bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Proliferation of Cells Derived From Adult Human β-Cells Revealed By Cell-Lineage Tracing
Authors: Russ Holger A. , Bar Yael , Ravassard Philippe , Efrat Shimon
Published: March 2008

OBJECTIVE— Expansion of insulin-producing β-cells from adult human islets could alleviate donor shortage for cell-replacement therapy of diabetes. A major obstacle to development of effective expansion protocols is the rapid loss of β-cell markers in the cultured cells. Here, we report a genetic cell-lineage tracing approach for following the fate of cultured β-cells.

RESEARCH DESIGN AND METHODS— Cells dissociated from isolated human islets were infected with two lentiviruses, one expressing Cre recombinase under control of the insulin promoter and the other, a reporter cassette with the structure cytomegalovirus promoter-loxP-DsRed2-loxP-eGFP.

RESULTS— β-Cells were efficiently and specifically labeled by the dual virus system. Label+, insulin− cells derived from β-cells were shown to proliferate for a maximum of 16 population doublings, with an approximate doubling time of 7 days. Isolated labeled cells could be expanded in the absence of other pancreas cell types if provided with medium conditioned by pancreatic non–β-cells. Analysis of mouse islet cells by the same method revealed a much lower proliferation of labeled cells under similar culture conditions.

CONCLUSIONS— Our findings provide direct evidence for survival and dedifferentiation of cultured adult human β-cells and demonstrate that the dedifferentiated cells significantly proliferate in vitro. The findings confirm the difference between mouse and human β-cell proliferation under our culture conditions. These findings demonstrate the feasibility of cell-specific labeling of cultured primary human cells using a genetic recombination approach that was previously restricted to transgenic animals.
Lifetime Prediction of Tires with Regard to Oxidative Aging
Authors: Nasdala L. , Wei Y. , Rothert H. , Kaliske M.
Published: March 2008

It is a challenging task in the design of automobile tires to predict lifetime and performance on the basis of numerical simulations. Several factors have to be taken into account to correctly estimate the aging behavior. This paper focuses on oxygen reaction processes which, apart from mechanical and thermal aspects, effect the tire durability. The material parameters needed to describe the temperature-dependent oxygen diffusion and reaction processes are derived by means of the time–temperature–superposition principle from modulus profiling tests. These experiments are designed to examine the diffusion-limited oxidation (DLO) effect which occurs when accelerated aging tests are performed. For the cord-reinforced rubber composites, homogenization techniques are adopted to obtain effective material parameters (diffusivities and reaction constants).

The selection and arrangement of rubber components influence the temperature distribution and the oxygen penetration depth which impact tire durability. The goal of this paper is to establish a finite element analysis based criterion to predict lifetime with respect to oxidative aging. The finite element analysis is carried out in three stages. First the heat generation rate distribution is calculated using a viscoelastic material model. Then the temperature distribution can be determined. In the third step we evaluate the oxygen distribution or rather the oxygen consumption rate, which is a measure for the tire lifetime. Thus, the aging behavior of different kinds of tires can be compared. Numerical examples show how diffusivities, reaction coefficients, and temperature influence the durability of different tire parts. It is found that due to the DLO effect, some interior parts may age slower even if the temperature is increased.
Thallium fractionation in polluted environmental samples using a modified BCR three-step sequential extraction procedure and its determination by electrothermal atomic absorption spectrometry
Authors: Medved’ Ján , Kališ Milan , Hagarová Ingrid , Matúš Peter , Bujdoš Marek , Kubová Jana
Published: March 2008

Determination of thallium in polluted environmental samples and their extracts obtained by a modified BCR three-step sequential extraction procedure was used to study thallium distribution and mobility in the monitored polluted area affected by acidification (Šobov, Central Slovakia). The results of fractionation applied to 5 soil certified reference materials and 14 environmental samples show that the vast majority of thallium occurred in the residual fraction. This means that highly toxic thallium is strongly entrapped in the parent rock materials remains immobile and its environmental toxicity is therefore reduced. The limit of detection for thallium in the studied fractions was lower than 0.050 mg kg−1, the precision (RSD) of the ultratrace determination of thallium in the studied fractions was better than 17 % and the accuracy of the used method was verified by analyzing certified reference materials.
Multiple Resources, Multiple Outcomes: Testing the “Improved”School Finance With NELS88
Authors: Grubb W. Norton
Published: March 2008

This article first presents the conceptual framework of the “improved” school finance. This approach clarifies that effective school resources include compound resources, complex resources, and abstract resources in addition to the simple resources usually included in production functions. The implications of this approach are then explored with the National Educational Longitudinal Survey of the Class of 1988 (NELS88), data rich enough to measure many school resources and many outcomes. The results indicate that simple resources are much less powerful than compound, complex, and abstract resources. Many effective resources are unaffected by spending levels and must be constructed within schools, explaining why money often does not make a difference to outcomes. The results also indicate that, while a few powerful resources affect all outcomes, some affect test scores but not progress through high school, while others affect progress but not learning.
Creating Hybrid Spaces for Engaging School Science Among Urban Middle School Girls
Authors: Barton Angela Calabrese , Tan Edna , Rivet Ann
Published: March 2008

