bluuebunny/crossref_metadata_2025 huggingface dataset:
On Some Principles of Statistical Inference
Authors: Reid Nancy , Cox David R.
Published: October 2014

Statistical theory aims to provide a foundation for studying the collection and interpretation of data, a foundation that does not depend on the particular details of the substantive field in which the data are being considered. This gives a systematic way to approach new problems, and a common language for summarising results; ideally, the foundations and common language ensure that statistical aspects of one study, or of several studies on closely related phenomena, can be broadly accessible. We discuss some principles of statistical inference, to outline how these are, or could be, used to inform the interpretation of results, and to provide a greater degree of coherence for the foundations of statistics.
The Statistical Foundations of the Fourth Estate
Authors: Kemeny Richard
Published: October 2014

Richard Kemeny surveys the state of statistical education in UK journalism, and finds a skill set whose time has come.
Changes in a West Indian bird community since the late Pleistocene
Authors: Steadman David W. , Franklin Janet
Published: October 2014

Aim

To establish a chronology for late Quaternary avian extinction, extirpation and persistence in the Bahamas, thereby testing the relative roles of climate change and human impact as causes of extinction.

Location

Great Abaco Island (Abaco), Bahamas, West Indies.

Methods

We analysed the resident bird community as sampled by Pleistocene (> 11.7 ka) and Holocene (< 11.7 ka) fossils. Each species was classified as extinct (lost globally), extirpated (gone from Abaco but persists elsewhere), or extant (still resident on Abaco). We compared patterns of extinction, extirpation and persistence to independent estimates of climate and sea level for glacial (late Pleistocene) and interglacial (Holocene) times.

Results

Of 45 bird species identified in Pleistocene fossils, 25 (56%) no longer occur on Abaco (21 extirpated, 4 extinct). Of 37 species recorded in Holocene deposits, 15 (14 extirpated, 1 extinct; total 41%) no longer exist on Abaco. Of the 30 extant species, 12 were recovered as both Pleistocene and Holocene fossils, as were 9 of the 30 extirpated or extinct species. Most of the extinct or extirpated species that were only recorded from Pleistocene contexts are characteristic of open habitats (pine woodlands or grasslands); several of the extirpated species are currently found only where winters are cooler than in the modern or Pleistocene Bahamas. In contrast, most of the extinct or extirpated species recorded from Holocene contexts are habitat generalists.

Main conclusions

The fossil evidence suggests two main times of late Quaternary avian extirpation and extinction in the Bahamas. The first was during the Pleistocene–Holocene transition (PHT; 15–9 ka) and was fuelled by climate change and associated changes in sea level and island area. The second took place during the late Holocene (< 4 ka, perhaps primarily < 1 ka) and can be attributed to human impact. Although some species lost during thePHTare currently found where climates are cooler and drier than in the Bahamas today, a taxonomically and ecologically diverse set of species persisted through that major climate change but did not survive the past millennium of human presence.
Phylogeography and evolution of three closely related species of Tsuga (hemlock) from subtropical eastern Asia: further insights into speciation of conifers
Authors: Cun Yu‐Zhi , Wang Xiao‐Quan
Published: October 2014

Aim

The biogeography and speciation of conifers are of special interest because of the ecological importance of these trees, but the boundaries and evolutionary relationships of closely related species of conifers are difficult to disentangle. To investigate how lineage sorting and gene flow affect species boundaries in conifers, we studied the population genetic structure and phylogeographical history of the Tsuga chinensis–T. forrestii complex and compared the results with those for a closely related species, T. dumosa.

Location

Subtropical eastern Asia.

Methods

Phylogeographical analyses, in combination with coalescent simulations, were performed based on sequence variation of paternal chloroplast and maternal mitochondrial DNA in 1368 individuals from 52 populations of the three Tsuga (hemlock) species.

Results

Mitotypes were shared extensively among the three species while the chlorotypes were relatively more species‐specific. Two genetic breaks and thus three distinct geographical groups were identified in the T. chinensis–T. forrestii species pair. Unidirectional pollen flow from T. forrestii to T. chinensis was detected.

Main conclusions

Tsuga forrestii originated from a pre‐existing isolate of T. chinensis, and a cryptic genetic break formed between eastern and western populations of the latter. Incomplete lineage sorting was responsible for the extensive sharing of mitotypes among the three hemlock species, and our results seem to support the idea that paternally inherited markers are more effective in delimiting species than maternally inherited markers. We also found that hemlock populations in the Himalayas were very likely to have experienced extinction, but that most populations in other areas of subtropical mainland China survived the late Quaternary glacial cycles by elevational shifts.
Autism spectrum disorders and coexisting disorders in a nationwide Swedish twin study
Authors: Lundström Sebastian , Reichenberg Abraham , Melke Jonas , Råstam Maria , Kerekes Nóra , Lichtenstein Paul , Gillberg Christopher , Anckarsäter Henrik
Published: October 2014

Background

Evidence from twin and molecular genetic studies is accumulating that Autism Spectrum Disorder (ASD) shares substantial etiological factors with other disorders. This is mirrored in clinical practice where ASD without coexisting disorders is rare. The present study aims to examine the range of coexisting disorders in ASD in a genetically informative cohort.

