bluuebunny/crossref_metadata_2025 huggingface dataset:
The Comparative Morphology of the Larval Ventromental Plates of Australasian Species of Kiefferulus Goetghebuer and Nilodorum Kieffer (Diptera, Chironomidae)
Authors: Webb CJ , Martin J
Published: June 2005

The morphology of larval ventromental plates of Australasian species of Kiefferulus Goetghebuer and Nilodorum Kieffer have been studied by light and scanning electron microscopy. The ventromental plates of all species studied were similar in their general pattern of micro-architecture, which incorporated a lamella-like system of striae and two marginal rows of spines on the inner surface. Information is presented on variation among species in plate features including size, shape, striae, and inner and outer rows of spines. Taxonomic implications of these data are discussed.
Phallic Morphology of Dasyuroides-Byrnei and Dasycercus-Cristicauda (Marsupialia, Dasyuridae)
Authors: Woolley PA
Published: June 2005

On the basis of phallic morphology Dasyuroides byrnei and Dasycercus cristicauda appear to be most similar to Dasykaluta rosamondae among the species of dasyurid marsupials which have been studied in this respect. The anatomy of the penis in all three appears to be primitive. Although the three species group together, there are differences in anatomy which suggest that there is no special relationship between any members of the group. This contrasts with the generally held view that D. byrnei and D. cristicauda are more closely related to each other than to D. rosamondae.
Logical Synthesis of an Animals Environment - Sponges to Non-Human Primates .6. The Chimpanzee, Pan-Troglodytes
Authors: Niven BS
Published: June 2005

The environment of the chimpanzee, Pan troglodytes, is classified according to the defining equations in the first paper of this series. An envirogram displaying objects in the environment in their correct place is presented. Notes on the envirogram include informal versions of the appropriate defining equations which are used for the classification.
Electromyography of the Stomach and Small-Intestine of the Tammar Wallaby, Macropus-Eugenii, and the Quokka, Setonix-Brachyurus
Authors: Richardson KC , Wyburn RS
Published: June 2005

Electromyographic activity recorded by chronically implanted bipolar electrodes showed the tammar wallaby (Macropus eugenii) and the quokka (Setonix brachyurus) to have slow wave activity over the entire stomach and small intestine. Slow wave mean frequency (min-') were: 5.5 and 5.3 for the forestomach; 5.4 and 5.0 for the pylorus; 26 and 17.8 for the duodenum; and 25 and 17.5 for the ileum in the tammar and quokka, respectively. There was virtually no frequency gradient of the slow wave along the length of the small intestine in both macropods, which is extremely unusual.
Action potentials were recorded from the quokka stomach but not from the tammar stomach. Action potentials were recorded from the small intestine of both species. The pattern of action potential activity was similar in both species. There were periods of up to 30 minutes during which the intestine was quiescent (q) with no action potential activity. This was followed by extended periods when bursts of action potentials occurred irregularly to be followed by periods of about 5 minutes when action potentials were associated with every slow wave.
Primary Genetic-Control of Sexual-Differentiation in Marsupials
Authors: Shaw G , Renfree MB , Short RV
Published: June 2005

Marsupials, like eutherians, normally require the presence of a Y chromosome for testicular formation. However some sexually dimorphic characters such as the scrotum, mammary anlagen, gubernaculum and processus vaginalis appear to be under direct genetic rather than secondary hormonal control. Scrota1 development occurs where only a single X chromosome is functional, whilst two X chromosomes are necessary for pouch formation.
Parasites of the Water Rat, Hydromys-Chrysogaster, From Victoria and South-Australia
Authors: Smales LR , Miller AK , Obendorf DL
Published: June 2005

Eighty-one H. chrysogaster from nineteen localities in Victoria and South Australia were examined for helminths. One acanthocephalan Corynosoma stanleyi: and one cestode, Hymenolepis diminuta, were found. Of the trematodes six were identified to species: Echinoparyphium hydromyos, Fibricola minor, F. intermedius, Microphaflus minutus, Maritrema oocysta and Plagiorchis jaenschi; two were placed in the families Heterophyidae, and Psilostomidae, both new locality records; and two new species Notocotylus sp. nov. and Paramonostomum sp. nov. were found. There were six nematode species: Synhimantus australiensis, Antechiniella suffodiax, Antechiniella sp., Woolleya hydromyos as well as Parastrongyloides sp. and a heteroxynematid both new host records. H. diminuta was the most prevalent helminth, with M. minutus and S. australiensis the most prevalent trematode and nematode respectively. A checklist of helminths from H. chrysogaster is given and comparisons between infections of Tasmanian, Victorian and South Australian hosts are made. Thirty-three of these water rats, trapped live in Victoria, were also examined for protozoa. Klossiella hydromyos, Toxoplasma gondii and Sarcocystis sp. were found. Twenty of the Victorian hosts were examined for ectoparasites. Three mites; Paraspeleognathopsis derricki, Murichirus parahydromys, and Radfordia sp.; one tick, Zxodes tasmani; one louse, Hoplopleura bidentata; and three flea species, Acanthopsylla rothschildi and Echidnophaga spp. were found.
The Biology of the Common Sheath-Tail Bat, Taphozous-Georgianus (Chiroptera, Emballonuridae), in Central Queensland
Authors: Jolly S
Published: June 2005

