bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the phase‐transition in phase‐change materials
Authors: Kohary Krisztian , Wright C. David
Published: March 2013

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Phase‐change materials have a wide range of optical and electrical applications due to a unique combination of structural, electronic and optical properties. The phase transition between the crystalline and amorphous phases is a central physical process in devices based on phase‐change materials. In order to design and to develop future applications with novel functionalities we need to understand on the nanometre length scale and the (sub)nanosecond timescale the electrical, thermal and phase‐transition behaviour of phase‐change materials. At the nanoscale the phase‐transformation in phase‐change materials is governed by the chemical composition, atomic structure, and the input energy due to temperature (Joule heat), electric field and/or electronic excitations. Therefore, a successful phase‐change model should capture all these elements and predict the phase information as an output. We discuss the theoretical models that have been used to study and predict the crystallization of phase‐change materials that span the materials modelling spectrum from electronic/atomistic simulations (atomic behaviour) to microscopic and continuum models (bulk behaviour). Real applications and device design require the use of microscopic and continuum models due to large computational times of atomistic simulations. On the other hand the predictions provided by microscopic and continuum models depend on the chosen parameter set used to describe the phase transition. We stress the importance of ‘building bridges’ between atomistic and continuum modelling to design future phase‐change devices with novel and enhanced functionalities.
Efficacy and Safety of Standardized Extract of Trigonella foenum‐graecum L Seeds as an Adjuvant to L‐Dopa in the Management of Patients with Parkinson's Disease
Authors: Nathan J. , Panjwani Siddika , Mohan V. , Joshi Veena , Thakurdesai Prasad Arvind
Published: March 2013

The objective of this study is to evaluate disease modifying efficacy and safety of a standardized extract of Trigonella foenum‐graecum L, Fenugreek (IBHB) (family Fabaceae) as a nutritional adjuvant to Levo‐dopa (L‐Dopa) in Parkinson's disease (PD) patients. We conducted double‐blind placebo‐controlled proof of concept clinical study of IBHB capsules (300 mg, twice daily) with matching placebo for 6 months of period in 50 patients of PD stabilized on L‐Dopa therapy. The efficacy outcome measures were the scores of Unified Parkinson's Disease Rating Scale (UPDRS ‐ total and its subsections), and Hoehn and Yahr (H&Y) staging at baseline and end of 6‐months treatment duration. Safety evaluation included haematology, biochemistry, urinalysis parameters and adverse event monitoring. Total UPDRS scores in IBHB treatment (0.098%) showed slower rise as opposed to steep rise (13.36%) shown by placebo. Further, Clinically Important Difference for total UPDRS scores and scores of motor subsection of UPDRS was found to be 5.3 and 4.8, respectively, in favour of IBHB treatment. Similar improvement was shown by IBHB in terms of H&Y staging as compared with placebo. IBHB was found to have excellent safety and tolerability profile. In conclusion, IBHB can be useful adjuvant treatment with L‐Dopa in management of PD patients. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis of O‐Acyl Isopeptides
Authors: Sohma Youhei , Kiso Yoshiaki
Published: March 2013

O‐Acyl isopeptides, in which the N‐acyl linkage on the hydroxyamino acid residue (e.g., Ser and Thr) is replaced with an O‐acyl linkage, generally possess superior water‐solubility to their corresponding native peptides, as well as other distinct physicochemical properties. In addition, O‐acyl isopeptides can be rapidly converted into their corresponding native peptide under neutral aqueous conditions through an O‐to‐N acyl migration. By exploiting these characteristics, researchers have applied the O‐acyl isopeptide method to various peptide‐synthesis fields, such as the synthesis of aggregative peptides and convergent peptide synthesis. This O‐acyl‐isopeptide approach also serves as a means to control the biological function of the peptide in question. Herein, we report the synthesis of O‐acyl isopeptides and some of their applications.
Heterogeneous sources of the Triassic granitoid plutons in the southern Qinling orogen: An E‐W tectonic division in central China
Authors: Ping Xianquan , Zheng Jianping , Zhao Junhong , Tang Huayun , Griffin W. L.
Published: March 2013

The Qinling orogen is an important orogenic belt formed by the collision between the North and South China blocks along the Mianlue suture during the Triassic. The orogen is customarily divided into the western and eastern Qinling terranes. However, the boundary has long been a matter of debate. There are many Triassic granitoid plutons in the orogen, especially in South Qinling, along the southern part of the Shangdan suture. Systematic analysis of U‐Pb ages and Hf isotopes in zircons frxom six granitoid plutons, including Guangtoushan, Gaoqiaopu, Xiba, Laocheng, Dongjiangkou, and Zhashui from west to east, allows us to trace their formation ages and source regions. All plutons yield ages that vary only from 218 to 211 Ma. However, zircon Hf‐isotope data for these Triassic plutons cluster in two distinct groups. Granitoids from the western segment (i.e., Guangtoushan, Gaoqiaopu, and Xiba) of the South Qinling belt have negative εHf(t) values (−20.9 to −5.2) and relatively old two‐stage Hf model ages (1.58 to 2.57 Ga). In contrast, those from the eastern segment (i.e., Laocheng, Dongjiangkou, and Zhashui) show higher εHf(t) values (−5.4 to +6.8) and younger two‐stage Hf model ages (0.82 to 1.60 Ga). Integrating these analyses with published Sr‐Nd‐Pb‐Hf isotopic data, we suggest that the division between the western and eastern South Qinling segments is located near the Taibai‐Chenggu line, between the Baoji‐Chengdu railway and 108°E longitude. The integrated data suggest that the western South Qinling segment separated from the North China block during the Paleoproterozoic and early Mesoproterozoic and then switched into continental convergence with the eastern South Qinling segment (northern margin of the Yangtze block) during the late Mesoproterozoic to early Neoproterozoic; finally, the two segments amalgamated during the late Neoproterozoic.
CRISPR‐Cas systems and RNA‐guided interference
Authors: Barrangou Rodolphe
Published: March 2013

