bluuebunny/crossref_metadata_2025 huggingface dataset:
Agglomerating seeds to enhance native seedling emergence and growth
Authors: Madsen Matthew D. , Davies Kirk W. , Williams C. Jason , Svejcar Tony J.
Published: March 2012

1. Restoration in rangelands is constrained by low establishment of species sown from seed. Non‐biotic soil‐surface crust is one of the major factors limiting reseeding success by acting as a barrier to seedling emergence.

2. The objective of this study was to determine whether seedling emergence could be improved by agglomerating multiple seeds into a single pellet, so that the seedlings growing from the pellet will collectively generate sufficient force to penetrate the soil crust. To evaluate this technology, we compared seedling emergence and biomass production from agglomerated, single and non‐coated seed (control) of Pseudoroegneria spicata. In the greenhouse, seeds were sown in either crust‐forming clay or non‐crusting sandy soil and studied for a 25‐day period. Starting seed density was constant across treatments.

3. In the clay soil, seedling emergence from the agglomeration treatment was 1·3 and 1·9 times higher than the single seed coating and control, respectively. In the sandy soil, the agglomeration and single seed coating responded similarly, producing 1·4 times more seedlings than the control.

4. Biomass production followed a similar trend as plant density. In the clay soil, increased biomass of the agglomeration treatment was not only because of higher plant densities but was also a product of having greater biomass per plant.

5. Synthesis and applications. This short‐duration ‘proof‐of‐concept’ study indicates that both the seed coating materials used to form the agglomerates and the act of agglomerating the seeds together improve P. spicata emergence and plant growth. These results also demonstrate that in the early seedling stage, facilitation outweighs competition in agglomeration plantings. Additional research is needed to verify these results in the field.
Managing fire mosaics for small mammal conservation: a landscape perspective
Authors: Kelly Luke T. , Nimmo Dale G. , Spence‐Bailey Lisa M. , Taylor Rick S. , Watson Simon J. , Clarke Michael F. , Bennett Andrew F.
Published: March 2012

1. Fire is a major driver of ecosystem structure and function worldwide. It is also widely used as a management tool to achieve conservation goals. A common objective is the maintenance of ‘fire mosaics’ comprising spatially heterogeneous patches of differing fire history. However, it is unclear what properties of fire mosaics most enhance conservation efforts. Here we focus on the spatial and temporal properties of fire‐prone landscapes that influence the distribution of small mammals.

2. We surveyed small mammals in 28 landscapes (each 12·6 km²) representing a range of fire histories in the Murray Mallee region (104 000 km²) of semi‐arid Australia. Generalised linear mixed models were used to examine the influence of five landscape properties on the capture rate of individual species and the species richness of native small mammals. We investigated the influence of the proportional extent of fire age‐classes, the diversity of fire age‐classes, the extent of the dominant vegetation type, rainfall history and biogeographic context.

3. Three of four study species were associated with the spatial extent of fire age‐classes. Older vegetation was found to provide important habitat for native small mammals. Overall, however, rainfall history and biogeographic context were dominant influences: for example, the species richness of native mammals was positively associated with above‐average rainfall. There was little evidence that the diversity of fire age‐classes influenced either the capture rate of individual species or species richness.

4. Synthesis and applications. In fire‐prone environments, habitat availability can change markedly over short time‐scales. Sufficient habitat at a suitable seral stage within the landscape is a key requirement for species conservation. In mallee ecosystems, the retention of older vegetation is recommended to create more desirable fire mosaics for native small mammals. In addition to such spatial properties of mosaics that are amenable to manipulation, an understanding of how ecological processes affect the biota (such as variation in rainfall‐driven productivity) is also essential for informed conservation management.
Using functional traits and phylogenetic trees to examine the assembly of tropical tree communities
Authors: Baraloto Christopher , Hardy Olivier J. , Paine C. E. Timothy , Dexter Kyle G. , Cruaud Corinne , Dunning Luke T. , Gonzalez Mailyn‐Adriana , Molino Jean‐François , Sabatier Daniel , Savolainen Vincent , Chave Jerome
Published: March 2012

1. Niche theory proposes that species differences underlie both coexistence within communities and the differentiation in species composition among communities via limiting similarity and environmental filtering. However, it has been difficult to extend niche theory to species‐rich communities because of the empirical challenge of quantifying niches for many species. This has motivated the development of functional and phylogeny‐based approaches in community ecology, which represent two different means of approximating niche attributes.

2. Here, we assess the utility of plant functional traits and phylogenetic relationships in predicting community assembly processes using the largest trait and phylogenetic data base to date for any set of species‐rich communities.

3. We measured 17 functional traits for all 4672 individuals of 668 tree species co‐occurring in nine tropical rain forest plots in French Guiana. Trait variation was summarized into two ordination axes that reflect species niche overlap.

4. We also generated a dated molecular phylogenetic tree based on DNA sequencing of two plastid loci (rbcLandmatK) comprising 97% of the individuals and 91% of the species in the plots.

