bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of interatomic potential on He bubble creation by cascades in α-iron
Authors: Yang L. , Zu X. T. , Wang Z. G. , Yang H. T. , Gao F. , Heinisch H. L. , Kurtz R. J.
Published: April 2008

The effects of using different interatomic potentials in molecular dynamics (MD) simulations of the formation of He-vacancy clusters within displacement cascades in α-Fe are investigated using two sets of potentials. Simulations of cascades produced by primary knock-on atoms of energy Ep=1–20keV were performed in α-Fe containing a concentration of substitutional He atoms varying from 1to5at.% at an irradiation temperature of 100K. Although the effects of interatomic potentials on the nucleation of He-vacancy clusters induced by cascades are relatively small, the number and size of He-vacancy clusters produced are significantly different for the different potentials employed in this study. Thus, these differences may influence the microstructural evolution predicted in damage accumulation models that use the results from MD cascade simulations as input. The observed differences in postcascade configurations can be attributed mainly to the differences in the Fe–Fe and Fe–He potentials.
Dynamic superconcentration at critical-point double-layer gates of conducting nanoporous granules due to asymmetric tangential fluxes
Authors: Wang Shau-Chun , Wei Hsien-Hung , Chen Hsiao-Ping , Tsai Min-Hsuan , Yu Chun-Ching , Chang Hsueh-Chia
Published: April 2008

A transient 106-fold concentration of double-layer counterions by a high-intensity electric field is demonstrated at the exit pole of a millimeter-sized conducting nanoporous granule that permits ion permeation. The phenomenon is attributed to a unique counterion screening dynamics that transforms half of the surface field into a converging one toward the ejecting pole. The resulting surface conduction flux then funnels a large upstream electro-osmotic convective counterion flux into the injecting hemisphere toward the zero-dimensional gate of the ejecting hemisphere to produce the superconcentration. As the concentrated counterion is ejected into the electroneutral bulk electrolyte, it attracts co-ions and produce a corresponding concentration of the co-ions. This mechanism is also shown to trap and concentrate co-ion microcolloids of micron sizes too (macroions) and hence has potential application in bead-based molecular assays.
Sustainable governance for small desert settlements: learning from the multi-settlement regionalism of Anmatjere Community Government Council
Authors: Sanders Will , Holcombe Sarah
Published: April 2008

In light of some basic desert demography, this paper examines governance patterns for small desert settlements. It traces policy histories which led to the emergence of highly localised, single settlement governance arrangements during the 1970s and ’80s. It also identifies the many pushes since within the Northern Territory local government system for more regional, multi-settlement governance structures. The paper goes on to examine the history of one such regional, multi-settlement arrangement in central Australia, the Anmatjere Community Government Council established in 1993. The paper details our work with this Council over the last 4 years on ‘issues of importance or concern’ to them. The paper aims to learn from the ACGC experience in order to inform the more radical restructuring of Northern Territory local government currently underway towards larger multi-settlement regionalism. It concludes with four specific lessons, the most important of which is that regionalism must build on single settlement localism.
Sustaining four wheel drive tourism in desert Australia: exploring the evidence from a demand perspective
Authors: Carson D. B. , Taylor A. J.
Published: April 2008

Four wheel drive tourism appears to offer some potential for economic development in desert Australia. Realising this potential in a sustainable way will require attention to issues of destination competitiveness, innovation and manageability (in regards to travellers’ safety, and environmental, social and cultural impacts). This paper reports on several surveys of four wheel drive travellers to present evidence of the extent to which the market favours deserts over other destinations (competitiveness), the extent to which the market can be diversified and made resilient (innovation), and the willingness of the market to engage in processes which mitigate environmental, social and cultural impacts (manageability). It finds that the desert is a favoured environment for four wheel drive travel but that other environments are more favoured. There appear to be a range of market segments based on motivations, activities, and demographics which offer potential for a diversified marketplace. There are major differences, for example, between domestic and international travellers. The extent to which travellers, and particularly relatively inexperienced travellers, are willing to engage in processes to mitigate environmental, social and cultural impacts is not well understood.
An introduction to patterns of fire in arid and semi-arid Australia, 1998 - 2004
Authors: Turner D. , Ostendorf B. , Lewis M.
Published: April 2008

Fire is a crucial element in shaping our world, whether of natural or anthropogenic origin. These fires can have both positive and negative consequences and impacts on our natural environment, society and its economics, not to mention global climate.
Previous analyses of fire regimes in arid and semi-arid Australia have been of limited spatial or temporal extent. This lack of knowledge has hampered attempts at effective fire management. Satellite imagery allows the continuous detection, monitoring and mapping of fires. Active fires can be detected as fire hotspots, and burned areas mapped as patches from the change of surface reflectance properties in successive images. Data from NOAA’s advanced very high resolution radiometer (AVHRR) were used to assess the distribution, seasonality, frequency, number and extent of fire hotspots (FHS) and fire affected areas (FAA) across the entire arid and semi-arid country of Australia from 1998 to 2004.
Utilising both of these fire datasets is important, as they complement each other and provide a more robust analysis of fire patterns. Between 1998 and 2004 almost 27% of arid and semi-arid Australia burnt at least once. The main trends in fire distribution follow latitudinal rainfall gradients. Regression analysis also shows a strong relationship with the pattern of antecedent rainfall. The seasonality of fire events varies between climate zones in accordance with the varying distribution of precipitation and temperature, which influence fuel accumulation and curing.
For the first time we have a picture of fire patterns across the entire arid and semi-arid regions of the country. This includes several high fire years in certain areas following above-average rainfall. This analysis highlights similarities and differences between regions, giving policy makers and managers a basis from which to make more informed decisions in the present, and with which to compare future regimes.
The demography of desert Australia
Authors: Brown Dominic , Taylor John , Bell Martin
Published: April 2008