Clustered regularly interspaced short palindromic repeats (CRISPR) together with associated sequences (cas) form the CRISPR‐Cas system, which provides adaptive immunity against viruses and plasmids in bacteria and archaea. Immunity is built through acquisition of short stretches of invasive nucleic acids into CRISPR loci as ‘spacers'. These immune markers are transcribed and processed into small noncoding interfering CRISPR RNAs (crRNAs) that guide Cas proteins toward target nucleic acids for specific cleavage of homologous sequences. Mechanistically, CRISPR‐Cas systems function in three distinct stages, namely: (1) adaptation, where new spacers are acquired from invasive elements for immunization; (2) crRNA biogenesis, where CRISPR loci are transcribed and processed into small interfering crRNAs; and (3) interference, where crRNAs guide the Cas machinery to specifically cleave homologous invasive nucleic acids. A number of studies have shown that CRISPR‐mediated immunity can readily increase the breadth and depth of virus resistance in bacteria and archaea. CRISPR interference can also target plasmid sequences and provide a barrier against the uptake of undesirable mobile genetic elements. These inheritable hypervariable loci provide phylogenetic information that can be insightful for typing purposes, epidemiological studies, and ecological surveys of natural habitats and environmental samples. More recently, the ability to reprogram CRISPR‐directed endonuclease activity using customizable small noncoding interfering RNAs has set the stage for novel genome editing and engineering avenues. This review highlights recent studies that revealed the molecular basis of CRISPR‐mediated immunity, and discusses applications of crRNA‐guided interference. WIREs RNA 2013, 4:267–278. doi: 10.1002/wrna.1159

This article is categorized under:

RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms

Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs

Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action
Effects of management intensity and orchard features on bird communities in winter
Authors: Myczko Łukasz , Rosin Zuzanna M. , Skórka Piotr , Wylegała Przemysław , Tobolka Marcin , Fliszkiewicz Monika , Mizera Tadeusz , Tryjanowski Piotr
Published: March 2013

The knowledge and conservation of diminishing valuable habitats in agricultural landscapes are of key importance in saving declining farmland biodiversity. One of these habitats is the traditional orchard whose role in supporting birds is still poorly known, especially in winter. We counted birds in 106 orchards differing in management intensity (abandoned, traditional, and intensive) during December 2009 and January 2010 in Wielkopolska, western Poland and measured site characteristics and composition of surrounding landscapes for every orchard. Old abandoned and traditionally managed orchards had significantly higher bird species richness than intensive ones. Irrespective of orchard type, bird species richness as well as density were positively influenced by the cover of unmown herb layer in orchards and tree diversity. Tree and fruit densities positively affected bird species richness and density mainly in abandoned orchards while in other orchard types the effect of these variables was less pronounced. Land cover diversity in a landscape had a positive effect on species richness and density mostly in abandoned orchards and we believe that this effect reflects the elevated utilization of such orchards by birds from the surrounding landscape. Thus, abandoned, as well as traditionally managed orchards seems to be especially important habitats that offer food source and refuge for wintering birds and should be protected. We propose to diversify fruit production by planting various tree species, leaving part of the herb layer unmown and several trees unharvested in intensive orchards in order to improve suitability of modern orchards for birds.
Down‐Regulation of Hepatic Stearoyl‐CoA Desaturase‐1 Expression by Fucoxanthin via Leptin Signaling in Diabetic/Obese KK‐Ay Mice
Authors: Beppu Fumiaki , Hosokawa Masashi , Yim Mi‐Jin , Shinoda Taro , Miyashita Kazuo
Published: March 2013

Stearoyl‐coenzyme A desaturase‐1 (SCD1) is a rate‐limiting enzyme that catalyzes the biosynthesis of monounsaturated fatty acids from saturated fatty acids. Recently, SCD1 down‐regulation has been implicated in the prevention of obesity, and the improvement of insulin and leptin sensitivity. In this study, we examined the effect of fucoxanthin, a marine carotenoid, on hepatic SCD1 in obese mouse models of hyperleptinemia KK‐Ay and leptin‐deficiency ob/ob. In KK‐Ay mice, providing a diet containing 0.2 % fucoxanthin for 2 weeks markedly suppressed SCD1 mRNA and protein expressions in the liver. The fatty acid composition of liver lipids was also affected by an observed decrease in the ratio of oleic acid to stearic acid. Furthermore, serum leptin levels were significantly decreased in hyperleptinemia KK‐Ay mice after 2 weeks of fucoxanthin feeding. However, the suppressive effects of fucoxanthin on hepatic SCD1 and body weight gain were not observed in ob/ob mice. These results show that fucoxanthin down‐regulates SCD1 expression and alters fatty acid composition of the liver via regulation of leptin signaling in hyperleptinemia KK‐Ay mice but not in leptin‐deficient ob/ob mice.
Religious Non-involvement Among African Americans, Black Caribbeans and Non-hispanic Whites: Findings from the National Survey of American Life
Authors: Brown R. Khari , Taylor Robert Joseph , Chatters Linda M.
Published: March 2013

