from its effect on foraging requirements. For locomotion, the effect of moving each additional unit distance probably depends on the proportional increase in energy expenditure. Other common measures of the cost of locomotion do not reflect the impact of energy expenditure on foraging requirements. In terrestrial mammals, both the effect of body mass and the unit cost itself are very small: moving one kilometre requires less than 2% of all other energy expenditures combined. Total locomotor energy expenditure ranges from 1/2% of daily metabolism for a 10 g mammal to 6% for an elephant. Potential sources of bias in the estimation of these costs include systematic bias in estimates of distance traversed and extra energy required for non‐linear locomotion. Because larger mammals can readily locomote at greater speeds, the primary locomotor advantage of large size may not be conservation of energy but of time, which can mean greater safety and more or better food.
Supernumerary teeth in Lynx lynx and the irreversibility of evolution
Authors: WERDELIN LARS
Published: March 2009

Supernumerary dental elements have been reported in Lynx lynx by several authors. These features have been given different evolutionary interpretations by different commentators. I note here that, since these features are absent in the plesiomorphic sister‐groups of L. lynx, they represent a true evolutionary reversal. If they were simply a retention of an evolutionarily older phenotype, we should expect to see them developed in at least one plesiomorphic sister‐group. Such development of a previously hidden character can occur if it is genetically linked to features selected for, until it becomes phenotypically expressed, whereupon selection can act on the character itself. Since Dollo's law, which is the theoretical issue behind the present discussion, is not a law, but a rule, and, like all rules based on probabilities, we should expect to find exceptions in the fossil record. Such exceptions are not rare, but few are as spectacular as the present one, in which the redeveloped feature is at least phenotypically identical with one which has been lost in the Felidae since the Miocene.
Case design, construction and ontogeny of building in Glyphotaelius pellucidus caddisfly larvae
Authors: ROWLANDS M. L. J. , HANSELL M. H.
Published: March 2009

Comparison was made of original and rebuilt cases of mature Glyphotaelius pellucidus (Retzius) (Trichoptera: Limnephilidae) larvae, and the procedure of case building was observed. A long‐term case‐building observation (1973 hours) was made to discover how cases change after the time in which building of a new case appears to cease. Ontogenetic changes in building procedure were observed in a sample of larvae reared to maturity from eggs. Examination was made of the technique of cutting single leaf discs. Finally, changes to cases prior to pupation were found through examination of pupal cases. The building trials led first to knowledge of the case design and building technique of mature larvae. Definitive cases have two walls of leaf discs covering side walls of small leaf panels. Like other case‐building caddis, all larvae made naked will first construct a rough preliminary case of panels, which is replaced by the typical case of discs and panels. This definitive style occurs in all larval instars. Across larval instars, size is the only major difference between cases. By stadium two (of five), the quality of leaf pieces cut by larvae has virtually reached its peak. During the building of a single case by an at first naked larva, it is observed that both leaf piece size and quality improve steadily, with an upward step coinciding with the point at which provisional style changes to the definitive style. For a naked larva, the need for a case evidently has a high priority. The rate of building is most rapid during the initial body covering. Not until after the change to definitive style does the rate decline and are activities such as feeding allowed. These case‐building experiments shed light upon development of the building control system in Glyphotaelius throughout larval ontogeny. Case attributes can be broken down into three features–size, quality and procedure. Procedurally, the building mechanism is constant, but apparent adjustments to that part of the control scheme that directs qualitative aspects of building results in size increase and a gradual improvement in the quality of leaf pieces cut.
Reproductive biology of the intertidal spider Desis marina (Araneae: Desidae) on a New Zealand rocky shore
Authors: MCLAY C. L. , HAYWARD T. L.
Published: March 2009