5. We found that, on average, co‐occurring species had greater functional and, to a lesser extent, phylogenetic similarity than expected by chance.

6. We also found that functional traits and their ordination loadings showed significant, albeit weak, phylogenetic signal, suggesting that phylogenetic distance provides pertinent information on niche overlap in tropical tree communities.

7. Synthesis. We provide the most comprehensive examination to date of the relative importance of environmental filtering and limiting similarity in structuring tropical tree communities. Our results confirm that environmental filtering is the overriding influence on community assembly in these species‐rich systems.
Helium ion microscopy for high‐resolution visualization of the articular cartilage collagen network
Authors: VANDEN BERG‐FOELS W.S. , SCIPIONI L. , HUYNH C. , WEN X.
Published: March 2012

The articular cartilage collagen network is an important research focus because network disruption results in cartilage degeneration and patient disability. The recently introduced helium ion microscope (HIM), with its smaller probe size, longer depth of field and charge neutralization, has the potential to overcome the inherent limitations of electron microscopy for visualization of collagen network features, particularly at the nanoscale. In this study, we evaluated the capabilities of the helium ion microscope for high‐resolution visualization of the articular cartilage collagen network. Images of rabbit knee cartilage were acquired with a helium ion microscope; comparison images were acquired with a field emission scanning electron microscope (FE‐SEM) and a transmission electron microscope (TEM). Sharpness of example high‐resolution helium ion microscope and field emission scanning electron microscope images was quantified using the 25–75% rise distance metric. The helium ion microscope was able to acquire high‐resolution images with unprecedented clarity, with greater sharpness and three‐dimensional‐like detail of nanoscale fibril morphologies and fibril connections, in samples without conductive coatings. These nanoscale features could not be resolved by field emission scanning electron microscopy, and three‐dimensional network structure could not be visualized with transmission electron microscopy. The nanoscale three‐dimensional‐like visualization capabilities of the helium ion microscope will enable new avenues of investigation in cartilage collagen network research.
Perceived poor sleep quality in the absence of polysomnographic sleep disturbance in women with severe premenstrual syndrome
Authors: BAKER FIONA C. , SASSOON STEPHANIE A. , KAHAN TRACEY , PALANIAPPAN LATHA , NICHOLAS CHRISTIAN L. , TRINDER JOHN , COLRAIN IAN M.
Published: March 2012

Women with severe premenstrual syndrome report sleep‐related complaints in the late‐luteal phase, but few studies have characterized sleep disturbances prospectively. This study evaluated sleep quality subjectively and objectively using polysomnographic and quantitative electroencephalographic measures in women with severe premenstrual syndrome. Eighteen women with severe premenstrual syndrome (30.5 ± 7.6 years) and 18 women with minimal symptoms (controls, 29.2 ± 7.3 years) had polysomnographic recordings on one night in each of the follicular and late‐luteal phases of the menstrual cycle. Women with premenstrual syndrome reported poorer subjective sleep quality when symptomatic in the late‐luteal phase compared with the follicular phase (P < 0.05). However, there were no corresponding changes in objective sleep quality. Women with premenstrual syndrome had more slow‐wave sleep and slow‐wave activity than controls at both menstrual phases (P < 0.05). They also had higher trait‐anxiety, depression, fatigue and perceived stress levels than controls at both phases (P < 0.05) and mood worsened in the late‐luteal phase. Both groups showed similar menstrual‐phase effects on sleep, with increased spindle frequency activity and shorter rapid eye movement sleep episodes in the late‐luteal phase. In women with premenstrual syndrome, a poorer subjective sleep quality correlated with higher anxiety (r = −0.64, P = 0.005) and more perceived nighttime awakenings (r = −0.50, P = 0.03). Our findings show that women with premenstrual syndrome perceive their sleep quality to be poorer in the absence of polysomnographically defined poor sleep. Anxiety has a strong impact on sleep quality ratings, suggesting that better control of mood symptoms in women with severe premenstrual syndrome may lead to better subjective sleep quality.
The csgD mRNA as a hub for signal integration via multiple small RNAs
Authors: Boehm Alex , Vogel Jörg
Published: March 2012

The transcription factor CsgD governing the production of curli fimbriae and cellulose is a key player in the complex regulatory circuit that decides whether Escherichia coli form biofilms. The csgD gene itself is tightly controlled at the level of transcription by a large array of DNA‐binding proteins, but what happens after transcription is less understood. In this issue of Molecular Microbiology, Jørgensen et al. (2012), Mika et al. (2012) and Thomason et al. (2012) report on small RNAs (McaS, RprA and GcvB) that together with the RNA‐chaperone Hfq regulate the mRNAs of csgD and other biofilm genes, and illustrate the burgeoning concept that the 5′ region of bacterial mRNA serves as a hub for sRNA‐mediated signal integration at the post‐transcriptional level.
The ethylene response factor AtERF98 enhances tolerance to salt through the transcriptional activation of ascorbic acid synthesis in Arabidopsis
Authors: Zhang Zhijin , Wang Juan , Zhang Rongxue , Huang Rongfeng
Published: March 2012

