bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency and difficulty in caregiving among spouses of individuals with cancer: effects of adult attachment and gender
Authors: Kim Youngmee , Carver Charles S.
Published: November 2006

How caregivers relate to care recipients can affect how well care is provided and how much burden is experienced in providing it. We conceptualized the relationship of spousal caregivers via adult attachment theory and examined how attachment qualities of caregivers related to level of caregiving involvement and difficulties in caregiving. Gender differences in the associations were also explored. From participants in the ACS Quality of Life Survey for Caregivers, 400 spousal caregivers provided valid data for the study variables. Findings indicated that frequency of various types of care was a joint function of attachment orientation and gender. In contrast, the difficulty that caregivers experienced in providing care related directly to attachment, without moderation by gender. Our findings suggest that ineffective caregivers of cancer patients, who can be identified by their attachment orientation and/or gender, may benefit from educational programs to improve their caregiving skills and to encourage them to utilize resources from other family members or community. Copyright © 2006 John Wiley & Sons, Ltd.
The cancer worry chart: a single‐item screening measure of worry about developing breast cancer
Authors: Gramling Robert , Anthony David , Frierson Georita , Bowen Deborah
Published: November 2006

Background: Brief pictograph measures of health functioning have clinical value to office‐based practice. Many women with a close family history of breast cancer will experience worry about their risk of developing breast cancer that influences decision‐making and can interfere with health‐related functioning.

Purpose: To develop a clinically ‐ useful triage measure of breast cancer worry for the field setting of office based practice.

Methods: Design: qualitative pilot testing followed by mailed survey. Survey sample: women registered with the Cancer Genetics Network who have a first or second‐degree family history of breast cancer and no personal history of any cancer. Novel measure: single pictograph item modeled upon the Dartmouth COOP Charts. Comparison gold‐standard measure: four‐item Cancer Worry Scale (CWS).

Results: Pilot testing: participants found the item to be easily understood, rapidly completed and unobtrusive. Quantitative: 469 women responded (78% response rate); the Cancer Worry Chart demonstrated strong correlation to the CWS (Pearson correlation coefficient: 0.66, P < 0.001); Receiver operator curve identified favorable characteristics (AUC = 0.86) of the Cancer Worry Chart for identifying cancer worry‐related mood or social role dysfunction.

Conclusions: The new Cancer Worry Chart is a valid triage measure for breast cancer worry. Copyright © 2006 John Wiley & Sons, Ltd.
Ensemble docking of multiple protein structures: Considering protein structural variations in molecular docking
Authors: Huang Sheng‐You , Zou Xiaoqin
Published: November 2006

One approach to incorporate protein flexibility in molecular docking is the use of an ensemble consisting of multiple protein structures. Sequentially docking each ligand into a large number of protein structures is computationally too expensive to allow large‐scale database screening. It is challenging to achieve a good balance between docking accuracy and computational efficiency. In this work, we have developed a fast, novel docking algorithm utilizing multiple protein structures, referred to as ensemble docking, to account for protein structural variations. The algorithm can simultaneously dock a ligand into an ensemble of protein structures and automatically select an optimal protein structure that best fits the ligand by optimizing both ligand coordinates and the conformational variable m, where m represents the m‐th structure in the protein ensemble. The docking algorithm was validated on 10 protein ensembles containing 105 crystal structures and 87 ligands in terms of binding mode and energy score predictions. A success rate of 93% was obtained with the criterion of root‐mean‐square deviation <2.5 Å if the top five orientations for each ligand were considered, comparable to that of sequential docking in which scores for individual docking are merged into one list by re‐ranking, and significantly better than that of single rigid‐receptor docking (75% on average). Similar trends were also observed in binding score predictions and enrichment tests of virtual database screening. The ensemble docking algorithm is computationally efficient, with a computational time comparable to that for docking a ligand into a single protein structure. In contrast, the computational time for the sequential docking method increases linearly with the number of protein structures in the ensemble. The algorithm was further evaluated using a more realistic ensemble in which the corresponding bound protein structures of inhibitors were excluded. The results show that ensemble docking successfully predicts the binding modes of the inhibitors, and discriminates the inhibitors from a set of noninhibitors with similar chemical properties. Although multiple experimental structures were used in the present work, our algorithm can be easily applied to multiple protein conformations generated by computational methods, and helps improve the efficiency of other existing multiple protein structure(MPS)‐based methods to accommodate protein flexibility. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Clinical Predictors of Ongoing Infection in Secondary Peritonitis: Systematic Review
Authors: Lamme Bas , Mahler Cecilia W. , van Ruler Oddeke , Gouma Dirk J. , Reitsma Johannes B. , Boermeester Marja A.
Published: November 2006

Introduction

The decision to perform a relaparotomy in patients with secondary peritonitis is based on “clinical judgment” with inherent variability among surgeons. Our objective was to review the literature on prognostic variables for ongoing abdominal infection. Predictive variables for positive findings at relaparotomy can generate more objective criteria to support the decision whether to perform a relaparotomy in patients with secondary peritonitis.

Methods

Multiple databases were searched for studies assessing the prognostic value of clinical variables predicting outcome of relaparotomy or general outcome in patients with secondary peritonitis. Data on the methodologic quality of the study as well as statistical strength of predictors and validity of individual variables were extracted and scored. A cumulative score was calculated from these three scores, and the variables were ranked.