Methods

Parents of all Swedish 9‐year‐old twins born between 1992 and 2001 (n = 19,130) underwent a telephone interview designed to screen for child psychiatric disorders, including ASD. To ensure full coverage of child psychiatric disorders, data were also retrieved from population‐based health registers. We investigated the coexistence of eight psychiatric disorders known to coexist with ASDs in probands and their co‐twins.

Results

Half of the individuals with ASDs (50.3%) had four or more coexisting disorders and only 4% did not have any concomitant disorder. The ‘healthy co‐twin’ in ASD discordant monozygotic twin pairs was very often (79% of boys and 50% of girls) affected by at least one non‐ASD disorder. The corresponding figures for ASD discordant dizygotic twin pairs were significantly lower (46% of males and 30% of females).

Conclusions

Detailed phenotypic descriptions including symptoms of problems associated with a wide range of child psychiatric disorders may aid in unraveling the genetic architecture of ASD and should guide the development of intervention strategies addressing each problem type specifically.
Novel Application of Freeze‐Dried Amaranth Sourdough in Gluten‐Free Bread Production
Authors: Różyło Renata , Rudy Stanisław , Krzykowski Andrzej , Dziki Dariusz
Published: October 2014

The purpose of this study was to describe the freeze‐drying of amaranth sourdough. Also, changes in the physical properties of bread caused by the addition of fresh or freeze‐dried amaranth sourdough were determined. Control gluten‐free bread was prepared from corn, rice and amaranth flour in two variants (45:45:10% and 40:40:20%). Amaranth flour was substituted with fresh or freeze‐dried sourdough. Two freeze‐drying temperatures (20 and 40C) were used for sourdough freeze‐drying. Consequently, the Page model was found to be the most appropriate to describe the drying of sourdough. Significant and beneficial changes in the physical properties of bread under the effect of both fresh and freeze‐dried sourdough were noted. Sensory evaluation of bread showed that bread with 20% amaranth sourdough is characterized by an unfavorable taste and smell; however, gluten‐free bread with 10% amaranth sourdough was accepted by consumers.

Practical Application

The obtained results have important meaning, as the use of freeze‐dried amaranth sourdough may improve the process of the production of natural gluten‐free bread by significantly shortening the production time required for this bread on the day of baking. The freeze‐dried amaranth sourdough in an amount of 10% may be a good substitute for fresh sourdough. To produce this sourdough, a freeze‐drying temperature of 40C is suggested. An increase of heating plate temperature from 20 to 40C caused a decrease of drying time of 26%. The bread is distinguished by a favorable qualitative assessment. Also, the reduced value of pH has a beneficial influence on extending bread durability.
Vitamin D and muscle strength throughout the life course: a review of epidemiological and intervention studies
Authors: McCarthy E. K. , Kiely M.
Published: October 2014

The putative role of vitamin D in muscle function and strength throughout the life course is of interest because muscle strength is required for engagement in physical activity at all ages. As vitamin D deficiency is widely reported in the population, especially in countries at high latitude, the potential importance of vitamin D in muscle function throughout life, and the potential impacts on growth and development, participation in physical activity, and effects on skeletal and cardio‐metabolic health, comprise an important topic for discussion. This review provides an overview of muscle function and summarises the role of the vitamin D receptor and the proposed molecular mechanisms of action of vitamin D in muscle cells. In addition, the review provides a comprehensive assessment of the clinical evidence surrounding the association between vitamin D and muscle strength. Among adults, particularly older adults, cross‐sectional and cohort studies reported a positive association between vitamin D status and muscle strength. These associations have been largely confirmed by intervention studies. Limited research has been carried out in adolescents and children; two cross‐sectional studies in adolescents have suggested an association between serum 25‐hydroxyvitamin D concentrations and muscle strength. However, the two intervention studies in adolescents have yielded conflicting results. Other than a single observational study, data in young children are very limited and further investigation in under 12‐year‐olds is warranted.
Cross‐sectional online survey of research productivity in young Japanese nursing faculty
Authors: Oyama Yumiko , Fukahori Hiroki , Miyashita Mitsunori , Narama Miho , Kono Ayumi , Atogami Fumi , Kashiwagi Masayo , Okaya Keiko , Takamizawa Emiko , Yoshizawa Toyoko
Published: October 2014

Aim

To investigate the factors affecting the research productivity of young nursing faculty in Japan.

Methods

An online survey targeting young nursing scholars (aged ≤39 years) who were members of the Japan Academy of Nursing Science was conducted from October to November 2012. Of 1634 potential respondents, 648 completed the survey (39.7%), and 400 full‐time faculty of a baccalaureate degree program were selected for the analysis. The numbers of English‐language and Japanese publications in the past 3 years were regressed onto personal characteristics, such as academic degree and type of university.

Results

The mean numbers of publications in English and Japanese in the past 3 years were 0.41 and 1.63, respectively. Holding a doctoral degree was significantly related to a higher number of publications in English and Japanese (eβ = 5.78 and eβ = 1.89, respectively). Working at a national university (eβ = 2.15), having a research assistant (eβ = 2.05), and the ability to read research articles in English (eβ = 2.27) were significantly related to more English‐language publications. Having the confidence to conduct quantitative research (eβ = 1.67) was related to a larger number of Japanese publications. The lack of mentoring (eβ = 0.97) and university workload (eβ = 0.96) were associated with a lesser number of Japanese publications.