In recent years, with the formation of organisations such as the Desert Knowledge Cooperative Research Centre, social science interest in the Australian desert has re-surfaced with a research emphasis that is focused on creating sustainable futures for the region. One consequence of this is a demand for detailed demographic information to allow an assessment of different quanta of need in social and economic policy, and for assessment of the impact of these in environmental policy. However, demographic analysis on human populations in the desert to date has attracted very little research attention. In this paper we begin to address this lack of analysis by focusing on the populations, both aboriginal and non-aboriginal, of the arid and semi-arid zones of Australia. We extend earlier analysis by including for the first time demographic information on the semi-arid as well as the arid zone to establish the spatial pattern of population growth within the whole desert area drawing attention to the resulting settlement structure as an outcome of prevailing social, cultural and economic conditions. By examining population structure and demographic components of population change we also present for the first time population projections for the semi-arid zone and, therefore, in combination with the arid zone, for the entire Australian desert. All of this provides a basis for considering social and economic policy implications and the nature of underlying processes that drive change in this region.
Constructing Aboriginal NRM livelihoods: Anmatyerr employment in water management
Authors: Rea Naomi , Messner Julia
Published: April 2008

The provision of livelihoods for desert Aboriginal people is a common goal for desert communities as well as governments, research agencies and other organisations. We examine six issues surrounding the creation of indigenous livelihoods in cultural and natural resource management. Our analysis draws from the character of the training pathways and the livelihoods in water management that are being constructed in central Australia as part of the Anmatyerr Water Project, a research program that identifies culturally-based livelihoods as a major mechanism for facilitating the process of having Aboriginal rights and cultural values provided for in water management. Such livelihoods aim to enhance the cultural and natural resource management needs of non-Aboriginal and Aboriginal owners and managers through integration of profit and non-profit activities, and previously disconnected policies. The building of inter-cultural capacity and inter-cultural arrangements would assist in creating livelihoods in existing enterprises and work programs. A broader approach aims for cultural and natural resource livelihoods that have additional socio-cultural and economic outcomes. We discuss relevant issues and make consequent recommendations that inform the construction of these livelihoods.
The 'viability' and resilience of communities and settlements in desert Australia
Authors: Smith Mark Stafford , Moran Mark , Seemann Kurt
Published: April 2008

There is a continuing policy debate about whether it is possible to have sustainable small settlements in outback regions of Australia, where there is low and variable primary production and a sparse and mobile population. This debate is focused largely on Aboriginal settlements, but applies equally to all desert dwellers. In this contribution, we review the sources of economic flows through settlements occupied by different communities with common livelihood sources, whether based on mining, grazing, tourism, cultural resources, welfare or services, concluding that most desert livelihoods depend directly or indirectly on temporally variable inputs. Individual remote settlements tend to be dominated by one such ‘community of livelihood’, and differ in nature according to the source of that livelihood. These create types of settlement and service aspirations which are alien to more densely settled regions.
Settlement ‘viability’ is a measure of the short-term balance between aspirations for services (technical, social, but also for livelihoods and well being) and the costs of fulfilling these aspirations, and consequently is not a simple on/off switch – the community can adjust both its aspirations and the cost factors involved in meeting them. We define a resilient settlement as one that is viable in the long term in the face of its variable inputs. Thus, we determine that the concepts of settlement viability and resilience must be analysed differently according to the strategy adopted by different resident communities. In particular, Aboriginal (and pastoral) communities are particularly dependent on social and natural capital, yet these are not monitored. The whole analysis emphasises the importance of taking a demand- rather than supply-driven approach to services in desert settlements. Our conclusion is that, if top-down solutions continue to be imposed without appreciating the fundamental drivers of settlement in desert regions, then those solutions will continue to be partial, and ineffective in the long term.
Protected areas and development in arid Australia - challenges to regional tourism
Authors: Tremblay Pascal
Published: April 2008

The principal contention of this paper is that the traditional approach to park management is inadequate to deal with the contemporary goals of protected areas, in particular, biodiversity conservation, cultural heritage management and the management of socio-economic development within parks. This is particularly true for parks in remote regions like Central Australia, where management on a broader scale is required. The benefits of park management embracing a regional approach to development and conservation are examined. This paper also identifies some serious restrictions to development. Parks rely heavily on abstract management plans, and do not have a transparent framework through which to set objectives and targets. These objectives would allow parks to evaluate their organisation’s performance. Iconic landscape assets dominate the tourism economy in Central Australia. The number of different institutions managing parks has hampered the establishment of a valuation framework. This framework would allow regional resource allocation decisions to be assessed and parks’ performances to be monitored. Proper assessment and monitoring would strengthen the case for additional park funding to pursue conservation and development responsibilities.
Managing arid zone natural resources in Australia for spatial and temporal variability - an approach from first principles
Authors: Stafford Smith Mark , McAllister Ryan R. J.
Published: April 2008

