bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Oxygen Depletion and High Phosphorus Content Indicate Pollution of Lahug River, Cebu City, Philippines
Authors: MAGLANGIT FLEURDELIZ F. , GALAPATE RITCHELITA P. , BENSIG EUKENE O.
Published: December 2014

The present study deals with the physico-chemical analysis of water samplescollected monthly from three established sites in Lahug River for a period ofsix months. The main purpose of the study is to provide baseline data on itsphysico-chemical characteristics as well as assess its water quality. Statistical toolswere used to analyze and interpret the data. The pH, temperature, TDS, DO, nitrates and total P varied significantly (p<0.05) across location. The pH valuesvaried from 7.2 to 7.7 are suitable for the largest variety of aquatic organisms.Water temperature, total suspended solids (TSS), total dissolved solids (TDS) and levels of nitrates were within the permissible DENR guidelines for Class D surface waters. However, the levels of dissolved oxygen (DO), biochemicaloxygen demand (BOD) and total P did not comply with the DENR Class Dstandard for surface waters. Rapid oxygen depletion and high phosphorus contentas it traversed downstream indicated that the river is polluted. Major sourcesof pollution were found to be anthropogenic activities such as indiscriminatedumping of refuse, disposal of waste water from laundry and piggery, and waterflow from backyard gardening which uses pesticides or fertilizers. Proper disposalof wastes, establishment of waste water treatment measures, education and publicenvironmental awareness should be done at the community level to reduce thelevel of pollution in Lahug River.Keywords: Aquatic Ecology, water quality, rivers, physico-chemical parameter, descriptivedesign, Philippines
Analysis of Iligan City Solid Waste Management: Basis for an Effective Solid Waste Management Program
Authors: Cuizon Rolando C.
Published: December 2014

This study analyzes the Iligan City Solid Waste Management as the basis for an effective Solid Waste Management Program. It was conducted among 1593 respondents from Barangays Maria Cristina, Del Carmen, San Miguel, San Roque, and Tubod. The research design is descriptive and employs a triangulation of quantitative and qualitative methods of data gathering and analysis. Data gathering was made with the use of a researcher-made questionnairethat measured the respondent’s level of knowledge and implementation of Recycling, Reducing, Reusing, and Composting solid waste.The data were statistically processed to get the frequency, percentage and mean. It was further analyzed with Kendall’s tau-b and Pearson Moment Correlation to determine the relationship between variables. The results show that the socioeconomic profile of the respondents has a relationship with the respondents’ Knowledge and Implementation of Solid Waste. All the socioeconomic profile of the respondents has a significant relationship with their knowledge on solid waste management, except for the gender of the respondents. Age has a significant relationship with composting; gender with reduction of solid waste generation and composting; family income and educational attainment with recycling, reduction, and reusing.   Keywords - Solid waste management; 3 r’s of solid waste management: recycle, reduce, reuse; composting, Iligan City, Philippines
Floristic Composition and Physiognomy of Pagbilao Mangrove, Quezon Province, Philippines
Authors: ALMAZOL AMALIA E. , CERVANCIA CLEOFAS R. , BUOT, JR. NOCENCIO E. , GRUEZO WILLIAM SM. , PAMPOLINA NELSON M.
Published: December 2014

The species composition, physiognomy and importance value of PagbilaoMangrove, a typical satoumi site in southern Luzon, Philippines was determinedfrom May 2009 to August 2010. Vegetation analysis was done within a 20x20mquadrat established in each of the landward, middleward and seaward zones.A total of 37 species were identified in all zones comprising 744 individualsbelonging to 28 genera and 18 families.  Using Shannon Index of diversity, thelandward zone has the highest diversity followed by the seaward zone. The leastdiverse was the middleward zone.   There was a similar trend in the proportion ofvarious tree heights and diameter in seaward, middleward and landward zones.The density of small trees was higher than those of the big ones.  The IV ofthe species varied within the zones. In the order of decreasing IV A. marina> A. floridum >  Sonneratia alba in seaward zone.  In the middleward zone, A.officinalis > C. decandra  > S. hydrophyllacea. At the landward zone, X. granatum> A. officinalis > R. mucronata > A. marina var. rumphiana. The current floristiccomposition of Pagbilao mangrove indicates that this ecosystem is still diversebased on the number and kinds of species present. With the satoumi frameworkin place, there is much hope in the conservation and management of thismangrove ecosystem.Keywords: Ecology, mangrove, floristic composition, physiognomy, species composition,physiognomy, importance value, descriptive design, Philippines
Catch, Effort and Socio–Economic Dynamics of Filter Net Fishery In Aparri Cagayan River Estuary - A Preliminary Study
Authors: MOLINA LENIMFA P. , URMENETA WILMA S. , RABANAL, JR. SIMEON R. , AMABA, JR. SAMUEL T.
Published: December 2014