Conclusion

The research productivity of young nursing faculty appeared to be quite low. Strategies to enhance research productivity in young nursing faculty, such as encouraging the achievement of a doctoral degree or enrichment of research resources, should be undertaken.
HBsAg plasma level kinetics: a new role for an old marker as a therapy response predictor in vertically infected children on combination therapy
Authors: Carey I. , Bruce M. , Horner M. , Zen Y. , D'Antiga L. , Bansal S. , Vergani D. , Mieli‐Vergani G.
Published: October 2014

We aimed to investigate the ability of HBsAg plasma level kinetics to predict therapy response by studying 23 children with infancy‐acquired chronic hepatitis B (CHB) during combination sequential therapy with lead‐in lamivudine (LAM) and add‐on interferon‐α (IFN‐α) [5 responders (R = anti‐HBs seroconversion) and 18 nonresponders (NR)] and to assess their relationship with pretreatment intrahepatic HBV‐DNA and cccDNA and HBsAg and HBcAg liver expression. Plasma HBsAg levels were measured in samples before (treatment week 0 = TW0), during (TW9, TW28, TW52) and after (follow‐up week = FUW24) therapy by Abbott ARCHITECT® assay [log10IU/mL]. Baseline liver HBV‐DNA and cccDNA were quantified by real‐time TaqMan PCR [log10copies/ng genomic DNA]. HBsAg and HBcAg liver expression was evaluated by immunostaining of formalin‐fixed, paraffin‐embedded specimens [number of positive cells/1000 hepatocytes]. All results are presented as medians. Plasma: at baseline, on‐treatment and during follow‐up, HBsAg levels were lower in R than NR (TW0: 4.36 vs 4.75;TW28: 2.44 vs 4.35;TW52: 0 vs 4.08 and FUW24: 0.17 vs 4.35, all P < 0.05). Liver: baseline HBV‐DNA (3.82 vs 4.71, P = 0.16) and cccDNA (1.98 vs 2.26, P = 0.18) tended to be lower in R than NR, HBsAg expression was lower in R than NR (0.5 vs 4.7, P = 0.03), and HBcAg expression was similar between R and NR. There were positive correlations between plasma HBsAg levels and liver HBV‐DNA (r = 0.44, P = 0.04), cccDNA (r = 0.41, P = 0.04) and HBsAg liver expression (r = 0.38, P = 0.05). Lower baseline HBsAg plasma levels, lower HBsAg expression in liver and on‐treatment decline of plasma HBsAg levels heralds HBsAg clearance and response to treatment in tolerant children with CHB.
Dominant amphipods ofPosidonia oceanicaseagrass meadows display considerable trophic diversity
Authors: Michel Loïc N. , Dauby Patrick , Gobert Sylvie , Graeve Martin , Nyssen Fabienne , Thelen Nicolas , Lepoint Gilles
Published: October 2014

Gut content examination and trophic markers (fatty acids, stable isotopes of C and N) were combined to delineate the diet of the dominant species of amphipods from MediterraneanPosidonia oceanicaseagrass meadows and to highlight trophic diversity among this community. Our results indicate that, although all dominant species heavily relied on macroalgal epiphytes, considerable interspecific dietary differences existed. Carbon stable isotope ratios notably showed that some of the amphipod species favored grazing on epiphytes from leaves or litter fragments (Apherusa chiereghinii,Aora spinicornis,Gammarus aequicauda), while others such asDexamine spiniventrispreferred epiphytes from rhizomes. The remaining amphipods (Caprella acanthifera, Ampithoe helleriandGammarella fucicola) readily consumed both groups. In addition, SIAR modeling suggested that most species had a mixed diet, and relied on several food items. Fatty acid analysis and gut contents revealed that contributions of microepiphytic diatoms and of benthic and suspended particulate organic matter to the diet of amphipods were anecdotal. None of the examined species seemed to graze on their seagrass host [low 18:2(n‐6) and 18:3(n‐3) fatty acids contents], butGammarus aequicaudapartly relied on seagrass leaf detritus, as demonstrated by the lesser13C‐depletion of their tissues. Overall, our findings suggest that amphipods, because of their importance in the transfer of organic matter from primary producers and detritus to higher rank consumers, are key items inP. oceanica‐associated food webs.
Land‐use legacies and present fire regimes interact to mediate herbivory by altering the neighboring plant community
Authors: Hahn Philip G. , Orrock John L.
Published: October 2014