Outback Australia is characterised by variability in its resource drivers, particularly and most fundamentally, rainfall. Its biota has adapted to cope with this variability. The key strategies taken by desert organisms (and their weaknesses) help to identify the likely impacts of natural resource management by pastoralists and others, and potential remedies for these impacts. The key strategies can be summarised as five individual species’ responses (ephemerals, in-situ persistents, refuging persistents, nomads and exploiters), plus four key emergent modes of organisation involving multiple species that contribute to species diversity (facilitation, self-organising communities, asynchronous and micro-allopatric co-existence). A key feature of the difference between the strategies is the form of a reserve, whether roots and social networks for Persistents, or propagules or movement networks for Ephemerals and Nomads. With temporally and spatially varying drivers of soil moisture inputs, many of these strategies and their variants can co-exist.
While these basic strategies are well known, a systematic analysis from first principles helps to generalise our understanding of likely impacts of management, if this changes the pattern of variability or interrupts the process of allocation to reserves. Nine resulting ‘weak points’ are identified in the system, and the implications of these are discussed for natural resource management and policy aimed at production or conservation locally, or the regional integration of the two.
Starvation-dependent differential stress resistance protects normal but not cancer cells against high-dose chemotherapy
Authors: Raffaghello Lizzia , Lee Changhan , Safdie Fernando M. , Wei Min , Madia Federica , Bianchi Giovanna , Longo Valter D.
Published: April 2008

Strategies to treat cancer have focused primarily on the killing of tumor cells. Here, we describe a differential stress resistance (DSR) method that focuses instead on protecting the organism but not cancer cells against chemotherapy. Short-term starved
S. cerevisiae
or cells lacking proto-oncogene homologs were up to 1,000 times better protected against oxidative stress or chemotherapy drugs than cells expressing the oncogene homolog

Ras2
val19

. Low-glucose or low-serum media also protected primary glial cells but not six different rat and human glioma and neuroblastoma cancer cell lines against hydrogen peroxide or the chemotherapy drug/pro-oxidant cyclophosphamide. Finally, short-term starvation provided complete protection to mice but not to injected neuroblastoma cells against a high dose of the chemotherapy drug/pro-oxidant etoposide. These studies describe a starvation-based DSR strategy to enhance the efficacy of chemotherapy and suggest that specific agents among those that promote oxidative stress and DNA damage have the potential to maximize the differential toxicity to normal and cancer cells.
In vivo
functions of the proprotein convertase PC5/6 during mouse development: Gdf11 is a likely substrate
Authors: Essalmani Rachid , Zaid Ahmed , Marcinkiewicz Jadwiga , Chamberland Ann , Pasquato Antonella , Seidah Nabil G. , Prat Annik
Published: April 2008

The proprotein convertase PC5/6 cleaves protein precursors after basic amino acids and is essential for implantation in CD1/129/Sv/C57BL/6 mixed-background mice. Conditional inactivation of
Pcsk5
in the epiblast but not in the extraembryonic tissue bypassed early embryonic lethality but resulted in death at birth. PC5/6-deficient embryos exhibited Gdf11-related phenotypes such as altered anteroposterior patterning with extra vertebrae and lack of tail and kidney agenesis. They also exhibited Gdf11-independent phenotypes, such as a smaller size, multiple hemorrhages, collapsed alveoli, and retarded ossification.
In situ
hybridization revealed overlapping PC5/6 and Gdf11 mRNA expression patterns.
In vitro
and
ex vivo
analyses showed that the selectivity of PC5/6 for Gdf11 essentially resides in the presence of a P1′ Asn in the RSRR↓N cleavage motif. This work identifies Gdf11 as a likely
in vivo
specific substrate of PC5/6 and opens the way to the identification of other key substrates of this convertase.
Variation at the mu-opioid receptor gene (OPRM1) influences attachment behavior in infant primates
Authors: Barr Christina S. , Schwandt Melanie L. , Lindell Stephen G. , Higley J. Dee , Maestripieri Dario , Goldman David , Suomi Stephen J. , Heilig Markus
Published: April 2008

In a variety of species, development of attachment to a caregiver is crucial for infant survival and partly mediated by the endogenous opioids. Functional mu-opioid receptor gene polymorphisms are present in humans (OPRM1A118G) and rhesus macaques (OPRM1C77G). We hypothesized that rhesus infants carrying a gain-of-functionOPRM177G allele would experience increased reward during maternal contact and would, therefore, display increased measures of attachment. We collected behavioral data from rhesus macaques (n= 97) during early infancy and at 6 months of age, across four cycles of maternal separation (4 days) and reunion (3 days). Animals were genotyped for theOPRM1C77G polymorphism, and the effects of this allele on attachment-related behaviors were analyzed. Infants carrying the G allele exhibited higher levels of attachment behavior during early infancy. During prolonged periods of maternal separation, although infant macaques homozygous for the C allele exhibited decreases in their levels of distress vocalization with repeated separation, this response persisted in G allele carriers. TheOPRM177G allele also affected social preference during reunion. C/G infants spent increasing amounts of time in social contact with their mothers as a function of repeated separation and were less likely to interact with other individuals in the social group, a pattern not observed among infants with the C/C genotype. These findings suggest a role forOPRM1variation in the expression of attachment behavior in human subjects, especially as a function of separation from the caregiver.
Palmitoylation and ubiquitination regulate exit of the Wnt signaling protein LRP6 from the endoplasmic reticulum
Authors: Abrami Laurence , Kunz Béatrice , Iacovache Ioan , van der Goot F. Gisou
Published: April 2008