Desis marina is an intertidal spider which lives within rock crevices and cavities in the holdfasts of the brown kelp Durvillaea antarctica, where it is submerged in the sea for long periods. Spiders live within silk‐lined retreats which enclose an air bubble, and mate location is restricted to periods when the nest is exposed to the air. Eggs are laid from September to January and emergence is complete by May, with the major recruitment period being from March to April. During June to August, females are reproductively inactive. Egg development requires two months and the first two instars remain in the nest for a further two months. Number of egg sacs laid is independent of female size but number of eggs per sac increases with size. Egg size and number of eggs per sac is independent of brood sequence. Female reproductive investment is only 17–6% of body weight, but with 3 to 4 egg sacs/female, nest‐guarding time is in excess of five months. Females reproduce only once per year and may reproduce again in the following summer. Desis marina has a much lower clutch size than comparable terrestrial spiders and is a ‘bet‐hedger’, producing sequential broods which spread recruitment over time and reduce the risk of total loss due to storms.
The wound healing and haemocyte response in the skin of the lesser octopus Eledone cirrhosa (Mollusca: Cephalopoda) in the presence of Vibrio tubiashii
Authors: BULLOCK A. M. , POLGLASE JANE L. , PHILLIPS SHEILA E.
Published: March 2009

The sequential response of wound closure in the skin of the lesser octopus Eledone cirrhosa is described following experimentally induced infections by the Gram‐negative bacterium, Vibrio tubiashii. Results show that the post‐infection healing response varied considerably from the response observed in non‐infected wounds reported previously. Prominent among the findings was the much more extensive haemocyte response noted throughout healing when compared with non‐infected wounds. In addition, there was a generalized inhibition of epidermal migration so that wound closure was never completed during the experiment. The presence of a ‘double tier’ amorphous zone was evident at certain stages of the healing response and the implications of this finding in relation to post‐infection wound closure is discussed.
Weights of salivary glands in some ruminant animals
Authors: KAY R. N. B.
Published: March 2009

The main paired salivary glands were dissected from Blackbuck, Chinese water deer, Reeves' muntjac and Red deer. The parotid glands, which have an important role in regulating ruminal digestion, were heaviest relative to body weight in the species (water deer and Muntjac) that naturally select the most digestible diet.
Some principles of ligament function, with examples from the tarsal joints of the sheep (Ovis aries)
Authors: ALEXANDER R. McN. , BENNETT M. B.
Published: March 2009

The effects of ligaments, in limiting or controlling movement, depend on the positions of their attachments relative to the axes of joints. Such effects are explored in a theoretical section, which considers ligaments that cross a single, congruent hinge joint; ligaments that cross two congruent hinge joints; and non‐congruent hinge joints controlled by crossed ligaments. The principles derived in the theoretical section are used to explain the complex mechanism of the sheep tarsal joints.
Crab and mollusc shell drilling by Octopus vulgaris (Mollusca: Cephalopoda) in the Ria de Vigo (north‐west Spain)
Authors: GUERRA A. , NIXON MARION
Published: March 2009

Octopus vulgaris living in the Ria de Vigo, north‐west Spain, sometimes drills a cavity in the carapace of crabs and shells of molluscs. These holes have features with the same characteristics as those made in molluscs by O. vulgaris and in crabs by Eledone cirrhosa when isolated in aquaria. This is the first report of drilling the carapace of crabs by Octopus vulgaris.
Fast locomotion of some kangaroos
Authors: Bennett M. B.
Published: March 2009

Five species of Macropodidae were filmed, hopping across level ground. They ranged in size from potoroo (about 0.5 kg) to eastern grey kangaroo (about 60 kg). Animals were pursued to make them hop as fast as possible. Analysis of film enabled speeds, stride lengths, stride frequencies, duty factors and Froude numbers to be determined. These are discussed in relation to body size.
Annual testicular cycle in captive budgerigars (Melopsittacus undulatus)
Authors: Samour J. H. , Moore H. D. M. , Bailey I. T. , Watson P. F.
Published: March 2009

Captive male budgerigars housed as a homosexual group, with a constant daily light period of 14 h/24 h, visually isolated but in vocal contact with other budgerigars of both sexes, showed some gonadal structural changes throughout the year. Testicular regression was not as marked as that shown in wild, non‐breeding budgerigars subjected to natural daylength changes. Production of spermatozoa occurred only four times during the year with alternate periods of sexual inactivity. During the latter, the body weight decreased, the cere colour changed to a pale blue and the birds moulted more heavily.
The gonadal anatomy and sexual pattern of the protandrous sex‐reversing fish, Rhabdosargus sarba (Teleostei: Sparidae)
Authors: Yeung W. S. B. , Chan S. T. H.
Published: March 2009