Past and present human activities, such as historic agriculture and fire suppression, are widespread and can create depauperate plant communities. Although many studies show that herbivory on focal plants depends on the density of herbivores or the composition of the surrounding plant community, it is unclear whether anthropogenic changes to plant communities alter herbivory. We tested the hypothesis that human activities that alter the plant community lead to subsequent changes in herbivory. At 20 sites distributed across 80 300 hectares, we conducted a field experiment that manipulated insect herbivore access (full exclosures and pseudo‐exclosures) to four focal plant species in longleaf pine woodlands with different land‐use histories (post‐agricultural sites or non‐agricultural sites) and degrees of fire frequency (frequent and infrequent). Plant cover, particularly herbaceous cover, was lower in post‐agricultural and fire suppressed woodlands. Density of the dominant insect herbivore at our site (grasshoppers) was positively related to plant cover. Herbivore access reduced biomass of the palatable forb Solidago odora in frequently burned post‐agricultural sites and in infrequently burned non‐agricultural woodlands and increased mortality of another forb (Pityopsis graminifolia), but did not affect two other less palatable species (Schizachyrium scoparium and Tephrosia virginiana). Herbivory on S. odora exhibited a hump‐shaped response to plant cover, with low herbivory at low and high levels of plant cover. Herbivore density had a weak negative effect on herbivory. These findings suggest that changes in plant cover related to past and present human activities can modify damage rates on focal S. odora plants by altering grasshopper foraging behavior rather than by altering local grasshopper density. The resulting changes in herbivory may have the potential to limit natural recovery or restoration efforts by reducing the establishment or performance of palatable plant species.
Eyes and vision in the coeval Furongian trilobites Sphaerophthalmus alatus (Boeck, 1938) and Ctenopyge (Mesoctenopyge) tumida Westergård, 1922, from Bornholm, Denmark
Authors: Schoenemann Brigitte , Clarkson Euan N. K.
Published: October 2014

The two olenid species Sphaerophthalmus alatus (Boeck, 1838) and Ctenopyge (Mesoctenopyge) tumida Westergård, 1922, occur together in the Ctenopyge tumida Zone (Zone 19) of the Furongian of Scandinavia. Material from Bornholm, Denmark, forms the basis of this study of the morphology and partial ontogeny of the eyes. The eyes of both species are directed laterally and have virtually panoramic vision, looking out sideways like those of a rabbit. The eye of S. alatus is comparatively smaller, with fewer lenses and a larger eye parameter; calculations show that this trilobite was adapted for dim light intensity, possibly suggesting a vagrant benthic habit. Ctenopyge (Mesoctenopyge) tumida, with a smaller eye parameter, was adapted for a higher light intensity, and this trilobite was most likely a pelagic swimmer. The two species, although preserved together, inhabited different levels in the water column.
Pathways of bacterial invasion and watermelon seed infection by Acidovorax citrulli
Authors: Dutta B. , Ha Y. , Lessl J. T. , Avci U. , Sparks A. C. , Johnson K. L. , Walcott R. R.
Published: October 2014

This study explored the pathways of ingress of Acidovorax citrulli, the causal agent of bacterial fruit blotch of cucurbits, into watermelon seeds. Up until 7 days post‐inoculation (DPI), a significantly higher percentage of watermelon seeds was infected with A. citrulli when the bacteria were applied (c. 1 × 106 colony‐forming units) to stigmas versus ovary pericarps of female flowers. Immunofluorescence microscopy showed that, with stigma inoculation, A. citrulli colonized style and ovary tissues by 1 DPI, and the bacteria co‐localized with pollen germ tubes in these tissues. With ovary pericarp inoculation, A. citrulli cells penetrated the epicarp and mesocarp tissues by 1 DPI but did not reach endocarp until 4 DPI. Finally, manual pollination followed by stigma inoculation led to >53% A. citrulli‐infected seed lots, while A. citrulli was not detected in seeds/ovules generated by stigma inoculation without pollination (chemically induced parthenocarpy). These results show that stigma inoculation results in faster colonization of watermelon ovules by A. citrulli than pericarp inoculation, even though there is no difference in the levels of infection in mature seeds. The data also indicate that pollen germ tubes play an important role in A. citrulli ingress into watermelon seeds via stigmas.
Clinical Use of Deslorelin (GnRH agonist) in Companion Animals: A Review
Authors: Lucas X
Published: October 2014

Contents

Over the years, many contraceptive medications have been developed for companion animals, but many secondary adverse effects have limited their use. A major advancement was achieved with the use of gonadotropin‐releasing hormone (GnRH) analogues, mainly GnRH agonists, which mimic the effects of native GnRH. The development of effective low‐dose, slow‐release implants with potent agonists such as deslorelin (Suprelorin®, Virbac) have allowed their use to become widespread in recent years, with many potential benefits in companion animals. While the major application of deslorelin was initially male contraception, due to its two differing actions, either the stimulation of oestrus or the sterilization of fertility, its use has been increasing in the bitch as well. The aim of this study is to review the applications of deslorelin GnRH agonist implants in companion animal, such as dogs, cats and some exotic pets.
Stem Cells and Regenerative Medicine in Domestic and Companion Animals: A Multispecies Perspective
Authors: Gonçalves NN , Ambrósio CE , Piedrahita JA
Published: October 2014