A field study was carried out over a 4-year period on the common sheath-tail bat, Taphozous georgianus, in central Queensland. Mating occurred in late August and early September, and females gave birth to a single young in late November or early December. Females mated at about 9 months of age. Spermatogenesis commenced in males at about 9 months but they were not able to take part in mating until they were approximately 21 months old. Bats were born well furred with their eyes open, and weighed an average of 24% of their mother's post-partum weight. Young bats attained independence at 3-4 weeks old when they reached 50% of their mothers' body weight. At 3 months old young bats were within a few millimetres of adult dimensions. Marked seasonal variations in body weight resulted from the deposition of fat. Peak weights were recorded in April and minimum weights in September. The mean annual survivial rate was estimated to be 0.61. Mature males have a mortality rate substantially greater than females and this is reflected in a sex ratio strongly biased towards females in older bats. The sex ratio was nearly even in young bats. Most roost caves were occupied by less than 20 individuals. There was little difference between the temperature and humidity at which bats roosted, and the temperature and humidity of available roosts. Most bats were known from only one cave, and few movements of more than 2 km were recorded. Bats appeared to regularly relocate their roosting site, however, and they may have been utilising roosts outside the study area.
Reproduction in the Western Pygmy-Possum, Cercartetus-Concinnus (Marsupialia, Burramyidae), With Notes on Reproduction of Some Other Small Possum Species
Authors: Ward SJ
Published: June 2005

The patterns of breeding and reproduction in Cercartetus concinnus were investigated through the histology of specimens in Australian museums, field observations in north-western Victoria, and published accounts. Histology of the reproductive tracts of museum specimens of female C. nanus, C. lepidus, Acrobates pygmaeus and Distoechurus pennatus was also undertaken to elaborate on reproduction in these species. Young of C. concinnus are born in most months, and some reproductively active males are probably present at all times of the year. Embryonic diapause occurs during the unilaminar blastocyst stage of embryonic development; the blastocysts expand slowly during diapause. The presence of embryos in the uteri of lactating female D. pennatus and C. lepidus suggests that diapause is also probable in these species. The gross anatomies of the female reproductive tracts of the five small possum species are described. Cercartetus spp. have a vaginal system characterised by voluminous culs-de-sac, and only vestigial remains of a median septum. This contrasts with the condition in the two acrobatids, in which the vaginal culs-de-sac are smaller and divided by a prominent septum. The male reproductive anatomy of C. concinnus is similar to that of C. lepidus. The prostate is carrot-shaped and its internal structure is unlike that described for other marsupial groups.
The Founding Population - the Effect of Differences in Its Size, Nature and Season of Establishment on the Subsequent Dynamics of Populations of House Mice, Mus-Musculus L
Authors: Pennycuik PR , Reisner AH
Published: June 2005

In south-eastern Australia, house mouse numbers in agricultural areas often reach plague proportions in the year following the breaking of a drought but numbers are usually low in subsequent years. The effects of differences in the size and nature of the groups invading ephemeral habitats on sub- sequent numbers, and on the time taken for the population to peak, were investigated by introducing groups of different size, age structure and composition into out-door pens where food supplies were abundant. The effects of differences in the season of invasion and the effects of allowing mice from one or two sources to invade empty home sites were also investigated. Varying the size of the founding groups had little effect on peak numbers or on the length of the establishment-peak interval. Peak numbers were usually higher in populations established with mice from a narrow band of age classes than in those established with mice from a wide band of age classes, and the establishment-peak interval was usually shorter in populations established with mice from one source than in populations established with mice from two sources. The establishment-peak interval was also shorter in populations established in spring than in those established at other seasons. When established groups were allowed access to empty home sites, the groups colonising the sites varied in size, age structure and composition. Peak heights in these colonies, too, appeared to be affected by the age structure of the founding group, and the establishment-peak interval was affected by the composition of the group. These results suggest that both between-year differences in the nature of the groups moving from the refuge areas to the growing crops, and between-year differences in the season at which the crops are colonised, could contribute to the observed differences in mouse numbers in the agricultural areas of south-eastern Australia. Possible reasons for between-year differences in the nature of the groups colonising the ephemeral habitats are discussed.
The Stereotyped Behavior of Sexual Cannibalism in Latrodectus-Hasselti Thorell (Araneae, Theridiidae), the Australian Redback Spider
Authors: Forster LM
Published: June 2005

This paper presents the first account of stereotyped behaviour in the practice of sexual cannibalism in any species. Cannibalism is achieved by female Latrodectus hasselti spiders, primarily because the copulatory orientation of the male in this species is unique and does not conform to the orthodox posture of males of other Latrodectus species. In this case, after penetration of the epigynum with one palpal embolus, the male turns a somersault through 180-degrees so that his abdomen comes to rest against the female's mouthparts, whereupon she begins to devour him. The cannibalistic process is slow and the male often succeeds in a second intromission with the other palp. The somersault is highly stereo-typed and predictable; it was observed in all 56 intromissions in the present study. The nuptial death risk to the male during copulation if both palps are employed is 0.66. However, even if he escapes copulatory demise he will die from his injuries within two days. Male Latrodectus hasselti can be mated with female L. katipo, an allopatric species native to New Zealand. Somersaulting by the male L. hasselti also occurs in this inter-specific copulation but the female L. katipo makes no attempt to devour him. It is concluded that male somersaults and female cannibalistic behaviour in L. hasselti are genetically programmed events.
Ultrastructure of the Genital Duct Epithelium of the Male Port Jackson Shark, Heterodontus-Portusjacksoni
Authors: Jones RC , Lin M
Published: June 2005