This study examines the association between race/ethnicity, socio-demographic characteristics, and religious non-involvement among a national sample of African Americans, Black Caribbeans and Non-Hispanic Whites. The relationship between religious non-involvement and selected measures of religious participation, spirituality, religious coping is also examined. The study utilizes data from a national multi-stage probability sample, the National Survey of American Life ( n = 6,082). Very few individuals, <1 out of 20 respondents, both never attended religious services and have no current denomination. Overall, <8 % have never attended religious services since the age of 18. Both African Americans and Black Caribbeans were significantly less likely than non-Hispanic Whites to report never attending religious services and not having a current denomination. The greater reliance upon religious institutions for support and guidance among African Americans and Black Caribbean Americans relative to Non-Hispanic Whites may help explain the importance of race in predicting religious non-involvement. Women, married persons, Southerners, and the more highly educated are significantly more likely to be involved in religion. Finally, this study indicates that the religiously non-involved are less likely than others to participate in religious activities, to identify as spiritual, and to rely upon religion to cope with trying circumstances. Nonetheless, even respondents who never attend religious services and do not have a denomination still report some level of religious participation along with relatively high levels of religious coping. We posit that religious non-involvement is less indicative of apostasy, but rather likely reflects a critique of organized religion.
Partitioning and confinement of GM1 ganglioside induced by amyloid aggregates
Authors: Calamai Martino , Pavone Francesco S.
Published: March 2013

Growing evidence shows that GM1 ganglioside is involved in amyloid deposition and toxicity. By means of real‐time single particle tracking, we show that amyloid oligomers and aggregates formed by Aβ1–42 and amylin, two peptides associated, respectively, with the development of Alzheimer's disease and type II diabetes, interact with GM1 and decrease dramatically its lateral diffusion on the plasma membrane of living neuroblastoma cells. The confinement of GM1, a constituent of membrane rafts involved in neuroprotection, at the level of both types of amyloid aggregates can interfere with cell signaling pathways and contribute to the loss of neuroprotection.
Crystal structure of metagenome‐derived LC9‐RNase H1 with atypical DEDN active site motif
Authors: Nguyen Tri-Nhan , You Dong-Ju , Kanaya Eiko , Koga Yuichi , Kanaya Shigenori
Published: March 2013

The crystal structure of metagenome‐derived LC9‐RNase H1 was determined. The structure‐based mutational analyses indicated that the active site motif of LC9‐RNase H1 is altered from DEDD to DEDN. In this motif, the location of the second glutamate residue is moved from αA‐helix to β1‐strand immediately next to the first aspartate residue, as in the active site of RNase H2. However, the structure and enzymatic properties of LC9‐RNase H1 highly resemble those of RNase H1, instead of RNase H2. We propose that LC9‐RNase H1 represents bacterial RNases H1 with an atypical DEDN active site motif, which are evolutionarily distinct from those with a typical DEDD active site motif.
Brugada syndrome and early repolarization syndrome: Cellular basis and clinical features
Authors: Nam Gi‐Byoung
Published: March 2013

Brugada syndrome (BS) and early repolarization syndrome (ERS) are newly introduced electrical disorders responsible for ventricular fibrillation (VF) and sudden cardiac death in patients with structurally normal hearts. The electrocardiographic J wave, a hallmark of these two syndromes, plays a critical role in the pathophysiology of malignant ventricular tachyarrhythmias. BS and ERS share many clinical characteristics, including male preponderance, circadian distribution of VF episodes, prevalence of concomitant atrial tachyarrhythmias, dynamic behavior of J waves, and response to therapeutic managements. In this review, we compare the key clinical manifestations of BS and ERS with their underlying cellular electrophysiologic mechanisms.
Effect of small asymmetries on axisymmetric stenotic flow
Authors: Griffith Martin D. , Leweke Thomas , Thompson Mark C. , Hourigan Kerry
Published: March 2013

Flow through axisymmetric and eccentric sinuous stenoses is investigated numerically, for Reynolds numbers up to 400. The eccentricity consists of an offset of the stenosis throat. A range of stenosis eccentricity is tested; the wake flow is found to be highly sensitive to small eccentricities in the stenosis geometry, even with stenosis offsets of the order of the machining precision of experimental test-sections. Comparisons are made between the numerically simulated flow through stenoses with small eccentricities and results from the literature of non-axisymmetric flows through nominally axisymmetric geometries. The effect of distortion to the inlet Poiseuille velocity profile is also investigated and found to have a significantly less severe effect on the downstream wake flow than geometric eccentricity.
A vanishing theorem in twisted de Rham cohomology
Authors: Ferreira Ana Cristina
Published: March 2013

We prove a vanishing theorem for the twisted de Rham cohomology of a compact manifold.
Optimisation of the hydrolysis of goat milk protein for the production of ACE-inhibitory peptides
Authors: Espejo-Carpio Francisco Javier , Pérez-Gálvez Raúl , Guadix Emilia M , Guadix Antonio
Published: March 2013