Canonical Wnt signaling is initiated by binding of Wnt proteins to members of the Frizzled family and subsequent complex formation with lipoprotein receptor-related proteins 5/6 (LRP5/6). Here, we show that LRP6 is palmitoylated on a juxtamembranous cysteine and that palmitoylation is required for exit from the endoplasmic reticulum (ER). We propose that palmitoylation serves to tilt the long, 23-residue transmembrane domain of LRP6 with respect to the plane of membrane to prevent a hydrophobic mismatch and subsequent recognition by the ER quality control. In support of this model, a palmitoylation-deficient LRP6 mutant could be rescued from ER retention by deletion of two to four residues in the transmembrane domain. Importantly, we found that palmitoylation-deficient LRP6 was retained in the ER by a completely novel monoubiquitination-dependent ER retention mechanism. Mutation of a specific lysine indeed abolished ubiquitination of palmitoylation-deficient LRP6 and led to a rescue from ER retention. Finally, at the cell surface, we found that interplay between palmitoylation and ubiquitination was necessary for efficient Wnt signaling.
Rational chemical design of the carbohydrate in a glycoconjugate vaccine enhances IgM-to-IgG switching
Authors: Guttormsen Hilde-Kari , Paoletti Lawrence C. , Mansfield Keith G. , Jachymek Wojcieck , Jennings Harold J. , Kasper Dennis L.
Published: April 2008

Many pathogens are sheltered from host immunity by surface polysaccharides that would be ideal as vaccines except that they are too similar to host antigens to be immunogenic. The production of functional IgG is a desirable response to vaccines; because IgG is the only isotype that crosses the placenta, it is of particular importance in maternal vaccines against neonatal disease due to group BStreptococcus(GBS). Clinical studies found a substantially lower proportion of IgG—relative to IgM—among antibodies elicited by conjugates prepared with purified GBS type V capsular polysaccharide (CPS) than among those evoked by CPSs of other GBS serotypes. The epitope specificity of IgG elicited in humans by a conjugate prepared with type V CPS is for chemically desialylated type V CPS (dV CPS). We studied desialylation as a mechanism for enhancing the ability of type V CPS to induce IgM-to-IgG switching. Desialylation did not affect the structural conformation of type V CPS. Rhesus macaques, whose isotype responses to GBS conjugates match those of humans, produced functionally active IgG in response to a dV CPS–tetanus toxoid conjugate (dV-TT), and 98% of neonatal mice born to dams vaccinated with dV-TT survived lethal challenge with viable GBS. Targeted chemical engineering of a carbohydrate to create a molecule less like host self may be a rational approach for improving other glycoconjugates.
Human glucocorticoid-induced TNF receptor ligand regulates its signaling activity through multiple oligomerization states
Authors: Zhou Zhaocai , Song Xiaomin , Berezov Alan , Zhang Geng , Li Yanjing , Zhang Hongtao , Murali Ramachandran , Li Bin , Greene Mark I.
Published: April 2008

Ligation between glucocorticoid-induced tumor necrosis factor receptor (GITR) and its ligand (GITRL) provides an undefined signal that renders CD4
+
CD25
−
effector T cells resistant to the inhibitory effects of CD4
+
CD25
+
regulatory T cells. To understand the structural basis of GITRL function, we have expressed and purified the extracellular domain of human GITR ligand in
Escherichia coli
. Chromotography and cross-linking studies indicate that human GITRL (hGITRL) exists as dimers and trimers in solution and also can form a supercluster. To gain insight into the nature of GITRL oligomerization, we determined the crystallographic structures of hGITRL, which revealed a loosely associated open trimer with a deep cavity at the molecular center and a flexible C-terminal tail bent for trimerization. Moreover, a tetramer of trimers (i.e., supercluster) has also been observed in the crystal, consistent with the cross-linking analysis. Deletion of the C-terminal distal three residues disrupts the loosely assembled trimer and favors the formation of a dimer that has compromised receptor binding and signaling activity. Collectively, our studies identify multiple oligomeric species of hGITRL that possess distinct kinetics of ERK activation. The studies address the functional implications and structural models for a process by which hGITRL utilizes multiple oligomerization states to regulate GITR-mediated signaling during T cell costimulation.
CASY-1, an ortholog of calsyntenins/alcadeins, is essential for learning in
Caenorhabditis elegans
Authors: Ikeda Daisuke D. , Duan Yukan , Matsuki Masahiro , Kunitomo Hirofumi , Hutter Harald , Hedgecock Edward M. , Iino Yuichi
Published: April 2008