The gonadal anatomy and sexual pattern of Rhabdosargus sarba (Teleostei: Sparidae) was studied to provide some basic structural information for the subsequent investigations on the endocrinology of protandrous hermaphroditism in this fish. Evidence derived from relating sex to differences in body size, from gonadal histology and from biopsy, revealed the occurrence of natural sex reversal from male to female in this species. The gonad of R. sarba possessed topographically distinct male and female zones that were well separated by connective tissue. Based on gross‐anatomical and histological observations, four types of gonad were distinguished and were designated as Types I‐IV in the present study. Active spermatogenetic tissue was present in the Type I, II and IV gonads. Dormant oogonia and perinucleolar oocytes were found in the Type I (male) and II (intersex) gonads, respectively. In the Type III (female) gonad, a functional ovarian zone was observed and the testicular tissue was vestigial. The existence of ovarian tissue as an oogonial band in the Type IV (male) gonad, which was found more commonly in large specimens, suggested that these functional males might not undergo sex reversal in their life cycle. The interrelationship of the different types of gonad is discussed with reference to protandrous hermaphroditism.
The demography and physiology of Melomys sp. (Rodentia: Muridae) in the Mitchell Plateau area, Kimberley, Western Australia
Authors: Kemper C. M. , Kitchener D. J. , Humphreys W. F. , How R. A. , Bradley A. J. , Schmitt L. H.
Published: March 2009

Populations of a mosaic‐tailed rat (Melomys sp.) were studied for one year in vine‐thicket and mangrove habitats in the Mitchell Plateau area of the tropical Kimberley district of Western Australia. Demographic and physiological (haematological values, androgens, corticosteroids and their binding proteins) parameters were measured together with parasite prevalence and electrophoretic protein variation. Seasonal variation occurred in most parameters measured. Higher values were found in the vine‐thicket for number of sympatric mammal species, growth rate of immatures and androgens. Higher values were found in the mangroves for population density, survival, size at sexual maturity, body weight, home range overlap, albumins, total and free‐corticosteroids and parasite prevalence. The phenotypic frequencies of two protein polymorphisms (albumin and 6–phosphogluconate dehydrogenase) differed between sites, while a third (adenosine deaminase) showed no between‐site differences; these suggest differential selection between the adjacent habitats which are separated by 10 km. The overall physiological response of Melomys was more entrained to seasonal variation in the vine‐thicket than in the mangroves, which is in accord with the relative variation in the vegetation and temperature in the two areas. It is hypothesized that the greater population density in the mangroves results in behavioural feedback through the hypothalamo‐pituitary‐adrenal axis. This results in increased stress (higher free‐corticosteroid levels) which slows the growth rate and the onset of sexual maturity. The study is the first to indicate that such a mechanism, commonly proposed for temperate small mammals, may operate in tropical areas.
Inherited differences within an island population of the House mouse (Mus domesticus)
Authors: BERRY R. J. , JAKOBSON M. E. , PETERS J.
Published: March 2009

Although geneticists now accept that much allozymic variation is adaptive, ecologists tend to ignore all non‐visible variation; in practice they treat inherited variation as if it was neutral. Studies on the House mice of Skokholm Island, Wales have shown that strong natural selection may operate under conditions where the animals are physiologically stressed (particularly by cold). The resulting genetic changes mean that the genetic constitution of the population can change considerably over periods of a few months; this seems likely to be the reason why physiological traits which affect survival in one year are poor predictors of survival in another year. Morphometric and haematological traits are associated with variation at some allozymic loci (especiallyHbb); although such traits directly affect phenotypes, their changes with time are complex. Any full description of the ecological response of a population to a variable environment clearly requires a better understanding of adaptation and gene‐environment interactions than exists at the moment; deterministic models and those assuming equilibrium seem to be inappropriate.
Grey seal, Halichoerus grypus, energetics: females invest more in male offspring
Authors: ANDERSON SHEILA S. , FEDAK MICHAEL A.
Published: March 2009