Ascorbic acid (AsA) is an important antioxidant in plants, and its biosynthesis is finely regulated through developmental and environmental cues; however, the regulatory mechanism remains unclear. In this report, the knockout and knockdown mutants of Arabidopsis AtERF98 decreased the AsA level, whereas the overexpression of AtERF98 increased it, which suggests that AtERF98 plays an important role in regulating AsA biosynthesis. AtERF98‐overexpressing plants showed enhanced expression of AsA synthesis genes in the d‐mannose/l‐galactose (d‐Man/l‐Gal) pathway and the myo‐inositol pathway gene MIOX4, as well as of AsA turnover genes. In contrast, AtERF98 mutants showed decreased expression of AsA synthesis genes in the d‐Man/l‐Gal pathway but not of the myo‐inositol pathway gene or AsA turnover genes. In addition, the role of AtERF98 in regulating AsA production was significantly impaired in the d‐Man/l‐Gal pathway mutant vtc1‐1, but the expression of the myo‐inositol pathway gene or AsA turnover genes was not affected, which indicates that the regulation of AtERF98 in AsA synthesis is primarily mediated by the d‐Man/l‐Gal pathway. Transient expression and chromatin immunoprecipitation assays further showed that AtERF98 binds to the promoter of VTC1, which indicates that AtERF98 modulates AsA biosynthesis by directly regulating the expression of the AsA synthesis genes. Moreover, the knockout mutant aterf98‐1 displayed decreased salt‐induced AsA synthesis and reduced tolerance to salt. The supplementation of exogenous AsA increased the salt tolerance of aterf98‐1; coincidently, the enhanced salt tolerance of AtERF98‐overexpressing plants was impaired in vtc1‐1. Thus, our data provide evidence that the regulation of AtERF98 in AsA biosynthesis contributes to enhanced salt tolerance in Arabidopsis.
Brain Base Arteries: Pattern and Variation in the European Otter (Lutra Lutra)
Authors: Brudnicki W.
Published: March 2012

The pattern and variation of the brain base arteries were investigated in 30 specimens of European otter. It was found that the vascular pattern in this species is similar to the vascular pattern found in other Carnivora. A very well‐developed basilar artery, which was formed as a result of the anastomosis of equally well‐developed vertebral arteries and the ventral spinal artery, was demonstrated to be characteristic of the species. Most of the variation in the pattern of origin concerned the origin of the middle cerebral arteries and labyrinthine arteries. In a single individual, a double middle cerebral artery was observed. Overall, the specimens demonstrated a clear regularity in the pattern of vessels in the base of the brain and a small range of variation.
Misinterpreting the potential benefits of aggregation for reducing desiccation in the intertidal: a simple analogy
Authors: Stafford Richard , Davies Mark S. , Williams Gray A.
Published: March 2012

The potential adaptive benefits of aggregation in intertidal invertebrates, in terms of preventing desiccation stress, are logical, but have proved difficult to confirm from field measurements. Through a simple analogy we explain why this may be so, especially for those species that do not solely forage when fully immersed. Measuring water content (or osmotic potentials of body fluids) of individuals that become inactive in aggregations and comparing this with non‐aggregated individuals, which is the most common method of determining adaptive benefits of aggregation to desiccation, (i) causes any relationships between desiccation and aggregation to be, at best, weakly related due to variability in the different times that individuals enter aggregations, and (ii) is not measuring the true benefit of aggregation, which in this case should be measured as a reduction in the rate of water loss. Further, the design of field studies or experiments to determine the benefits of aggregation in terms of desiccation reduction is extremely challenging, due to the unavoidable repeated disturbances to individuals that are necessary to measure water levels at multiple occasions, in order to measure the rate of water loss. We suggest that development of biomimetic sensors, such as modification of the robolimpet sensor, are required to measure in situ rates of water loss with a high temporal resolution. Although such sensors may not be truly physiologically realistic, they are likely to provide the least confounded approach to understanding benefits of aggregation in terms of physical stress reduction.
Antioxidant Mechanisms and their Benefit on Post‐thaw Boar Sperm Quality
Authors: Bathgate R
Published: March 2012

Contents

While being an important component of normal cellular function, excess levels of reactive oxygen species (ROS) cause cell damage and death. The ability to protect sperm against oxidative damage is of particular importance in the artificial reproduction industry because of the increased production of ROS by the sperm cell during processing. This review discusses the formation of ROS and the use of antioxidants in protecting boar sperm against oxidative damage.
Biological Markers of Boar Fertility
Authors: Dyck MK , Foxcroft GR , Novak S , Ruiz‐Sanchez A , Patterson J , Dixon WT
Published: March 2012