Goat milk protein was hydrolysed with subtilisin and trypsin. As input variables, temperature was assayed in the interval 45–70 °C for subtilisin and 30–55 °C for trypsin, while the enzyme-substrate ratio varied from 1 to 5%. The effect of the input variables on the degree of hydrolysis and ACE-inhibitory activity (output variables) was modelled by second order polynomials, which were able to fit the experimental data with deviations below 10%. The individual maximum values of the degree of hydrolysis and the ACE-inhibitory activity were found at conflicting conditions of temperature and enzyme-substrate ratio. Since such maximum values could not be reached simultaneously, a bi-objective optimisation procedure was undertaken, producing a set of non-inferior solutions that weighted both objectives.
HOSPITAL-BASED HEALTH TECHNOLOGY ASSESSMENT FOR INNOVATIVE MEDICAL DEVICES IN UNIVERSITY HOSPITALS AND THE ROLE OF HOSPITAL PHARMACISTS: LEARNING FROM INTERNATIONAL EXPERIENCE
Authors: Martelli Nicolas , Lelong Anne-Sophie , Prognon Patrice , Pineau Judith
Published: March 2013

Objectives: Several models of hospital-based health technology assessment (HTA) have been developed worldwide, for the introduction of innovative medical devices and support evidence-based decision making in hospitals. Two such models, the HTA unit and mini-HTA models, are widespread in university hospitals and involve various stakeholders. The purpose of this work was to highlight the potential role of hospital pharmacists in hospital-based HTA activities.

Methods: We searched for articles, reviews, and letters relating to hospital-based HTA, as defined by the Hospital-Based Health Technology Assessment Worldwide Surveypublished by the Health Technology Assessment International (HTAi) Society, in the Health Technology Assessment database, MEDLINE, EMBASE, and hospital pharmacyjournals.

Results: The number of university hospitals performing hospital-based HTA has increased since the 2008 Hospital-Based Health Technology Assessment Worldwide Survey. Our own experience and international findings show that hospital pharmacists already contribute to hospital-based HTA activities and have developed study interpretation skills and a knowledge of medical devices.

Conclusions: Promoting multidisciplinary approaches is one of the key success factors in hospital-based HTA. Hospital pharmacists occupy a position between hospital managers, clinicians, health economists, biomedical engineers, and patients and can provide a new perspective. In the future, hospital pharmacists are likely to become increasingly involved in hospital-based HTA activities.
CASE STUDIES THAT ILLUSTRATE DISINVESTMENT AND RESOURCE ALLOCATION DECISION-MAKING PROCESSES IN HEALTH CARE: A SYSTEMATIC REVIEW
Authors: Polisena Julie , Clifford Tammy , Elshaug Adam G. , Mitton Craig , Russell Erin , Skidmore Becky
Published: March 2013

Objective:Technological change accounts for approximately 25 percent of health expenditure growth. To date, limited research has been published on case studies of disinvestment and resource allocation decision making in clinical practice. Our research objective is to systematically review and catalogue the application of frameworks and tools for disinvestment and resource allocation decision making in health care.

Methods:An electronic literature search was executed for studies on disinvestment, obsolete and ineffective technologies, and priority healthcare setting, published from January 1990 until January 2012. Databases searched were MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, Embase, The Cochrane Library, PubMed, and HEED.

Results:Fourteen case studies on the application of frameworks and tools for disinvestment and resource allocation decisions were included. Most studies described the application of program budgeting and marginal analysis (PBMA), and two reports used health technology assessment (HTA) methods for coverage decisions in a national fee-for-service structure. Numerous healthcare technologies and services were covered across the studies. We describe the multiple criteria considered for decision making, and the strengths and limitations of these frameworks and tools are highlighted.

Conclusions:Disinvestment and resource allocation decisions require evidence to ensure their transparency and objectivity. PBMA was used to assess resource allocation of health services and technologies in a fixed budget jurisdiction, while HTA reviews focused on specific technologies, principally in fee-for-service structures. Future research can review the data requirements and explore opportunities to increase the quantity of available evidence for disinvestment and resource allocation decisions.
Populations of breeding birds in Byers Peninsula, Livingston Island, South Shetland Islands
Authors: Gil-Delgado J.A. , González-Solís J. , Barbosa A.
Published: March 2013

Data about breeding populations of birds in the Antarctica are rare and fragmented. Thus, information about the status of the breeding populations of Antarctic birds is crucial given the current scenario of climate change, which is particularly acute in Antarctica. This paper presents new information about the populations of the Antarctic tern Sterna vittata, the kelp gull Larus dominicanus, the southern giant petrel Macronectes giganteus, the Antarctic skua Catharacta antarctica lonnbergi, the chinstrap penguin Pygoscelis antarctica and the gentoo penguin Pygoscelis papua on Byers Peninsula (Livingston Island, South Shetland Islands). We used line transects counts to estimate both densities and numbers of nests of the different species. We estimate that there are 398.96 birds km-2 of southern giant petrels (2793 individuals), 62.4 birds km-2 of Antarctic tern (3746 individuals) and 269.1 birds km-2 of kelp gull (1884 individuals). Furthermore, we found 15 nests of Antarctic skua in 25 km2, from which we can estimate that 60–91 birds must breed on Byers Peninsula. We also censused two colonies of gentoo penguins (3000 and 1200 pairs) and 50 pairs of chinstrap. Compared to previous estimates, gentoo penguins seem to have increased whereas chinstrap penguin have decreased. Finally, the populations of Antarctic tern, southern giant petrel and kelp gull have stabilized or slightly increased.
Chronostratigraphy of the sedimentary record of Limnopolar Lake, Byers Peninsula, Livingston Island, Antarctica
Authors: Toro Manuel , Granados Ignacio , Pla Sergi , Giralt Santiago , Antoniades Dermot , Galán Luis , Cortizas Antonio Martínez , Lim Hyoun Soo , Appleby Peter G.
Published: March 2013