Calsyntenins/alcadeins are type I transmembrane proteins with two extracellular cadherin domains highly expressed in mammalian brain. They form a tripartite complex with X11/X11L and APP (amyloid precursor protein) and are proteolytically processed in a similar fashion to APP. Although a genetic association of calsyntenin-2 with human memory performance has recently been reported, physiological roles and molecular functions of the protein in the nervous system are poorly understood. Here, we show that CASY-1, the
Caenorhabditis elegans
ortholog of calsyntenins/alcadeins, is essential for multiple types of learning. Through a genetic screen, we found that
casy-1
mutants show defects in salt chemotaxis learning.
casy-1
mutants also show defects in temperature learning, olfactory adaptation, and integration of two sensory signals.
casy-1
is widely expressed in the nervous system. Expression of
casy-1
in a single sensory neuron and at the postdevelopmental stage is sufficient for its function in salt chemotaxis learning. The fluorescent protein-tagged ectodomain of CASY-1 is released from neurons. Moreover, functional domain analyses revealed that both cytoplasmic and transmembrane domains of this protein are dispensable, whereas the ectodomain, which contains the LG/LNS-like domain, is critically required for learning. These results suggest that learning is modulated by the released ectodomain of CASY-1.
Suppression of immediate-early viral gene expression by herpesvirus-coded microRNAs: Implications for latency
Authors: Murphy Eain , Vaníček Jiří , Robins Harlan , Shenk Thomas , Levine Arnold J.
Published: April 2008

A quantitative algorithm was developed and applied to predict target genes of microRNAs encoded by herpesviruses. Although there is almost no conservation among microRNAs of different herpesvirus subfamilies, a common pattern of regulation emerged. The algorithm predicts that herpes simplex virus 1, human cytomegalovirus, Epstein–Barr virus, and Kaposi's sarcoma-associated herpesvirus all employ microRNAs to suppress expression of their own genes, including their immediate-early genes. In the case of human cytomegalovirus, a virus-coded microRNA, miR-112-1, was predicted to target the viral immediate-early protein 1 mRNA. To test this prediction, mutant viruses were generated that were unable to express the microRNA, or encoded an immediate-early 1 mRNA lacking its target site. Analysis of RNA and protein within infected cells demonstrated that miR-UL112-1 inhibits expression of the major immediate-early protein. We propose that herpesviruses use microRNA-mediated suppression of immediate-early genes as part of their strategy to enter and maintain latency.
Microbial carbohydrate depolymerization by antigen-presenting cells: Deamination prior to presentation by the MHCII pathway
Authors: Duan Jinyou , Avci Fikri Y. , Kasper Dennis L.
Published: April 2008

After uptake by the endosome of an antigen-presenting cell (APC), exogenous proteins are known to be degraded into peptides by protease digestion. Here, we report the mechanism by which pure carbohydrates can be depolymerized within APC endosomes/lysosomes by nitric oxide (NO)-derived reactive nitrogen species (RNSs) and/or superoxide-derived reactive oxygen species (ROSs). Earlier studies showed that depolymerization of polysaccharide A (PSA) from
Bacteroides fragilis
in the endosome depends on the APC's having an intact inducible nitric oxide synthase (iNOS) gene; the chemical mechanism underlying depolymerization of a carbohydrate within the endosome/lysosome is described here. Examining the ability of the major RNSs to degrade PSA, we determined that deamination is the predominant mechanism for PSA processing in APCs and is a required step in PSA presentation to CD4
+
T cells by MHCII molecules. Structural characterization of the NO-derived product PSA-NO indicates that partial deaminative depolymerization does not alter the zwitterionic nature of PSA. Unlike native PSA, PSA-NO is presented by iNOS-deficient APCs to induce CD4
+
T cell proliferation. Furthermore, metabolically active APCs are required for PSA-NO presentation. In contrast to PSA degradation by RNSs, dextran depolymerization in the endosome depends on ROSs, including hydrogen peroxide- and superoxide-derived ROSs. This study provides evidence that MHCII pathway-mediated carbohydrate antigen processing in APCs is achieved by chemical reactions. RNSs and ROSs may be involved in the presentation of glycopeptides by MHC molecules via the processing of other carbohydrate-containing antigens, such as bacterial or viral glycoproteins or glycoconjugate vaccines.
ℬ(
H
) has a pure state that is not multiplicative on any masa
Authors: Akemann Charles , Weaver Nik
Published: April 2008

Assuming the continuum hypothesis, we prove that ℬ(
H
) has a pure state whose restriction to any masa is not pure. This resolves negatively old conjectures of Kadison and Singer and of Anderson.
Placental pathology in women with gestational diabetes
Authors: DASKALAKIS GEORGE , MARINOPOULOS SPYROS , KRIELESI VASILIKI , PAPAPANAGIOTOU ANGELIKI , PAPANTONIOU NIKOLAOS , MESOGITIS SPYROS , ANTSAKLIS ARIS
Published: April 2008