Contents

The semen evaluation techniques used in most commercial artificial insemination centers, which includes sperm motility and morphology measurements, provides a very conservative estimate of the relative fertility of individual boars. As well, differences in relative boar fertility are masked by the widespread use of pooled semen for commercial artificial insemination (AI) in many countries. Furthermore, the relatively high sperm numbers used in commercial AI practice usually compensate for reduced fertility, as can be seen in some boars when lower numbers of sperm are used for AI. The increased efficiency of pork production should involve enhanced use of boars with strong reproductive efficiency and the highest genetic merit for important production traits. Given that the current measures of semen quality are not always indicative of fertility and reproductive performance in boars, accurate and predictive genetic and protein markers are still needed. Recently, significant efforts have been made to identify reliable markers that allow for the identification and exclusion of sires with reduced reproductive efficiency. This paper reviews the current status of proteomic and genomic markers of fertility in boars in relation to other livestock species.
International Conference on Boar Semen Preservation (ICBSP): The First 25 Years
Authors: Johnson LA
Published: March 2012

Contents

The International Conference on Boar Semen Preservation (ICBSP) has been in existence for 25 years. During that time, six conferences have been held in Europe and North America. Each conference has sought to communicate research advances in pig semen technology and artificial insemination (AI). Clearly, the conference has been a catalyst for the advancement of various improvements in semen preservation and AI. In addition, the conference has served to initiate collaboration among scientists worldwide. A summary of problems that remain to be investigated and solved in swine semen technology is provided.
Mechanisms of Sperm Storage in the Female Reproductive Tract: an Interspecies Comparison
Authors: Holt William V.
Published: March 2012

Contents

Once semen has been collected for artificial insemination, it is diluted into extenders designed to prevent its deterioration over the period prior to insemination. If the semen is not frozen, the extenders provide protection for a period of a few hours to a few days, depending on species. Despite the efforts of biotechnologists to increase the duration of storage without compromising fertility, there has been relatively little progress for many years. However, comparative studies in diverse species have revealed that long‐term sperm storage (up to months and years) within the female reproductive tract is relatively commonplace in reptiles, fishes, birds and amphibians. Even among mammals, some species of bat have evolved mechanisms for storing spermatozoa for several months in the uterus or oviduct so that they can mate in the autumn but postpone fertilization until the spring. We currently know little about the mechanisms that support such long‐term sperm storage, mainly because evidence from such species is either absent or fragmentary. Nevertheless, parallels between mammalian and other systems, where spermatozoa are sequestered in sperm storage tubules, suggest that the enclosure of spermatozoa within pockets of epithelial cells may be sufficient to achieve long‐term sperm storage. In addition, recent evidence from sperm‐storing bats has suggested an alternative, or additional, hypothesis that the modulation of apoptosis within epithelial cells is important in controlling sperm survival. Despite a lack of direct experimental evidence from a wide variety of species, I propose that there is now enough evidence to warrant investigation of these hypotheses.
Stress and Dietary Factors Modify Boar Sperm for Processing
Authors: Radomil L , Pettitt MJ , Merkies KM , Hickey KD , Buhr MM
Published: March 2012

Contents

This paper reviews stresses boar sperm undergo during processing and presents preliminary results of dietary modification that minimize this damage. Processing for artificial insemination (AI) stresses boar sperm by osmotic effects; altering cell size, shape and membranes; intracellular ice formation; and production of reactive oxygen species (ROS). Sperm response to ROS is concentration‐dependent, with low levels activating the ERK pathway to stimulate tyrosine phosphorylation (Tyr‐P) and capacitation, but high concentrations or inappropriately timed onset of ROS pathways can harm sperm. Fresh boar sperm exposed to ROS increased intracellular hydrogen peroxide (H2O2) phospholipase and lipid peroxidation, maintained viability but lost motility and underwent acrosome reactions (AR). Direct incorporation of lipids ± the antioxidant Vitamin E improves the survival of liquid‐ and frozen‐stored semen. Boars fed dietary flaxseed for 8 weeks to increase n‐3 fatty acids displayed improved sperm morphology (p < 0.05), increased membrane fluidity (p < 0.05) and better retention of motility and viability during 5–7 day storage (p < 0.05). Processes reducing oxidative damage to stored sperm should be evaluated.
Do CASA Systems Satisfy Consumers Demands? A Critical Analysis
Authors: Feitsma H , Broekhuijse MLWJ , Gadella BM
Published: March 2012

Contents

Boar studs are often offered new technologies including several CASA (computer‐assisted semen analysis) systems. However, independent information to assist their purchase decisions is not available. The systems accuracy and repeatability variation because of different factors can be evaluated through duplicate testing of semen samples and comparison of the results according to WHO standards for humans. This primary analysis and a thorough economic cost benefit evaluation will help to decide whether the purchase of a CASA system will be profitable for a boar stud. Our experience of implementing several CASA systems in the cooperative Dutch Artificial Insemination (AI) centres is used as a base for this discussion.
Framework for describing community integration for people with acquired brain injury
Authors: Parvaneh Shahriar , Cocks Errol
Published: March 2012

Background/aim

Community integration is the ultimate goal of rehabilitation of adults with acquired brain injury which has a high incidence in the Australian population. The literature shows a need for a more comprehensive framework for community integration. This study developed a descriptive community integration framework drawn from views of five stakeholder groups and was compared with four similar frameworks.