This research undertaking was conducted in Aparri, Cagayan, particularlyat the Cagayan River Estuary. The study generally characterized the catch rates and socio–economic dynamics of the filter net fisheries of the said estuary. The study utilized of questionnaires to obtain the data. It also considered personalinterviews and observation to validate the data. Results revealed that majorityof the respondents were married, have children ranging from 1-4, aged 26-40,finished elementary level of education, with no extended family. Majority of therespondents were engaged in fishing without alternative source of income. Ongear species accounting, most of the drift filter net fishers consumed 1-2 hoursper haul with alamang catch of 11-20 cans per haul and 9-10 hours per haulwith 1-5 kilograms per haul for the stationary filter net fishers. Majority of thefishers have 3-4 hauls per day. On sales and sharing scheme of the drift filter netfishers, majority of the drift filter net fishers had sales of 10,000 and below perfishing trip, majority of the fishermen had a share of 500.00 per fishing trip. Asto the respondents’ involvement in community activities, most of them joinedcommunity activities despite the fact that they do not hold any position in thecommunity. There were 19 identified species that were caught by the drift filternet (DFN) and stationary filter net (SFN) for the months of May & June, withrespect to moon phases. Catch per unit effort of “saplar” was higher than that of“banwar”.Keywords: Aquatic Ecology, catch, effort, Filter Net Fisheries, descriptive design,Cagayan, Philippines
National Policies and Local Ordinances on Ifugao Rice Terraces
Authors: LICYAYO DINAH CORAZON M.
Published: December 2014

The Ifugao Rice Terraces (IRT) was declared by United Nations EducationalScientific and Cultural Organization (UNESCO) as a World Heritage Site. It wasknown to the foreigners, particularly the Spaniards in the latter years of 1800sand to the Americans during the early 1900s. Articles and photographs furtherpopularized Ifugao to foreign countries, opening the doors to tourism. Thegovernment of the Philippines formally recognized the Ifugao Rice Terraces in1972 as a national cultural treasure having a high value of world culture. Severalnational and local policies were enacted for the preservation and restoration of theIRT while maintaining it as a tourism destination. However, the implementationof these policies remains a big challenge, calling for a more determined politicalamong the national and local leaders most especially that the IRT is deterioratingdue to man-made and natural factors, which led to the declaration of the IRT asa world heritage in danger.Keywords: Legal Ecology, Ifugao Rice Terraces, policies, World Heritage Site, Tourism,descriptive design, Philippines
Brassinolide on In Vitro Growth of Apical Meristem of Bananas
Authors: BALLESTEROS-TEMANEL FLORENDA C.
Published: December 2014

Brassinosteroids (BRs) are new class of hormones noted to perform multiplephysiological functions in plant growth and development and have the potentialof influencing cell and tissue growth in vitro. Many naturally occurring BRs,including brassinolide, have been discovered, their mode of action and their growthpromoting activities on plants. The use of brassinolide in in vitro propagation isnew. The Murashige and Skoog (1962) medium was used as basal medium. Plantgrowth regulators - IAA, BA and BR - were added to the medium. The study usedthe Completely Randomized Design (CRD) in factorial with three replications.The cultivar of banana and plant growth substances affected the number of budsproduced, shoot length, root length, and stem girth. The interaction of thesetwo factors (cultivar x PGR) influenced the number of buds produced in vitroand the shoot length of the meriplants. The study shows that brassinolide has aninfluence on shoot induction, proliferation, and elongation of bananas in in vitro propagation.Keywords: Agriculture, in vitro propagation, induction, proliferation, elongation, apical meristem, plant growth regulators, cultivars, Isabela, Philippines
The Current Status of Emergency Operations at a High-Volume Cancer Center
Authors: Komori Koji , Kimura Kenya , Kinoshita Takashi , Ito Seiji , Abe Tetsuya , Senda Yoshiki , Misawa Kazunari , Ito Yuichi , Uemura Norihisa , Natsume Seiji , Kawai Ryosuke , Kawakami Jiro , Asano Tomonari , Iwata Yoshinori , Kurahashi Shintaro , Tsutsuyama Masayuki , Shigeyoshi Itaru , Shimizu Yasuhiro
Published: December 2014

This study aimed to assess the pathogenic causes, clinical conditions, surgical procedures, in-hospital mortality, and operative death associated with emergency operations at a high-volume cancer center. Although many reports have described the contents, operative procedures, and prognosis of elective surgeries in high-volume cancer centers, emergency operations have not been studied in sufficient detail. We retrospectively enrolled 28 consecutive patients who underwent emergency surgery. Cases involving operative complications were excluded. The following surgical procedures were performed during emergency operations: closure in 3 cases (10.7%), diversion in 22 cases (78.6%), ileus treatment in 2 cases (7.1%), and hemostasis in 1 case (3.6%). Closure alone was performed only once for peritonitis. Diversion was performed in 17 cases (77.3%) of peritonitis, 4 cases (18.2%) of stenosis of the gastrointestinal tract, and 1 case (4.5%) of bleeding. There was a significant overall difference (P = 0.001). The frequency of emergency operations was very low at a high-volume cancer center. However, the recent shift in treatment approaches toward nonoperative techniques may enhance the status of emergency surgical procedures. The results presented in this study will help prepare for emergency situations and resolve them as quickly and efficiently as possible.
Report Addresses Timeline For Cutting Greenhouse Gas Emissions
Authors: Showstack Randy
Published: December 2014

A new report states that “global carbon neutrality” needs to be achieved by 2055–2070 to limit global temperature rise to a 2°C increase relative to the preindustrial period. The report was released a few weeks prior to the United Nations (UN) Climate Change Conference, which will be held on 1–12 December in Lima, Peru.
AGU Hosts Amazon Hack‐A‐Thon at Fall Meeting
Authors: McCarter Tricia
Published: December 2014