Background. The aim of this study was to investigate pathologic differences of the placenta in pregnancies complicated by gestational diabetes compared to non‐diabetic pregnancies. Methods. Forty singleton pregnancies complicated by gestational diabetes were recruited and compared to 40 consecutive normal pregnancies. A pathologist, blinded to all clinical data, reviewed all histological samples of the placentas. The histological assessment was carried out with regard to the following aspects: fetal vessel thrombosis, villous immaturity, chorangiosis, presence of nucleated fetal red blood cells (NFRBCs), ischemia, infarction, presence of hydropic or avascular villi, lymphohistiocytic villitis and villous fibrinoid necrosis. Results. The presence of degenerative lesions such as fibrinoid necrosis and vascular lesions like chorangiosis was apparent, mainly in the diabetes group. Villous immaturity and the presence of NFRBC as an indication of chronic fetal hypoxia were significantly increased in the placentas of women with diabetes compared with the control group. Fetal/placental weight ratio was significantly lower in the diabetic group. Conclusion. Histological abnormalities were observed more frequently in the diabetic placentas compared to the controls. These findings support the hypothesis that impaired placental function is one of the main reasons for the increased frequency of fetal complications in diabetic pregnancies.
Impaired maternal cognitive functioning after pregnancies complicated by severe pre‐eclampsia: a pilot case‐control study
Authors: BRUSSÉ INGRID , DUVEKOT JOHANNES , JONGERLING JORAN , STEEGERS ERIC , DE KONING INGE
Published: April 2008

Background. Pre‐eclampsia is the most significant cause of neurological symptoms in pregnancy. Neurological symptoms may persist even after pregnancy. Somatic symptoms of pre‐eclampsia, such as hypertension and proteinuria, generally disappear after delivery. However, formerly pre‐eclamptic women more often complain of cognitive disturbances compared to women after uncomplicated pregnancies. Methods. Three to eight months postpartum, a neuropsychological test battery was performed in 10 former severely pre‐eclamptic women (according to the guidelines of the American College Obstetricians and Gynecologists) and 10 women after uncomplicated normotensive pregnancies. The control group was matched for age, educational level and mode of anesthesia. All women delivered by cesarean section either under general or regional anesthesia. Tests were performed for premorbid intelligence, short‐ and long‐term memory, attention, concentration, executive functions, visual and spatial abilities. Anxiety and depression levels were measured. Results. The formerly pre‐eclamptic women had significantly lower scores on most indices of the auditory‐verbal memory test. Formerly pre‐eclamptic patients learned considerably fewer words than controls and recalled less after interference. Both case and control group did not differ in age, parity or level of education. There were no differences in the level of intellectual functioning and language tests, such as naming and word fluency. No persistent differences were observed in tests for attention/concentration and executive functioning. There were no significant differences on depression and anxiety scales. Conclusions. Maternal memory seems to be impaired after pregnancies complicated by severe pre‐eclampsia. This effect cannot be attributed to depression and/or anxiety or method of anesthesia.
Serum visfatin levels in late pregnancy and pre‐eclampsia
Authors: HU WENSHENG , WANG ZHENGPING , WANG HANZHI , HUANG HEFENG , DONG MINYUE
Published: April 2008

Objectives. To characterise the changes in serum visfatin levels in late normal pregnancy and pre‐eclampsia. Methods. Twenty‐seven women with pre‐eclampsia were recruited. Twenty‐eight women in the third trimester of normal pregnancy served as pregnant control and 28 healthy non‐pregnant women as non‐pregnant control. Serum levels of visfatin were measured with an enzyme‐linked immunosorbent assay. Results. The means of serum visfatin were 626.4±45.5ng/ml (mean±SEM) in non‐pregnant control, 695.9±92.5ng/ml in pregnant control, and 308.3±80.0 ng/ml in pre‐eclampsia, respectively, and were significantly different among the groups (p <0.001). Visfatin level was significantly lower in pre‐eclampsia compared to non‐pregnant control (p = 0.004) and pregnant control (p <0.001). Women with severe pre‐eclampsia had a significantly lower serum visfatin level than those with mild pre‐eclampsia (114.6±80.9 versus 425.2±122.1ng/ml, p = 0.037). Conclusions. A decrease in visfatin level was demonstrated in pre‐eclampsia, suggesting that visfatin and adipokine‐associated metabolic abnormalities are involved in the pathogenesis of the disease.
Genital prolapse surgery after a shift in treatment tradition: an analysis of subsequent prolapse surgery
Authors: CRAFOORD KRISTINA , SYDSJÖ ADAM , KJØLHEDE PREBEN
Published: April 2008

Objective. To determine whether the shift in treatment tradition of genital prolapse surgery was followed by a change in the occurrence of subsequent prolapse surgery, and to analyze the complementary and recurrent surgery with respect to the size of the prolapse and the extent of the primary surgery. Methods. A retrospective study of patients consecutively operated with primary prolapse surgery in three Swedish hospitals in two time periods: 261 patients in 1983 (Period I) and 281 patients in 1993 (Period II). Clinical data were obtained from the patient records. A follow‐up period of 6 years was used for both periods. Results. Subsequent prolapse surgery was seen significantly more often in Period II than in Period I (7.7 versus 2.7%), and after selective repairs compared with complete repairs (7.7 versus 3.2%). Despite a significant reduction in the use of posterior repair between the time periods, no significant increase was seen in complementary posterior repairs compared with complementary repair in any of the other compartments. Size of the prolapse at the primary surgery or hysterectomy did not seem to influence the occurrence of subsequent prolapse surgery. The postoperative complication rate was significantly higher after complete repairs than after selective repair, and especially when posterior repair was included in the operation. Conclusion. Subsequent prolapse surgery is slightly more common after selective repair than after complete repair. However, selective repairs are encumbered with a lower complication rate. The results of this study appear to be in favor of a restrictive use of ‘prophylactic’ posterior repair.
Prognostic significance of the micropapillary pattern in patients with serous borderline ovarian tumors
Authors: CHANG SUK‐JOON , RYU HEE‐SUG , CHANG KI‐HONG , YOO SEUNG‐CHUL , YOON JONG‐HYUCK
Published: April 2008