Methods

Thirty‐seven experts in acquired brain injury, including practitioners, researchers, policy makers, people with acquired brain injury and family members participated. Using a Delphi method, an iterative process of surveys, interviews, and focus groups sought their views on community integration. Responses were analysed in three stages systematically to reduce a large quantity of raw data into a core set of descriptive themes. A final member checking process rated participants’ agreement with the importance of each theme.

Results

Seven themes were identified and described: Relationships, Community Access, Acceptance, Occupation, Being at Home, Picking up Life Again, and Heightened Risks and Vulnerability. Themes were congruent with elements of the frameworks from the literature.

Conclusions

Rich data came from the diverse stakeholders in the participant groups. Two unique themes reflected the importance of re‐integration and recovering important aspects of previous lives, and identifying risks and vulnerabilities and providing safeguards. The framework reflected emphases that may be specific to acquired brain injury. It can be used as a basis for development of community integration programmes and outcome measures.
Pathophysiology of varicocele in male infertility in the era of assisted reproductive technology
Authors: Shiraishi Koji , Matsuyama Hideyasu , Takihara Hiroshi
Published: March 2012

Varicocele is the most common and treatable cause of male infertility. Studies of a rat experimental left varicocele model and human testicular biopsy samples have shown the involvement of various factors in its pathophysiology. Among them, oxidative stress plays a major role in impairing spermatogenesis and sperm function. Therefore, in addition to palpation, scrotal ultrasonography and color Doppler ultrasound, evaluation of testicular oxidative stress (e.g. scrotal temperature is a surrogate parameter) is recommended to enable diagnosis and suitable treatment of varicocele. Varicocelectomy increases the fertilization, pregnancy and live birth rates, indicating improved sperm function; it is therefore important even in couples undergoing intracytoplasmic sperm injection. Routine sperm‐function tests are warranted to monitor the sperm quality after varicocelectomy and consequent improvement in the outcomes of assisted reproductive technology. Furthermore, the indications of varicocelectomy in assisted reproductive technology should be widened.
Mental health nurses' views on therapeutic optimism
Authors: Cleary Michelle , Horsfall Jan , O'Hara‐Aarons Maureen , Hunt Glenn E.
Published: March 2012

Registered nurses (RN) coordinate acute mental health units on a 24‐hour basis and it behoves researchers to actually ask these nurses what they think contributes to their ability to work with patients in optimistic ways. In this study, 40 RN working in acute mental health settings were asked a series of questions to explore positive aspects of nursing work, which includes therapeutic optimism. Three themes were identified: (i) different ways nurses foster therapeutic optimism; (ii) perceptions of how an optimistic environment is fostered, and (iii) improvement of ward culture. Findings show the pivotal role mental health nurses have in improving teamwork, good communication, sharing, and collaboration, in addition to preceptoring and supervision. Furthermore, effective clinical management is essential to therapeutic optimism and, in this research, is considered to be the aspect of acute mental health nursing most relevant to improving the ward culture.
Pit morphology characterization and corrosion fatigue crack nucleation analysis based on energy principle
Authors: XIAO‐GUANG H. , JIN‐QUAN X.
Published: March 2012

Pit always changes its shape and size during corrosion fatigue. The actual morphology of pit is an outcome of the interaction between the variation in the elastic energy, surface energy and electrochemical energy stored in the cyclically stressed solid. In this paper, a two‐variable semi‐elliptical model is proposed to depict the pit's growing morphology. The critical condition for corrosion fatigue crack nucleation is deduced according to dislocation theory, and the influences of some important factors on critical pit size and crack nucleation life are discussed.
Thermoelastic crack analysis in functionally graded materials and structures by a BEM
Authors: EKHLAKOV A. , KHAY O. , ZHANG C. , SLADEK J. , SLADEK V. , GAO X. W.
Published: March 2012

In this paper, transient thermoelastic crack analysis in two‐dimensional, isotropic, continuously non‐homogeneous and linear elastic functionally graded materials subjected to a thermal shock is presented. The Laplace transform technique is used to eliminate the time dependence of the governing equations of the linear coupled thermoelasticity. Fundamental solutions for isotropic, homogeneous and linear elastic solids in the Laplace‐transformed domain are applied to derive boundary–domain integral equations for the mechanical and thermal fields. The radial integration method is employed to transform the domain integrals into the boundary integrals. A collocation‐based boundary element method is implemented for the spatial discretization of the boundary–domain integral equations. The time‐dependent numerical solutions are obtained by using Stehfest's inversion algorithm. Numerical results are presented and discussed to show the influences of the material gradation, the thermo‐mechanical coupling, the crack orientation and the thermal shock loading on the dynamic stress intensity factors.
Overload effects on fatigue crack‐tip fields under plane stress conditions: surface and bulk analysis
Authors: LOPEZ‐CRESPO P. , WITHERS P. J. , YUSOF F. , DAI H. , STEUWER A. , KELLEHER J. F. , BUSLAPS T.
Published: March 2012