The chronostratigraphy of the sedimentary record of Limnopolar Lake, located on Byers Peninsula (Livingston Island, South Shetland Islands, Maritime Antarctica), is described based on radionuclides and radiocarbon age dating. The oldest moss macrofossil age was 6700±50 yrbp(7510±80 cal yrbp) from which the age/depth model estimates a basal age for the sedimentary record ofc.8300 cal yrbp, suggesting an earlier deglaciation of Byers Peninsula than reported in previous studies. Lithological units and other stratigraphic zones are described throughout the sediment core, showing different mineralogical composition and a fine alternation of clays and silty clays and moss layers ofDrepanocladus longifolius.Based on magnetic susceptibility analyses, a number of probable primary and reworked tephra layers were identified, seven of them confirmed by SEM observations, and most of them in agreement with the regional tephrachronology stratigraphy for the north-west Antarctic Peninsula. Sedimentation rates showed no significant changes during the last 5000 years with the exception of an abrupt event that took place around 5400 cal yrbp, which implied the sedimentation ofc.30 cm of clays in a very short time, probably related to a period of glacial re-advance that caused abrupt changes in geomorphological processes in the catchment.
Changes in radiobiological parameters in 131Cs permanent prostate implants
Authors: Kehwar Than S. , Jones Heather A. , Huq M. Saiful , Smith Ryan P.
Published: March 2013

In prostate permanent implants using 131Cs seeds, the prostatic edema developed during the implantation procedure, increases the separation between the seeds. This leads to a decrease in the prostate coverage and thus causes an edema induced dose reduction, which results in an increase in tumour cell surviving fraction (SF) with a corresponding decrease in tumour control probability (TCP). To investigate the impact of edema on the SF and the TCP, the expression of the SF of the linear quadratic (LQ) model was extended to account for the effects of edema using the exponential nature of edema resolution and the dose delivered to the edematous prostate. The SF and the TCP for edematous prostate implants were calculated for 31 patients who underwent real time 131Cs permanent seed implantation. The dose delivered to the edematous prostate was calculated to compute the SF and the TCP for these patients for edema half lives (EHL) ranging from 4 days to 34 days and for edemas of magnitudes (M0) varying from 5 to 60% of the actual prostate volume.

A reduction in the dose delivered to the edematous prostate was found with the increase of EHL and edema magnitude which results in an increase of the SF, and corresponding decrease in the TCP. The dose reductions in 131Cs implants varied from 1.1% (for EHL = 4 days and M0 = 5%) to 32.3% (for EHL = 34 days and M0 = 60%). These are higher than the dose reduction in 125I implants, which vary from 0.3% (for EHL = 4 days and M0 = 5%) to 17.5% (for EHL = 34 days and M0 = 60%). As edema half life increased from 4 days to 34 days and edema magnitude increased from 5 to 60% the SF increased by 4.57 log, and the TCP decreased by 0.80. Compensation of edema induced increase in the SF and decrease in the TCP in 131Cs seed implants should be carefully done by redefining seed positions with the guidance of post-needle plans. The presented model in this study can be used to estimate the SF or the TCP for pre plan or real time permanent prostate implants using day 0 post-implant CT images.
Genebank data-management software incorporating seed-viability test results
Authors: Takeya Masaru , Yamasaki Fukuhiro , Hattori Sachiko , Oyanagi Chie , Chibana Takashi , Tomooka Norihiko
Published: March 2013

The National Institute of Agrobiological Sciences' (NIAS) Genebank is the coordinating institute in Japan for the conservation of plant, microorganism and animal genetic resources related to food and agriculture. The NIAS Genebank manages this activity in collaboration with sub-banks located across Japan and acts as the central bank. It is important for genebanks to maintain the viability of genetic resources during conservation. Generally, seeds are stored at low temperature and low humidity. Germination percentage is used to monitor seed viability. We have developed data-management software to manage germination testing data in the NIAS Genebank. The software can monitor the pattern of the loss of seed viability of each accession and also support the selection of accessions that need regeneration of seeds. Web-based plant accessions search software displays the latest data on the availability and germination percentages of accessions.
A search for pulsars in the central parsecs of the Galactic center
Authors: Siemion Andrew , Bailes Matthew , Bower Geoff , Chennamangalam Jayanth , Cordes Jim , Demorest Paul , Deneva Julia , Desvignes Gregory , Ford John , Frail Dale , Jones Glenn , Kramer Michael , Lazio Joseph , Lorimer Duncan , McLaughlin Maura , Ransom Scott , Roshi Anish , Wagner Mark , Werthimer Dan , Wharton Robert
Published: March 2013

The discovery of a pulsar or pulsars orbiting near the Galactic Center (GC) could offer an unprecedented probe of strong-field gravity, the properties of our galaxy's supermassive black hole and insights into the paradoxical star formation history of the region. However, searching for pulsars near the GC is severely hampered by the large electron densities along our line of sight and the scattering-induced pulse broadening of the pulsar emission observed through it. As the broadened pulse length approaches the pulsar period, the periodicity in pulsar emission becomes nearly undetectable. Searches extended to higher frequencies, in an effort to reduce scattering, suffer from reduced intrinsic flux, higher system temperatures and increased atmospheric opacity. We are currently attempting to mitigate the challenges associated with searching for pulsars near the GC by employing new wide bandwidth receivers, upgraded IF distribution systems and novel digital spectrometers in a GC pulsar search campaign at the Green Bank Telescope in West Virginia, USA.