Results

A total of 37 of 197 retrieved articles were included for final assessment. The median score for methodologic quality of individual articles was 36 (range 19–54). After calculation of the combined scores, 76 individual variables (patient, peritonitis, surgery, clinical, and laboratory variables) were identified from which the top 10 were eventually selected. These variables were age, concomitant disease, upper gastrointestinal source of peritonitis, generalized peritonitis, elimination of the focus, bilirubin, creatinine, lactate, PaO2/FiO2 ratio, and albumin. This set of variables proved to be moderately predictive for positive findings during relaparotomy in a retrospective cohort of 219 patients operated on for secondary peritonitis (receiver operator curve 0.75, with 95% confidence interval 0.68–0.82).

Conclusions

This review generated a hierarchy (weighted ranking) of published variables that could play a role in the decision to perform a relaparotomy in patients with secondary peritonitis. The top sixtile of ranked variables (10 variables) showed promising results in the discrimination between patients having a positive and negative relaparotomy when tested on a peritonitis patient database. This ranking of variables provides evidence for potential inclusion of variables in future predictive scores, although improvement in overall predictive strength of a set of variables in such a score is needed.
Current Concepts in Anal Fissures
Authors: Ayantunde Abraham A. , Debrah Samuel A.
Published: November 2006

Introduction

Anal fissure is a common and distressing problem the true incidence of which is probably higher than recorded. There is a progressive understanding of the etiopathogenesis of this entity and the changing trend in its management approach. This is a systematic review of available published literature looking at current management options in anal fissures.

Methods

A MEDLINE‐based search of the relevant literature from 1970 to 2004 was performed on the current concepts in etiopathogenesis and management of anal fissure.

Results

The current opinion is a drift toward conservative measures as the first‐ and second‐line approaches rather than surgery for treatment of anal fissure. Simple and readily available measures with less complication, good patient compliance, and satisfaction requiring no hospitalization should first be considered.

Conclusions

Most anal fissures heal with medical therapy, but their limitations include side effects, poor compliance, and recurrence of the fissure. A cautious surgical approach is required to treat those who do not respond to medical therapy.
Correlations and bounds for stochastic volatility models
Authors: Lions P.-L. , Musiela M.
Published: November 2006

We investigate here, systematically and rigorously, various stochastic volatility models used in Mathematical Finance. Mathematically, such models involve coupled stochastic differential equations with coefficients that do not obey the natural and classical conditions required to make these models “well-posed”. And we obtain necessary and sufficient conditions on the parameters, such as correlation, of these models in order to have integrable or

L^{p}

solutions (for

1 < p < \infty

).
Trace amounts of copper induce neurotoxicity in the cholesterol‐fed mice through apoptosis
Authors: Lu Jun , Zheng Yuan-lin , Wu Dong-mei , Sun Dong-xu , Shan Qun , Fan Shao-hua
Published: November 2006

Evidence has been gathered to suggest that trace amounts of copper induce neurotoxicity by interaction with elevated cholesterol in diet. Copper treatment alone showed no significant learning and memory impairments in behavioral tasks. However, copper‐induced neurotoxicity was significantly increased in mice given elevated‐cholesterol diet. Trace amounts of copper decreased the activity of SOD and increased the level of malondialdehyde (MDA) in the brain of cholesterol‐fed mouse. Copper also caused an increase in amyloid precursor protein (APP) mRNA level and the activation of caspase‐3 in the brain of cholesterol‐fed mice. The apoptosis‐induced nuclear DNA fragmentation was detected in the brain of those mice by terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP nick‐end‐labeling staining. These findings suggest that trace amounts of copper induce neurotoxicity in cholesterol‐fed mice through apoptosis caused by oxidative stress.
Glycosylation regulates turnover of cyclooxygenase‐2
Authors: Sevigny Mary B. , Li Chai-Fei , Alas Monika , Hughes-Fulford Millie
Published: November 2006

Cyclooxygenase‐2 (COX‐2) catalyzes the rate‐limiting step in the prostanoid biosynthesis pathway, converting arachidonic acid into prostaglandin H2. COX‐2 exists as 72 and 74 kDa glycoforms, the latter resulting from an additional oligosaccharide chain at residue Asn580. In this study, Asn580 was mutated to determine the biological significance of this variable glycosylation. COS‐1 cells transfected with the mutant gene were unable to express the 74 kDa glycoform and were found to accumulate more COX‐2 protein and have five times greater COX‐2 activity than cells expressing both glycoforms. Thus, COX‐2 turnover appears to depend upon glycosylation of the 72 kDa glycoform.
Dysfunction of regulatory volume increase is a key component of apoptosis
Authors: Maeno Emi , Takahashi Nobuyuki , Okada Yasunobu
Published: November 2006