The middle grades are a crucial time for girls in making decisions about how or if they want to follow science trajectories. In this article, the authors report on how urban middle school girls enact meaningful strategies of engagement in science class in their efforts to merge their social worlds with the worlds of school science and on the unsanctioned resources and identities they take up to do so. The authors argue that such merging science practices are generative both in terms of how they develop over time and in how they impact the science learning community of practice. They discuss the implications these findings have for current policy and practice surrounding gender equity in science education.
Comer’s School Development Program in Chicago: Effects on Involvement With the Juvenile Justice System From the Late Elementary Through the High School Years
Authors: Cook Thomas D. , Hirschfield Paul J.
Published: March 2008

In 2000, Cook, Murphy, and Hunt published a multilevel study of Chicago inner-city schools in order to evaluate James Comer’s School Development Program (SDP). One main finding was that SDP reduced the rate of change and final posttest mean when delinquency was assessed annually between Grades 5 and 8 using a self-report measure of acting out. The present study examined whether these same mean and slope effects would be observed when delinquency was measured from juvenile justice system records instead of self-reports. Hierarchical models of official statistics revealed no evidence favoring SDP between Grades 5 and 8, and the same was basically true during the high school years. So the Chicago variant of SDP did not have a general effect on reducing delinquency. Speculations are offered about why the two delinquency measures produced different results.
Applying Psychological Theories to Educational Practice
Authors: Sternberg Robert
Published: March 2008

Two approaches to the application of psychological theories to education might be referred to as domain-general and domain-specific. The domain-general approach seeks a general theory of cognitive and other skills that apply across subject-matter areas. The domain-specific approach seeks to apply specific theories within given domains, such as reading or mathematics. The latter approach is more widely used. But it fails to provide a unified model of learning and instruction. One of the greatest challenges facing modern research in learning and instruction is devising and then empirically testing domain-general theories. This article describes efforts to devise and test one such model, the theory of successful intelligence.
Subchronic and Chronic Toxicity/Carcinogenicity Feeding Studies with Lactitol in Rats
Authors: Sinkeldam E. J. , Woutersen R.A. , Hollanders V.M.H. , Til H.P. , Van Garderen-Hoetmer A. , Bär A.
Published: March 2008

The toxicity and possible carcinogenicity of lactitol, a lactose-derived reduced calorie sugar substitute, were examined in Wistar Cpb:WU rats. In a first 13-week study, groups of 10 weanling rats of each sex were fed diets containing 0, 5, 10, or 20% lactitol, or 25% lactose. In a second 13-week study, groups of 20 rats of each sex received diets with 0, 10, or 20% lactitol, or 25% lactose starting from an age of 3 months. In a lifetime toxicity/cancerogenicity study with in utero exposure, groups of 50 rats of each sex consumed diets with 0, 2, 5, or 10% lactitol, or 20% lactose for 130 weeks. Satellite groups of 10 rats/group received the same diet but were sacrificed after 53 weeks. Subchronic and chronic ingestion of lactitol and lactose was generally well tolerated and an effect on mortality rate was not seen. Body weight gains were slightly decreased in a dose-related manner in all experiments. Dose-related cecal enlargement was observed consistently with lactitol and lactose. Examinations for hematological parameters and urine composition did not reveal any treatment-related abnormalities. The clinical chemistry examinations revealed increased plasma alkaline phosphatase (AP) levels in rats fed 5 or 10% lactitol, or 20% lactose. Slight (microscopic) cytoplasmic alterations in the staining pattern of hepatocytes were observed in the first but not the second 13-week study in a number of male rats of the 10 and 20% lactitol groups. In the chronic study, a statistically significant increase in bile duct hyperplasia was noted in female rats fed 5 or 10% lactitol, or 20% lactose. Measurement of femur calcium content in terminated female rats revealed a dose-related, yet statistically nonsignificant decrease in the lactitol groups and lowest levels in the 20% lactose group. The histopathological examination of rats treated with lactitol and lactose for their lifetime showed an increased incidence of (1) pelvic nephrocalcinosis (5% lactitol females, and 10% lactitol and 20% lactose males and females), (2) adrenomedullary proliferative changes (10% lactitol and 20% lactose males), and (3) hyperplastic and neoplastic changes of Leydig cells (10% lactitol and 20% lactose males). Results from other studies suggest that nephrocalcinosis and adrenal medullary proliferative disease represent sequelae of a chronic, treatment-related hyperabsorption of calcium which does not occur in man. The mechanism of the testicular effect is not yet identified. However, lactitol gave completely negative results in standard tests for mutagenicity and clastogenicity, and no testicular effects or other neoplastic response was observed in lactitol-fed mice. Since Leydig cell tumors occur in humans at an extremely low rate despite the ingestion of substantial amounts of lactose with ordinary meals, the observation made in rats lacks apparent relevance for man.
Pulmonary arterial hypertension and left‐sided heart disease in sickle cell disease: Clinical characteristics and association with soluble adhesion molecule expression
Authors: Klings Elizabeth S. , Anton Bland Demedrick , Rosenman Dara , Princeton Stephanie , Odhiambo Adam , Li Guihua , Bernard Sheilah A. , Steinberg Martin H. , Farber Harrison W.
Published: March 2008