Background. The impact of micropapillary histology on survival in patients with serous borderline ovarian tumors is not established. The purpose of this study was to evaluate the significance and influence of micropapillary pattern on clinical outcome of patients with serous borderline ovarian tumors. Methods. Eighty‐five patients who underwent surgery and were diagnosed with serous borderline ovarian tumors were retrospectively studied. Among these patients, 18 patients showed micropapillary pattern on histologic examination, while the remaining 67 patients did not. The significance of the presence of micropapillary pattern and relationship with various clinicopathologic findings and progression‐free survival were evaluated by statistical analysis. Results. No differences with regard to age, parity, body mass index, pretreatment CA‐125 level, tumor size, bilaterality, and the duration of follow‐up were observed between the two groups, but there was a significant difference in terms of FIGO stage (p<0.001), invasive implants (p = 0.004), performing lymphadenectomy (p = 0.009), operation time (p = 0.003), estimated blood loss (p<0.001), residual disease>1 cm (p = 0.001), adjuvant chemotherapy (p<0.001), and the length of hospital stay (p = 0.013). Progression‐free survival was found to be significantly decreased in patients with invasive implants (HR, 5.06; p = 0.025) and micropapillary pattern (HR, 4.20; p = 0.056) on multivariate analysis. Conclusions. Micropapillary serous borderline ovarian tumors were associated with a more aggressive clinical course compared with typical serous borderline ovarian tumor. The presence of invasive implants and micropapillary pattern were significant prognostic factors in patients with serous borderline ovarian tumors.
Interleukin‐10 −1082 G/A promoter polymorphism and pregnancy complications: results of a prospective cohort study in 1,616 pregnant women
Authors: STONEK FELIX , METZENBAUER MARTIN , HAFNER ERICH , PHILIPP KARL , TEMPFER CLEMENS
Published: April 2008

Objective. To investigate the frequency of the interleukin‐10 (IL‐10)−1082 G/A single nucleotide polymorphism in women with intrauterine fetal death (IUFD), pre‐eclampsia (PE), preterm delivery (PD), and small for gestational age (SGA) infants. Methods. In a prospective cohort study, DNA from 1,616 consecutive pregnant women was analyzed for IL‐10 −1082 G/A by polymerase chain reaction. Women who developed at least one of the predefined pregnancy complications were used as cases and compared to women without pregnancy complications. Results. Of 1,616 women, 254 (15.7%) developed at least one pregnancy complication. IL‐10 −1082 G/A allele frequencies (G: 233/508 [45.9%] and A: 275/508 [54.1%] versus G: 1,143/2,724 [42.0%] and A: 1,581/2,724 [58.0%], respectively; p = 0.10; OR 0.85; 95% CI 0.69–1.04) and genotype distributions (A/A+G/A: 201/254 [79.1%] and G/G 53/254 [20.9%] versus A/A+G/A: 1,125/1,362 [82.6%] and G/G 237/1,362 [17.4%], respectively, p = 0.19; OR 0.79; 95% CI 0.54–1.15) were not significantly different between cases and controls. We observed no statistically significant difference in IL‐10 −1082 G/A genotype distribution comparing controls and women with IUFD, PE, PD <37 weeks gestation, and SGA infants (<10th percentile). Conclusion. IL‐10 −1082 G/A polymorphism is not a genetic marker for identifying women at increased risk of common pregnancy complications.
New African Choices? The Politics of Chinese Engagement
Authors: Mohan Giles , Power Marcus
Published: April 2008

The role of China in Africa must be understood in the context of competing and intensified global energy politics, in which the US, India and China are among the key players vying for security of supply. Contrary to popular representation, China's role in Africa is much more than this however, opening up new choices for African development for the first time since the neo-liberal turn of the 1980s. As such it is important to start by disaggregating ‘China’ and ‘Africa’ since neither represents a coherent and uniform set of motivations and opportunities. This points to the need for, at minimum, a comparative case study approach which highlights the different agendas operating in different African states. It also requires taking a longue durée perspective since China-Africa relations are long standing and recent intervention builds on cold war solidarities, in polemic at least. It also forces us to consider Chinese involvement in Africa as ambivalent, but contextual. Here we look at the political dimensions of this engagement and set out a research agenda that focuses on class and racial dynamics, state restructuring, party politics, civil society responses and aid effectiveness.
History & Identity in the Construction of China's Africa Policy
Authors: Alden Chris , Alves Cristina
Published: April 2008

One of the most notable features of the forging of China's new activist foreign policy towards Africa is its emphasis on the historical context of the relationship. These invocations of the past, stretching back to the 15th century but rife with references to events in the 19th century and the cold war period, are regular features of Chinese diplomacy in Africa. Indeed, it is the persistence of its use and the concurrent claim of a continuity of underlying purpose that marks Chinese foreign policy out from western approaches which have by and large been content to avoid discussions of the past (for obvious reasons) or insisting on any policy continuities. However, beneath the platitudes of solidarity is a reading of Chinese historical relations with Africa emanating from Beijing that is, as any student of contemporary African history will know, at times at odds with the historical record of Chinese involvement on the continent.