Sustained cell shrinkage is a major hallmark of apoptotic cell death. In apoptotic cells, whole cell volume reduction, called apoptotic volume decrease (AVD), proceeds until fragmentation of cells. Under non‐apoptotic conditions, human epithelial HeLa cells exhibited a slow regulatory volume increase (RVI) after osmotic shrinkage induced by exposure to hypertonic solution. When AVD was induced by treatment with a Fas ligand, TNF‐α or staurosporine, however, it was found that HeLa cells failed to undergo RVI. When RVI was inhibited by combined application of Na+/H+ exchanger (NHE) and anion exchanger blockers, hypertonic stress induced prolonged shrinkage followed by caspase‐3 activation in HeLa cells. Hypertonicity also induced apoptosis in NHE1‐deficient PS120 fibroblasts, which lack the RVI response. When RVI was restored by transfection of these cells with NHE1, hypertonicity‐induced apoptosis was completely prevented. Thus, it is concluded that RVI dysfunction is indispensable for the persistence of AVD and induction of apoptosis.
Aluminum inhibits proteolytic degradation of amyloid β peptide by cathepsin D: A potential link between aluminum accumulation and neuritic plaque deposition
Authors: Sakamoto Takashi , Saito Hisaka , Ishii Kazuyuki , Takahashi Hidenobu , Tanabe Shinzo , Ogasawara Yuki
Published: November 2006

Neuritic plaques are the key pathological feature of Alzheimer's disease, and amyloid β (Aβ) peptides are major component of these plaques. In this study, we demonstrated the influence of aluminum (Al) on the Aβ peptide degradation by cathepsin D. Al did not directly affect the cathepsin D activity using small synthetic substrate. However, when Aβ peptides were used as substrate, the apparent inhibitory effect of Al on cathepsin D activity was observed. This inhibitory effect disappeared by treatment of desferrioxamine. These results indicate that Al has the potential to interact and disrupt Aβ peptide catabolism via the inhibition of proteolytic degradation.
Gain‐ and loss‐of‐function mutations in Zat10 enhance the tolerance of plants to abiotic stress
Authors: Mittler Ron , Kim YongSig , Song Luhua , Coutu Jesse , Coutu Alicia , Ciftci-Yilmaz Sultan , Lee Hojoung , Stevenson Becky , Zhu Jian-Kang
Published: November 2006

C2H2‐zinc finger proteins that contain the EAR repressor domain are thought to play a key role in modulating the defense response of plants to abiotic stress. Constitutive expression of the C2H2‐EAR zinc finger protein Zat10 in Arabidopsis was found to elevate the expression of reactive oxygen‐defense transcripts and to enhance the tolerance of plants to salinity, heat and osmotic stress. Surprisingly, knockout and RNAi mutants of Zat10 were also more tolerant to osmotic and salinity stress. Our results suggest that Zat10 plays a key role as both a positive and a negative regulator of plant defenses.
Combined methods of otolith shape analysis improve identification of spawning areas of Atlantic cod
Authors: Galley Elizabeth A. , Wright Peter J. , Gibb Fiona M.
Published: November 2006

The effectiveness of otolith shape for identifying Atlantic cod (Gadus morhua) spawning populations in the northern North Sea and west coast of Scotland was investigated. Otolith shape was described using Cartesian Fourier analysis of the otolith outline and morphometric variable rectangularity. Pairwise randomization analysis of Fourier descriptors, and discriminant analysis of rectangularity and Fourier descriptors were used to identify differences between spawning stocks. Significant differences and a high classification success (>70%) in otolith shape indicated that spawning groups from Viking Bank and Moray Firth had different shapes from those of cod in other spawning areas. Significant differences in otolith shape of age 2 cod suggested that otoliths from the South Minch and Irish Sea were different from those from the Moray Firth and the Clyde. These results appear consistent with genetic evidence for a low gene flow, and tag-recapture evidence of resident populations. The results of pairwise randomization analysis and discriminant analysis differed slightly, indicating that use of a combination of methods increases the potential to identify spawning groups on the basis of otolith shape.
Acoustic harassment devices reduce seal interaction in the Baltic salmon-trap, net fishery
Authors: Fjälling Arne , Wahlberg Magnus , Westerberg Håkan
Published: November 2006

Acoustic harassment devices (AHDs) were deployed at salmon-trap nets in the Baltic Sea to reduce gear and catch damage by grey seals (Halichoerus grypus). The AHDs emitted pulses of 250–500-ms duration, worked at a frequency of 15 kHz, and a source level of 179 dB re 1 μPa rms at 1 m. AHDs were deployed during three consecutive fishing seasons. Catches were significantly higher in traps with AHDs (25.5 kg d−1) than in controls (12.0 kg d−1), and catch damage was less (3.5 vs. 6.7 kg d−1). These results persisted over and between fishing seasons, but late in the season damage to the catches was common also in traps with AHDs. This study shows that the AHD may be a complementary mitigation tool in the seal–fishery conflict in certain types of fisheries, even though it is technically demanding, and for environmental reasons should be used with great care.
An investigation of the population genetic structure of pollack (Pollachius pollachius) based on microsatellite markers
Authors: Charrier Grégory , Durand Jean-Dominique , Quiniou Louis , Laroche Jean
Published: November 2006

In order to explore the population genetic structure of pollack (Pollachius pollachius) along the European coast, of 282 fish sampled from four locations along the Atlantic French coast and from one location off southern Norway were genotyped at six microsatellite loci. The limited genetic differentiation among samples may be due to high levels of larval dispersal, through passive drift with oceanic currents. Alternatively, populations may have diverged too recently for significant genetic differentiation to have become evident. Furthermore, small sample sizes and the limited number of loci may have hampered the detection of genetic structure. Nevertheless, a weak but significant genetic differentiation was detected between samples originating from the western English Channel and the Bay of Biscay.
Spreading nucleonics: the Isotope School at the Atomic Energy Research Establishment, 1951–67
Authors: HERRAN NÉSTOR
Published: November 2006