The genital ducts of Heterodontus portusjacksoni are lined by a ciliated epithelium. In the ductuli efferentes the epithelium is low and contains numerous intraepithelial leucocytes which often contain large dense bodies. All epithelial cells are ciliated and are characterised by apical vesicles, vacuoles and glycogen granules, some rough endoplasmic reticulum, dense bodies and lipid droplets, and a Golgi apparatus. The initial segment of the ductus epididymidis is lined by a very tall epithelium of ciliated and non-ciliated cells. The non-ciliated cells contain numerous apical vesicles, a large Golgi apparatus and numerous mitochondria and secretory granules in close association with an extensive endoplasmic reticulum. The terminal segment of the ductus epididymidis is lined by a low columnar epithelium. A proximal region, occupying part of the head of the epididymis, is similar to the epithelium in the ductuli efferentes. Distally, all the epithelial cells are ciliated. They are characterised by considerable dilated endoplasmic reticulum, a Golgi apparatus, apical vesicles, and numerous mitochondria and secretory granules. The secretory tubules of Leydig's glands are lined by a very tall epithelium with non-ciliated cells containing extensive, dilated, rough endoplasmic reticulum, a large Golgi apparatus, and numerous mitochondria and secretory granules. The significance of the structural differentiation of the duct is discussed in relation to the evolution of the mammalian epididymis.
Iridophores in the Mantle of Giant Clams
Authors: Griffiths DJ , Winsor H , Luongvan T
Published: June 2005

Iridophores in the mantle of the giant clams Tridacna gigas and T. crocea comprise an aggregation of cells (iridocytes) containing stacks of regularly arranged platelet, (iridosomal platelets) of uniform thickness (c. 70 nm). The platelets are separated by cytoplasm of roughly the same thickness permeated by a single flattened cisterna, the bounding membrane of which is continuous with the plasmalemma of the iridocyte. Iridosome formation starts with the laying down of the cisternae and subsequent deposition of proteinaceous platelet material between them in a regular crystalline arrangement. The iridosomal platelets form a space lattice giving maximum light interference at a wavelength of around 400 nm or just above. Interference may extend into the blue and green portions of the visible spectrum, which would be consistent with the observed interference colours displayed by the giant clams in situ. The iridosomes may also function as diffraction gratings or they may redirect light to the zooxanthellae.
Vigilance and Grouping in the Eastern Gray Kangaroo, Macropus giganteus
Authors: Colagross AML , Cockburn A
Published: June 2005

Group formation may help animals reduce their risk of predation and allow more time for activities other than vigilance against predators. Eastern grey kangaroos, Macropus giganteus, are gregarious and form open-membership groups. Vigilance behaviour of free-ranging kangaroos was observed in relation-to number of individuals within the group, sex and reproductive status of individuals, proximity to cover and position within the group. Our data support the view that kangaroos adjust their behaviour in relation to the risk of predation. Reproductive females, individuals on the periphery of the group and individuals in groups far from cover were most vigilant. Contrary to previous reports, vigilance behaviour was not influenced by group size except through the edge effect-the tendency of the proportion of individuals on the periphery of the group to decline as group size increases.
Sensory Receptors and Epidermal Structures of a Meiofaunal Turbellarian (Proseriata, Monocelididae, Minoninae)
Authors: Rohde K , Watson NA
Published: June 2005

The senogram (set of sensory receptors) of a proseriate turbellarian from the meiofauna of a high-energy beach in south-eastern Australia is described, based on serial ultrathin sections. It comprises a pair of rhabdomeric eyes that lack a pigment cup, a statocyst located ventro-anteriorly to the brain and consisting of one lithocyte with a single ovoid statolith in the electron-lucent cytoplasm, several parietal and accessory cells and nerve fibres penetrating the statocyst capsule, and at least eight (and possibly eleven) types of epidermal receptors: A, an anterior and antero-lateral receptor with basal bodies and strongly branched processes (modified cilia); B, an 'insunk' collar receptor in all parts of the body surface, with eight microvilli surrounding the single cilium; C, a ciliary bundle arising from basal bodies at the base of a deep pit, in anterior third of body; D, a bundle of dendrites, reaching the surface, in anterior third of body, possibly a protonephridial pore; E, a multiciliate receptor with long branched ciliary rootlets, in anterior and antero-lateral part of body; F, as for E but with a single rootlet; G, as for F but with a vertical and an oblique rootlet arising from the basal body (F and G are possibly modifications of E); H, a receptor with a single cilium and short rootlet, somewhat raised above the epidermal surface; I, a pharyngeal receptor with a short cilium; J, a pharyngeal receptor with a long cilium; K, an anterior receptor with a bulbous cilium. A single cilium or up to three cilia surrounded by a cytoplasmic tube may constitute a further receptor type. Most epidermal perikarya are 'insunk', and epidermal cilia have large anteriorly directed, very thin vertical rootlets and short 'spurs' at the basal body. Bundles of rootlets of epidermal cilia converge towards their tips, some tips located close to the epidermal surface; it is suggested that they may be directly stimulated by mechanical stimuli. The variety of receptors indicates that the animal must respond to a complex array of stimuli. It is stressed that morphological studies of sensory receptors are the basis for an understanding of their function and of the ecological requirements of a species.
Gastric Nematode Communities in Lizards From the Great Victoria Desert, and an Hypothesis for Their Evolution
Authors: Jones HI
Published: June 2005