The surface crack opening displacements are characterised by digital image correlation for a (thin) plane stress 316 stainless steel compact tension sample subjected to an overload event. This supports a traditional plasticity‐induced closure interpretation showing a knee in the closure response prior to overload, an absence of closure in the accelerated growth regime followed by accentuated closure in the retardation regime. By contrast, measurement of the mid‐thickness elastic strain field behind and ahead of the crack made by synchrotron X‐ray diffraction shows no evidence of significant crack face contact stresses behind the crack tip on approaching minimum loading. Rather the changes during loading and overloading can mostly be explained by a simple elastic plastic analysis using a value of the yield stress intermediate between the initial yield stress and the UTS. This shows very significant compressive reverse plastic strains ahead of the crack that start to form early during unloading. At the moment it is not clear whether this difference is because of the increasing stress intensity applied as the crack grows, or for some other reason, such as prevention of the crack faces closing mid‐thickness due to the reverse plastic zone.
A comparative numerical study of combined cold expansion and local torsion on fastener holes
Authors: SHAMDANI A. H , KHODDAM S
Published: March 2012

Cold expansion and local torsion processes provide controllable strengthening mechanisms for a fastener hole and therefore have engineering significance. They rely on the residual stress and the accumulated shearing strain, respectively, which are difficult to measure. Due to the complex closed form solutions for these mechanisms, their numerical study is of great importance. In this work, a combination of the cold expansion and the local torsion on a fastener hole has been investigated numerically to evaluate the amount and nature of the total accumulated residual stresses around a fastener hole. Different cases of the cold expansion and the local torsion processes were modelled and studied by finite element simulation to investigate the existence of a loading case which produces a beneficial compressive residual stress field in the vicinity of a hole. Sensitivity of the final residual stress with respect to a range of process parameters including adequate diametral interference and angle of rotation was investigated.
A single climate driver has direct and indirect effects on insect population dynamics
Authors: Boggs Carol L. , Inouye David W.
Published: March 2012

Ecology Letters (2012) 15: 502–508

Weather drives population dynamics directly, through effects on vital rates, or indirectly, through effects on the population’s competitors, predators or prey and thence on vital rates. Indirect effects may include non‐additive interactions with density dependence. Detection of climate drivers is critical to predicting climate change effects, but identification of potential drivers may depend on knowing the underlying mechanisms. For the butterfly Speyeria mormonia, one climate driver, snow melt date, has multiple effects on population growth. Snow melt date in year t has density‐dependent indirect effects. Through frost effects, early snow melt decreases floral resources, thence per‐capita nectar availability, which determines fecundity in the lab. Snow melt date in year t + 1 has density‐independent direct effects. These effects explain 84% of the variation in population growth rate. One climate parameter thus has multiple effects on the dynamics of a species with non‐overlapping generations, with one effect not detectable without understanding the underlying mechanism.
A simple strategy for screening for glucose intolerance, using glycated haemoglobin, in individuals admitted with acute coronary syndrome
Authors: Gholap N. , Davies M. J. , Mostafa S. A. , Squire I. , Khunti K.
Published: March 2012

Diabet. Med. 29, 838–843 (2012)

Glucose intolerance is common but often remains undiagnosed and untreated in people with acute coronary syndrome. The best approach to screening for glucose intolerance post‐acute coronary syndrome remains debated. The World Health Organization has recently advocated the use of HbA1c in diagnosing Type 2 diabetes. A screening strategy using HbA1c as the preferred test would be pragmatic and improve early detection and management of glucose intolerance in acute coronary care practice. In this commentary, we discuss the relevant literature and guidelines in this area and propose a simple and pragmatic algorithm based on the use of HbA1c to screen for glucose intolerance during and after admission with acute coronary syndrome.
Relative risk of acute pancreatitis in initiators of exenatide twice daily compared with other anti‐diabetic medication: a follow‐up study
Authors: Wenten M. , Gaebler J. A. , Hussein M. , Pelletier E. M. , Smith D. B. , Girase P. , Noel R. A. , Braun D. K. , Bloomgren G. L.
Published: March 2012

Aims  Previously, a retrospective cohort study found no increased risk of acute pancreatitis with current or recent use of exenatide twice daily compared with use of other anti‐diabetic drugs. This follow‐up study investigated incident acute pancreatitis, with the use of a different data source and analytic method, in patients exposed to exenatide twice daily compared with patients exposed to other anti‐diabetic medications.

Methods  A large US health insurance claims database was used. Eligible patients had ≥ 9 months continuous enrollment without a claim for pancreatitis and a claim for a new anti‐diabetic medication on or after 1 June 2005 to 31 March 2009. Cases of acute pancreatitis were defined as hospitalized patients with an Internation Classification of Disease 9 code of 577.0 in the primary position. A discrete time survival model was used to evaluate the relationship between exenatide twice daily and acute pancreatitis.