Our search will cover two frequency bands, from 12-15 GHz (Ku Band) and 18-26 GHz (K Band), during a total of approximately 30 hours of observations, with expected characteristic 10-sigma sensitivities between 5-10 micro-Jy. Our first observations are scheduled for mid-March 2012. Here we will present the status of our observations and initial results.
Structure of Quark Stars
Authors: Weber Fridolin , Orsaria Milva , Rodrigues Hilario , Yang Shu-Hua
Published: March 2013

This paper gives an brief overview of the structure of hypothetical strange quarks stars (quark stars, for short), which are made of absolutely stable 3-flavor strange quark matter. Such objects can be either bare or enveloped in thin nuclear crusts, which consist of heavy ions immersed in an electron gas. In contrast to neutron stars, the structure of quark stars is determined by two (rather than one) parameters, the central star density and the density at the base of the crust. If bare, quark stars possess ultra-high electric fields on the order of 1018 to 1019 V/cm. These features render the properties of quark stars more multifaceted than those of neutron stars and may allow one to observationally distinguish quark stars from neutron stars.
Numerical modeling of core-collapse supernovae and compact objects
Authors: Sumiyoshi Kohsuke
Published: March 2013

Massive stars (M ≥ 10M⊙) end their lives with spectacular explosions due to gravitational collapse. The collapse turns the stars into compact objects such as neutron stars and black holes with the ejection of cosmic rays and heavy elements. Despite the importance of these astrophysical events, the mechanism of supernova explosions has been an unsolved issue in astrophysics. This is because clarification of the supernova dynamics requires the full knowledge of nuclear and neutrino physics at extreme conditions, and large-scale numerical simulations of neutrino radiation hydrodynamics in multi-dimensions. This article is a brief overview of the understanding (with difficulty) of the supernova mechanism through the recent advance of numerical modeling at supercomputing facilities. Numerical studies with the progress of nuclear physics are applied to follow the evolution of compact objects with neutrino emissions in order to reveal the birth of pulsars/black holes from the massive stars.
How “free” are free neutrons in neutron-star crusts and what does it imply for pulsar glitches?
Authors: Chamel N.
Published: March 2013

The neutron superfluid permeating the inner crust of mature neutron stars is expected to play a key role in various astrophysical phenomena like pulsar glitches. Despite the absence of viscous drag, the neutron superfluid can still be coupled to the solid crust due to non-dissipative entrainment effects. Entrainment challenges the interpretation of pulsar glitches and suggests that a revision of the interpretation of other observed neutron-star phenomena might be necessary.
Rotating Radio Transients and their place among pulsars
Authors: Burke-Spolaor S.
Published: March 2013

Six years ago, the discovery of Rotating Radio Transients (RRATs) marked what appeared to be a new type of sparsely-emitting pulsar. Since 2006, more than 70 of these objects have been discovered in single-pulse searches of archival and new surveys. With a continual inflow of new information about the RRAT population in the form of new discoveries, multi-frequency follow ups, coherent timing solutions, and pulse rate statistics, a view is beginning to form of the place in the pulsar population RRATs hold. Here we review the properties of neutron stars discovered through single pulse searches. We first seek to clarify the definition of the term RRAT, emphasising that “the RRAT population” encompasses several phenomenologies. A large subset of RRATs appears to represent the tail of an extended distribution of pulsar nulling fractions and activity cycles; these objects present several key open questions remaining in this field.
Discoveries of Rotating Radio Transients in the 350 MHz Green Bank Telescope Drift-scan Survey
Authors: Karako-Argaman Chen ,   the GBT Drift-scan Collaboration
Published: March 2013

Rotating Radio Transients (RRATs) are a class of pulsars characterized by sporadic bursts of radio emission, which make them difficult to detect in typical periodicity-based pulsar searches. Using newly developed post-processing techniques for automatically identifying single bright astrophysical pulses, such as those emitted from RRATs, we have discovered approximately 30 new RRAT candidates in data from the Green Bank Telescope 350 MHz drift-scan survey. A total of 6 of these have already been confirmed and the remainder look extremely promising. Here we describe these techniques and present the most recent results on these new RRAT candidates.
Binary pulsar evolution: unveiled links and new species
Authors: Possenti Andrea
Published: March 2013

In the last years a series of blind and/or targeted pulsar searches led to almost triple the number of known binary pulsars in the galactic field with respect to a decade ago. The focus will be on few outliers, which are emerging from the average properties of the enlarged binary pulsar population. Some of them may represent the long sought missing links between two kinds of neutron star binaries, while others could represent the stereotype of new groups of binaries, resulting from an evolutionary path which is more exotic than those considered until recently. In particular, a new class of binaries, which can be dubbed Ultra Low Mass Binary Pulsars (ULMBPs), is emerging from recent data.
Surrounded by spiders! New black widows and redbacks in the Galactic field
Authors: Roberts Mallory S. E.
Published: March 2013