Pulmonary hypertension (PH), a risk factor for mortality in sickle cell disease (SCD), has pathologic features of both pulmonary arterial hypertension (PAH) and PH related to left‐sided heart disease (LHD) suggesting a link between these two entities. We hypothesized that both are characterized by endothelial dysfunction and increased adhesion molecule expression. SCD patients and normal volunteers underwent a screening questionnaire, echocardiogram, and blood donation for preparation of platelet‐poor plasma. PAH was defined as a tricuspid regurgitant jet (TRJ) velocity ≥2.5 m/sec and/or the presence of isolated right ventricular hypertrophy or decreased systolic function. LHD was defined as either left‐sided systolic/diastolic dysfunction or significant valvular disease. Plasma vascular cell adhesion molecule‐1 (VCAM‐1), intercellular adhesion molecule‐1 (ICAM‐1), P‐ and E‐selectin, nitric oxide (NOx), erythropoietin, and vascular endothelial growth factor (VEGF) levels were assayed by enzyme‐linked immunoassay. Forty‐three percent of sickle cell anemia (HbSS) and 28% of hemoglobin SC disease (HbSC) disease patients had PAH. Additionally, 10–15% of SCD patients had LHD. VCAM‐1 levels were significantly increased in HbSS patients compared with HbSC patients and normal volunteers. VCAM‐1 and P‐selectin levels correlated positively with TRJ velocity in HbSS patients (r = 0.45, P = 0.03, r = 0.2, P = 0.05, respectively). ICAM‐1, E‐selectin, NOx, erythropoietin, and VEGF levels were similar across subject groups. PH is common in SCD and, at times, due to LHD. Increased VCAM‐1 and P‐selectin expression was associated with TRJ elevation regardless of etiology suggesting a similar effect on endothelial gene expression and possibly providing a pathologic link between PAH and PH related to LHD in SCD. Am. J. Hematol. 2008. © 2008 Wiley‐Liss, Inc.
Surveillance of musculoskeletal injuries and disorders in a diverse cohort of workers at a tertiary care medical center
Authors: Pompeii Lisa A. , Lipscomb Hester J. , Dement John M.
Published: March 2008

Background

The purpose of this study was to investigate the incidence of work‐related musculoskeletal (MSK) injuries and disorders among a dynamic cohort of health care workers, including direct care providers and support services, employed at a tertiary care medical center.

Methods

Human resources data were used to define the cohort and time at risk. Workers' compensation (WC) records (1997–2003) were utilized to identify work‐related MSK claims. Poisson regression was used to generate gender specific rate ratios and 95% confidence intervals (CI) of MSK injuries among workgroups.

Results

MSK injuries resulted equally (∼30% each) from lift/push/pull of equipment, patient handling, and slip/trip/falls. Injury rates and their mechanisms varied substantially by occupational group, gender, and race. Even with declining injury rates over time, black workers had rates 2.5 times higher than other workers and women had rates 1.8 times higher than men. Male and female nurses' aides, housekeepers, and radiology technicians had among the highest rates of injury, while lost workdays rates were highest for male and female nurses' aides, female housekeepers, and male patient transporters.

Conclusions

Differential risk associated with work tasks in highly segregated work populations can contribute to disparities in health, and the patterns we observed partly reflect the high concentration of female and black workers in occupations with increased physical demands. While the greatest public health impact will be achieved by implementing prevention strategies among large workgroups with high injury rates, public health efforts must not ignore smaller, often segregated, workgroups identified in this study as high risk. Am. J. Ind. Med. 51:344–356, 2008. © 2008 Wiley‐Liss, Inc.
Associations between patella lead and blood pressure in lead workers
Authors: Weaver Virginia M. , Ellis Lenworth R. , Lee Byung‐Kook , Todd Andrew C. , Shi Weiping , Ahn Kyu‐Dong , Schwartz Brian S.
Published: March 2008

Background

To compare associations of patella lead, a lead pool that may capture aspects of both current bioavailable and cumulative lead dose thus offering advantages over tibia or blood lead, with blood lead in models of blood pressure and hypertension and to examine effect modification by age, sex and polymorphisms of the genes encoding for the vitamin D receptor (VDR) and δ‐aminolevulinic acid dehydratase (ALAD).

Methods

Cross‐sectional data in 652 current and former lead workers were analyzed.

Results

Blood lead, but not patella lead, was positively associated with systolic blood pressure. Neither lead measure was associated with diastolic blood pressure or hypertension status. There was no evidence of effect modification.