Grey seal females transfer large amounts of energy to their pups during the brief lactation period. The costs of lactation have been measured using weight changes of mother and pup pairs. Large females come ashore to give birth earlier in the season and lose weight more rapidly than smaller females. The sex ratio of Grey seal pups born is skewed towards males in the early part of the breeding season. Male pups are larger at birth and gain weight more rapidly than female pups, and their mothers show a correspondingly faster rate of weight loss than mothers of female pups. The energy costs of gestation and lactation to a Grey seal mother are 31 GJ for male pups and2–8 GJ for female pups. Males are therefore 10% more costly in energy terms to raise to weaning. Because, on average, large females arrive at breeding sites before smaller animals, biased results on weight changes would be obtained from methods which do not use repeated weighings. We suggest that the high efficiencies of lactation estimated for Harp seals compared with other phocid seals could be accounted for by such a bias.
Surface sculpturing and water retention of elephant skin
Authors: LlLLYWHITE H. B. , STEIN B. R.
Published: March 2009

The integument of elephants is highly sculptured with wrinkles and crevices arranged in prominent geometric patterns. These features are shown to adsorb water and to facilitate its movement over the body surface. The retention of water attributable to epidermal morphology was quantified by studying latex casts of integumentary surfaces. Retention of water by casts of integument is4–5 to 10 times greater than that of flat surfaces and is greater in African elephants than in Asian elephants. Both species lack sebum and sweat glands and require regular wetting of their skin. However, the skin of African elephants is sculptured more deeply and retains significantly more water than does that of Asian elephants adapted to more mesic habitats. We propose that the highly sculptured morphology functions to enhance retention of surface moisture during periodic wallowing, thereby impeding dehydration of the exposed epidermis and mediating evaporative heat losses. These functions could have great physiological significance during periods of drought when intense heat and solar radiation coincide with limited availability of water.
Age and sex differences in the timing of moult in the common seal, Phoca vitulina
Authors: Thompson P. , Rothery P.
Published: March 2009

This study followed the progress of the annual moult within a population of common seals in Orkney, Scotland. Moulting seals were seen over a three‐month period, from 7 June until 16 September. Yearlings were first to start moulting. Amongst older seals, females completed their moult an average of seven days earlier than immature males and 19 days earlier than mature males. Differences in the timing of moult appeared to be related to the age or reproductive status of the animals, and may be the result of differential changes in levels of the sex hormones.
EMG of chimpanzee shoulder muscles during knuckle‐walking: problems of terrestrial locomotion in a suspensory adapted primate
Authors: Larson Susan G. , Stern Jack T.
Published: March 2009

By most accounts, the upper limb of the chimpanzee is primarily adapted to suspensory postures and locomotion. In order to determine how the derived morphology of the chimpanzee forelimb has affected the form of quadrupedal locomotion displayed by these animals, electromyographic activity patterns of 10 shoulder muscles during knuckle‐walking in two chimpanzee subjects were analysed and compared to data on the opossum and cat taken from the literature. Telemetered electromyography coupled with simultaneous video recording was employed in order to study unfettered locomotion in the chimpanzee subjects.

Chimpanzees are characterized by a quadrupedal gait in which the hind limb overstrides the ipsilateral forelimb. Forelimb position in the plane of abduction/adduction is significantly affected by whether the hind limb passes inside or outside its ipsilateral forelimb. The degree of abduction adduction of the forelimb, in turn, influences many of the muscle activity patterns. That is, some muscles would be more frequently or less frequently active, depending on whether the arm was relatively abducted or adducted during a stride. Thus, there can be no single motor programme that generates the step cycle in chimpanzees.

While there are some parallels between muscle recruitment patterns for chimpanzee, opossum and cat quadrupedalism, the results of this study also indicate that many aspects of muscle use in chimpanzees have been significantly influenced by factors related to increased mobility of the upper limb. Finally, this study has revealed that moving the arm forward during swing phase of knuckle‐walking is not a simple product of muscular elTort. and that other mechanisms must be involved. However, it is unclear at present exactly what these mechanisms may be.
Testing historical phylogeographic inferences with contemporary gene flow data: population genetic structure of the Qinghai toad‐headed lizard
Authors: Wang Y. , Zhan A. , Fu J.
Published: March 2009