This study examines the biology of gastric nematodes in two communities of lizards from the Great Victoria Desert, and develops an hypothesis for their evolution. Abbreviata antarctica A. hastaspicula, A, levicauda, A. tumidocapitis, Skrjabinoptera goldmanae, Kreisiella chrysocampa, Physalopteroides filicauda, Wanaristrongylus ctenoti and W. papangawurpae were recovered from 3023 lizards of 45 species from two different habitats. Genera in the Physalopterinae (Abbreviata, Skrjabinoptera and Kreisiella) exhibited narrow host specificities, Abbreviara and Skrjabinoptera occurring as adults only in larger host species (Varanus gouldii, V. tristis and Pogona minor). P. filicauda and encysted larvae of Physalopterinae occurred widely in the smaller lizard species in all five families represented. Eight of the nine nematode species were recovered from both lizard populations, and differences in prevalence and number of host species infected are discussed in terms of core hosts providing an infective pool. Associations were derived between parameters of infection (prevalence, intensity and abundance) and host size across and within species; abundance of nematodes in Ctenotus skinks correlated with host geographical range. Epidemiological evidence is presented that suggests that termites are intermediate hosts to species of Physalopterinae, and that Orthoptera may be intermediate hosts to P.filicauda. It is suggested that species in the Physalopterinae arose in smaller lizards (where they are now represented by the morphologically primitive Kreisiella), and that they were acquired by large predatory species by host capture, and in which they are now speciating. The small lizards now act as paratenic hosts to their larvae, and the niches left vacant have been occupied by P. filicauda. It is concluded that P.filicauda is at an early non-interactive phase and that Abbreviata and Skrjabinoptera are at an evolutionary phase, and are evolving along with their hosts. Thus, the two principal nematode groups arose at different times in response to the radiation and ecology of their hosts, and are at different stages in their own evolution.
Frequency Distribution and Host-Parasite Relationships of Zschokkella Leptatherinae (Myxozoa: Myxiidae), a Parasite of Atherinid Fishes
Authors: Su XQ , White RWG
Published: June 2005

The frequency distribution and aspects of host-parasite relationship of the myxosporean Zschokkella leptatherinae Su and White (1995) in the hepatic ducts and gall bladder of two atherinid fishes, Atherinosoma microstoma (Gunther) and Leptatherina presbyteroides (Richardson), were studied from January 1990 to June 1992. In both fish species, the distribution of Z. leptatherinae fitted the log-normal model. The prevalence and intensity of infection did not vary seasonally. The infection of the parasite occurred more frequently in larger hosts in both fish species but no relationship existed either between the intensity of parasite infection and the size of fish or between the prevalence of parasite infection and sex of fish.
Can Social Behaviour Influence Food Preference of Wild Mice, Mus Domesticus, in Confined Field Populations?
Authors: Valsecchi P , Singleton GR , Price WJ
Published: June 2005

The role of social transmission in directing food preference was assessed in adult wild mice living in seminatural outdoor enclosures located in south-eastern Australia. We first examined whether mice recently fed one novel food and then released back into the enclosure (demonstrator mice) influenced the food preference of mice presented with a choice between that novel food and one other novel food. Then we examined the food preference of mice presented with a novel food and their staple food, after demonstrator mice were fed with the novel food and returned to the enclosure. The main results were as follows: (i) mice given a choice between two novel foods, in the presence of demonstrator mice, consumed significantly more of the novel food to which demonstrator mice had been exposed; and (ii) mice given a choice of one novel food and their staple food, in the presence of demonstrator mice that had been exposed to the novel food, ate similar amounts of the two foods. The adaptive value of different strategies of food selection is discussed.
Enhanced antiinflammatory capacity of a
Lactobacillus plantarum
mutant synthesizing modified teichoic acids
Authors: Grangette Corinne , Nutten Sophie , Palumbo Emmanuelle , Morath Siegfried , Hermann Corinna , Dewulf Joelle , Pot Bruno , Hartung Thomas , Hols Pascal , Mercenier Annick
Published: June 2005