Conclusions

In these workers, blood lead was more relevant to elevations in blood pressure than was patella lead. Additional research will be required to determine whether patella lead assessment provides unique information on vascular risk from lead exposure. Am. J. Ind. Med. 51:336–343, 2008. © 2008 Wiley‐Liss, Inc.
Preparation and evaluation of β‐TCP/polylactide microspheres as osteogenesis materials
Authors: Lin Li Chun , Chang Shwu Jen , Kuo Shyh Ming , Niu Gregory Cheng‐Chie , Keng Hao Kai , Tsai Pei Hua
Published: March 2008

In the osteological field, the study of repairing and recovering processes for bone tissues has been one of the major clinical research subjects. To promote the bone healing, bioactive composite materials have been employed for the filling and supporting of defects, voids or diseased parts. In this study, a series of microsphere composites made from polylactide (PLA), a biodegradable polymer, and β‐calcium phosphate (β‐TCP), an osteogenesis material, were prepared and estimated their potential applications in participation to the growth of new bone tissues on bone defects. By employing the water/oil/water (w/o/w) emulsion technique to fabricate a series of bioactive and biodegradable microspheres materials, we have found that one type of the microspheres: with diameter at 177 ± 33 μm, and enclosure of β‐TCP at 18% (wt/wt), exhibiting smooth surface by the optical microscopy and scanning electron microscopy (SEM) observations, and showing slow yet steady calcium ion release and PLA degradation by in vitro test, showed excellent repairing and recovery of the chondrocyte and osteocyte tissues on drilled defects on the condyle of New Zealand rabbits within 1 month of application. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Phthalocyanine/laponite nanocomposites as multifunction additives for stabilization of polymeric materials
Authors: El‐Ghaffar M. A. Abd , El‐Halawany N. R. , Essawy H. A.
Published: March 2008

Novel phthalocyanine amide polymers (Pc) based on 1,8‐naphthalenediamine (Ar) as an aromatic amine and 1,4‐diaminobutane (Al) as an aliphatic amine, were synthesized to improve the limited stabilization modes of conventional phthalocyanines. The metal‐free phthalocyanines polymers (MF‐Pc) were moderately soluble in DMSO only while the metalized forms (Cu&Ni‐Pc) were completely insoluble. The structure of the samples was confirmed using Fourier transform infrared (FTIR), ultraviolet–visible spectrometry (UV–vis) and nuclear magnetic resonance (NMR). Additionally, the thermal stability and glass transition temperatures (Tg) were investigated by thermal gravimetric analyzer (TGA) and differential scanning calorimeter (DSC), respectively. The intercalation of the metal‐free phthalocyanines, based on the aliphatic amine (MF‐PcAl) and aromatic amine (MF‐PcAr), into laponite from DMSO solution, was proved by X‐ray diffraction (XRD). The basal space of laponite increased from 1.2 to 1.36 nm upon intercalation of MF‐PcAl and extended more to 1.91 nm on using MF‐PcAr as intercalant while the quaternized forms of MF‐Pcs behaved likewise and could not widen the basal space of laponite to more than 1.43 nm which was attributed to the random distribution of the positive charges over the Pc chains which imposed confined arrangement inside the basal space and consequently narrower space than the attained one in the case of nonquaternized phthalocyanines. The plasticized PVC composites based on laponite treated with either MF‐PcAl or MF‐PcAr exhibited improved resistance to the UV radiation as revealed by the retention of the tensile strength and elongation at rupture after exposure to UV radiation for different time intervals. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A study on dynamic friction of different spun yarns
Authors: Ghosh Anindya , Patanaik Asis , Anandjiwala R. D. , Rengasamy R. S.
Published: March 2008

This article presents the results from a study of yarn‐to‐yarn (YY) and yarn‐to‐metal (YM) frictions conducted on ring, rotor, air‐jet, and open‐end friction (OE friction) spun yarns at different relative speeds and input tensions. The results indicate that the behavior of frictions for YY is different than that of YM. In case of YY friction, OE friction yarn shows maximum friction followed by rotor, air‐jet, and ring spun yarns; however, a reverse order is noticed for YM friction. The relative speed and input tension have significant influence on the frictional behavior of spun yarns. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Ruthenium (II) complexes immobilized on swellable polyacrylate matrices: Synthesis and catalytic applications
Authors: Liu Z. S. , Rempel G. L.
Published: March 2008

RuH2(PPh3)4 has been immobilized on swellable polyacrylate matrices to provide heterogenized carboxylate‐derivatives. These swellable polymer supported ruthenium (II) complex catalysts have been used in the transfer hydrogenation of aldehydes. Hydrogen donors are formate salt, cyclohexanol, and benzyl alcohol. The catalysts exhibit good activity for hydrogen transfer reduction of aldehydes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synergistic toughening effects of nucleating agent and ethylene–octene copolymer on polypropylene
Authors: Bai Hongwei , Wang Yong , Song Bo , Han Liang
Published: March 2008