Over the last few years, the number of known eclipsing radio millisecond pulsar systems in the Galactic field has dramatically increased, with many being associated with Fermi gamma-ray sources. All are in tight binaries (orbital period < 24 hr) with many being classical “black widows” which have very low mass companions (companion mass Mc ≪ 0.1 M⊙) but some are “redbacks” with low mass (Mc ~ 0.2-0.4 M⊙) companions which are probably non-degenerate. These latter are systems where the mass transfer process may have only temporarily halted, and so are transitional systems between low mass X-ray binaries and ordinary binary millisecond pulsars. Here we review the new discoveries and their multi-wavelength properties, and briefly discuss models of shock emission, mass determinations, and evolutionary scenarios.
Neutron star masses
Authors: Nice David
Published: March 2013

Neutron star masses can be inferred from observations of binary pulsar systems, particularly by the measurement of relativistic phenomena within these orbits. The observed distribution of masses can be used to infer or constrain the equation of state for nuclear matter and to study astrophysical processes such as supernovae and binary star evolution. In this talk, I will review our present understanding of the neutron star mass distribution with an emphasis on the observational data.
Stochastic and continuous gravitational wave analysis pipelines for pulsar timing array data
Authors: Ellis Justin , Jenet Fredrick , Siemens Xavier , McLaughlin Maura
Published: March 2013

The Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration aims to detect gravitational waves (GWs) through the precise timing of millisecond pulsars. GWs will come in the form of a stochastic background, continuous sources and burst sources. Here we will review recent progress on the development of data analysis pipelines aimed at the detection of a stochastic background as well as continuous sources. We will introduce the Optimal Statistic and F-Statistic methods that are used in the stochastic and continuous pipelines, respectively. Both pipelines are fully functional on real pulsar timing data and take into account the timing models for each pulsar. Finally, we will present the efficacy of each pipeline on locally simulated data as well as data from the 2012 IPTA data challenge.
The spin evolution of young pulsars
Authors: Espinoza Cristóbal M.
Published: March 2013

The current understanding of the spin evolution of young pulsars is reviewed through a compilation of braking index measurements. An immediate conclusion is that the spin evolution of all pulsars with a measured braking index is not purely caused by a constant magnetic dipole. The case of PSR J1734-3333 and its upward movement towards the magnetars is used as a guide to try to understand why pulsars evolve with n < 3. Evolution between different pulsar families, driven by the emergence of a hidden internal magnetic field, appears as one possible picture.
Vela Glitch Monitoring from HartRAO
Authors: Buchner Sarah
Published: March 2013

The Vela pulsar, like many other young pulsars, undergoes occasional sudden “spin-ups” in rotational frequency known as glitches. These glitches are characterised by a sudden (less than 30s) rise in the rotation frequency accompanied by a jump in the spin-down. This is generally followed by rapidly decaying transients in the spin-down and a gradual linear recovery. This recovery provides insight into the internal structure of the neutron star.

The telescopes at HartRAO was been used to monitor the Vela pulsar almost daily from 1985 in order to monitor these glitches. The vast majority of these observations were made using the 26m antenna at 1.6 GHz and 2.3 Ghz. When the 26m antenna was offline due to a bearing failure for two years from 2008 the 15m MeerKAT prototype antenna was used to observe Vela.

During the entire monitoring campaign 10 large glitches have been observed. The majority of the glitches show a similar recovery pattern. We discuss the characteristics of this common recovery. We compare the standard glitch recovery to that predicted by a hydrodynamic model of the neutron star interior.

An exception to the standard glitch are the two glitches which occurred in 1994 separated by 32 days. This “double” glitch is unique amongst Vela glitches. The event is accompanied by typical transients in rotation frequency derivative but all of the long-term offset occurs at the first event and the rapidly-decaying transient is only seen with the second spin-up.
FRATs: Searching for fast radio transient in real-time with LOFAR
Authors: Falcke Heino ,   the ILT LOFAR Consortium
Published: March 2013

LOFAR is an innovative new radio interferometer operating at low radio frequencies from 10 to 270 MHz. It combines a large field-of-view, high fractional bandwidth, rapid response, and a wide range of baselines from tens of meters to thousand kilometers. Its use of phased-array technology and its digital nature make LOFAR an extremely versatile instrument to search for transient radio phenomena on all time scales. Here we discuss in particular the search for fast radio transients (FRATs) at sub-second time scales. In fact, at these time scales the radio sky is rather dynamic due to coherent emission processes. Objects like pulsars, flaring stars, or planets like Jupiter are able to produce bright short flares. For pulsars, most previous detection strategies made use of the rotation of pulsars to detect them, using Fourier techniques, but it is also possible to detect pulsars and other objects through their single pulses. Such surveys have, e.g., led in the previous decade to the detection of Rapid Radio Transients (RRATS), but the unprobed search space is still rather large. LOFAR is now conducting a rather unique survey over the entire northern sky, searching for bright dispersed single radio pulses. This FRATs survey makes use of the LOFAR transient buffer boards (TBBs), which had initially been used to detect nanosecond radio pulses from cosmic rays. The TBBs store the radio data from each single receiver element of LOFAR and allow one to look back in time. A trigger system that runs parallel to normal imaging observation allows one to detect single pulses in an incoherent beam of all LOFAR stations, covering several tens to hundred square degrees at once. Once triggered, the data can be used to localize the pulse and to discriminate cosmic sources from terrestrial interference through 3D localization. The system has been successfully tested with known pulsars and first results of the ongoing survey will be presented.
The Galactic Millisecond Pulsar Population
Authors: Lorimer Duncan R.
Published: March 2013