Using data from 11 microsatellite DNA loci and a population genetic approach, the phylogeographic patterns of the Qinghai toad‐headed lizard Phrynocephalus vlangalii revealed by mitochondrial DNA (mtDNA) were tested and the congruence between the nuclear and mitochondrial genes was examined. Both analysis of molecular variance (AMOVA) and BARRIER analyses suggested that the Arjin and the A'nyemaqen Mountains were significant genetic barriers to contemporary gene flow of the P. vlangalii populations. On the other hand, the Qaidam populations, where no major mountains are present, showed a weak but significant isolation by distance pattern. The patterns of population genetic structure were largely congruent with the phylogeographic patterns inferred from the mtDNA, and therefore, supported the hypothesis that the uplift of the Arjin and the A'nyemaqen Mountains caused the initial vicariant events that led to the formation of the diverged lineages within P. vlangalii. The only major difference between the mtDNA and nuclear DNA (nuDNA) results was the allocation of variance to different hierarchical levels in AMOVA. While the among group component, which were defined by mountains, accounted for most of the mitochondrial variance (81.73%), most of the nuDNA variance was at the among individuals within population level (83.69%). Differences in effective population sizes, social structure and male/female dispersal patterns might have contributed to the discrepancy.
Agricultural Land, Gender and Kinship in Rural China and Vietnam: A Comparison of Two Villages
Authors: BÉLANGER DANIÈLE , LI XU
Published: March 2009

This study examines the impact of current land policies in China and Vietnam on women's entitlement to land, women's wellbeing and gender power relations. The ethnographic study of one village in each of the two countries contextualizes women's lives in the kinship and marriage system in which power and gender relations are embedded. Current land policies, when implemented in the existing kinship and marriage system, make women's entitlement to land more vulnerable than men's, limit women's choices and weaken their power position. Variations in kinship rules in the two countries lead to different outcomes. In the Chinese village the dominance of patrilocal marriage and exogamous marriages limits women's access to land, whereas in the Vietnamese village the rigid concentration of inheritance to males puts women in a difficult position. The comparison between communities of rural China and Vietnam reveals the importance of considering gender and kinship when studying the implementation and impact of land policies.
Global Food Chains, African Smallholders and World Bank Governance
Authors: AMANOR KOJO SEBASTIAN
Published: March 2009

This paper critically examines the World Bank's analysis of the development of agribusiness in Africa in the World Development Report 2008 in relationship to its governance policies, which seek to introduce institutional reforms to promote private and public sector linkages with the participation of civil society. The paper argues that this confuses food chain governance (control over quality and the logistics of production) with democratic governance and essentially promotes oligopolization of the food industry and the interests of the powerful in the name of smallholder farmers.
BAG‐1M is up‐regulated in hippocampus of Alzheimer’s disease patients and associates with tau and APP proteins
Authors: Elliott Evan , Laufer Offir , Ginzburg Irith
Published: March 2009

The accumulation of tau and amyloid beta proteins is the major molecular pathology of Alzheimer’s disease (AD). The mechanisms leading to the accumulation of these proteins are not completely clear. Hsc‐70/Hsp‐70, a chaperone protein, has been shown to bind both these proteins and regulate their degradation. We have previously shown that the co‐chaperone protein BAG‐1 can inhibit the degradation of tau by forming a complex with Hsc‐70 and tau. In this current work, we show that there is an increase in the BAG‐1M isoform in the hippocampus of AD patients. In addition, BAG‐1 binds to both tau and amyloid precursor protein physically, and is found highly expressed in the same neurons that contain intracellular tau or amyloid in hippocampal sections from AD patients. Over‐expression of BAG‐1M in cell culture also induced an increase in both tau and amyloid precursor protein levels. In conclusion, we report a specific increase of BAG‐1M in human AD patients, which is both physically and functionally associated to the two major molecular markers of AD.
Interleukin‐1β enhances nucleotide‐induced and α‐secretase‐dependent amyloid precursor protein processing in rat primary cortical neurons via up‐regulation of the P2Y2 receptor
Authors: Kong Qiongman , Peterson Troy S. , Baker Olga , Stanley Emily , Camden Jean , Seye Cheikh I. , Erb Laurie , Simonyi Agnes , Wood W. Gibson , Sun Grace Y. , Weisman Gary A.
Published: March 2009