Contents

Since their original isolation, the majority of the work on embryonic stem cells (ESC) has been carried out in mice. While the mouse is an outstanding model for basic research, it also has considerable limitations for translational work, especially in the area of regenerative medicine. This is due to a combination of factors that include physiological and size differences when compared to humans. In contrast, domestic animal species, such as swine, and companion animal species, such as dogs, provide unique opportunities to develop regenerative medicine protocols that can then be utilized in humans. Unfortunately, at present, the state of knowledge related to, and availability of, ESC from domestic animals vary among species such as pig, horse, dog and cat, and without exception lags significantly behind the mouse and human. It is clear that much still needs to be discovered. The ‘stem cell‐like’ cell lines being reported are still not satisfactorily used in regenerative medicine, due to reasons such as heterogeneity and chromosomal instability. As a result, investigators have searched for alternate source of cells that can be used for regenerative medicine. This approach has uncovered a range of adult stem cells and adult progenitor cells that have utility in both human and veterinary medicine. Here, we review a range of stem cells, from ESC to induced pluripotent stem cells, and discuss their potential application in the field of regenerative medicine.
Transcervical Artificial Insemination in Dogs and Cats: Review of the Technique and Practical Aspects
Authors: Romagnoli S , Lopate C
Published: October 2014

Contents

The technique of transcervical catheterization for artificial insemination has gained practical importance over the last 3 and 1 decades in bitches and queens, respectively. The vagina of both species has a thickening of the dorsal aspect called dorsal medial fold, which restricts the lumen of the paracervix, making catheterization of the cervix difficult both with manual and endoscopic techniques. Manual catheters have been used initially in the bitch and are now gradually being replaced by rigid endoscopy through the adaptation of human cystoscopes and ureteroscopes. Cystoscopes provide excellent imaging of the vagina, but cervical catheterization is more difficult due to the oblique 30° viewing angle of its telescope and may not be long enough to catheterize large size bitches. Ureteroscopes allow an acceptable view of the vaginal mucosa and offer advantages such as the possibility to catheterize the cervix of bitches of all body sizes, manipulate the cervical tubercle when the external cervical os is not visible, offer a better visualization of the cervix using the shunt (a large Foley catheter which allows insufflation and distention of the vagina). Feline cervical catheterization has been achieved with three different types of catheters; the last one, developed following careful anatomical studies of how the feline vaginal lumen changes during estrus, allows cervical catheterization thanks to digital manipulation of the cervix through the rectum.
Current Status of Freeze‐Drying Technology to Preserve Domestic Animals Sperm
Authors: Gil L , Olaciregui M , Luño V , Malo C , González N , Martínez F
Published: October 2014

Contents

In recent years, there has been an increased interest in new preservation techniques that facilitate sperm storage and distribution, with freeze‐drying (FD) having been proposed as an alternative method for sperm preservation and maintenance of genetic resources in different animal species. FD is a method in which frozen material is dried by sublimation of ice, thereby involving a direct transition from a solid (ice) to a vapour (gas) phase. One of the main advantages of FD is that nitrogen and dry ice are no longer required for the storage and shipment of frozen sperm, which can be stored at room temperature or 4°C, thereby resulting in enormous reductions in storage and shipping costs. Unlike sperm cryopreserved after gradual freezing, the sperm membrane may be further damaged by both snap‐freezing and drying stresses during the FD procedure. As mammalian spermatozoa lose their motility, viability and, at least partially, their DNA integrity when freeze‐dried, they must be microinjected into an oocyte by intracytoplasmic sperm injection (ICSI). Although the efficiency of ICSI is limited when freeze‐dried spermatozoa are used, embryos and live offspring can be produced. DNA fragmentation in freeze‐dried spermatozoa is one of the main causes of failure of embryonic development and successful pregnancy. In this regard, it has been suggested that endonucleases are among the leading causes of DNA fragmentation in spermatozoa along with oxidative stress caused by the release of reactive oxygen species (ROS). Many factors influence the FD process, and it is not clear how FD affects specific components of sperm from different animal species. As such, a sound understanding of the FD process would result in increased production of embryos and/or live offspring. The aim of this review was to study the various stages and techniques used in the FD process and to further evaluate the results obtained.
Understanding Sperm Heterogeneity: Biological and Practical Implications
Authors: Ramón M , Jiménez‐Rabadán P , García‐Álvarez O , Maroto‐Morales A , Soler AJ , Fernández‐Santos MR , Pérez‐Guzmán MD , Garde JJ
Published: October 2014

Contents

Sperm are the most diverse cell type known. This diversity is thought to reflect adaptation to conditions under which sperm function as a way to ensure the survival of sperm in fertilization environments and to maximize fertilizing capacity thereof. The existence of morphological diversity among species is widely assumed, although this diversity seems less clear as we go deeper (between males, between ejaculates from the same male and even within the same ejaculate), with different theories addressing this heterogeneity. Moreover, the development of assisted reproductive techniques (ART) has led to changes in the physiological conditions in which sperm fertilize, which could lead, ultimately, to a selection towards more favourable sperm design. Regardless of the origin of this diversity, when studying the relationship between shape and function of sperm, it is advisable to assess the degree of heterogeneity of sperm and takes into account to be more likely to identify those morphological characteristics determining the fertile ability of sperm. Otherwise, these relationships could be hidden as a result of considering an average shape not representative of morphological characteristics of sperm. In addition, the knowledge of this morphological diversity in terms of changes arising from modifications in the sperm environment and mechanisms that generate these changes could be useful for understanding the reproductive capacity of males but also in enhancing their fertile ability.
High‐resolution reconstruction of a coastal barrier system: impact of Holocene sea‐level change
Authors: Fruergaard Mikkel , Andersen Thorbjørn J. , Nielsen Lars H. , Johannessen Peter N. , Aagaard Troels , Pejrup Morten
Published: October 2014