Among the current sample of over 2000 radio pulsars known primarily in the disk of our Galaxy, millisecond pulsars now number almost 200. Due to the phenomenal success of blind surveys of the Galactic field, and targeted searches of Fermi gamma-ray sources, for the first time in over a decade, Galactic millisecond pulsars now outnumber their counterparts in globular clusters! In this paper, I briefly review earlier results from studies of the Galactic millisecond pulsar population and present new constraints based on a sample of 60 millisecond pulsars discovered by 20 cm Parkes multibeam surveys. I present a simple model of the population containing ~ 30,000 potentially observable millisecond pulsars with a luminosity function, radial distribution and scale height that matches the observed sample of objects. This study represents only a first step towards a more complete understanding of the parent population of millisecond pulsars in the Galaxy and I conclude with some suggestions for further study in this area.
Constraining the luminosity function parameters and population size of radio pulsars in globular clusters
Authors: Chennamangalam Jayanth , Lorimer D. R. , Mandel Ilya , Bagchi Manjari
Published: March 2013

The luminosity distribution of Galactic radio pulsars is believed to be log-normal in form. Applying this functional form to populations of pulsars in globular clusters, we employ Bayesian methods to explore constraints on the mean and standard deviation of the function, as well as the total number of pulsars in the cluster. Our analysis is based on an observed number of pulsars down to some limiting flux density, measurements of flux densities of individual pulsars, as well as diffuse emission from the direction of the cluster. We apply our analysis to Terzan 5 and demonstrate, under reasonable assumptions, that the number of potentially observable pulsars is in a 95.45% credible interval of 133+101−58. Beaming considerations would increase the true population size by approximately a factor of two.
A multi-wavelength campaign to study giant pulses from the Crab Pulsar
Authors: Majid Walid
Published: March 2013

We are currently undertaking a monitoring campaign with NASA 70-m antennas to capture a large sample of Crab Giant Pulses (CGP) at multiple radio wavelengths. The goal of this campaign is to carry out a correlation study of CGPs at radio frequencies with pulsed emission from the Crab pulsar with Fermi photons at X-ray. After a year of this study, we expect around 200 Fermi photons to coincide with a CGP radio-frequency detection, allowing us to either confirm a predicted correlation in average gamma-ray pulsed flux increase with GP emission, or place a tight upper limit, at least a factor of 10 more constraining than previous work. We will report on the status of this campaign and will present our preliminary results and prospects for future improvements in receivers and back-end instrumentation.
Constraints on Yukawa parameters by double pulsars
Authors: Deng Xue-Mei , Xie Yi , Huang Tian-Yi
Published: March 2013

Although Einstein's general relativity has passed all the tests so far, alternative theories are still required for deeper understanding of the nature of gravity. Double pulsars provide us a significant opportunity to test them. In order to probe some modified gravities which try to explain some astrophysical phenomena without dark matter, we use periastron advance $\dot{\omega}$ of four binary pulsars (PSR B1913+16, PSR B1534+12, PSR J0737-3039 and PSR B2127+11C) to constrain their Yukawa parameters: λ = (3.97 ± 0.01) × 108m and α = (2.40 ± 0.02) × 10−8. It might help us to distinguish different gravity theories and get closer to the new physics.
Can we see pulsars around Sgr A⋆? The latest searches with the Effelsberg telescope.
Authors: Eatough R. P. , Kramer M. , Klein B. , Karuppusamy R. , Champion D. J. , Freire P. C. C. , Wex N. , Liu K.
Published: March 2013

Radio pulsars in relativistic binary systems are unique tools to study the curved space-time around massive compact objects. The discovery of a pulsar closely orbiting the super-massive black hole at the centre of our Galaxy, Sgr A⋆, would provide a superb test-bed for gravitational physics. To date, the absence of any radio pulsar discoveries within a few arc minutes of Sgr A⋆ has been explained by one principal factor: extreme scattering of radio waves caused by inhomogeneities in the ionized component of the interstellar medium in the central 100 pc around Sgr A⋆. Scattering, which causes temporal broadening of pulses, can only be mitigated by observing at higher frequencies. Here we describe recent searches of the Galactic centre region performed at a frequency of 18.95 GHz with the Effelsberg radio telescope.
An XMM-Newton study of the supernova remnant G296.7–0.9
Authors: Huang R. H. H. , Hui C. Y. , Trepl L. , Kong A. K. H.
Published: March 2013

We report on XMM-Newton observations of the Galactic supernova remnant G296.7–0.9. A detailed spectro-imaging X-ray study of G296.7–0.9 was performed. We detected an incomplete shell-like X-ray structure which is located near the boundary of the radio emission at a frequency of 843 MHz. The X-ray spectrum can be best described by an absorbed ionization plasma model accompanied with metallic emission lines, which suggests the plasma is shock heated. No promising compact stellar remnant associated with G296.7–0.9 was found. No Gamma-ray emission of G296.7–0.9 from Fermi-LAT telescope was detected in our study.