The synergistic toughening effect of nucleating agent (NA) and ethylene–octene copolymer (POE) on polypropylene was studied in the present work. Two different nucleating agents, such as α‐form nucleating agent 1,3 : 2,4‐bis (3,4‐dimethylbenzylidene) sorbitol (DMDBS, Millad 3988) and β‐form nucleating agent aryl amides compounds (TMB‐5), were selected to blend with PP or PP/POE blends, respectively. The results show that PP containing 0.5–0.25 wt % DMDBS or 0.5–0.25 wt % TMB‐5 has relatively low impact strength. For PP/POE blends, although the impact strength increases gradually with the increasing of POE content, high content of POE is needed to obtain the available PP toughness. However, once nucleating agent and POE are simultaneously added into PP, PP/POE/NA blends show great improvement of toughness even at low POE content. Furthermore, the synergistic toughening effect of POE/TMB‐5 is more apparent than that of POE/DMDBS. SEM results show that whether DMDBS or TMB‐5 has no apparent effect on the morphologies of POE in the PP/POE/NA blends. Further investigations using DSC and POM indicate that both DMDBS and TMB‐5 induce the apparent enhancement of the crystallization temperature of PP and the sharp decrease of spherulites size of PP in the PP/POE/NA blends. The possible synergistic toughening mechanism is discussed in the work. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Grafted CMC/silica gel superabsorbent composite: Synthesis and investigation of swelling behavior in various media
Authors: Pourjavadi A. , Seidi F. , Salimi H. , Soleyman R.
Published: March 2008

In the present study, we attempt to synthesize and characterize novel CMC‐g‐poly (acrylic acid‐co‐2‐acrylamido‐2‐methylpropanesulfonic acid)/silica gel composite. Infrared spectroscopy and TGA thermal analysis were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy. The effect of reaction variables affecting on water absorbency of the composite and swelling behavior in various solvents, salt, and pH solutions was investigated. Maximum water absorbency of the optimized final product was found to be 4000 g/g in distilled water. The absorbency under load (AUL) of the hydrogel was also determined by using an AUL tester at various applied pressures. Finally, dynamic swelling kinetics of the hydrogel was studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search): A possible expert‐system based cooperative effort to hunt for planets of Earth mass and below
Authors: Dominik M. , Horne K. , Allan A. , Rattenbury N.J. , Tsapras Y. , Snodgrass C. , Bode M.F. , Burgdorf M.J. , Fraser S.N. , Kerins E. , Mottram C.J. , Steele I.A. , Street R.A. , Wheatley P.J. , Wyrzykowski Ł.
Published: March 2008

The technique of gravitational microlensing is currently unique in its ability to provide a sample of terrestrial exoplanets around both Galactic disk and bulge stars, allowing to measure their abundance and determine their distribution with respect to mass and orbital separation. Thus, valuable information for testing models of planet formation and orbital migration is gathered, constituting an important piece in the puzzle for the existence of life forms throughout the Universe. In order to achieve these goals in reasonable time, a well‐coordinated effort involving a network of either 2m or 4×1m telescopes at each site is required. It could lead to the first detection of an Earth‐mass planet outside the Solar system, and even planets less massive than Earth could be discovered. From April 2008, ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search) is planned to provide a platform for a three‐step strategy of survey, follow‐up, and anomaly monitoring. As an expert system embedded in eSTAR (e‐Science Telescopes for Astronomical Research), ARTEMiS will give advice for follow‐up based on a priority algorithm that selects targets to be observed in order to maximize the expected number of planet detections, and will also alert on deviations from ordinary microlensing light curves by means of the SIGNALMEN anomaly detector. While the use of the VOEvent (Virtual Observatory Event) protocol allows a direct interaction with the telescopes that are part of the HTN (Heterogeneous Telescope Networks) consortium, additional interfaces provide means of communication with all existing microlensing campaigns that rely on human observers. The success of discovering a planet by microlensing critically depends on the availability of a telescope in a suitable location at the right time, which can mean within 10 min. To encourage follow‐up observations, microlensing campaigns are therefore releasing photometric data in real time. On ongoing planetary anomalies, world‐wide efforts are being undertaken to make sure that sufficient data are obtained, since there is no second chance. Real‐time modelling offers the opportunity of live discovery of extra‐solar planets, thereby providing “Science live to your home”. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A tale of four surveys:What have we learned about the variable sky?
Authors: Howell S.B.
Published: March 2008

Four tales concerning a set of photometric imaging surveys are spun. The reader is lead through a brief description of each survey and major results are presented. The four surveys are summarized in a few simple “rules”: 1) The fraction of point sources that are variable with respect to those that are found to be constant, increases as a power law as the photometric precision of the survey improves, and 2) This fact can be simply formulated as a power law function granting the user a predictive power. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Object classification at the Nearby Supernova Factory
Authors: Bailey S. , Aragon C. , Romano R. , Thomas R. C. , Weaver B. A. , Wong D.
Published: March 2008

We present the results of applying new object classification techniques to the supernova search of the Nearby Supernova Factory. In comparison to simple threshold cuts, more sophisticated methods such as boosted decision trees, random forests, and support vector machines provide dramatically better object discrimination: we reduced the number of nonsupernova candidates by a factor of 10 while increasing our supernova identification efficiency. Methods such as these will be crucial for maintaining a reasonable false positive rate in the automated transient alert pipelines of upcoming large optical surveys. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The SuperNova Early Warning System
Authors: Scholberg K.
Published: March 2008