This study presents a detailed reconstruction of the sedimentary effects of Holocene sea‐level rise on a modern coastal barrier system. Increasing concern over the evolution of coastal barrier systems due to future accelerated rates of sea‐level rise calls for a better understanding of coastal barrier response to sea‐level changes. The complex evolution and sequence stratigraphic framework of the investigated coastal barrier system is reconstructed using facies analysis, high‐resolution optically stimulated luminescence and radiocarbon dating. During the formation of the coastal barrier system starting 8 to 7 ka rapid relative sea‐level rise outpaced sediment accumulation. Not before rates of relative sea‐level rise had decreased to ca 2 mm yr−1 did sediment accumulation outpace sea‐level rise. From ca 5·5 ka, rates of regionally averaged sediment accumulation increased to 4·3 mm yr−1 and the back‐barrier basin was filled in. This increase in sediment accumulation resulted from retreat of the barrier island and probably also due to formation of a tidal inlet close to the study area. Continued transgression and shoreface retreat created a distinct hiatus and wave ravinement surface in the seaward part of the coastal barrier system before the barrier shoreline stabilized between 5·0 ka and 4·5 ka. Back‐barrier shoreline erosion due to sediment starvation in the back‐barrier basin was pronounced from 4·5 to 2·5 ka but, in the last 2·5 kyr, barrier sedimentation has kept up with and outpaced sea‐level. In the last 0·4 kyr the coastal barrier system has been prograding episodically. Sediment accumulation shows considerable variation, with periods of rapid sediment deposition and periods of non‐deposition or erosion resulting in a highly punctuated sediment record. The study demonstrates how core‐based facies interpretations supported by a high‐resolution chronology and a well‐documented sea‐level history allow identification of depositional environments, erosion surfaces and hiatuses within a very homogeneous stratigraphy, and allow a detailed temporal reconstruction of a coastal barrier system in relation to sea‐level rise and sediment supply.
Modifying fatty acid profiles through a new cytokinin‐based plastid transformation system
Authors: Dunne Aisling , Maple‐Grødem Jodi , Gargano Daniela , Haslam Richard P. , Napier Johnathan A. , Chua Nam‐Hai , Russell Rosalind , Møller Simon Geir
Published: October 2014

The widespread use of herbicides and antibiotics for selection of transgenic plants has not been very successful with regard to commercialization and public acceptance. Hence, alternative selection systems are required. In this study, we describe the use of ipt, the bacterial gene encoding the enzyme isopentenyl transferase from Agrobacterium tumefaciens, as a positive selectable marker for plastid transformation. A comparison between the traditional spectinomycin‐based aadA selection system and the ipt selection system demonstrated that selection of transplastomic plants on medium lacking cytokinin was as effective as selection on medium containing spectinomycin. Proof of principle was demonstrated by transformation of the kasIII gene encoding 3‐ketoacyl acyl carrier protein synthase III into tobacco plastids. Transplastomic tobacco plants were readily obtained using the ipt selection system, and were phenotypically normal despite over‐expression of isopentenyl transferase. Over‐expression of KASIII resulted in a significant increase in 16:0 fatty acid levels, and a significant decrease in the levels of 18:0 and 18:1 fatty acids. Our study demonstrates use of a novel positive plastid transformation system that may be used for selection of transplastomic plants without affecting the expression of transgenes within the integrated vector cassette or the resulting activity of the encoded protein. This system has the potential to be applied to monocots, which are typically not amenable to traditional antibiotic‐based selection systems, and may be used in combination with a negative selectable marker as part of a two‐step selection system to obtain homoplasmic plant lines.
The polycomb group gene EMF2B is essential for maintenance of floral meristem determinacy in rice
Authors: Conrad Liza J. , Khanday Imtiyaz , Johnson Cameron , Guiderdoni Emmanuel , An Gynheung , Vijayraghavan Usha , Sundaresan Venkatesan
Published: October 2014

Polycomb Repressive Complex 2 (PRC2) represses the transcriptional activity of target genes through trimethylation of lysine 27 of histone H3. The functions of plant PRC2 have been chiefly described in Arabidopsis, but specific functions in other plant species, especially cereals, are still largely unknown. Here we characterize mutants in the rice EMF2B gene, an ortholog of the Arabidopsis EMBRYONIC FLOWER2 (EMF2) gene. Loss of EMF2B in rice results in complete sterility, and mutant flowers have severe floral organ defects and indeterminacy that resemble loss‐of‐function mutants in E‐function floral organ specification genes. Transcriptome analysis identified the E‐function genes OsMADS1, OsMADS6 and OsMADS34 as differentially expressed in the emf2b mutant compared with wild type. OsMADS1 and OsMADS6, known to be required for meristem determinacy in rice, have reduced expression in the emf2b mutant, whereas OsMADS34 which interacts genetically with OsMADS1 was ectopically expressed. Chromatin immunoprecipitation for H3K27me3 followed by quantitative (q)RT‐PCR showed that all three genes are presumptive targets of PRC2 in the meristem. Therefore, in rice, and possibly other cereals, PRC2 appears to play a major role in floral meristem determinacy through modulation of the expression of E‐function genes.
Reduction of Rapid Positioning Time by Reference Path Modification: A Preliminary Investigation
Authors: Lin Chan-Rong , Chen Bokai , Okwudire Chinedum E.
Published: October 2014