Teichoic acids (TAs), and especially lipoteichoic acids (LTAs), are one of the main immunostimulatory components of pathogenic Gram-positive bacteria. Their contribution to the immunomodulatory properties of commensal bacteria and especially of lactic acid bacteria has not yet been investigated in detail. To evaluate the role of TAs in the interaction between lactic acid bacteria and the immune system, we analyzed the antiinflammatory properties of a mutant of
Lactobacillus plantarum
NCIMB8826 affected in the TA biosynthesis pathway both
in vitro
(mononuclear cells stimulation) and
in vivo
(murine model of colitis). This Dlt
-
mutant was found to incorporate much less
d
-Ala in its TAs than the WT strain. This defect significantly impacted the immunomodulation reactions induced by the bacterium, as shown by a dramatically reduced secretion of proinflammatory cytokines by peripheral blood mononuclear cells and monocytes stimulated by the Dlt
-
mutant as compared with the parental strain. Concomitantly, a significant increase in IL-10 production was stimulated by the Dlt
-
mutant in comparison with the WT strain. Moreover, the proinflammatory capacity of
L. plantarum
-purified LTA was found to be Toll-like receptor 2-dependent. Consistent with the
in vitro
results, the Dlt
-
mutant was significantly more protective in a murine colitis model than its WT counterpart. The results indicated that composition of LTA within the whole-cell context of
L. plantarum
can modulate proinflammatory or antiinflammatory immune responses.
Localized RhoA Activation as a Requirement for the Induction of Membrane Ruffling
Authors: Kurokawa Kazuo , Matsuda Michiyuki
Published: June 2005

We examined the spatio-temporal activity of RhoA in migrating cells and growth factor-stimulated cells by using probes based on the principle of fluorescence resonance energy transfer. In HeLa cells migrating at a low cell density, RhoA was activated both at the contractile tail and at the leading edge. However, RhoA was activated only at the leading edge in MDCK cells migrating as a monolayer sheet. In growth factor-stimulated Cos1 and NIH3T3 cells, the activity of RhoA was greatly decreased at the plasma membrane, but remained high at the membrane ruffles in nascent lamellipodia. These observations are in agreement with the proposed role played by RhoA in stress fiber formation, but they also implicated RhoA in the regulation of membrane ruffling, the induction of which is a typical phenotype of activated Rac. In agreement with this view, dominant negative RhoA was found to inhibit membrane ruffling induced by active Rac. Furthermore, we found that Cdc42 activity was also required for high RhoA activity in membrane ruffles. Finally, we found that mDia1, but not ROCK, was stably associated with membrane ruffles. In conclusion, these results suggested that RhoA cooperates with Rac1 and Cdc42 to induce membrane ruffles via the recruitment of mDia.
Analysis of global mRNA expression in human skeletal muscle during recovery from endurance exercise
Authors: Mahoney D. J. , Parise G. , Melov S. , Safdar A. , Tarnopolsky M. A.
Published: June 2005

To search for novel transcriptional pathways that are activated in skeletal muscle after endurance exercise, we used cDNA microarrays to measure global mRNA expression after an exhaustive bout of high‐intensity cycling (∼75 min). Healthy, young, sedentary males performed the cycling bout, and skeletal muscle biopsies were taken from the vastus lateralis before, and at 3 and 48 h after exercise. We examined mRNA expression in individual muscle samples from four subjects using cDNA microarrays, used repeated‐measures significance analysis of microarray (SAM) to determine statistically significant expression changes, and confirmed selected results using real‐time RT‐PCR. In total, the expression of 118 genes significantly increased 3 h postcycling and 8 decreased. At 48 h, the expression of 29 genes significantly increased and 5 decreased. Many of these are potentially important novel genes involved in exercise recovery and adaptation, including several involved in 1) metabolism and mitochondrial biogenesis (FOXO1, PPARδ, PPARγ, nuclear receptor binding protein 2, IL‐6 receptor, ribosomal protein L2, aminolevulinate δ‐synthase 2); 2) the oxidant stress response (metalothioneins 1B, 1F, 1G, 1H, 1L, 2A, 3, interferon regulatory factor 1); and 3) electrolyte transport across membranes [Na+‐K+‐ATPase (β3), SERCA3, chloride channel 4]. Others include genes involved in cell stress, proteolysis, apoptosis, growth, differentiation, and transcriptional activation, as well as all three nuclear receptor subfamily 4A family members (Nur77, Nurr1, and Nor1). This study is the first to characterize global mRNA expression during recovery from endurance exercise, and the results provide potential insight into 1) the transcriptional contributions to homeostatic recovery in human skeletal muscle after endurance exercise, and 2) the transcriptional contributions from a single bout of endurance exercise to the adaptive processes that occur after a period of endurance exercise training.
Uncertainties and constraints on breaching and their implications for flood loss estimation
Authors: Muir Wood Robert , Bateman William
Published: June 2005

Around the coasts of the southern North Sea, flood risk is mediated everywhere by the performance of natural and man-made flood defences. Under the conditions of extreme surge with tide water levels, the performance of the defences determines the extent of inland flooding. Sensitivity tests reveal the enormous increase in the volume of water that can pass through a defence once breaching is initiated, with a 1 m reduction in sill elevation doubling the loss. Empirical observations of defence performance in major storm surges around the North Sea reveal some of the principal controls on breaching. For the same defence type, the maximum size and depth of a breach is a function of the integral of the hydraulic gradient across the defence, which is in turn determined by the elevation of the floodplain and the degree to which water can continue to flow inland away from the breach. The most extensive and lowest floodplains thereby ‘generate’ the largest breaches. For surges that approach the crest height, the weaker the protection of the defence, the greater the number of breaches. Defence reinforcement reduces both the number and size of the breaches.
Quantum physics in neuroscience and psychology: a neurophysical model of mind–brain interaction
Authors: Schwartz Jeffrey M , Stapp Henry P , Beauregard Mario
Published: June 2005