As part of the Amazon Web Services Hack‐A‐Thon, this year's AGU Fall Meeting attendees will be challenged to create an idea for a Web product based on climate change data for individual cities.
Cloud variations in current climate a guide to climate changes
Authors: Rosen Julia
Published: December 2014

Clouds come in many flavors—like wispy cirrus, cotton‐puff altocumulus, and ominous stratus—and each presents a unique set of challenges for scientists trying to understand their effects on climate. Because of this, clouds have long accounted for much of the disagreement between climate models, and for most of the uncertainty in estimates of how much the Earth is expected to warm with a doubling of atmospheric carbon dioxide (CO2).
Sea levels changing in response to natural variations
Authors: Wendel JoAnna
Published: December 2014

Scientists have widely accepted that sea levels have been rising since the end of the 19th century due to human activities that warm the planet and melt land‐locked ice. Models of future sea level rise suggest that sea levels will continue to increase at an accelerating rate if emissions of greenhouse gases continue at the current rate. This has motivated a number of scientists to search for already existing accelerations in global and regional sea level during the past 2 decades. However, Dangendorf et al. note that current attempts to detect a significant acceleration in sea level rise might have overestimated the role of anthropogenic forcing.
New radar observations of temporal and spatial dynamics of the midnight temperature maximum at low latitude and midlatitude
Authors: Hickey Dustin A. , Martinis Carlos R. , Erickson Philip J. , Goncharenko Larisa P. , Meriwether John W. , Mesquita Rafael , Oliver William L. , Wright Ashley
Published: December 2014

Presented here are several cases of midnight temperature maximum (MTM) observations using the Millstone Hill incoherent scatter radar (ISR) and Arecibo ISR. The MTM, a temperature enhancement in the upper atmosphere (at ~300 km altitude), is a poorly understood phenomenon as observations are sparse. An upward propagating terdiurnal tide and coupling between atmospheric regions may play a large part in the generation of the MTM, yet this phenomenon and its implications are not fully understood. Two nights (6 March 1989 and 12 July 1988) show clear cases of the MTM occurring between 30 and 34°N with amplitudes of ~100 K and at ~18°N with amplitudes of ~40 K. The MTMs occurred later at the higher latitude. Experiments in 2013 also show a clear MTM at 34° and 36°N from 250 to 350 km altitude. The ionospheric measurements presented here demonstrate a new application of a well‐established technique to study atmospheric parameters and allow us to study the latitudinal extent of the MTM. The results provide evidence of the phenomenon occurring at latitudes and altitudes not previously sampled by radar techniques, showing that the MTM is not just an equatorial process, but one that can easily reach midlatitudes. Simultaneous measurements with a Fabry‐Perot interferometer allow us to compare the neutral temperatures with the ion temperature. Overall, these are key observations that point to large‐scale effects that can help constrain model outputs at different heights and latitudes.
Premium Principles
Authors: Young Virginia R.
Published: December 2014

In this review article, we discuss how premium principles arise in theory and in practice. We propose three methods that actuaries use to derive premium principles: (1) thead hoc methodin which the actuary simply proposes a (potentially) reasonable premium principle then studies its properties; (2) thecharacterization methodin which the actuary lists the properties that she wants the premium principle to satisfy, then finds (all) the premium principles that satisfy those properties; and (3) theeconomic methodin which the actuary espouses an economic theory and determines the resulting premium principle. These methods are not exclusive, as we note in the article.
Reinsurance Supervision
Authors: Boller Hans Peter , Haegin Thomas
Published: December 2014

The discussion of reinsurance regulation and supervision falls into a period where heightened regulatory vigilance and uncertainty can be observed in the entire financial services industry. It is widely accepted today, that there is a need for a globally recognized method of conducting reinsurance regulation. At the international level the ambition is to create a system of common and shared standards under which the world's reinsurers will, through mutual recognition, be able to trade globally without having to comply with the different regulatory demands of national and regional authorities. This would contribute to a more efficient and transparent global market place.
Reinsurance ‐ Terms, Conditions, and Methods of Placing
Authors: Czapiewski Colin , Gates Paul
Published: December 2014

The placing of reinsurance business is changing, with the role of intermediaries and methods of placement being constantly assessed in light of the costs. Smaller lines with many reinsurers are being replaced by much larger lines with few reinsurers. New forms of reinsurance are being introduced to reflect the requirements of the reinsured more accurately. In view of the more legal examination of contracts, the accuracy of the terms, conditions, exclusions, and other aspects of policy wording are now more important than ever before.
Agreement, Modeling of Categorical
Authors: Barlow William
Published: December 2014

This entry describes models that can be used to describe the agreement between observers in ways that are more satisfactory than using simple single measures such as kappa. These models may take chance agreement and ordinal association into account, and the effects of covariates may also be incorporated. Modeling techniques include the conditional logistic regression model and the loglinear model when more than two categories are involved. More complex models are required if there are more than two raters.
An item response theory analysis of the Olweus Bullying scale
Authors: Breivik Kyrre , Olweus Dan
Published: December 2014