Results  Of 482 034 eligible patients, 24 237 initiated exenatide twice daily and 457 797 initiated another anti‐diabetic medication. Initiators of exenatide twice daily had more severe diabetes compared with initiators of other anti‐diabetic medications. After adjustments for propensity score, insulin and use of medication potentially associated with acute pancreatitis, the odds ratio with exenatide twice daily exposure was 0.95 (95% CI 0.65–1.38). A secondary analysis that examined current, recent and past medication exposure found no increased risk of acute pancreatitis with exenatide twice daily, regardless of exposure category.

Conclusion  This study indicates that exposure to exenatide twice daily was not associated with an increased risk of acute pancreatitis compared with exposure to other anti‐diabetic medications. These results should be interpreted in light of potential residual confounding and unknown biases.
Lifestyle intervention for preventing weight gain in young adults: a systematic review and meta‐analysis of RCTs
Authors: Hebden L. , Chey T. , Allman‐Farinelli M.
Published: March 2012

Younger generations of Australians are gaining weight faster than their parents. Associated health consequences are likely to ensue unless weight gains are prevented; however, it is unclear how to effectively intervene in this population. Electronic databases for health sciences were searched from April to the end of August 2011. Nine studies were included in the review, eight in the meta‐analysis, from 771 abstracts reviewed for eligibility criteria: randomized controlled trials of lifestyle interventions, published in English (1980 onward), aimed at preventing weight gain among healthy subjects 18–35 years. Mean body weight change was the primary outcome. The combined weighted mean change in intervention participants was −0.87 kg (95% CI −1.56, −0.18) and in control participants 0.86 kg (95% CI 0.14, 1.57). Post hoc meta‐regression analyses revealed evidence‐based interventions of 4 months or longer duration were significantly associated with greater weight loss (−1.62 [95% CI −3.21, −0.04], P = 0.045). The small number, short duration and large heterogeneity of trials means the effectiveness of lifestyle intervention for preventing young adult weight gain remains unclear. Future trials conducted over longer periods with larger samples are urgently required to develop effective programmes that will protect against weight gains in future generations.
Illusionary inclusion – what went wrong with New Labour's landmark educational policy?
Authors: Hodkinson Alan
Published: March 2012

This article examines the emergence and evolution of New Labour's landmark educational policy; namely that of inclusion. The author, Alan Hodkinson, associate professor at the Centre for Cultural and Disability Studies at Liverpool Hope University, illuminates his conceptual difficulties in attempting to define what inclusion was and what inclusive education became during the latter part of the twentieth century and first decade of the twenty‐first century. Throughout this article he endeavours to observe and define inclusive education in England through the employment of critical analysis of teacher discourse and examination of the vocabulary of inclusion. The article's contextual precept is that, rather than creating a brave new world for equality and social justice, inclusive education here was rendered illusionary by the actors who colonised and striated inclusion's space upon a stage of competing policy initiatives and practicalities of educational settings.
Beyond Semantic Accuracy: Preschoolers Evaluate a Speaker’s Reasons
Authors: Koenig Melissa A.
Published: March 2012

Children’s sensitivity to the quality of epistemic reasons and their selective trust in the more reasonable of 2 informants was investigated in 2 experiments. Three‐, 4‐, and 5‐year‐old children (N= 90) were presented with speakers who stated different kinds of evidence for what they believed. Experiment 1 showed that children of all age groups appropriately judged looking, reliable testimony, and inference as better reasons for belief than pretense, guessing, and desiring. Experiment 2 showed that 3‐ and 4‐year‐old children preferred to seek and accept new information from a speaker who was previously judged to use the “best” way of thinking. The findings demonstrate that children distinguish certain good from bad reasons and prefer to learn from those who showcased good reasoning in the past.
Preschoolers Acquire General Knowledge by Sharing in Pretense
Authors: Sutherland Shelbie L , Friedman Ori
Published: March 2012

Children acquire general knowledge about many kinds of things, but there are few known means by which this knowledge is acquired. In this article, it is proposed that children acquire generic knowledge by sharing in pretend play. In Experiment 1, twenty‐two 3‐ to 4‐year‐olds watched pretense in which a puppet represented a “nerp” (an unfamiliar kind of animal). For instance, in one scenario, the nerp ate and disliked a carrot. When subsequently asked generic questions about real nerps, children’s responses suggested that they had learned general facts (e.g., nerps dislike carrots). In Experiment 2, thirty‐two 4‐ to 5‐year‐olds learned from scenarios lacking pretend speech or sound effects. The findings reveal a long overlooked means by which children can acquire generic knowledge.
Against ‘DummyDo’: The ‘LowDoAUX’ Hypothesis1
Authors: González Escribano José Luis
Published: March 2012