Neuropsychological research on the neural basis of behaviour generally posits that brain mechanisms will ultimately suffice to explain all psychologically described phenomena. This assumption stems from the idea that the brain is made up entirely of material particles and fields, and that all causal mechanisms relevant to neuroscience can therefore be formulated solely in terms of properties of these elements. Thus, terms having intrinsic mentalistic and/or experiential content (e.g. ‘feeling’, ‘knowing’ and ‘effort’) are not included as primary causal factors. This theoretical restriction is motivated primarily by ideas about the natural world that have been known to be fundamentally incorrect for more than three-quarters of a century. Contemporary basic physical theory differs profoundly from classic physics on the important matter of how the consciousness of human agents enters into the structure of empirical phenomena. The new principles contradict the older idea that local mechanical processes alone can account for the structure of all observed empirical data. Contemporary physical theory brings directly and irreducibly into the overall causal structure certain psychologically described choices made by human agents about how they will act. This key development in basic physical theory is applicable to neuroscience, and it provides neuroscientists and psychologists with an alternative conceptual framework for describing neural processes. Indeed, owing to certain structural features of ion channels critical to synaptic function, contemporary physical theory must in principle be used when analysing human brain dynamics. The new framework, unlike its classic-physics-based predecessor, is erected directly upon, and is compatible with, the prevailing principles of physics. It is able to represent more adequately than classic concepts the neuroplastic mechanisms relevant to the growing number of empirical studies of the capacity of directed attention and mental effort to systematically alter brain function.
Boundaries and physical characterization of a new domain shared between mammalian 53BP1 and yeast Rad9 checkpoint proteins
Authors: Alpha‐Bazin Béatrice , Lorphelin Alain , Nozerand Nathalie , Charier Gaëlle , Marchetti Charles , Bérenguer Frédéric , Couprie Joël , Gilquin Bernard , Zinn‐Justin Sophie , Quéméneur Eric
Published: June 2005

Eukaryotic cells have evolved DNA damage checkpoints in response to genome damage. They delay the cell cycle and activate repair mechanisms. The kinases at the heart of these pathways and the accessory proteins, which localize to DNA lesions and regulate kinase activation, are conserved from yeast to mammals. For Saccharomyces cerevisiae Rad9, a key adaptor protein in DNA damage checkpoint pathways, no clear human ortholog has yet been described in mammals. Rad9, however, shares localized homology with both human BRCA1 and 53BP1 since they all contain tandem C‐terminal BRCT (BRCA1 C‐terminal) motifs. 53BP1 is also a key mediator in DNA damage signaling required for cell cycle arrest, which has just been reported to possess a tandem Tudor repeat upstream of the BRCT motifs. Here we show that the major globular domain upstream of yeast Rad9 BRCT domains is structurally extremely similar to the Tudor domains recently resolved for 53BP1 and SMN. By expressing several fragments encompassing the Tudor‐related motif and characterizing them using various physical methods, we isolated the independently folded unit for yeast Rad9. As in 53BP1, the domain corresponds to the SMN Tudor motif plus the contiguous HCA predicted structure region at the C terminus. These domains may help to further elucidate the structural and functional features of these two proteins and improve knowledge of the proteins involved in DNA damage.
An NMR view of the unfolding process of rusticyanin: Structural elements that maintain the architecture of a β‐barrel metalloprotein
Authors: Alcaraz Luis A. , Jiménez Beatriz , Moratal José María , Donaire Antonio
Published: June 2005

The unfolding process of the blue copper protein rusticyanin (Rc) as well as its dynamic and D2O/H2O exchange properties in an incipient unfolded state have been studied by heteronuclear NMR spectroscopy. Titrations of apo, Cu(I), and Cu(II)Rc with guanidinium chloride (GdmCl) show that the copper ion stabilizes the folded species and remains bound in the completely unfolded state. The oxidized state of the copper ion is more efficient than the reduced form in this respect. The long loop of Rc (where the first ligand of the copper ion is located) is one of the most mobile domains of the protein. This region has no defined secondary structure elements and is prone to exchange its amide protons. In contrast, the last loop (including a short α‐helix) and the last β‐strand (where the other three ligands of the metal ion are located) form the most rigid domain of the protein. The results taken as a whole suggest that the first ligand detaches from the metal ion when the protein unfolds, while the other three ligands remain bound to it. The implications of these findings for the biological folding process of Rc are also discussed.
Solution structure of APETx2, a specific peptide inhibitor of ASIC3 proton‐gated channels
Authors: Chagot Benjamin , Escoubas Pierre , Diochot Sylvie , Bernard Cédric , Lazdunski Michel , Darbon Hervé
Published: June 2005