In the present article, we used IRT (graded response) modeling as a useful technology for a detailed and refined study of the psychometric properties of the various items of the Olweus Bullying scale and the scale itself. The sample consisted of a very large number of Norwegian 4th–10th grade students (n = 48 926). The IRT analyses revealed that the scale was essentially unidimensional and had excellent reliability in the upper ranges of the latent bullying tendency trait, as intended and desired. Gender DIF effects were identified with regard to girls' use of indirect bullying by social exclusion and boys' use of physical bullying by hitting and kicking but these effects were small and worked in opposite directions, having negligible effects at the scale level. Also scale scores adjusted for DIF effects differed very little from non‐adjusted scores. In conclusion, the empirical data were well characterized by the chosen IRT model and the Olweus Bullying scale was considered well suited for the conduct of fair and reliable comparisons involving different gender‐age groups. Information Aggr. Behav. 41:1–13, 2015. © 2014 Wiley Periodicals, Inc.
Current Understanding of Van der Waals Effects in Realistic Materials
Authors: Tkatchenko Alexandre
Published: December 2014

Van der Waals (vdW) interactions arise from correlated electronic fluctuations in matter and are therefore present in all materials. Our understanding of these relatively weak yet ubiquitous quantum mechanical interactions has improved significantly during the past decade. This understanding has been largely driven by the development of efficient methods that now enable the modeling of vdW interactions in many realistic materials of interest for fundamental scientific questions and technological applications. In this work, the physics behind the currently available vdW methods are reviewed, and their applications to a wide variety of materials are highlighted, ranging from molecular assemblies to solids with and without defects, nanostructures of varying size and dimensionality, as well as interfaces between inorganic and organic materials. The origin of collective vdW interactions in materials is discussed using the concept of topological dipole waves. Focus is placed on the important observation that the full many‐body treatment of vdW interactions becomes crucial in the investigation and characterization of materials with increasing complexity, especially when studying their response properties, including vibrational, mechanical, and optical phenomena. Despite significant recent advances, many challenges still remain in the development of accurate and efficient methods for treating vdW interactions that will be broadly applicable to the modeling of functional materials at all relevant length and timescales.
Shedding Light on Living Cells
Authors: Antognazza Maria Rosa , Martino Nicola , Ghezzi Diego , Feyen Paul , Colombo Elisabetta , Endeman Duco , Benfenati Fabio , Lanzani Guglielmo
Published: December 2014

An overview of the optical methods available to modulate the cellular activity in cell cultures and biological tissues is presented, with a focus on the use of exogenous functional materials that absorb electromagnetic radiation and transduce it into a secondary stimulus for cell excitation, with high temporal and spatial resolution. Both organic and inorganic materials are critically evaluated, for in vitro and in vivo applications. Finally, as a direct practical application of optical‐stimulation techniques, the most recent results in the realization of artificial visual implants are discussed.
Photochemical Synthesis of Solution‐Processable Graphene Derivatives with Tunable Bandgaps for Organic Solar Cells
Authors: Stylianakis Minas M. , Sygletou Maria , Savva Kyriaki , Kakavelakis George , Kymakis Emmanuel , Stratakis Emmanuel
Published: December 2014

A photochemical route for the facile synthesis of tunable bandgap graphene‐based derivatives from graphene oxide (GO) through controlled laser irradiation in liquid phase is presented. The method is facile and fast, yielding these materials within 2 h and with excellent long‐term stability. It makes use of photogenerated‐solvated electrons that give rise to GO reduction, accompanied by preferential attachment of the desired functional unit, intentionally dispersed into the precursor GO solution. As a proof of concept, laser GO‐ethylene‐dinitro‐benzoyl (LGO‐EDNB) was photochemically synthesized and utilized as the electron acceptor material in organic bulk heterojunction solar cells (OSCs) with the poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)] as the electron donor. The graphene derivatives are highly dispersible in organic solvents used in OSCs, while their energy levels can be readily tuned upon fine‐tuning of the bandgap, which is directly related to the irradiation dose applied during the synthesis process. The utilization of LGO‐EDNB with a band gap of 1.7 eV, and a resultant lowest unoccupied molecular orbital level of 4.1 eV, leads to maximum open‐circuit voltage of 1.17 V and to power conversion efficiency (PCE) of 2.41%, which is the highest PCE for graphene‐based electron acceptors to date.
CYP17 genotype modifies the impact of anthropometric variation on salivary estradiol in healthy women
Authors: Rowe Elizabeth , Van Horn Andrew , Rockwell L. Christie
Published: December 2014

Several studies demonstrate that human ovarian function is responsive to the energetic environment, which has led to the development of theoretical models that explain this phenomenon. Although many genes are involved in ovarian hormone production, the possibility that genetic polymorphism may affect ovarian response to energetic conditions has not been considered. Cytochrome P450c17α is an enzyme that produces androgen precursors used to make estrogens during ovarian steroidogenesis, and is encoded by the CYP17 gene. A functionally significant variant within the promoter region of CYP17 has been linked to variation in steroid production, and some evidence suggests that this polymorphism could alter transcription of CYP17 in an insulin‐dependent manner. We tested the hypothesis that the CYP17 variant affected the relationship between anthropometric measurements and salivary estradiol in healthy women in the United States (n = 28). PCR‐RLFP analysis was used to genotype women for the genetic variant, and estradiol was assayed from saliva by EIA. Moderated regression analysis of these preliminary data revealed a significant interaction between waist‐to‐hip ratio and CYP17 genotype (P = 0.004). Our study provides evidence that gene–environment interactions should be considered in future adaptive models for human ovarian function. Moreover, our results stand to illuminate possible associations between this genetic variant and reproductive disease. Am J Phys Anthropol 156:665–670, 2015. © 2014 Wiley Periodicals, Inc.
Different mechanisms of ripple‐like oscillations in the human epileptic subiculum
Authors: Alvarado‐Rojas Catalina , Huberfeld Gilles , Baulac Michel , Clemenceau Stéphane , Charpier Stéphane , Miles Richard , de la Prida Liset Menendez , Le Van Quyen Michel
Published: December 2014

