bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of Urban Development on Precipitation in the Tropical Maritime Climate of Puerto Rico
Authors: Torres-Valcárcel Ángel , Harbor Jonathan , González-Avilés Cesar , Torres-Valcárcel Ana
Published: April 2014

Water is critical for sustaining natural and managed ecosystems, and precipitation is a key component in the water cycle. To understand controls on long-term changes in precipitation for scientific and environmental management applications it is necessary to examine whether local land use and land cover change (LULCC) has played a significant role in changing historical precipitation patterns and trends. For the small tropical island of Puerto Rico, where maritime climate is dominant, we used long-term precipitation and land use and land cover data to assess whether there were any detectable impacts of LULCC on monthly and yearly precipitation patterns and trends over the past century. Particular focus was given to detecting impacts from the urban landscape on mesoscale climates across Puerto Rico. We found no statistical evidence for significant differences between average monthly precipitation in urban and non-urban areas directly from surface stations, but, after subdividing by Holdridge Ecological Life Zones (HELZs) in a GIS, there were statistically significant differences (α = 0.05) in yearly average total precipitation between urban and non-urban areas in most HELZs. Precipitation in Puerto Rico has been decreasing over the past century as a result of a decrease in precipitation during periods (months or years) of low rain. However, precipitation trends at particular stations contradict synoptic-scale long-term trends, which suggests that local land use/land cover effects are driving precipitation variability at local scales.
Geometric Characteristics of Three Dimensional Reconstructed Anode Electrodes of Lithium Ion Batteries
Authors: Lim Cheolwoong , Yan Bo , Yin Leilei , Zhu Likun
Published: April 2014

The realistic three dimensional (3D) microstructure of lithium ion battery (LIB) electrode plays a key role in studying the effects of inhomogeneous microstructures on the performance of LIBs. However, the complexity of realistic microstructures imposes a significant computational cost on numerical simulation of large size samples. In this work, we used tomographic data obtained for a commercial LIB graphite electrode to evaluate the geometric characteristics of the reconstructed electrode microstructure. Based on the analysis of geometric properties, such as porosity, specific surface area, tortuosity, and pore size distribution, a representative volume element (RVE) that retains the geometric characteristics of the electrode material was obtained for further numerical studies. In this work, X-ray micro-computed tomography (CT) with 0.56 μm resolution was employed to capture the inhomogeneous porous microstructures of LIB anode electrodes. The Sigmoid transform function was employed to convert the initial raw tomographic images to binary images. Moreover, geometric characteristics of an anode electrode after 2400 cycles at the charge/discharge rate of 1 C were compared with those of a new anode electrode to investigate morphological change of the electrode. In general, the cycled electrode shows larger porosity, smaller tortuosity, and similar specific surface area compared to the new electrode.
Impacts of Frequent Burning on Live Tree Carbon Biomass and Demography in Post-Harvest Regrowth Forest
Authors: Collins Luke , Penman Trent , Ximenes Fabiano , Binns Doug , York Alan , Bradstock Ross
Published: April 2014

The management of forest ecosystems to increase carbon storage is a global concern. Fire frequency has the potential to shift considerably in the future. These shifts may alter demographic processes and growth of tree species, and consequently carbon storage in forests. Examination of the sensitivity of forest carbon to the potential upper and lower extremes of fire frequency will provide crucial insight into the magnitude of possible change in carbon stocks associated with shifts in fire frequency. This study examines how tree biomass and demography of a eucalypt forest regenerating after harvest is affected by two experimentally manipulated extremes in fire frequency (i.e., ~3 year fire intervals vs. unburnt) sustained over a 23 year period. The rate of post-harvest biomass recovery of overstorey tree species, which constituted ~90% of total living tree biomass, was lower within frequently burnt plots than unburnt plots, resulting in approximately 20% lower biomass in frequently burnt plots by the end of the study. Significant differences in carbon biomass between the two extremes in frequency were only evident after >15–20 years of sustained treatment. Reduced growth rates and survivorship of smaller trees on the frequently burnt plots compared to unburnt plots appeared to be driving these patterns. The biomass of understorey trees, which constituted ~10% of total living tree biomass, was not affected by frequent burning. These findings suggest that future shifts toward more frequent fire will potentially result in considerable reductions in carbon sequestration across temperate forest ecosystems in Australia.
Interactions between Fine Wood Decomposition and Flammability
Authors: Zhao Weiwei , Blauw Luke , Van Logtestijn Richard , Cornwell William , Cornelissen Johannes
Published: April 2014