The heterologous expression and activation of the human P2Y2 nucleotide receptor (P2Y2R) in human 1321N1 astrocytoma cells stimulates α‐secretase‐dependent cleavage of the amyloid precursor protein (APP), causing extracellular release of the non‐amyloidogenic protein secreted amyloid precursor protein (sAPPα). To determine whether a similar response occurs in a neuronal cell, we analyzed whether P2Y2R‐mediated production of sAPPα occurs in rat primary cortical neurons (rPCNs). In rPCNs, P2Y2R mRNA and receptor activity were virtually absent in quiescent cells, whereas overnight treatment with the pro‐inflammatory cytokine interleukin‐1β (IL‐1β) up‐regulated both P2Y2R mRNA expression and receptor activity by four‐fold. The up‐regulation of the P2Y2R was abrogated by pre‐incubation with Bay 11‐7085, an IκB‐α phosphorylation inhibitor, which suggests that P2Y2R mRNA transcript levels are regulated through nuclear factor‐κ‐B (NFκB) signaling. Furthermore, the P2Y2R agonist Uridine‐5′‐triphosphate (UTP) enhanced the release of sAPPα in rPCNs treated with IL‐1β or transfected with P2Y2R cDNA. UTP‐induced release of sAPPα from rPCNs was completely inhibited by pre‐treatment of the cells with the metalloproteinase inhibitor TACE inhibitor (TAPI‐2) or the phosphatidylinositol 3‐kinase (PI3K) inhibitor LY294002, and was partially inhibited by the MAPK/extracellular signal‐regulated kinase inhibitor U0126 and the protein kinase C inhibitor GF109203. These data suggest that P2Y2R‐mediated release of sAPPα from cortical neurons is directly dependent on a disintegrin and metalloproteinase (ADAM) 10/17 and PI3K activity, whereas extracellular signal‐regulated kinase 1/2 and PI3K activity may indirectly regulate APP processing. These results demonstrate that elevated levels of pro‐inflammatory cytokines associated with neurodegenerative diseases, such as IL‐1β, can enhance non‐amyloidogenic APP processing through up‐regulation of the P2Y2R in neurons.
Measurements and Calculations of the Width of the Fracture Process Zones on the Surface of Notched Concrete Beams
Authors: Skarżyński Ł. , Syroka E. , Tejchman J.
Published: March 2009

Abstract:  The paper presents the results of experimental and theoretical investigations of the width of the fracture process zone (FPZ) on the surface of notched concrete beams during quasi‐static three‐point bending. To measure two‐dimensional deformations on the surface of beams, a Digital Image Correlation (DIC) technique was used. Laboratory tests were performed with different notched concrete beams. The experiments were simulated with two different isotropic continuum crack models under two‐dimensional conditions: an elasto‐plastic and a damage one with non‐local softening.
Piezonuclear Neutrons From Brittle Fracture: Early Results of Mechanical Compression Tests1
Authors: Carpinteri A. , Cardone F. , Lacidogna G.
Published: March 2009

Abstract:  Neutron emission measurements by means of helium‐3 neutron detectors were performed on solid test specimens during crushing failure. The materials used were marble and granite, selected in that they present a different behaviour in compression failure (i.e. a different brittleness index) and a different iron content. All the test specimens were of the same size and shape. Neutron emissions from the granite test specimens were found to be of about one order of magnitude larger than the natural background level at the time of failure. These neutron emissions were caused by piezonuclear reactions that occurred in the granite, but did not occur in the marble. This is because of the fact that in granite the release rate of accumulated elastic energy ΔE exceeds the power threshold for the generation of piezonuclear reactions, Wstrong = 7.69 × 1011 W. Moreover, granite contains iron, which has been ascertained to be the most favourable element for the production of piezonuclear reactions when the nuclear interaction energy threshold, E0,strong = 5.888 × 10−8 J, is exceeded in deformed space‐time conditions.
Novel Approach of Semiconductor Manufacturing Process on Copper Dual Damascene Processes Integration
Authors: Weng C.‐J.
Published: March 2009