Objective

Transient high‐frequency oscillations (HFOs; 150–600Hz) in local field potentials generated by human hippocampal and parahippocampal areas have been related to both physiological and pathological processes. The cellular basis and effects of normal and abnormal forms of HFOs have been controversial. This lack of agreement is clinically significant, because HFOs may be good markers of epileptogenic areas. Better defining the neuronal correlate of specific HFO frequency bands could improve electroencephalographic analyses made before epilepsy surgery.

Methods

Here, we recorded HFOs in slices of the subiculum prepared from human hippocampal tissue resected for treatment of pharmacoresistant epilepsy. With combined intra‐ or juxtacellular and extracellular recordings, we examined the cellular correlates of interictal and ictal HFO events.

Results

HFOs occurred spontaneously in extracellular field potentials during interictal discharges (IIDs) and also during pharmacologically induced preictal discharges (PIDs) preceding ictal‐like events. Many of these events included frequencies >250Hz and so might be considered pathological, but a significant proportion were spectrally similar to physiological ripples (150–250Hz). We found that IID ripples were associated with rhythmic γ‐aminobutyric acidergic and glutamatergic synaptic potentials with moderate neuronal firing. In contrast, PID ripples were associated with depolarizing synaptic inputs frequently reaching the threshold for bursting in most pyramidal cells.

Interpretation

Our data suggest that IID and PID ripple‐like oscillations (150–250Hz) in human epileptic hippocampus are associated with 2 distinct population activities that rely on different cellular and synaptic mechanisms. Thus, the ripple band could not help to disambiguate the underlying cellular processes. Ann Neurol 2015;77:281–290.
Novel 4‐Thiazolidinones as Non‐Nucleoside Inhibitors of Hepatitis C Virus NS5B RNA‐Dependent RNA Polymerase
Authors: Çakır Gizem , Küçükgüzel İlkay , Guhamazumder Rupa , Tatar Esra , Manvar Dinesh , Basu Amartya , Patel Bhargav A. , Zia Javairia , Talele Tanaji T. , Kaushik‐Basu Neerja
Published: December 2014

In continuation of our efforts to develop new derivatives as hepatitis C virus (HCV) NS5B inhibitors, we synthesized novel 5‐arylidene‐4‐thiazolidinones. The novel compounds 29–42, together with their synthetic precursors 22–28, were tested for HCV NS5B inhibitory activity; 12 of these compounds displayed IC50 values between 25.3 and 54.1 µM. Compound 33, an arylidene derivative, was found to be the most active compound in this series with an IC50 value of 25.3 µM. Molecular docking studies were performed on the thumb pocket‐II of NS5B to postulate the binding mode for these compounds.
Modified methods of stellar magnetic field measurements
Authors: Kholtygin A. F.
Published: December 2014

The standard methods of the magnetic field measurement, based on an analysis of the relation between the Stokes V‐parameter and the first derivative of the total line profile intensity, were modified by applying a linear integral operator L to both sides of this relation. As the operator L, the operator of the wavelet transform with DOG‐wavelets is used. The key advantage of the proposed method is an effective suppression of the noise contribution to the line profile and the Stokes parameter V. The efficiency of the method has been studied using model line profiles with various noise contributions. To test the proposed method, the spectropolarimetric observations of the A0 star α2 CVn, the Of?p star HD 148937, and the A0 supergiant HD 92207 were used. The longitudinal magnetic field strengths calculated by our method appeared tobe in good agreement with those determined by other methods. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Search for circum‐planetary material and orbital period variations of short‐period Kepler exoplanet candidates
Authors: Garai Z. , Zhou G. , Budaj J. , Stellingwerf R.F.
Published: December 2014