Acid‐sensing ion channels (ASIC) are proton‐gated sodium channels that have been implicated in pain transduction associated with acidosis in inflamed or ischemic tissues. APETx2, a peptide toxin effector of ASIC3, has been purified from an extract of the sea anemone Anthopleura elegantissima. APETx2 is a 42‐amino‐acid peptide cross‐linked by three disulfide bridges. Its three‐dimensional structure, as determined by conventional two‐dimensional 1H‐NMR, consists of a compact disulfide‐bonded core composed of a four‐stranded β‐sheet. It belongs to the disulfide‐rich all‐β structural family encompassing peptide toxins commonly found in animal venoms. The structural characteristics of APETx2 are compared with that of PcTx1, another effector of ASIC channels but specific to the ASIC1a subtype and to APETx1, a toxin structurally related to APETx2, which targets the HERG potassium channel. Structural comparisons, coupled with the analysis of the electrostatic characteristics of these various ion channel effectors, led us to suggest a putative channel interaction surface for APETx2, encompassing its N terminus together with the type I‐β turn connecting β‐strands III and IV. This basic surface (R31 and R17) is also rich in aromatic residues (Y16, F15, Y32, and F33). An additional region made of the type II′‐β turn connecting β‐strands I and II could also play a role in the specificity observed for these different ion effectors.
Structure—function analysis of the α5 and the α13 helices of human glucokinase: Description of two novel activating mutations
Authors: Pedelini Leda , Garcia‐Gimeno Maria Adelaida , Marina Alberto , Gomez‐Zumaquero Juan M. , Rodriguez‐Bada Pablo , López‐Enriquez Soledad , Soriguer Federico C. , Cuesta‐Muñoz Antonio L. , Sanz Pascual
Published: June 2005

It was recently described that the α5 and the α13 helices of human pancreatic glucokinase play a major role in the allosteric regulation of the enzyme. In order to understand the structural importance of these helices, we have performed site‐directed mutagenesis to generate glucokinase derivatives with altered residues. We have analyzed the kinetic parameters of these mutated forms and compared them with wild‐type and previously defined activating mutations in these helices (A456V and Y214C). We found two new activating mutations, A460R and Y215A, which increase the affinity of the enzyme for glucose. Our results suggest that substitutions in the α5 or the α13 helices that favor the closed, active conformation of the enzyme, either by improving the interaction with surrounding residues or by improving the flexibility of the region defined by these two helices, enhance the affinity of the enzyme for glucose, and therefore its performance as a glucose phosphorylating enzyme.
Compliance and convenience: do physicians and patients see depot medication differently?
Authors: Chue Pierre
Published: June 2005

Physicians' attitudes to depot medication are often focused on improved compliance (adherence), and thus, short- and long-term treatment outcomes. By contrast, patients receiving such formulations tend to have a quite different viewpoint of medication. Factors such as convenience, side-effects and their beliefs about their illness play an important role in determining whether patients will adhere to their prescribed treatment regimen. The relationship between the patient and physician is of crucial importance in determining a patient's attitude to their medication; it is becoming increasingly clear that managing the illness in the long-term and avoiding relapse, while ensuring compliance, should be reframed as a collaborative process between the patient and physician.
Identification of karyopherin β as an immunogenic antigen of the malaria parasite using immune mice and human sera
Authors: Mohmmed Asif , Kishore Shivendra , Patra Kailash P. , Dasaradhi Palakodeti V. N. , Malhotra Pawan , Chauhan Virander S.
Published: June 2005

A differential immunoscreening of the λgt11 Plasmodium falciparum genomic expression library was carried out using anti‐P. yoelii sera (convalescent‐phase mouse sera) and immune sera collected from healthy adults, to identify novel cross‐reactive and possibly protective antigens of the parasite. One clone, with an insert size of 1132 bp that reacted strongly with both the sera was selected. The insert was found to be a part of the P. falciparum karyopherin β (PfKβ) homologue. RT‐PCR and Northern blot analysis confirmed the expression of PfKβ in the blood stages of the parasite. The ∼110 kDa protein was localized in the cytoplasm at the ring and trophozoite, and in the parasitophorous vacuole at the schizont stage. Two large fragments of PfKβ representing the N‐ and C‐terminal halves were expressed in E. coli. The recombinant proteins were highly immunogenic in mice, and also found to be the target for immune response in natural infections of Plasmodium spp. Anti‐sera against the protein showed a low level of anti‐parasitic activity. Immunization with recombinant PfKβ fragments was only partially protective against a heterologous challenge infection in mice. Our results show that the parasite releases a highly immunogenic, cytoplasmic protein into the host which may not contribute to the development of protective immunity.
Exploring the relationship between nursing protocols and nursing practice in an Irish intensive care unit
Authors: Flynn Angela V , Sinclair Marlene
Published: June 2005

Nursing practice no longer relies on tradition or ritual; instead, it is based on research and empirical evidence. The emphasis on evidence‐based nursing, as well as standardization of nursing practice, has resulted in the production of policies, protocols and guidelines aimed at directing numerous aspects of nursing care. The aim of this study was to explore the relationship between these documents and actual nursing practice. To this end, this descriptive study employed a case study approach to examine the experiences of nurses in an Irish intensive care unit with a protocol on endotracheal tube suctioning. Focus group interviews of 17 nurses in six focus groups provided a significant insight into the experiences of these nurses in relation to policies, protocols and guidelines. Analysis of the data afforded some highly relevant findings, including the fact that nurses adapt clinical protocols as they see fit, thus demonstrating the importance that they place on their own professional judgement and autonomy.
Reaching for the stars: Career advancement and the registered nurse
Authors: Walker Kim
Published: June 2005