A core collapse in the Milky Way will produce an enormous burst of neutrinos in detectors world‐wide. Such a burst has the potential to provide an early warning of a supernova's appearance. I will describe the nature of the signal, the sensitivity of current detectors, and SNEWS, the SuperNova Early Warning System, a network designed to alert astronomers as soon as possible after the detected neutrino signal. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radio wavelength transients: Current and emerging prospects
Authors: Lazio J.
Published: March 2008

Known classes of radio wavelength transients range from the nearby stellar flares and radio pulsars to the distant Universe γ‐ray burst afterglows. Hypothesized classes of radio transients include analogs of known objects, e.g., extrasolar planets emitting Jovian‐like radio bursts and giant‐pulse emitting pulsars in other galaxies, to the exotic, prompt emission from γ‐ray bursts, evaporating black holes, and transmitters from other civilizations. A number of instruments and facilities are either under construction or in early observational stages and are slated to become available in the next few years. With a combination of wide fields of view and wavelength agility, the detection and study of radio transients will improve immensely. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transient detection and classification
Authors: Becker A.C.
Published: March 2008

I provide an incomplete inventory of the astronomical variability that will be found by next‐generation time‐domain astronomical surveys. These phenomena span the distance range from near‐Earth satellites to the farthest Gamma Ray Bursts. The surveys that detect these transients will issue alerts to the greater astronomical community; this decision process must be extremely robust to avoid a slew of “false” alerts, and to maintain the community's trust in the surveys. I review the functionality required of both the surveys and the telescope networks that will be following them up, and the role of VOEvents in this process. Finally, I offer some ideas about object and event classification, which will be explored more thoroughly by other articles in these proceedings. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An RTML transport implementation on the Liverpool Telescope
Authors: Clay N.R.
Published: March 2008

The Liverpool Telescope is a 2.0m fully robotic telescope based on the Canary island of LaPalma. In this paper I describe the Java(TM) implementation of a method to transport RTML (Remote Telescope Markup Language) between a Node Agent (Web Services endpoint) embedded at the telescope and a remote Agent. The advantages and disadvantages of the method are discussed, along with the suitability of the protocol for HTN standardisation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Robonet‐1.0
Authors: Mottram C.J. , Fraser S.N.
Published: March 2008

Robonet‐1.0 is a prototype network of 2m robotic telescopes spread out around the world, consisting of three 2 metre telescopes. In this paper we present some of the science done with the network and how we use eSTAR and HTN technologies to perform observing programmes in an efficient manner. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Does your robot need a flamethrower? Automated astronomical instrumentation in Antarctica
Authors: Tothill N.F.H. , Martin C.L. , Kulesa C.A. , Briguglio R.
Published: March 2008

The Antarctic Plateau contains sites with the potential to be the best in the world for many astronomical observations. The Plateau has strong advantages in the waveband between thermal‐IR and millimetre‐waves, for time‐based astronomy, and for adaptive optics and interferometry. In such a harsh environment, automation of instrument functions becomes very important. At entirely remote (i.e., uncrewed) locations, automated instruments require robustness above all, especially in their self‐contained logistics functions (power and communications). At crewed stations, with human intervention available, automation should concentrate on increasing functionality and decreasing workload on the winterover scientists, enhancing the scientific return on a significant investment. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GRB satellite triggers for neutrino telescopes
Authors: Bouwhuis M.
Published: March 2008

The real‐time distribution of alert messages from satellites that detect gamma‐ray bursts are of key importance to neutrino telescopes.We describe how the distribution network of these alert messages is used by the ANTARES neutrino telescope, and the resulting increase in detection efficiency for neutrinos from gamma‐ray bursts. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Automated probabilistic classification of transients and variables
Authors: Mahabal A. , Djorgovski S.G. , Turmon M. , Jewell J. , Williams R.R. , Drake A.J. , Graham M.G. , Donalek C. , Glikman E. , Palomar‐QUEST team
Published: March 2008

There is an increasing number of large, digital, synoptic sky surveys, in which repeated observations are obtained over large areas of the sky in multiple epochs. Likewise, there is a growth in the number of (often automated or robotic) follow‐up facilities with varied capabilities in terms of instruments, depth, cadence, wavelengths, etc., most of which are geared toward some specific astrophysical phenomenon. As the number of detected transient events grows, an automated, probabilistic classification of the detected variables and transients becomes increasingly important, so that an optimal use can be made of follow‐up facilities, without unnecessary duplication of effort. We describe a methodology now under development for a prototype event classification system; it involves Bayesian and Machine Learning classifiers, automated incorporation of feedback from follow‐up observations, and discriminated or directed follow‐up requests. This type of methodology may be essential for the massive synoptic sky surveys in the future. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The ORAC‐DR data reduction pipeline
Authors: Cavanagh B. , Jenness T. , Economou F. , Currie M.J.
Published: March 2008

The ORAC‐DR data reduction pipeline has been used by the Joint Astronomy Centre since 1998. Originally developed for an infrared spectrometer and a submillimetre bolometer array, it has since expanded to support twenty instruments from nine different telescopes. By using shared code and a common infrastructure, rapid development of an automated data reduction pipeline for nearly any astronomical data is possible. This paper discusses the infrastructure available to developers and estimates the development timescales expected to reduce data for new instruments using ORAC‐DR. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Integrating and deploying a VOEvent service
Authors: Warner P.B. , Seaman R.L. , Smith R.C.
Published: March 2008