A unique short‐period (P = 0.65356(1) d) Mercury‐size Kepler exoplanet candidate KIC012557548b has been discovered recently by Rappaport et al. (2012). This object is a transiting disintegrating exoplanet with a circum‐planetary material–comet‐like tail. Close‐in exoplanets, like KIC012557548b, are subjected to the greatest planet‐star interactions. This interaction may have various forms. In certain cases it may cause formation of the comet‐like tail. Strong interaction with the host star, and/or presence of an additional planet may lead to variations in the orbital period of the planet. Our main aim is to search for comet‐like tails similar to KIC012557548b and for long‐term orbital period variations. We are curious about frequency of comet‐like tail formation among short‐period Kepler exoplanet candidates. We concentrate on a sample of 20 close‐in candidates with a period similar to KIC012557548b from the Kepler mission. We first improved the preliminary orbital periods and obtained the transit light curves. Subsequently we searched for the signatures of a circum‐planetary material in these light curves. For this purpose the final transit light curve of each planet was fitted with a theoretical light curve, and the residuals were examined for abnormalities. We then searched for possible long‐term changes of the orbital periods using the method of phase dispersion minimization. In 8 cases out of 20 we found some interesting peculiarities, but none of the exoplanet candidates showed signs of a comet‐like tail. It seems that the frequency of comet‐like tail formation among short‐period Kepler exoplanet candidates is very low. We searched for comet‐like tails based on the period criterion. Based on our results we can conclude that the short‐period criterion is not enough to cause comet‐like tail formation. This result is in agreement with the theory of the thermal wind and planet evaporation (Perez‐Becker & Chiang 2013). We also found 3 cases of candidates which showed some changes of the orbital period. Based on our results we can see that orbital period changes are not caused by comet‐like tail disintegration processes, but rather by possible massive outer companions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Propagation of acoustic waves in the non‐isothermal solar atmosphere
Authors: Routh S. , Musielak Z. E.
Published: December 2014

The acoustic cutoff frequency was originally introduced by Lamb in the study of the propagation of acoustic waves in a stratified, isothermal medium. In this paper, we use a new method to generalize Lamb's result for a stratified, non‐isothermal medium and obtain the local acoustic cutoff frequency, which describes the propagation of acoustic waves in such a medium. The main result is that the cutoff frequency is a local quantity and that its value at a given atmospheric height determines the frequency acoustic waves must have in order to propagate at this height. Application of this result to specific physical problems like the solar atmosphere is discussed. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
E‐cadherin's role in development, tissue homeostasis and disease: Insights from mouse models
Authors: Schneider Marlon R. , Kolligs Frank T.
Published: December 2014

Recent studies uncovered critical roles of the adhesion protein E‐cadherin in health and disease. Global inactivation of Cdh1, the gene encoding E‐cadherin in mice, results in early embryonic lethality due to an inability to form the trophectodermal epithelium. To unravel E‐cadherin's functions beyond development, numerous mouse lines with tissue‐specific disruption of Cdh1 have been generated. The consequences of E‐cadherin loss showed great variability depending on the tissue in question, ranging from nearly undetectable changes to a complete loss of tissue structure and function. This review focuses on these studies and discusses how they provided important insights into E‐cadherin's role in cell adhesion, proliferation and differentiation, and its consequences for biological processes as epithelial‐to‐mesenchymal transition, vascularization, and carcinogenesis. Lastly, we present some perspectives and possible approaches for future research.
Improving olefin tolerance and production in E. coli using native and evolved AcrB
Authors: Mingardon Florence , Clement Camille , Hirano Kathleen , Nhan Melissa , Luning Eric G. , Chanal Angelique , Mukhopadhyay Aindrila
Published: December 2014

Microorganisms can be engineered for the production of chemicals utilized in the polymer industry. However many such target compounds inhibit microbial growth and might correspondingly limit production levels. Here, we focus on compounds that are precursors to bioplastics, specifically styrene and representative alpha‐olefins; 1‐hexene, 1‐octene, and 1‐nonene. We evaluated the role of the Escherichia coli efflux pump, AcrAB‐TolC, in enhancing tolerance towards these olefin compounds. AcrAB‐TolC is involved in the tolerance towards all four compounds in E. coli. Both styrene and 1‐hexene are highly toxic to E. coli. Styrene is a model plastics precursor with an established route for production in E. coli (McKenna and Nielsen, 2011). Though our data indicates that AcrAB‐TolC is important for its optimal production, we observed a strong negative selection against the production of styrene in E. coli. Thus we used 1‐hexene as a model compound to implement a directed evolution strategy to further improve the tolerance phenotype towards this alpha‐olefin. We focused on optimization of AcrB, the inner membrane domain known to be responsible for substrate binding, and found several mutations (A279T, Q584R, F617L, L822P, F927S, and F1033Y) that resulted in improved tolerance. Several of these mutations could also be combined in a synergistic manner. Our study shows efflux pumps to be an important mechanism in host engineering for olefins, and one that can be further improved using strategies such as directed evolution, to increase tolerance and potentially production. Biotechnol. Bioeng. 2015;112: 879–888. © 2015 Wiley Periodicals, Inc.
Simultaneous quantification of leukotrienes and hydroxyeicosatetraenoic acids in cell culture medium using liquid chromatography/tandem mass spectrometry
Authors: Furugen Ayako , Yamaguchi Hiroaki , Mano Nariyasu
Published: December 2014

Leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs) are important bioactive lipid mediators that participate in various pathophysiological processes. To advance understanding of the mechanisms that regulate these mediators in physiological and pathological processes, an analytical method using liquid chromatography/tandem mass spectrometry for the simultaneous quantification of LTB4, LTC4, LTD4, LTE4, 5‐HETE, 8‐HETE, 12‐HETE and 15‐HETE in cell culture media was developed. A Supel™‐Select HLB solid‐phase extraction cartridge was used for sample preparation. The compounds were separated on a C18 column using gradient elution with acetonitrile–water–formic acid (20:80:0.1, v/v/v) and acetonitrile–formic acid (100:0.1, v/v). The calibration curves of LTB4, LTD4, LTE4 and HETEs were linear in the range of 0.025–10 ng/mL, and the calibration curve of LTC4 was linear in the range of 0.25–10 ng/mL. Validation assessment showed that the method was highly reliable with good accuracy and precision. The stability of LTs and HETEs was also investigated. Using the developed method, we measured LTs and HETEs in the culture supernatant of the human mast cell line HMC‐1. The present method could facilitate investigations of the mechanisms that regulate the production, release and signaling of LTs and HETEs. Copyright © 2014 John Wiley & Sons, Ltd.
Spontaneous delivery through a cervical tear without cervical os dilatation
Authors: Djokovic Dusan , Costa Cristina , Martins Ana , Abushad Shadi
Published: December 2014

Key Clinical Message

Spontaneous delivery through a cervical tear, provoked by prostaglandin‐induced uterine contractions, was described in a G2P0 woman with a history of cervical dilatation and uterine curettage. This rare complication with potentially serious maternal–fetal consequences can be predicted by an aberrant cervical response to prostaglandins in parturients with previous cervical interventions.
Vom Blutlaugensalz zur größten europäischen Filmfabrik
Authors: Gill Manfred , Mustroph Heinz
Published: December 2014

Zwei Berliner Chemieunternehmen, 1850 und 1863 gegründet und 1873 fusioniert zur Aktiengesellschaft für Anilinfabrikation und ab 1897 mit dem Warenzeichen “Agfa” auf dem Markt, begannen mit der Erforschung und Produktion von Anilinfarbstoffen. Dank exzellenter Beziehungen zu hervorragenden Wissenschaftlern, wie August Wilhelm von Hofmann, gelang es dem Unternehmen neben erfolgreichen eigenen Forschungen, die Verfahren für eine Reihe neuer Farbstoffe wie das Malachitgrün und Hofmanns Violett zu übernehmen, zu produzieren und erfolgreich auf den Markt zu bringen.

Ein neuer Standort und ein zweites Geschäftsfeld mussten gefunden werden, um gegen die bereits etablierten Chemieunternehmen im Rhein‐Main‐Gebiet bestehen zu können. Dank eines Zufalls, der bei der Agfa beschäftigte Farbstoffchemiker Andresen befasste sich in seiner Freizeit mit der aufstrebenden Fotografie, gelang erfolgreich der Einstieg in das neue Geschäftsfeld.

In Wolfen, Sachsen‐Anhalt, wurde der ideale Standort für neue Fabrikbauten gefunden. Im Jahr 1895 begann dort der Aufbau einer neuen Farbenfabrik und 1909 der Aufbau einer Filmfabrik. Bereits 1912 war sie mit der Produktion von 20 Millionen Meter Kinefilm die größte europäische Filmfabrik. Bis 1918 gelang es ihr, neben dem amerikanischen Eastman Kodak Konzern zum Marktführer aufzusteigen.
Faszinierende Blicke in die Nanowelt
Authors: Welter Kira
Published: December 2014

Der Nobelpreis für Chemie 2014 geht an die Wissenschaftler Stefan W. Hell, W. E. Moerner und Eric Betzig für die Entwicklung der superauflösenden Fluoreszenzmikroskopie, auch Nanoskopie genannt. Mithilfe fluoreszierender Moleküle konnten die drei Forscher die Auflösungsgrenze der Lichtmikroskopie bis in den molekularen Bereich verschieben. Ihre Arbeit hat neue Wege in der Erforschung der allerkleinsten Dinge eröffnet und faszinierende Einblicke in lebende Zellen ermöglicht.
Thermo‐physical properties of bio‐oil and its fractions: Measurement and analysis
Authors: Abedi Jalal , Nourozieh Hossein , Kariznovi Mohammad , Seyedeyn‐Azad Fakhry
Published: December 2014

Thermo‐physical properties including densities and viscosities of bio‐oil itself and its two fractions (aqueous fraction and organic fraction) are important for practical utilization. In this study, the bio‐oil fractions were prepared in various weight ratios of 2:1, 1:1, and 1:2. Density and viscosity of a bio‐oil itself, and its aqueous and organic fractions were accurately measured at various temperatures varying from ambient to 343 K and pressures from ambient to 10 MPa. Increasing temperature decreased the density of bio‐oil itself and the two separated phases (aqueous and organic phases) by almost 2.5 %, and 0.3 to 0.4 %, respectively. Increasing the temperature also decreased the viscosity of the bio‐oil by almost 86 % and its aqueous and organic fractions by up to 68 % and 98 %, respectively. The density of the bio‐oil and its organic and aqueous fractions was enhanced by increasing the pressure, whereas increasing the pressure increased the viscosity of bio‐oil and the organic fraction, but not the viscosity of aqueous phase. The generated experimental density and viscosity data of bio‐oil and its aqueous and organic fractions were evaluated with existing models that account for the effects of temperature and pressure. The impacts of pressure and temperature on the density and viscosity were considered in the correlations and evaluated with the experimental results.
Energy gas storage in template‐synthesized carbons with different porous structures
Authors: Yong Liang Guana C. , Elkamel Ali , Wang Kean
Published: December 2014