The Isotope School was established in 1951 by the British Atomic Energy Research Establishment (AERE) at Harwell following the model of the American Oak Ridge Institute of Nuclear Studies. Until its dissolution in 1967, it played an important role in the expansion of radioisotope techniques in Britain and Western Europe. This paper traces the origin and activities of the Isotope School, and describes the content of its courses and the composition of its audiences both in Britain and abroad. These illustrate the motivations behind the early diffusion of nuclear technology and the importance of Cold War politics in shaping the flows of materials and expertise. In particular, the ban on attendance of Eastern European students at the courses reveals a persistent tension inside the British nuclear programme: the conflict between the drive for disseminating nucleonics and the restrictions forced by national security concerns.
Looking Like a State: Colonialism and the Discourse of Corruption in Northern Nigeria
Authors: Pierce Steven
Published: November 2006

In the international press Nigeria is represented almost exclusively as a state in crisis. Recurrent military coups, ethnic and religious sectionalism, a civil war, a series of bloody riots and local unrest (of which the Niger delta situation is the best-known example), economic turmoil, and the re-imposition of the Islamic criminal code in many northern states have all been used to paint a picture of chaos and collapse. Journalists and government officials alike tend to find the roots of Nigeria's problems in intractable ethnic conflict, the collapse of oil prices in 1983, structural adjustment mandated by the International Monetary Fund in 1986, and hatred between Muslims and Christians. The trouble with Nigeria is also understood to illustrate the trouble with Africa. With 25 percent of the population of sub-Saharan Africa, Nigeria appears as representative of Africa. Potentially wealthy from its oil revenue, it symbolizes Africa's promise denied.
How to Be a Khoziain in a Transforming State: State Formation and the Ethics of Governance in Post-Soviet Russia
Authors: Rogers Douglas
Published: November 2006

The rapid and pervasive changes of the past decade and a half have thrown the political field wide open across the former Soviet bloc. An extensive array of actors has laid claim to the mantle of the postsocialist state, seeking to siphon off its resources, to leverage its putative power, and often to do both in the same breath. At the same time, others have fled the institutional and discursive purview of the state, taking advantage of the near disappearance of centralized authority in the early 1990s to stake out powerful non- and quasi-state domains. The density of these strategies, which in practice have been complementary as often as contradictory, has made for nothing short of an ethical thicket for postsocialist citizens and state functionaries alike.
Nonlinear interactions between three inertial Alfvén waves
Authors: BRODIN G. , STENFLO L. , SHUKLA P. K.
Published: November 2006

The resonant coupling between Alfvén waves is reconsidered. New results are found for cold magnetoplasmas where temperature effects are negligible.
Numerical analysis of strong Langmuir turbulence excited by transverse plasmons in a laser plasma
Authors: LIU X. L. , LIU S. Q.
Published: November 2006

Langmuir waves excited by transverse pumping plasmons near the critical surface in a laser-plasma may collapse, leading to the formation of a density cavity owing to the ponderomotive force. The collapse behavior of electromagnetic waves, Langmuir waves and ion-sound waves are studied numerically. The interactions of the three-wave system will lead to the tendency for an equilibration of energy over both the transverse and Langmuir plasmons with the same frequency near ωpe, which is shown in our numerical analysis.
Collisionless trapped-electron-mode turbulence and transport in fluid descriptions
Authors: NORDMAN H. , STRAND P. , GARBET X.
Published: November 2006

A study of particle and electron heat transport in tokamaks due to trapped-electron-mode (TEM) turbulence is presented. The study is based on the Weiland fluid model for ion-temperature-gradient (ITG) modes and TEMs, complemented and compared with a trapped electron fluid treatment which retains contributions from the weakly trapped electrons. The dependence of the fluid transport coefficients on magnetic shear and other plasma parameters is discussed and compared with results obtained from nonlinear gyrokinetic simulations. Inward (pinch) flows of particles and heat, previously reported for the coupled ITG–TEM system, are also found in the TEM dominated regime.
The global system of international migrations, 1900 and 2000: a comparative approach
Authors: Gozzini Giovanni
Published: November 2006

The aim of this paper is to compare international migrations in two different periods of history, both of them marked by a rapid increase in the trend: the first period runs from 1870 to 1914, and the second from 1965 to 2000. Historical and current migration system maps are compared, together with their different combinations of push and pull factors, and of coerced and free migrations. The various repercussions that international migrations have on demographic structure and on the economic systems of the sending and receiving countries are counterbalanced by a number of significant analogies that occur at the microlevel (individual and community) of the mechanisms governing the decision to migrate, and of migrants’ identities and behavioural patterns. The final section shows that migrants in both periods retain ties to both their old and new countries (as indicated by remittances and return migration), despite the major obstacles that stand in the way of the free circulation of international migrants today. This suggests that an analysis of migration systems, emphasizing ongoing interactions of various sorts between sending and receiving areas, is superior to either a model based on the presumption that assimilation will occur over time or one which presumes an irreducible ‘multiculturalism’.
The Survivin–Crm1 interaction is essential for chromosomal passenger complex localization and function
Authors: Knauer Shirley K , Bier Carolin , Habtemichael Negusse , Stauber Roland H
Published: November 2006