Abstract:  The performance of the manufacturing process in each of these areas determines the overall manufacturability of the process. As device geometries are reduced, understanding and minimising the sources of process‐induced defects is critical to achieving and maintaining high device yields. This paper presents a comprehensive investigation of a novel metrology on semiconductor process module integration and technology on optimal integrated lithography processes and solution to the problem of defects reduction on semiconductor wafer in sub‐micron processes integration. As dual damascene integration copper process is complicated and critical in semiconductor processes. It has been common knowledge that pattern collapse and missing of this process and numerous defects could be prevented by optimal the process module tuning. To investigate novel semiconductor process integration on deep pattern aspect ratio effects of sub‐micron semiconductor wafer BEOL (Back‐End‐Of‐Line) structure were included in this study. Moreover, the electrical device investigations of device checking were also included.
An Experimental Study of the Mechanical Behaviour of the ‘Conchyliates’ Shell‐Stone: Some Irregularities of the Size Effects
Authors: Kourkoulis S. K.
Published: March 2009

Abstract:  A detailed experimental study of the size effect, i.e. of the dependence of the mechanical properties on the size of the (self‐similar) specimens used for the laboratory tests is presented in this paper for the case of a relatively soft natural building stone called ‘conchyliates’ (shell‐stone). ‘Conchyliates’ was used by ancient Greeks for the erection of the Zeus Temple at the Olympia archaeological site. The motive of the study was the need of the scientists working for a partial restoration of the monument for an in‐depth knowledge of the mechanical behaviour of both the original building material of the monument as well as of the material that could be used for the completion of damaged structural elements. During the study various classes of cylindrical ‘conchyliates’ specimens were subjected to uniaxial (unconfined) compression. It was concluded that the dependence of the peak stress of the material on the size of the specimen is not only very strong but it appears to be, also, non‐monotonous. In addition it was indicated that the size of the specimens also influences the elasticity modulus as well as the strain energy density in a more or less similar manner. On the contrary it is concluded that the slope of the strain energy density plotted versus strain is not seriously affected by the size of the specimen, at least for the working‐load portion of the stress‐strain graph.
Interpretation of Fringes Produced by Time‐Averaged Projection Moiré
Authors: Ragulskis M. , Navickas Z.
Published: March 2009

Abstract:  New exact formulas describing the observed shift of projected moiré grating lines on a surface of an object are derived for the paraxial model. These formulas enable to construct more accurate explicit relationship among the amplitude of oscillation, the pitch of the projected grating and the order of the fringe. Analytical derivations and numerical illustrations are used throughout the text to explain the process of formation of double‐exposure and time‐averaged projection moiré fringes.
Baicalin attenuates air embolism‐induced acute lung injury in rat isolated lungs
Authors: Li Min‐Hui , Huang Kun‐Lun , Wu Shu‐Yu , Chen Chien‐Wen , Yan Horng‐Chin , Hsu Kang , Hsu Ching‐Wang , Tsai Shih‐Hung , Chu Shi‐Jye
Published: March 2009

Background and purpose:  Baicalin has been reported to have anti‐inflammatory effects and protect against various tissue injuries. However, the effect of baicalin on air embolism‐induced acute lung injury has not been tested yet.

Experimental approach:  Acute lung injury was induced by infusion of air at a rate of 0.25 mL·min−1 for 1 min into the pulmonary artery of rat isolated lungs. At the end of the experiment, samples were collected for assessment of lung injury, biochemical analysis and histology. Different doses of baicalin (1, 2 and 4 mg·kg−1) were given into the perfusate before air infusion.

Key results:  Air embolism elicited a significant increase in microvascular permeability (Kf), lung weight gain, wet/dry weight ratio, pulmonary artery pressure and protein concentration in the bronchoalveolar lavage fluid. Levels of the cytokines, tumour necrosis factor α and cytokine‐induced neutrophil chemoattractant‐1 in perfusate, and malondialdehyde levels and myeloperoxidase activities in lung tissue were also significantly increased. In addition, histological examination showed increased neutrophil infiltration in lung tissues. Furthermore, nuclear factor‐κB activity and degradation of IκB‐α were significantly increased in lungs. Pretreatment of the lungs with baicalin (4 mg·kg−1) showed a statistically significant difference in all of the assessed parameters, except for alteration in the pulmonary artery pressure.