Three activated carbon samples were synthesized via the template synthesis, in which a polymer was impregnated into the porous networks of zeolite Y and carbonized at three different temperatures. The carbon samples were structurally characterized and examined, respectively, for the application of energy gas (CH4 and H2) storage. It was found that (1) at high pressure end (P > 35 bar) the methane storage capacity is approximately proportional to the surface area while the hydrogen storage capacity is predominated by the volume of micropores; (2) at low pressure end (P < 1bar), however, the adsorption capacity is a strong function of the size and volume fraction of micropores/small micropores. The role of mesopore, micropore, and small micropore was discussed in details with respect to the adsorption of H2/CH4.
Dual‐polarized MIMO antenna system for WiFi and LTE wireless access point applications
Authors: Moradikordalivand Alishir , Rahman Tharek Abd , Leow Chee Yen , Ebrahimi Sepideh
Published: December 2014

In this paper, a dual‐polarized multiple‐input multiple‐output (MIMO) antenna system suitable for indoor wireless access point is proposed. The presented MIMO antenna system consists of two coplanar‐waveguide‐fed monopole antennas with orthogonally polarized modes. According to the closely spaced structure of the MIMO antenna system, the mutual coupling between the ports is a big challenge. Therefore, a new structure of parasitic element is introduced in order to improve the mutual coupling between the ports. For the purpose of validating the simulated results, the antenna prototype has been fabricated and measured; the comparison of the results shows that there is an acceptable agreement between the measurement and simulation results. The proposed design covers the frequency bands of WiFi (2.4 GHz), Worldwide Interoperability for Microwave Access (2.3 and 2.5 GHz), and Long‐Term Evolution (LTE; 1.5 and 2.6 GHz) applications with a reflection coefficient less than −10 dB and a mutual coupling coefficient better than −15 dB. The MIMO antenna system provides an envelope correlation coefficient less than 0.15, polarization diversity gain more than 9.985 dB, and quasi‐omnidirectional pattern within the expected frequency band. In addition, LTE downlink throughput measurements show that the proposed antenna system delivers data rates close to the theoretical maximum for quadrature phase shift keying, 16 quadrature amplitude modulation (QAM), and 64‐QAM modulations. Copyright © 2014 John Wiley & Sons, Ltd.
User communities and contents co‐ranking for user‐generated content quality evaluation in social networks
Authors: Li Lei , Lin Xin , Zhai Yue , Yuan Caixia , Zhou Yanquan , Qi Jiayin
Published: December 2014

With the massive popularity of social networks, more and more users can produce millions of user‐generated contents (UGCs) daily. However, UGC quality is uneven, which has posed challenges to finding superior contents in such a large data set. In this paper, we present a new idea of UGC quality evaluation exploiting user communities, which are formed by users either in a friend circle or with similar interests in social networks. The intuition is that a user community can help evaluate the UGC quality better than a single user. Hence, we propose a new graph‐theoretic user communities and contents co‐ranking (UCCC) algorithm for UGC quality evaluation. UCCC evaluates UGCs and their related user communities simultaneously based on three different relationship networks: the network connecting UGCs, the network connecting user communities, and a third network that ties the two together. Contents and user communities are ranked following a co‐ranking algorithm based on the assumption that there is a mutually reinforcing relationship between them. Experiments using real‐world data have shown that UCCC outperforms competitive algorithms by a good margin in most cases and a user community is more useful than a single user for UGC quality evaluation. Copyright © 2014 John Wiley & Sons, Ltd.
Associations between clinical characteristics and chronic complications in latent autoimmune diabetes in adults and type 2 diabetes
Authors: Lu Jun , Hou Xuhong , Zhang Lei , Hu Cheng , Zhou Jian , Pang Can , Pan Xiaoping , Bao Yuqian , Jia Weiping
Published: December 2014

Background

This study aimed to assess the associations between clinical characteristics and chronic complications in latent autoimmune diabetes in adults (LADA) and type 2 diabetes.

Methods

This is a retrospective study. Our diabetes registry included 6975 patients aged 30–75 years old with phenotypic type 2 diabetes who underwent islet autoantibody screening between 2003 and 2012; 384 patients were identified to have LADA. Rates of chronic complications for LADA and type 2 diabetes were compared using a 1 : 2 matched design. Logistic models were fitted to identify the presence of chronic diabetic complications using clinical characteristics including gender, age, duration of diabetes, glycemic control and metabolic syndrome.

Results

When duration of diabetes is <5 years, the prevalence of diabetic nephropathy (nephropathy; 12.2% versus 21.8%, p = 0.018) and diabetic retinopathy (retinopathy; 8.1% versus 15.9%, p = 0.011) were significantly lower in patients with LADA than in patients with type 2 diabetes; the prevalence of nephropathy and retinopathy were comparable between both groups when duration is ≥5 years. There was no significant difference in the prevalence of macrovascular complications between groups. The areas under the receiver operating characteristic curves based on the nephropathy and retinopathy models were larger for LADA than for type 2 diabetes (0.72 versus 0.61, p = 0.013; 0.76 versus 0.68, p = 0.056).

Conclusions

Patients with LADA had a lower prevalence of microvascular complications than patients with type 2 diabetes when the duration of diabetes was <5 years. Regression equation fitted by clinical characteristics can better predict the risk of microvascular complications in LADA than in type 2 diabetes. Copyright © 2014 John Wiley & Sons, Ltd.