This article will examine the use and meaning of history in the construction of China's Africa policy. It will do so through first, a brief discussion of the relationship between foreign policy, identity and history; second, a survey of Chinese foreign policy towards Africa from 1955 to 1996; third, an analysis of the implications of Beijing's approach for its efforts to achieve foreign policy aims regionally and globally.
The Clp1/Cdc14 phosphatase contributes to the robustness of cytokinesis by association with anillin-related Mid1
Authors: Clifford Dawn M. , Wolfe Benjamin A. , Roberts-Galbraith Rachel H. , McDonald W. Hayes , Yates John R. , Gould Kathleen L.
Published: April 2008

Cdc14 phosphatases antagonize cyclin-dependent kinase–directed phosphorylation events and are involved in several facets of cell cycle control. We investigate the role of the fission yeast Cdc14 homologue Clp1/Flp1 in cytokinesis. We find that Clp1/Flp1 is tethered at the contractile ring (CR) through its association with anillin-related Mid1. Fluorescent recovery after photobleaching analyses indicate that Mid1, unlike other tested CR components, is anchored at the cell midzone, and this physical property is likely to account for its scaffolding role. By generating a mutation in mid1 that selectively disrupts Clp1/Flp1 tethering, we reveal the specific functional consequences of Clp1/Flp1 activity at the CR, including dephosphorylation of the essential CR component Cdc15, reductions in CR protein mobility, and CR resistance to mild perturbation. Our evidence indicates that Clp1/Flp1 must interact with the Mid1 scaffold to ensure the fidelity of Schizosaccharomyces pombe cytokinesis.
Relaxing the actin cytoskeleton for adhesion and movement with Ena/VASP
Authors: Trichet Léa , Sykes Cécile , Plastino Julie
Published: April 2008

At cell–cell contacts, as well as at the leading edge of motile cells, the plasticity of actin structures is maintained, in part, through labile connections to the plasma membrane. Here we explain how and why Drosophila enabled/vasodilator stimulated phosphoprotein (Ena/VASP) proteins are candidates for driving this cytoskeleton modulation under the membrane.
Plk1- and β-TrCP–dependent degradation of Bora controls mitotic progression
Authors: Seki Akiko , Coppinger Judith A. , Du Haining , Jang Chang-Young , Yates John R. , Fang Guowei
Published: April 2008

Through a convergence of functional genomic and proteomic studies, we identify Bora as a previously unknown cell cycle protein that interacts with the Plk1 kinase and the SCF–β-TrCP ubiquitin ligase. We show that the Bora protein peaks in G2 and is degraded by proteasomes in mitosis. Proteolysis of Bora requires the Plk1 kinase activity and is mediated by SCF–β-TrCP. Plk1 phosphorylates a conserved DSGxxT degron in Bora and promotes its interaction with β-TrCP. Mutations in this degron stabilize Bora. Expression of a nondegradable Bora variant prolongs the metaphase and delays anaphase onset, indicating a physiological requirement of Bora degradation. Interestingly, the activity of Bora is also required for normal mitotic progression, as knockdown of Bora activates the spindle checkpoint and delays sister chromatid segregation. Mechanistically, Bora regulates spindle stability and microtubule polymerization and promotes tension across sister kinetochores during mitosis. We conclude that tight regulation of the Bora protein by its synthesis and degradation is critical for cell cycle progression.
IP3 sensitizes TRPV4 channel to the mechano- and osmotransducing messenger 5′-6′-epoxyeicosatrienoic acid
Authors: Fernandes Jacqueline , Lorenzo Ivan M. , Andrade Yaniré N. , Garcia-Elias Anna , Serra Selma A. , Fernández-Fernández José M. , Valverde Miguel A.
Published: April 2008

Mechanical and osmotic sensitivity of the transient receptor potential vanilloid 4 (TRPV4) channel depends on phospholipase A2 (PLA2) activation and the subsequent production of the arachidonic acid metabolites, epoxyeicosatrienoic acid (EET). We show that both high viscous loading and hypotonicity stimuli in native ciliated epithelial cells use PLA2–EET as the primary pathway to activate TRPV4. Under conditions of low PLA2 activation, both also use extracellular ATP-mediated activation of phospholipase C (PLC)–inositol trisphosphate (IP3) signaling to support TRPV4 gating. IP3, without being an agonist itself, sensitizes TRPV4 to EET in epithelial ciliated cells and cells heterologously expressing TRPV4, an effect inhibited by the IP3 receptor antagonist xestospongin C. Coimmunoprecipitation assays indicated a physical interaction between TRPV4 and IP3 receptor 3. Collectively, our study suggests a functional coupling between plasma membrane TRPV4 channels and intracellular store Ca2+ channels required to initiate and maintain the oscillatory Ca2+ signal triggered by high viscosity and hypotonic stimuli that do not reach a threshold level of PLA2 activation.