The chromosomal passenger complex (CPC) of Aurora‐B, Borealin, INCENP (inner centromere protein) and Survivin coordinates essential chromosomal and cytoskeletal events during mitosis. Here, we show that the nuclear export receptor Crm1 is crucially involved in tethering the CPC to the centromere by interacting with a leucine‐rich nuclear export signal (NES), evolutionarily conserved in all mammalian Survivin proteins. We show that inhibition of the Survivin–Crm1 interaction by treatment with leptomycin B or by RNA‐interference‐mediated Crm1 depletion prevents centromeric targeting of Survivin. The genetic inactivation of the Survivin–Crm1 interaction by mutation of the NES affects the correct localization and function of Survivin and the CPC during mitosis. By contrast, CPC assembly does not seem to require the Survivin–Crm1 interaction. Our report shows the functional significance of the Survivin–Crm1 interface and provides a novel link between the mitotic effector Crm1 and the CPC.
Dietary preferences of cows offered choices between white clover and 'high sugar' and 'typical' perennial ryegrass cultivars
Authors: Francis S. A. , Chapman D. F. , Doyle P. T. , Leury B. J.
Published: November 2006

An experiment was conducted to compare dietary preferences of cows offered simple choices between spatially separated monocultures of perennial ryegrass cvv. AberDawn (AD) and AberElan (AE), and white clover (WC) under strip grazing. AberDawn was bred to express high water soluble carbohydrate concentrations, whereas AE has typical levels. The proposed hypotheses were that cows would exhibit a partial preference for the ryegrass cultivar with a higher concentration of non-structural carbohydrates, and that there would be an interaction between the non-structural carbohydrate concentration of the ryegrass and strength of preference for WC. Non-lactating cows were offered a pasture allowance of about 20 kg DM each day for 9 days in 3 ‘choice’ treatments: AD + WC, AE + WC and AD + AE. All pastures had similar estimated metabolisable energy contents, but AD had a higher crude protein (136 v. 118 g/kg DM) and slightly lower neutral detergent fibre (480 v. 497 g/kg DM) concentration than AE, and non-structural carbohydrate concentrations were similar in both grasses. White clover had higher crude protein (236 v. 127 g/kg DM), and lower neutral detergent fibre (317 v. 489 g/kg DM) and non-structural carbohydrate concentrations (140 v. 183 g/kg DM), and contained less dead material (60 v. 242 g/kg DM) than the grasses. AberDawn contained less (P<0.05; 578 v. 698 g/kg DM) green ryegrass than AE. Pre-grazing pasture mass (1870 v. 2010 kg DM/ha), pasture allowance (23 v. 25 kg DM/cow), and residual pasture mass (1610 v. 1710 kg DM/ha) were lower for AD than AE, and for WC were lower (P<0.05) than for both grasses. Dry matter intake, intake rate and bite size were lower (P<0.05) on AD + AE than on treatments containing WC. Cows grazing AD + AE ruminated longer (P<0.05), ruminated more (P<0.05) boli, and had more (P<0.05) ruminating chews than those on treatments including WC. The cows on AD + AE had more (P<0.05) total chews than those on AD + WC or AE + WC, but grazing time was not always significantly different between choice treatments. It is suggested that the longer ruminating times and greater number of boli processed in cows grazing only grass may reflect the slower digestion rates of ryegrass compared with clover. Cows grazing the AD + WC or AE + WC choice treatments showed a partial preference for WC, spending more (P<0.001) time grazing and consuming more (P<0.001) WC than ryegrass. Within the AD + AE choice treatment, cows spent more (P<0.05) time grazing and consumed more (P<0.05) AE than AD. Using the mean of 2 methods of estimation, the partial preferences for AD + WC, AE + WC and AD + AE were 39 : 61, 41 : 59 and 45 : 55, respectively.
Factors influencing the rooting of Gisela 5 (Prunus cerasus × Prunus canescens) cherry rootstock hardwood cuttings
Authors: Exadaktylou E. , Thomidis T. , Tsipouridis C. , Grout B.
Published: November 2006

In this study, the effect of double splitting, cooling in pre-storage, collection date, indole-3-butyric acid (IBA) dipping of shoot tip and base, gibberellic acid (GA3), Agrobacterium radiobacter and A. rhizogenes on the callusing and rooting of Gisela 5 cherry rootstock hardwood cuttings was investigated. Double splitting and bacteria did not affect the callusing and rooting of cuttings. The callusing and rooting of cuttings kept at 0–3°C for 15 days or more were significantly reduced. The callusing and rooting percentages were highest when only the base of cuttings was treated with 1000 mg/L IBA solution. The rooting percentage of cuttings increased when 10–20 mg/L GA3 was applied the same day cuttings were placed on a bottom heat bench. The results showed that the best periods to collect Gisela 5 hardwood cuttings were the later half of November and early March. No correlation between the collection date and starch content, and the starch content and the callusing and rooting of Gisela 5 hardwood cuttings was found.
Effect of defoliation stress on 2-hydroxy cinnamic acid content at different growth stages in Melilotus albus
Authors: Nair R. M. , Whittall A. , Revell D. K. , Dowling K. , Hughes S. , Craig A. D. , Auricht G. C.
Published: November 2006