This paper presents a preliminary investigation into a method for reducing servo delays that occur after the execution of rapid positioning commands in computer numerically controlled (CNC) machines. A model of the machine’s dynamics is used to predict the servo error resulting from a prescribed rapid positioning command. Based on this information, the reference path is extended by an amount calculated to ensure that the predicted error falls within a user-specified threshold in the shortest possible time. The proposed method is shown in simulations to significantly shorten rapid positioning time compared to the industry-standard approach of compensating for servo delays by pausing motion until servo errors fall within user-specified thresholds. However, experiments reveal the need for further research to enhance the versatility and robustness of the method.
Effect of Weld Defects on Tensile Properties of Lightweight Materials and Correlations With Phased Array Ultrasonic Nondestructive Evaluation
Authors: Dewan Mohammad W. , Wahab M. A. , Okeil Ayman M.
Published: October 2014

Fusion welding of Aluminum and its alloys is a great challenge for the structural integrity of lightweight material structures. One of the major shortcomings of Aluminum alloy welding is the inherent existence of defects in the welded area. In the current study, tests have been conducted on tungsten inert gas (TIG) welded AA6061-T651 aluminum alloy to determine the effects of defect sizes and its distribution on fracture strength. The information will be used to establish weld acceptance/rejection criteria. After welding, all specimens were non-destructively inspected with phased array ultrasonic and measured the projected area of the defects. Tensile testing was performed on inspected specimens containing different weld defects: such as, porosity, lack of fusion, and incomplete penetration. Tensile tested samples were cut along the cross section and inspected with Optical Microscope (OM) to measure actual defect sizes. Tensile properties were correlated with phased array ultrasonic testing (PAUT) results and through microscopic evaluations. Generally, good agreement was found between PAUT and microscopic defect sizing. The tensile strength and toughness decreased with the increase of defect sizes. Small voids (area ratio <0.04) does not have significant effect on the reduction of tensile strength and toughness values. Once defective “area ratio (cross sectional area of the defect) / (total specimen cross sectional area)” reached a certain critical value (say, 0.05), both strength and toughness values decline sharply. After that critical value both the tensile strength and toughness values decreases linearly with the increase of defect area ratio.
A Method for Identifying Error Sources in Complex Assembly Process Based on Multi-Level Network
Authors: Diao Guangzhou , Zhao Liping , Yao Yiyong , Hu Sheng
Published: October 2014

In complex assembly process, there are many error sources which influence the final product quality, so the identification and compensation of error sources are the important ways to improve product quality. The purpose of this paper is to identify the error sources by establishing the relationships between assembly errors and product performance. Firstly, a new concept of multi-level network is proposed to describe the complexity of product structure. Then the multi-level assembly network (MLAN) model is established and its self-organization stability is discussed to explore the influences from assembly errors on product performance. The sensitive fluctuation index (SFI) is defined and calculated to identify the error sources in assembly process. Based on this, the error sensitivity is discussed so that measures for error compensation are made to improve the assembly quality of product. Finally, an assembly experiment about blade rotation is conducted to verify the feasibility of proposed method.
A Multi-Axis Deep Drawing Servo Press With Non-Overconstrained Architecture
Authors: Meoni Francesco , Lutey Adrian , Fortunato Alessandro , Carricato Marco
Published: October 2014

Servo actuated presses can provide maximum pressing force at any slide position in the same manner that hydraulic presses do, while offering several benefits in terms of precision, energy conversion efficiency and simplicity due to their lack of hydraulic circuitry and oil. Several press builders have developed electric-spindle actuated presses; however, issues relating to multi-axis architecture have been neglected. The present study proposes an innovative method of avoiding overconstrained architecture by implementing a kinematic mechanism that connects multiple servo axes to one slide. Servo axis design is developed by creating a dynamic model of a kinematic chain composed of a servo-motor, gearbox reducer and ball screw transmission. A study of a biaxial industrial servo press prototype with non-overconstrained architecture, currently under construction, is presented as proof of concept. It is shown that such a non-overconstrained multi-axis press can be constructed from commercially available components, achieving high energy efficiency at high load with relatively simple construction.
Modeling of Helical Gear Carbide Re-Hobbing Process
Authors: Khurana Pravin , King David , Marseilles Kevin , Sengupta Sankar
Published: October 2014

Carbide re-hobbing is a variation of the gear hobbing process. It is typically used for finishing fully-hardened gear blanks that have been semi-finished, generally by a previous hobbing operation. This paper will discuss a new approach to modeling the carbide re-hobbing process with the goal of improving part quality for a typical pinion. Prior modeling approaches have been based on analytical chip calculation methods. Such approaches, however, limit the geometry of the tool and candidate workpiece to such profiles as would be implemented in the model initially. This new modeling approach involves the use of CAD/CAM/CAE tools to simulate the hobbing process in a virtual 3D environment. As such, the models may now take into account the specific tool geometries, workpiece geometries, setup errors and various cutting conditions with much greater ease. The results of the simulation in predicting cutting forces, part deflection and the resulting profile deviations will be presented. Further, the effect of tool setup error, in particular both synchronous and asynchronous runout, on part quality will be examined in simulation. The simulation results reveal that each type of runout provides a unique signature of profile deviation error for the left and right flanks. The relationship between these setup errors and resulting profile errors will be examined in detail and compared with data from controlled machining tests.
Modelling Static and Dynamic Kinetics of Microstructure Evolution in Type 316 Stainless Steel During Hot Rolling
Authors: Dupin Eduardo E. V. , Yanagida Akira , Yanagimoto Jun
Published: October 2014