This paper challenges the prevailing view that ‘dummydo’ is an empty object inserted near Tense or added in Morphology/PF to make the ‘stranded’ tense pronounceable. It argues, instead, that it is the overt exponent of an existential quantifier required to bind the ‘e’ variable of events and a default auxiliary in a ‘low Aux’ position. ‘Low Aux’ is alternatively occupied bybePRED, a complementary quantifier over states. The fact that the ‘e/s’ variable of IP is unique forces the quantifier–variable relation to be local. As a consequence, other auxiliaries cannot intervene betweendoAUX/bePREDand the lowest IP and never follow either at PF.DoAUXis covert unless it can raise into Force, so is apparently never preceded by other auxiliaries. Main verbs cannot raise in English only because covertdoAUXblocks their ascent. In V‐raising languages, there is nodoAUX‐like auxiliary and V itself must raise into ‘low Aux’ and, if higher auxiliaries do not prevent it, further up. The present solution removes a flagrant semantics–syntax mismatch, explains the apparent incompatibility betweendoAUXand other auxiliaries, accounts for the Vin situconstraint of current English, and avoids many generally overlooked conceptual flaws of the ‘dummy do’ account.
Grammar Writing and Provincial Grammar Printing in the Eighteenth‐Century British Isles1
Authors: Yáñez‐Bouza Nuria
Published: March 2012

This paper presents an account of the chronological and geographical distribution of grammars of the English language printed in the eighteenth century in the British Isles. The analysis, which views linguistic historiography in the light of the history of the book, is based on a new electronic database of eighteenth‐century grammars and grammar writers (ECEG). The focus of this study lies in the dissemination of printing in the provinces – by country, county and town/city. Printers and their networks with grammar writers are explored, as are printing activities involving grammars written for schools. Furthermore, the cross‐examination of the grammar writers’ place of birth and the grammars’ place of printing brings to light interesting patterns of geographical mobility, e.g. between Wales and the West Midlands. As grammars played a pivotal role in the codification of the English language, the findings of this paper offer new insights into market forces and the role of printers in the context of the eighteenth‐century normative grammatical tradition. This study thus takes a unique perspective which it is hoped will open the path for future interdisciplinary investigations into the production of books in general, and of English grammars in particular.
Morphological Causatives in Old English: the Quest for a Vanishing Formation1
Authors: García García Luisa
Published: March 2012

A few present‐day English verb pairs, such as lie/lay or fall/fell, are remnants of a Germanic word‐formation type which was productive in the derivation of causative from primary verbs by means of the suffix *‐(i)ja‐. In Old English texts a substantial number of these verb pairs are attested, although often diachronic change has rendered them difficult to recognise. The aims of this paper are to make a new assessment of deverbal jan‐pairs in Old English with the help of an updated theoretical approach and newly available sources; to establish the semantic and syntactic relationship between the members of each pair; to reveal some tendencies in the evolution of these verbs from Germanic to Old English; and to connect these to wider issues of morpho‐syntactic change in English. The paper attempts a rigorous philological description sustained by relevant contemporary typological and linguistic findings.
Quantifying the uncertainty in change points
Authors: Nam Christopher F. H. , Aston John A. D. , Johansen Adam M.
Published: March 2012

Quantifying the uncertainty in the location and nature of change points in time series is important in a variety of applications. Many existing methods for estimation of the number and location of change points fail to capture fully or explicitly the uncertainty regarding these estimates, whilst others require explicit simulation of large vectors of dependent latent variables. This article proposes methodology for approximating the full posterior distribution of various change point characteristics in the presence of parameter uncertainty. The methodology combines recent work on evaluation of exact change point distributions conditional on model parameters via finite Markov chain imbedding in a hidden Markov model setting, and accounting for parameter uncertainty and estimation via Bayesian modelling and sequential Monte Carlo. The combination of the two leads to a flexible and computationally efficient procedure, which does not require estimates of the underlying state sequence. We illustrate that good estimation of the posterior distributions of change point characteristics is provided for simulated data and functional magnetic resonance imaging data. We use the methodology to show that the modelling of relevant physical properties of the scanner can influence detection of change points and their uncertainty.
Estimation of regression and dynamic dependence paremeters for non‐stationary multinomial time series
Authors: Loredo‐Osti J. C. , Sutradhar Brajendra C.
Published: March 2012

In a time‐series regression setup, multinomial responses along with time dependent observable covariates are usually modelled by certain suitable dynamic multinomial logistic probabilities. Frequently, the time‐dependent covariates are treated as a realization of an exogenous random process and one is interested in the estimation of both the regression and the dynamic dependence parameters conditional on this realization of the covariate process. There exists a partial likelihood estimation approach able to deal with the general dependence structures arising from the influence of both past covariates and past multinomial responses on the covariates at a given time by sequentially conditioning on the history of the joint process (response and covariates), but it provides standard errors for the estimators based on the observed information matrix, because such a matrix happens to be the Fisher information matrix obtained by conditioning on the whole history of the joint process. This limitation of the partial likelihood approach holds even if the covariate history is not influeced by lagged response outcomes. In this article, a general formulation of the auto‐covariance structure of a multinomial time series is presented and used to derive an explicit expression for the Fisher information matrix conditional on the covariate history, providing the possibility of computing the variance of the maximum likelihood estimators given a realization of the covariate process for the multinomial‐logistic model. The difference between the standard errors of the parameter estimators under these two conditioning schemes (covariates Vs. joint history) is illustrated through an intensive simulation study based on the premise of an exogenous covariate process.