Melilotus albus (Medik.) is a pasture legume with potential value in Australian farming systems, especially in salt-affected areas. However, the use of this species has been limited because of concerns over high coumarin concentrations. The aim of this trial was to determine the effect of defoliation on the concentration of 2-hydroxy cinnamic acid, a coumarin precursor, at 3 stages of growth (vegetative, flowering and post-flowering) in 6 accessions. The concentration of 2-hydroxy cinnamic acid was determined by high performance liquid chromatography in leaves of plants grown in a glasshouse. Defoliation stress increased the 2-hydroxy cinnamic acid content in the leaves of all accessions studied by about 8%, from 0.89 to 0.96% of dry matter. The 2-hydroxy cinnamic acid concentrations were not significantly different between vegetative and flowering stages in any of the accessions studied, but showed a significant increase post-flowering for 4 out of the 6 accessions studied. This study indicates that grazing may increase the coumarin or 2-hydroxy cinnamic acid concentration in Melilotus albus, but in screening for suitable accessions to progress to new cultivars, it is not necessary to subject plants to a defoliation stress to rank the accessions for 2-hydroxy cinnamic acid or coumarin concentration.
Tillage system effects on weed ecology, herbicide activity and persistence: a review
Authors: Chauhan B. S. , Gill G. S. , Preston C.
Published: November 2006

In the past few years, there has been a growing trend towards reducing tillage in cropping systems to allow stubble retention, earlier planting and improved soil structure. However, the adoption of conservation tillage systems will change weed control practices. Different tillage systems interact with the micro-environment of weed seeds and can influence the pattern of recruitment from the weed seed bank. Here, we present a review of the effect of different tillage systems on weed ecology, herbicide activity and herbicide persistence. Tillage systems can have a major influence on the vertical distribution of weed seeds in the soil seed bank. However, the impact of the changes in the vertical seed distribution on weed seedling recruitment is not well understood. Usually weed seedling recruitment increases if tillage equipment brings buried seed to, or close to, the soil surface, and seedling recruitment decreases if surface seed is buried deeper in the soil. However, tillage responses have a tendency to be species specific and can also be influenced by the intensity of tillage. Any weed species in which germination is stimulated by exposure to light is likely to become more prevalent under reduced tillage systems. Similarly, species that require burial for germination may become less prevalent. Crop residue present on the soil surface can also influence weed seedling recruitment by modifying the physical environment (mainly temperature) of weed seeds. Weed responses to plant residue could also be influenced by the allelopathic activity of the residue and the sensitivity of the weed species present. Few studies have investigated the fate of weed seeds that fail to germinate under any tillage system. Further research is needed to determine whether the weed seeds that fail to germinate decay before the start of the next growing season or become part of a persistent seed bank. Crop residues present on the soil surface can intercept a considerable amount of the applied herbicide and, depending on the herbicide, this intercepted component is susceptible to losses. Therefore, conservation tillage systems are expected to have lower efficacy of soil active herbicides. However, there has been little investigation of rate of loss of soil active herbicides under reduced tillage systems and the results reported have been inconsistent. Much of the research on these effects is from overseas and may not be true in Australian conditions. Therefore, further work is needed to clearly understand the impact of changing tillage systems on weed ecology, herbicide performance and persistence.
Ecology: A Science of Nation? The Utilization of Plant Ecology in New Zealand, 1896 - 1930
Authors: Star Paul
Published: November 2006

Following the creation of the Empire Marketing Board in 1926, Australia's development was influenced by an imperial science increasingly aware of ecology. The present paper traces similar New Zealand links in the ecological approach to pasture development promoted in the Dominion by Bruce Levy and fuelled by the vision of George Stapledon of the Welsh Plant Breeding Station, who visited New Zealand in 1926. However, plant ecology came much earlier to New Zealand by way of Leonard Cockayne, who in 1908 used ecological arguments to press for the extension of Tongariro National Park and who saw New Zealand's unique plant associations as emblems of nation rather than endowments of empire. By comparing the application of ecology, in New Zealand at different times, to the separate (though not necessarily opposed) goals of building a nation and supporting an empire, insight is gained into the changing ways in which any science may be drawn into the service of societal priorities and aspirations.
Cooperative deformation of mineral and collagen in bone at the nanoscale
Authors: Gupta Himadri S. , Seto Jong , Wagermaier Wolfgang , Zaslansky Paul , Boesecke Peter , Fratzl Peter
Published: November 2006

In biomineralized tissues such as bone, the recurring structural motif at the supramolecular level is an anisotropic stiff inorganic component reinforcing the soft organic matrix. The high toughness and defect tolerance of natural biomineralized composites is believed to arise from these nanometer scale structural motifs. Specifically, load transfer in bone has been proposed to occur by a transfer of tensile strains between the stiff inorganic (mineral apatite) particles via shearing in the intervening soft organic (collagen) layers. This raises the question as to how and to what extent do the mineral particles and fibrils deform concurrently in response to tissue deformation. Here we show that both mineral nanoparticles and the enclosing mineralized fibril deform initially elastically, but to different degrees. Using
in situ
tensile testing with combined high brilliance synchrotron X-ray diffraction and scattering on the same sample, we show that tissue, fibrils, and mineral particles take up successively lower levels of strain, in a ratio of 12:5:2. The maximum strain seen in mineral nanoparticles (≈0.15–0.20%) can reach up to twice the fracture strain calculated for bulk apatite. The results are consistent with a staggered model of load transfer in bone matrix, exemplifying the hierarchical nature of bone deformation. We believe this process results in a mechanism of fibril–matrix decoupling for protecting the brittle mineral phase in bone, while effectively redistributing the strain energy within the bone tissue.
Some G protein heterotrimers physically dissociate in living cells
Authors: Digby Gregory J. , Lober Robert M. , Sethi Pooja R. , Lambert Nevin A.
Published: November 2006