The NOAO VOEvent software components will provide a mechanism for publishing and general distribution of compliant VOEvents produced initially from Type Ia supernova event notifications from the NOAO ESSENCE survey, and eventually from any source of event notifications, to the astronomical community. We present a description of the NOAO VOEvent software architecture and components. We discuss technologies used, and provide a brief description of configuration and installation of the services and dependencies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An autonomous adaptive scheduling agent for period searching
Authors: Saunders E.S. , Naylor T. , Allan A.
Published: March 2008

We describe the design and implementation of an autonomous adaptive software agent that addresses the practical problem of observing undersampled, periodic, time‐varying phenomena using a network of HTN‐compliant robotic telescopes. The algorithm governing the behaviour of the agent uses an optimal geometric sampling technique to cover the period range of interest, but additionally implements proactive behaviour that maximises the optimality of the dataset in the face of an uncertain and changing operating environment. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
VOEvent authentication via XML digital signature
Authors: Allen S.L.
Published: March 2008

A trivial modification to the XML schema of VOEvent v1.1 allows the inclusion of W3C digital signatures. Signatures enable identification, identification enables trust, and trust enables authorization. Such changes would inhibit abuse of the VOEvent networks. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eudoxos: An HTN within the HTN
Authors: Solomos N. , Dimitrakopoulos I.
Published: March 2008

“Eudoxos” Observatories administered from mount Ainos, Kefallinia island, Greece, target in becoming a multi‐telescope, multi‐site observational complex. This article presents the self‐similarity aspect of the Observatories, as an internal Heterogeneous Telescope Network structure (HTN) within the actual HTN. It proposes an architecture which allows for re‐use of the HTN protocol and the Remote Telescope Markup Language (RTML) in the internal HTN, describes the status of work so far and the technologies used for the development of the various software components. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Architectures for science: Intelligent agent technology
Authors: Naylor T.
Published: March 2008

I review the current architecture of the HTN and make three suggestions for the future. (i) We should retain the expertise split between agents which deal with the science programmes and those which deal with telescope constraints. This makes it easy to add new programmes or new telescopes. (ii) We should develop “look ahead” schedulers which attempt to schedule a whole night at once. This will give reliable calculations for the chance an observation will be carried out, and give a better chance that high priority time critical observations are successfully scheduled. (iii)We should strive to attract more science programmes to the HTN, in particular time critical observations spread over many nights, and non‐time critical work which can benefit from access to databases and the literature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Distributed intelligence in an astronomical Distributed Sensor Network
Authors: White R.R. , Davis H. , Vestrand W.T. , Wozniak P.R.
Published: March 2008

The Telescope Alert Operations Network System (TALONS) was designed and developed in the year 2000, around the architectural principles of a distributed sensor network. This network supported the original Rapid Telescopes for Optical Response (RAPTOR) project goals; however, only with further development could TALONS meet the goals of the larger Thinking Telescope Project. The complex objectives of the Thinking Telescope project required a paradigm shift in the software architecture – the centralised intelligence merged into the TALONS network operations could no longer meet all of the new requirements. The intelligence needed to be divorced from the network operations and developed as a series of peripheral intelligent agents, distributing the decision making and analytical processes based on the temporal volatility of the data. This paper is presented as only one part of the poster from the workshop and in it we will explore the details of this architecture and how that merges with the current Thinking Telescope system to meet our project goals. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Autonomous software: Myth or magic?
Authors: Allan A. , Naylor T. , Saunders E.S.
Published: March 2008

We discuss work by the eSTAR project which demonstrates a fully closed loop autonomous system for the follow up of possible micro‐lensing anomalies. Not only are the initial micro‐lensing detections followed up in real time, but ongoing events are prioritised and continually monitored, with the returned data being analysed automatically. If the “smart software” running the observing campaign detects a planet‐like anomaly, further follow‐up will be scheduled autonomously and other telescopes and telescope networks alerted to the possible planetary detection.We further discuss the implications of this, and how such projects can be used to build more general autonomous observing and control systems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Taguchi methodology as a statistical tool for biotechnological applications: A critical appraisal
Authors: Rao Ravella Sreenivas , Kumar C. Ganesh , Prakasham R. Shetty , Hobbs Phil J.
Published: March 2008

Success in experiments and/or technology mainly depends on a properly designed process or product. The traditional method of process optimization involves the study of one variable at a time, which requires a number of combinations of experiments that are time, cost and labor intensive. The Taguchi method of design of experiments is a simple statistical tool involving a system of tabulated designs (arrays) that allows a maximum number of main effects to be estimated in an unbiased (orthogonal) fashion with a minimum number of experimental runs. It has been applied to predict the significant contribution of the design variable(s) and the optimum combination of each variable by conducting experiments on a real‐time basis. The modeling that is performed essentially relates signal‐to‐noise ratio to the control variables in a 'main effect only' approach. This approach enables both multiple response and dynamic problems to be studied by handling noise factors. Taguchi principles and concepts have made extensive contributions to industry by bringing focused awareness to robustness, noise and quality. This methodology has been widely applied in many industrial sectors; however, its application in biological sciences has been limited. In the present review, the application and comparison of the Taguchi methodology has been emphasized with specific case studies in the field of biotechnology, particularly in diverse areas like fermentation, food processing, molecular biology, wastewater treatment and bioremediation.
RNA interference: An emerging generation of biologicals
Authors: Shrivastava Neeta , Srivastava Anshu
Published: March 2008