In this study, the kinetics of microstructure evolution during hot rolling of type 316 austenitic stainless steel is investigated. First, its kinetics during the dynamic and static events, known as the material genome, is driven by single- and double-compression tests at several temperatures and strain rates. Inverse analysis is used to obtain the flow curves and regression analysis is applied on the coefficients of these flow curves in order to obtain the parameters of the constitutive equations. This new material genome is then used as the boundary condition on an incremental type formulation, taking the dislocation density as the representative variable, to estimate the flow stress and microstructural evolution after the transient changes during rolling schedules of seamless pipes. Actual rolling schedules are simulated and the microstructural changes are compared to industrial data. The outcome of the grain size evolution was reproduced reasonably well showing that proposed methodology can be used to simulate a complex thermomechanical process akin to the rolling schedules of seamless pipes.
A Numerical Study on Welding Stainless Steel With Lasers
Authors: Jiao Junke , Zhang Wenwu , Sun Jiaqing
Published: October 2014

The technique to weld stainless steel with fiber lasers was investigated. The main objective of this study was to determine the influence of the welding parameters, such as laser power, defocusing amount, velocity, on weld characteristics. The mathematical model was put forward. And, the temperature and thermal stress distribution in the welding process was calculated by ANSYS. Through numerical prediction, the theoretical effects of laser parameters to the welding quality were analyzed.
Superoleophobic Surfaces on Al and Mg Alloy Substrates Through Rapid Surface Micro/Nanometer-Scale Structuring
Authors: Song Jinlong , Huang Shuai , Liu Xin , Xu Wenji
Published: October 2014

A facile and highly efficient electroless deposition method to rapidly fabricate superoleophobic surfaces on Al and Mg alloy substrates is described herein. Hierarchical micro/nanometer-scale rough Cu structures required by superoleophobic surfaces were fabricated on Al substrates via immersing Al plates in the mixed solution containing CuSO4 and NaCl. Hierarchical micro/nanometer-scale rough Ag structures were fabricated on Mg alloy substrates via immersing Mg alloy plates in the aqueous AgNO3 solution. After perfluorooctanoic acid modification, in-air superoleophobic Al and Mg alloy surfaces were obtained. The contact angles of peanut oil on superoleophobic Al and Mg alloy surfaces are 156.5 ± 2.5° and 150.5 ± 1°, respectively. The sliding angles of peanut oil on the aforementioned two surfaces are 4° and 50°, respectively. The shortest times for the fabrication of superoleophobic Al and Mg alloy surfaces are no more than 60 s and 20 min, respectively. Applications of such surfaces are envisioned in the fields of industrial processing of low-surface tension liquids such as distilling and pipe-line transport of petroleum products or where surfaces are exposed to dirty oil/water environments.
A Q-Learning Based Selective Disassembly Planning Service in the Cloud Based Remanufacturing System for WEEE
Authors: Xia Kai , Gao Liang , Li Weidong , Wang Lihui , Chao Kuo-Ming
Published: October 2014

Cloud based approach for remanufacturing is becoming a new technical solution for sustainable management of Waste Electrical and Electronic Equipment (WEEE). This paper presents a service-oriented framework of a Cloud Based Remanufacturing System (CBRS) for WEEE. In remanufacturing of WEEE, disassembly plays an important role. However, complete disassembly is rarely an ideal solution due to the high disassembly cost, with the increasing customization and diversity, and more complex assembly processes of Electrical and Electronic Equipment (EEE). Selective disassembly focusing on disassembling only a few selected components is a better choice. In this paper, a Q-Learning based Selective Disassembly Planning (QL-SDP) approach embedded with a multi-criteria decision making model is developed. The multi-criteria decision making model is built according to the legislative and economic considerations of specific stakeholders of WEEE. And the QL-SDP approach is used to achieve optimized selective disassembly planning. An implementation example has been used to verify and demonstrate the effectiveness and robustness of the approach. The developed QL-SDP approach is designed as a service implemented in the presented CBRS for WEEE.
Concept for Function Block Enabled Process Planning Towards Multi-Site Cloud Collaboration
Authors: Helgoson Martin , Wang Lihui , Karlsson Robin , Givehchi Mohammad , Tedeborg Mikael
Published: October 2014

In global enterprises an essential challenge is how to enable efficient sharing of knowledge, capacity, and resources in order to meet demands on speed, flexibility and adaptability.

This paper highlights challenges and aspects regarding framework and technical platform for process planning that enable global multi-site collaboration. To get an industrial perspective, this topic is discussed in the context of Sandvik Coromant’s globally distributed application centers. Further on, function block technology as enabling technology to achieve flexible and adaptable process planning as a part of the framework is presented and discussed together with results from the on-going research work.