Clinical nursing has long struggled to secure the place of primacy it deserves in the profession's hierarchy of importance and worth. It is ironic that, even at the beginning of the 21st century, a clinical nurse is generally not as well‐recognized, rewarded or remunerated as a colleague working in nursing management, education or research. Until the profession recognizes and takes serious action to remedy this situation, the crisis of recruitment and retention in nursing currently ravaging the globe is likely to continue. In this paper, I present a discursive account of an exciting initiative by a leading private, acute‐care hospital which addresses this very problem. A new ladder for clinical nurse specialists (CNSs) introduces a rigorous and systematic approach to the appointment of three classifications of CNS, each requiring evidence of successively higher levels of competency, and which are accompanied by fiscal reward and stronger peer recognition.
Recognition of Aboriginal rights, interests and values in river research and management: Perspectives from northern Australia
Authors: Jackson Sue , Storrs Michael , Morrison Joe
Published: June 2005

Summary  Aboriginal people perceive land and water as equal components of country, and hold distinct perspectives on water relating to identity and attachment to place, environmental knowledge, resource security, and the exercise of custodial responsibilities to manage interrelated parts of customary estates. This paper documents Aboriginal perspectives from certain areas in northern Australia, defined as the region of tropical savannas stretching from Townsville to Broome, and offers a number of suggestions for improving current knowledge of Aboriginal values and Aboriginal participation rates in water and catchment management. The paper highlights the cultural significance of rivers and water in selected northern regions, and provides a preliminary outline of research and management priorities as determined by key north Australian Aboriginal land management organizations. Priorities include developing the capacity for collaborative aquatic resource management, conservation of traditional ecological knowledge, riparian resource inventories and threat assessment, as well as improved Aboriginal participation in catchment management and water policy. Although there is a strong north Australian focus to this paper, the issues raised are relevant to water and natural resource management policy throughout Australia.
Maternal gestures with 20‐month‐old infants in two contexts
Authors: O'Neill Maria , Bard Kim A. , Linnell Maggie , Fluck Michael
Published: June 2005

Speech directed towards young children (‘motherese’) is subject to consistent systematic modifications. Recent research suggests that gesture directed towards young children is similarly modified (gesturese). It has been suggested that gesturese supports speech, therefore scaffolding communicative development (the facilitative interactional theory). Alternatively, maternal gestural modification may be a consequence of the semantic simplicity of interaction with infants (the interactional artefact theory). The gesture patterns of 12 English mothers were observed with their 20‐month‐old infants while engaged in two tasks, free play and a counting task, designed to differentially tap into scaffolding. Gestures accounted for 29% of total maternal communicative behaviour. English mothers employed mainly concrete deictic gestures (e.g. pointing) that supported speech by disambiguating and emphasizing the verbal utterance. Maternal gesture rate and informational gesture–speech relationship were consistent across tasks, supporting the interactional artefact theory. This distinctive pattern of gesture use for the English mothers was similar to that reported for American and Italian mothers, providing support for universality. Child‐directed gestures are not redundant in relation to child‐directed speech but rather both are used by mothers to support their communicative acts with infants.
Can the Non‐executive Director be an Effective Gatekeeper? The Possible Development of a Legal Framework of Accountability
Authors: Kirkbride James , Letza Steve
Published: June 2005

In the UK there has been a recent debate over the role of the independent non‐executive director, with that debate resulting in changes to a revised Code applicable to companies reporting after 1 November, 2003. This article reflects on an aspect of the proposed changes that was ignored, namely changes to the legal duties and liabilities of non‐executive directors. This appears to have been a missed opportunity in seeking to enhance the effectiveness of independent non‐executives and their contributions to enhancing corporate governance. This paper considers enhancing the governance role of non‐executive directors by introducing “gatekeeper liability”.
Selectively increasing inducible heat shock protein 70 via TAT‐protein transduction protects neurons from nitrosative stress and excitotoxicity
Authors: Lai Yichen , Du Lina , Dunsmore Katherine E. , Jenkins Larry W. , Wong Hector R. , Clark Robert S. B.
Published: June 2005

Induction of heat shock protein 70 (Hsp70) via sublethal stress protects neurons from subsequent lethal injuries. Here we show that specific and efficient intracellular transduction of Hsp70 can be achieved utilizing an 11 amino acid leading sequence from human immunodeficiency virus (TAT‐Hsp70) in primary neuronal cultures. Western blot and immunohistochemistry demonstrated intracellular accumulation of Hsp70 in insoluble protein fractions and mitochondrial compartments. We then examined the effects of Hsp70 overexpression using TAT‐Hsp70 in models of nitrosative and excitotoxic neuronal death in vitro. Neurons were pre‐incubated with 300 nm TAT‐Hsp 70 overnight, then exposed to either peroxynitrite (ONOO–) or glutamate. TAT‐Hsp70 maintained cellular respiration, inhibited extracellular lactate dehydrogenase release, and/or reduced cell death assessed by flow cytometry vs. vehicle, wild‐type Hsp70, and TAT‐β‐galactosidase controls. Hsp70 transduction using a TAT fusion protein is an effective method to selectively increase Hsp70 in neurons and is sufficient to provide neuroprotection from nitrosative stress and excitotoxicity. Further study is needed to confirm whether TAT‐Hsp70 is protective in in vivo models of brain injury.