RNA interference (RNAi) is a mechanism displayed by most eukaryotic cells to rid themselves of foreign double‐stranded RNA molecules. RNAi has now been demonstrated to function in mammalian cells to alter gene expression, and has been used as a means for genetic discovery as well as a possible strategy for genetic correction. RNAi was first described in animal cells by Fire and colleagues in the nematode, Caenorhabditis elegans. Knowledge of RNAi mechanism in mammalian cell in 2001 brought a storm in the field of drug discovery. During the past few years scientists all over the world are focusing on exploiting the therapeutic potential of RNAi for identifying a new class of therapeutics. The applications of RNAi in medicine are unlimited because all cells possess RNAi machinery and hence all genes can be potential targets for therapy. RNAi can be developed as an endogenous host defense mechanism against many infections and diseases. Several studies have demonstrated therapeutic benefits of small interfering RNAs and micro RNAs in animal models. This has led to the rapid advancement of the technique from research discovery to clinical trials.
Identification of mouse heart transcriptomic network sensitive to various heart diseases
Authors: Hong Seong‐Eui , Park Inju , Cha Hyeseon , Rho Seong‐Hwan , Park Woo Jin , Cho Chunghee , Kim Do Han
Published: March 2008

Exploring biological systems from highly complex datasets is an important task for systems biology. The present study examined co‐expression dynamics of mouse heart transcriptome by spectral graph clustering (SGC) to identify a heart transcriptomic network. SGC of microarray data produced 17 classified biological conditions (called condition spectrum, CS) and co‐expression patterns by generating bi‐clusters. The results showed dynamic co‐expression patterns with a modular structure enriched in heart‐related CS (CS‐1 and ‐13) containing abundant heart‐related microarray data. Consequently, a mouse heart transcriptomic network was constructed by clique analysis from the gene clusters exclusively present in the heart‐related CS; 31 cliques were used for constructing the network. The participating genes in the network were closely associated with important cardiac functions (e. g., development, lipid and glycogen metabolisms). Online Mendelian Inheritance in Man (OMIM) database indicates that mutations of the genes in the network induced serious heart diseases. Many of the tested genes in the network showed significantly altered gene expression in an animal model of hypertrophy. The results suggest that the present approach is critical for constructing a heart‐related transcriptomic network and for deducing important genes involved in the pathogenesis of various heart diseases.
Mining marine shellfish wastes for bioactive molecules: Chitin and chitosan – Part B: Applications
Authors: Hayes Maria , Carney Brian , Slater John , Brück Wolfram
Published: March 2008

Due to their unique chemical characteristics (including biodegradability to non‐toxic products, physiological inertness and hydrophilicity), chitin, chitosan and their derivatives may be expansively utilized in the biotechnological, agricultural, food protection and nutraceutical, medicinal and pharmacological fields and in the areas of bioremediation and gene therapy. Biological actions associated with chitin and shell waste by‐products include among others antibacterial, angiotensin‐1‐converting enzyme‐inhibitory and immunomodulatory activities, while the chitinolytic microbes and enzymes associated with chitinolysis also play a role in the de novo generation of further bioactivites. In Part B of this review we relate in more detail some of the bioactivities and applications of chitin and shell waste by‐products.
Management of early rectal cancer
Authors: Tytherleigh M G , Warren B F , McC. Mortensen N J
Published: March 2008

Background

Early rectal cancer (ERC) is adenocarcinoma that has invaded into, but not extended beyond, the submucosa of the rectum (that is a T1 tumour). Local excision is curative for low-risk ERCs but for high-risk cancers such management is controversial.

Methods

This review is based on published literature obtained by searching the PubMed and Cochrane databases, and the bibliographies of extracted articles.

Results and conclusion

ERC presents as a focus of malignancy within an adenoma, as a polyp, or as a small ulcerating adenocarcinoma. Preoperative staging relies on endorectal ultrasonography and magnetic resonance imaging. Pathological staging uses the Haggitt and Kikuchi classifications for adenocarcinoma in pedunculated and sessile polyps respectively. Lymph node metastases increase with the Kikuchi level, with a 1–3 per cent risk for submucosal layer (Sm) 1, 8 per cent for Sm2 and 23 per cent for Sm3 lesions. Low-risk ERCs may be treated endoscopically or by a transanal procedure. Transanal excision or transanal endoscopic microsurgery may be inadequate for high-risk ERCs and adjuvant chemoradiotherapy may be appropriate. There is a low rate of recurrence after local surgery for low-risk ERCs but this increases to up to 29 per cent for high-risk cancers.