Conclusions and implications:  Our study suggests that baicalin attenuated air embolism‐induced acute lung injury and may be considered a useful adjunct drug therapy in this clinical condition.
Involvement of PKCα and G‐protein‐coupled receptor kinase 2 in agonist‐selective desensitization of µ‐opioid receptors in mature brain neurons
Authors: Bailey CP , Oldfield S , Llorente J , Caunt CJ , Teschemacher AG , Roberts L , McArdle CA , Smith FL , Dewey WL , Kelly E , Henderson G
Published: March 2009

Background and purpose:  The ability of an agonist to induce desensitization of the µ‐opioid receptor (MOR) depends upon the agonist used. Furthermore, previous data suggest that the intracellular mechanisms underlying desensitization may be agonist‐specific. We investigated the mechanisms underlying MOR desensitization, in adult mammalian neurons, caused by morphine (a partial agonist in this system) and DAMGO (a high‐efficacy agonist).

Experimental approach:  MOR function was measured in locus coeruleus neurons, by using whole‐cell patch‐clamp electrophysiology, in rat and mouse brain slices (both wild‐type and protein kinase C (PKC)α knockout mice). Specific isoforms of PKC were inhibited by using inhibitors of the receptors for activated C‐kinase (RACK), and in vivo viral‐mediated gene‐transfer was used to transfect neurons with dominant negative mutants (DNMs) of specific G‐protein‐coupled receptor kinases (GRKs).

Key results:  Morphine‐induced desensitization was attenuated by using RACK inhibitors that inhibit PKCα, but not by other isoform‐specific inhibitors. Further, the PKC component of morphine‐induced desensitization was absent in locus coeruleus neurons from PKCα knockout mice. The PKC‐enhanced morphine‐induced desensitization was not affected by over‐expression of a GRK2 dominant negative mutant (GRK2 DNM). In contrast, DAMGO‐induced MOR desensitization was independent of PKC activity but was reduced by over‐expression of the GRK2 DNM but not by that of a GRK6 DNM.

Conclusions and implications:  In mature mammalian neurons, different MOR agonists can induce MOR desensitization by different mechanisms, morphine by a PKCα‐mediated, heterologous mechanism and DAMGO by a GRK‐mediated, homologous mechanism. These data represent functional selectivity at the level of receptor desensitization.
Activation of iGluR5 kainate receptors inhibits neurogenic dural vasodilatation in an animal model of trigeminovascular activation
Authors: Andreou AP , Holland PR , Goadsby PJ
Published: March 2009

Background and purpose: Migraine is a disabling neurological disorder involving activation, or the perception of activation, of trigeminovascular afferents containing calcitonin gene‐related peptide (CGRP). Released CGRP from peripheral trigeminal afferents causes dilatation of dural blood vessel, and this is used to measure trigeminal nerve activation. Kainate receptors with the GluR5 subunit (iGluR5, ionotropic glutamate receptor) are present in the trigeminal ganglion and may be involved in nociception. We investigated the possible involvement of prejunctional iGluR5 kainate receptors on CGRP release from trigeminal afferents.

Experimental approach: We used neurogenic dural vasodilatation, which involves reproducible vasodilatation in response to CGRP release after electrical stimulation of the dura mater surrounding the middle meningeal artery. The effects of the specific iGluR5 receptor antagonist UBP 302 and agonist (S)‐(‐)‐5‐iodowillardiine were investigated on neurogenic and CGRP‐induced dural vasodilatation in rats, by using intravital microscopy.

Key results: Administration of 10 and 20 mg·kg−1of iodowillardiine inhibited electrically induced dural vessel dilatation, an effect blocked by pretreatment with 50 mg·kg−1UBP 302. Administration of the iGluR5 receptor antagonist UBP 302 alone had no significant effect. CGRP (1 mg·kg−1)‐induced dural vasodilatation was not inhibited by the iGluR5 receptor agonist iodowillardiine.

Conclusions and implications: This study demonstrates that activation of the iGluR5 kainate receptors with the selective agonist iodowillardiine is able to inhibit neurogenic dural vasodilatation probably by inhibition of prejunctional release of CGRP from trigeminal afferents. Taken together with recent clinical studies the data reinforce CGRP mechanisms in primary headaches and demonstrate a novel role for kainate receptor modulation of trigeminovascular activation.