Heterotrimeric G proteins mediate physiological processes ranging from phototransduction to cell migration. In the accepted model of G protein signaling, Gαβγ heterotrimers physically dissociate after activation, liberating free Gα subunits and Gβγ dimers. This model is supported by evidence obtained
in vitro
with purified proteins, but its relevance
in vivo
has been questioned. Here, we show that at least some heterotrimeric G protein isoforms physically dissociate after activation in living cells. Gα subunits extended with a transmembrane (TM) domain and cyan fluorescent protein (CFP) were immobilized in the plasma membrane by biotinylation and cross-linking with avidin. Immobile CFP-TM-Gα greatly decreased the lateral mobility of intracellular Gβ
1
γ
2
-YFP, indicating the formation of stable heterotrimers. A GTPase-deficient (constitutively active) mutant of CFP-TM-Gα
oA
lost the ability to restrict Gβ
1
γ
2
-YFP mobility, whereas GTPase-deficient mutants of CFP-TM-Gα
i3
and CFP-TM-Gα
s
retained this ability. Activation of cognate G protein-coupled receptors partially relieved the constraint on Gβ
1
γ
2
-YFP mobility induced by immobile CFP-TM-Gα
oA
and CFP-TM-Gα
i3
but had no effect on the constraint induced by CFP-TM-Gα
s
. These results demonstrate the physical dissociation of heterotrimers containing Gα
oA
and Gα
i3
subunits in living cells, supporting the subunit dissociation model of G protein signaling for these subunits. However, these results are also consistent with the suggestion that G protein heterotrimers (e.g., Gα
s
) may signal without physically dissociating.
Oligozoospermia with normal fertility in male mice lacking the androgen receptor in testis peritubular myoid cells
Authors: Zhang Caixia , Yeh Shuyuan , Chen Yen-Ta , Wu Cheng-Chia , Chuang Kuang-Hsiang , Lin Hung-Yun , Wang Ruey-Sheng , Chang Yu-Jia , Mendis-Handagama Chamindrani , Hu Liquan , Lardy Henry , Chang Chawnshang
Published: November 2006

Androgens and the androgen receptor (AR) play important roles in the testes. Previously we have shown that male total AR knockout (T-AR−/y) mice revealed incomplete germ cell development and lowered serum testosterone levels, which resulted in azoospermia and infertility. However, the consequences of AR loss in particular types of testicular cells remain unclear. Using a Cre-loxP conditional knockout strategy, we generated a tissue-selective knockout mouse with the AR gene deleted in testis peritubular myoid cells (PM-AR−/y). Phenotype analyses showed that PM-AR−/ymice were indistinguishable from WT AR (AR+/y) mice with the exception of smaller testes size. PM-AR−/ymice have serum testosterone concentrations comparable with AR+/ymice. PM-AR−/ymice have oligozoospermia in the epididymis; however, fertility was normal. Although normal germ cell distribution ratio was found, total germ cell number decreased in PM-AR−/ymice. Further mechanistic studies demonstrated that PM-AR−/ymice have defects in the expression of Sertoli cells' functional marker genes such as tranferrin, epidermal fatty acid-binding protein, androgen-binding protein, and other junction genes including occludin, testin, nectin, zyxin, vinculin, lamininγ3, gelsolin, connection43, and N-cadherin. Furthermore, there were defects in peritubular myoid cell contractility-related genes such as endothelin-1, endothelin receptor A and B, adrenomedullin, adrenomedullin receptor, and vasopressin receptor 1a. Together, our PM-AR−/ymice providein vivoevidence for the requirement of functional AR in peritubular myoid cells to maintain normal Sertoli cells function and peritubular myoid cell contractility, thus ensuring normal spermatogenesis and sperm output.
An immunocompetent mouse model for the tolerance of human chronic hepatitis B virus infection
Authors: Huang Li-Rung , Wu Hui-Lin , Chen Pei-Jer , Chen Ding-Shinn
Published: November 2006

An animal model for human hepatitis B virus (HBV) tolerance is needed to investigate the mechanisms. This model will also facilitate therapeutic strategies for the existing 350 million patients with chronic hepatitis B. We established a mouse model by hydrodynamic injection of an engineered, replication-competent HBV DNA into the tail veins of C57BL/6 mice. In 40% of the injected mice, HBV surface antigenemia persisted for >6 months. Viral replication intermediates, transcripts, and proteins were detected in the liver tissues of the injected mice for up to 1 year. The tolerance toward HBV surface antigen in this model was shown to be due to an insufficient cellular immunity against hepatitis B core antigen, as was documented in humans. This animal model will accelerate further genetic and mechanistic studies of human chronic hepatitis B infection.
CD8+ T cell-mediated immune responses in West Nile virus (Sarafend strain) encephalitis are independent of gamma interferon
Authors: Wang Yang , Lobigs Mario , Lee Eva , Koskinen Aulikki , Müllbacher Arno
Published: November 2006