Fire is nearly ubiquitous in the terrestrial biosphere, with profound effects on earth surface carbon storage, climate, and forest functions. Fuel quality is an important parameter determining forest fire behavior, which differs among both tree species and organs. Fuel quality is not static: when dead plant material decomposes, its structural, chemical, and water dynamic properties change, with implications for fuel flammability. However, the interactions between decomposition and flammability are poorly understood. This study aimed to determine decomposition’s effects on fuel quality and how this directly and indirectly affects wood flammability. We did controlled experiments on water dynamics and fire using twigs of four temperate tree species. We found considerable direct and indirect effects of decomposition on twig flammability, particularly on ignitability and burning time, which are important variables for fire spread. More decomposed twigs ignite and burn faster at given water content. Moreover, decomposed twigs dry out faster than fresh twigs, which make them flammable sooner when drying out after rain. Decomposed fine woody litters may promote horizontal fire spread as ground fuels and act as a fuel ladder when staying attached to trees. Our results add an important, previously poorly studied dynamic to our understanding of forest fire spread.
Characteristics, Perceived Side Effects and Benefits of Electronic Cigarette Use: A Worldwide Survey of More than 19,000 Consumers
Authors: Farsalinos Konstantinos , Romagna Giorgio , Tsiapras Dimitris , Kyrzopoulos Stamatis , Voudris Vassilis
Published: April 2014

Background: Electronic cigarette (EC) use has grown exponentially over the past few years. The purpose of this survey was to assess the characteristics and experiences of a large sample of EC users and examine the differences between those who partially and completely substituted smoking with EC use. Methods: A questionnaire was prepared, translated into 10 different languages and uploaded in an online survey tool. EC users were asked to participate irrespective of their current smoking status. Participants were divided according to their smoking status at the time of participation in two subgroups: former smokers and current smokers. Results: In total, 19,414 participants were included in the analysis, with 88 of them (0.5%) reported not being smokers at the time of EC use initiation. Complete substitution of smoking was reported by 81.0% of participants (former smokers) while current smokers had reduced smoking consumption from 20 to 4 cigarettes per day. They were using ECs for a median of 10 months. They initiated EC use with a median of 18 mg/mL nicotine-concentration liquids; 21.5% used higher than 20 mg/mL. Only 3.5% of participants were using 0-nicotine liquids at the time of the survey. Former smokers were highly dependent (Fagerström Test for Cigarette Dependence = 7) and were heavier smokers (21 cigarettes per day when smoking) compared to current smokers. The most important reasons for initiating EC use for both subgroups was to reduce the harm associated with smoking and to reduce exposure of family members to second-hand smoking. Most considered ECs as less harmful than tobacco cigarettes, while 11.0% considered them absolutely harmless. Side effects were reported by more than half of the participants (59.8%), with the most common being sore/dry mouth and throat; side effects were mild and in most cases were subsequently resolved (partially or completely). Participants experienced significant benefits in physical status and improvements in pre-existing disease conditions (including respiratory disease such as asthma and chronic obstructive lung disease). Being former smoker was independently associated with positive effects in health and improvements in disease conditions. Conclusions: The results of this worldwide survey of dedicated users indicate that ECs are mostly used to avoid the harm associated with smoking. They can be effective even in highly-dependent smokers and are used as long-term substitutes for smoking. High levels of nicotine are used at initiation; subsequently, users try to reduce nicotine consumption, with only a small minority using non-nicotine liquids. Side effects are minor and health benefits are substantial, especially for those who completely substitute smoking with EC use. Further population and interventional studies are warranted.
Mortality from Cancers of the Digestive System among Grand Multiparous Women in Taiwan
Authors: Chen Brian , Yang Chun-Yuh
Published: April 2014

The aim of this study is to evaluate the significance of grand multiparous (GM) status in the mortality from cancers of the digestive system among a cohort of GM women in Taiwan during the period 1978–2008. The study cohort consisted of 144,922 women with at least five children (GM women) in the Taiwan Birth Register between 1 January 1978 and 31 December 2003. Standardized mortality ratios (SMRs) for cancers of the digestive system including esophagus, stomach, colon, rectum, liver, and pancreas were calculated by dividing the numbers of observed cancer deaths to the expected numbers of deaths based on the rates of national female population. Among the 144,922 GM women, a total of 23, 220, 213, 92, 397, and 65 deaths were caused by cancers of the esophagus, stomach, colon, rectum, liver, and pancreas, respectively. The SMRs among GM women were 1.61 (95% confidence intervals (CI): 0.95–2.27) for esophageal cancer, 1.15 (95% CI: 1.00–1.31) for stomach cancer, 1.07 (95% CI: 0.93–1.22) for colon cancer, 0.94 (95% CI: 0.75–1.14) for rectal cancer, 1.18 (95% CI: 1.06–1.30) for liver cancer, and 0.79 (95% CI: 0.60–0.98) for pancreatic cancer. This study provides evidence that grand multiparity may confer a protective effect on the risk of death from pancreatic cancer. However, the results suggest that GM women may increase the risk of death from cancers of the liver and stomach.
Joint Exposure to Chemical and Nonchemical Neurodevelopmental Stressors in U.S. Women of Reproductive Age in NHANES
Authors: Evans Amanda , Rice Glenn , Teuschler Linda , Wright J.
Published: April 2014