The flavivirusWest Nile virus(WNV) can cause fatal encephalitis in humans and mice. It has recently been demonstrated, in an experimental model using WNV strain Sarafend and C57BL/6 mice, that both virus- and immune-mediated pathology is involved in WNV encephalitis, with CD8+T cells being the dominant subpopulation of lymphocyte infiltrates in the brain. Here, the role of activated WNV-immune CD8+T cells in mouse WNV encephalitis was investigated further. Passive transfer of WNV-immune CD8+T cells reduced mortality significantly and prolonged survival times of mice infected with WNV. Early infiltration of WNV-immune CD8+T cells into infected brains is shown, suggesting a beneficial contribution of these lymphocytes to recovery from encephalitis. This antiviral function was not markedly mediated by gamma interferon (IFN-γ), as a deficiency in IFN-γdid not affect mortality to two strains of WNV (Sarafend and Kunjin) or brain virus titres significantly. The cytolytic potential, as well as precursor frequency, of WNV-immune CD8+T cells were not altered by the absence of IFN-γ. This was reflected in transfer experiments of WNV-immune CD8+T cells from IFN-γ−/−mice into WNV-infected wild-type mice, which showed that IFN-γ-deficient T cells were as effective as those from WNV-immune wild-type mice in ameliorating disease outcome. It is speculated here that one of the pleiotropic functions of IFN-γis mimicked by WNV-Sarafend-mediated upregulation of cell-surface expression of major histocompatibility complex antigens, which may explain the lack of phenotype of IFN-γ−/−mice in response to WNV.
Synergistic and strain-specific effects of bovine spongiform encephalopathy and scrapie prions in the cell-free conversion of recombinant prion protein
Authors: Eiden Martin , Palm Gottfried J. , Hinrichs Winfried , Matthey Ulrich , Zahn Ralph , Groschup Martin H.
Published: November 2006

This study describes the conversion of murine PrPC by PrPSc from three different mouse scrapie strains (ME7, 87V and 22A) and from a mouse-passaged bovine spongiform encephalopathy (BSE) strain (BSE/Bl6). This was demonstrated by a modified, non-radioactive, cell-free conversion assay using bacterial prion protein, which was converted into a proteinase K (PK)-resistant fragment designated PrPres. Using this assay, newly formed PrPres could be detected by an antibody that discriminated de novo PrPres and the original PrPSc seed. The results suggested that PrPres formation occurs in three phases: the first 48 h when PrPres formation is delayed, followed by a period of substantially accelerated PrPres formation and a plateau phase when a maximum concentration of PrPres is reached after 72 h. The conversion of prokaryotically expressed PrPC by ME7 and BSE prions led to unglycosylated, PK-digested, abnormal PrPres fragments, which differed in molecular mass by 1 kDa. Therefore, prion strain phenotypes were retained in the cell-free conversion, even when recombinant PrPC was used as the substrate. Moreover, co-incubation of ME7 and BSE prions resulted in equal amounts of both ME7- and BSE-derived PrPres fragments (as distinguished by their different molecular sizes) and also in a significantly increased total amount of de novo-generated PrPres. This was found to be more than twice the amount of either strain when incubated separately. This result indicates a synergistic effect of both strains during cell-free conversion. It is not yet known whether such a cooperative action between BSE and scrapie prions also occurs in vivo.
Cultured skin fibroblast cells derived from bluetongue virus-inoculated sheep and field-infected cattle are not a source of late and protracted recoverable virus
Authors: Lunt R. A. , Melville L. , Hunt N. , Davis S. , Rootes C. L. , Newberry K. M. , Pritchard L. I. , Middleton D. , Bingham J. , Daniels P. W. , Eaton B. T.
Published: November 2006

A recent hypothesis to explain the recurrence of bluetongue disease after winter seasonal absences of the vector has suggested a role for persistent infection of sheep. This report presents combined independent work from two laboratories investigating the possible recovery of Bluetongue virus (BTV) over a protracted period after infection of both sheep and cattle. Prior to infection with either cell-culture-adapted or non-culture-adapted BTV, sheep were subjected to a preliminary exposure to Culicoides sp. insects, which reportedly facilitates recovery of virus from infected sheep several months post-infection (p.i.). A series of skin biopsies at different intervals p.i. was used to establish skin fibroblast (SF) cultures from which attempts were made to detect virus by isolation and by molecular and immunological methods. Also examined was the effect on virus recovery of additional exposure to Culicoides sp. prior to skin biopsy during the post-inoculation period. A herd of cattle sentinels for surveillance of natural BTV infection in northern Australia was monitored prospectively for seroconversion. Evidence of infection initiated attempted virus recovery by establishing SF cultures. It was found that in both cattle and sheep there was not a protracted period over which BTV could be recovered from SF cultures. The data do not support a general hypothesis that BTV persists in either sheep or cattle.
Infectious agent of sheep scrapie may persist in the environment for at least 16 years
Authors: Georgsson Gudmundur , Sigurdarson Sigurdur , Brown Paul
Published: November 2006

In 1978, a rigorous programme was implemented to stop the spread of, and subsequently eradicate, sheep scrapie in Iceland. Affected flocks were culled, premises were disinfected and, after 2–3 years, restocked with lambs from scrapie-free areas. Between 1978 and 2004, scrapie recurred on 33 farms. Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded. Of special interest was one farm with a small, completely self-contained flock where scrapie recurred 18 years after culling, 2 years after some lambs had been housed in an old sheep-house that had never been disinfected. Epidemiological investigation established with near certitude that the disease had not been introduced from the outside and it is concluded that the agent may have persisted in the old sheep-house for at least 16 years.