Lead (Pb) and methyl mercury (MeHg) are well established neurodevelopmental toxicants (NDTs), but joint exposure to chemical and nonchemical (e.g., maternal stress) stressors has rarely been considered. We characterized exposure to Pb, MeHg and a measure of physiological dysregulation associated with chronic stress and examined race/ethnicity as a predictor of joint NDT exposure. Using data from the 2003−2004 NHANES, potential chronic stress exposure was estimated using allostatic load (AL), a quantitative measure of physiological dysregulation. A Hazard Index was calculated for joint exposure to Pb and MeHg (HINDT). Logistic regression was used to assess the relationship between an indicator of elevated joint NDT exposures (HINDT > 1) and race/ethnicity. The multivariate model was stratified by AL groups to examine effect measure modification. African American (adjusted odds ratio [OR] [95% confidence interval] = 2.2 [1.4, 3.3]) and Mexican American (1.4 [0.7, 2.6]) women were more likely to have an HINDT > 1 compared to Caucasian women. Chronic stress was identified as an effect measure modifier with the largest ORs among women with high AL scores (African Americans = 4.3 [2.0, 9.5]; Mexican Americans = 4.2 [1.3, 14.1]). Chronic stress was found to modify the association between elevated joint NDT exposure and race/ethnicity, highlighting the importance of evaluating chemical and nonchemical stressor exposures leading to a common endpoint.
Association of Overweight and Elevation with Chronic Knee and Low Back Pain: A Cross-Sectional Study
Authors: Hamano Tsuyoshi , Kamada Masamitsu , Kitayuguchi Jun , Sundquist Kristina , Sundquist Jan , Shiwaku Kuninori
Published: April 2014

It is known that overweight is associated with chronic knee pain (CKP) and chronic low back pain (CLBP). Several risk factors for these conditions have been postulated, including age, sex, overweight, occupation, and socioeconomic factors. In addition, physical environment has been studied as a potential risk factor in recent years. However, the associations of overweight and physical environment with CKP and CLBP remains unclear. The aim of this study conducted in a rural mountainous region was to examine whether overweight individuals living at higher elevations have an increased probability of experiencing CKP and CLBP. In 2009, we conducted a mail survey with a random sample aged between 40 to 79 years. Questionnaires were sent to 6,000 individuals and a total of 4,559 individuals responded to this survey. After excluding the respondents with missing data, we conducted a logistic regression analysis of the data for 3,109 individuals. There was statistically significantly higher adjusted odds ratio (aOR) of CKP for those who were overweight living at low elevation (aOR = 1.90, 95% CI = 1.21–2.98), moderate elevation (aOR = 1.73, 95% CI = 1.05–2.87), and high elevation (aOR = 2.13, 95% CI = 1.31–3.46) than those who were not overweight living at low elevation. However, similar patterns were not observed for CLBP. Our results show that specific overweight–elevation associations were observed for CKP in a rural mountainous region.
Modeling and Docking Studies on Novel Mutants (K71L and T204V) of the ATPase Domain of Human Heat Shock 70 kDa Protein 1
Authors: Elengoe Asita , Naser Mohammed , Hamdan Salehhuddin
Published: April 2014

The purpose of exploring protein interactions between human adenovirus and heat shock protein 70 is to exploit a potentially synergistic interaction to enhance anti-tumoral efficacy and decrease toxicity in cancer treatment. However, the protein interaction of Hsp70 with E1A32 kDa of human adenovirus serotype 5 remains to be elucidated. In this study, two residues of ATPase domain of human heat shock 70 kDa protein 1 (PDB: 1 HJO) were mutated. 3D mutant models (K71L and T204V) using PyMol software were then constructed. The structures were evaluated by PROCHECK, ProQ, ERRAT, Verify 3D and ProSA modules. All evidence suggests that all protein models are acceptable and of good quality. The E1A32 kDa motif was retrieved from UniProt (P03255), as well as subjected to docking interaction with NBD, K71L and T204V, using the Autodock 4.2 program. The best lowest binding energy value of −9.09 kcal/mol was selected for novel T204V. Moreover, the protein-ligand complex structures were validated by RMSD, RMSF, hydrogen bonds and salt bridge analysis. This revealed that the T204V-E1A32 kDa motif complex was the most stable among all three complex structures. This study provides information about the interaction between Hsp70 and the E1A32 kDa motif, which emphasizes future perspectives to design rational drugs and vaccines in cancer therapy.
Preparation and Characterization of Gelatin Nanofibers Containing Silver Nanoparticles
Authors: Jeong Lim , Park Won
Published: April 2014

Ag nanoparticles (NPs) were synthesized in formic acid aqueous solutions through chemical reduction. Formic acid was used for a reducing agent of Ag precursor and solvent of gelatin. Silver acetate, silver tetrafluoroborate, silver nitrate, and silver phosphate were used as Ag precursors. Ag+ ions were reduced into Ag NPs by formic acid. The formation of Ag NPs was characterized by a UV-Vis spectrophotometer. Ag NPs were quickly generated within a few minutes in silver nitrate (AgNO3)/formic acid solution. As the water content of formic acid aqueous solution increased, more Ag NPs were generated, at a higher rate and with greater size. When gelatin was added to the AgNO3/formic acid solution, the Ag NPs were stabilized, resulting in smaller particles. Moreover, gelatin limits further aggregation of Ag NPs, which were effectively dispersed in solution. The amount of Ag NPs formed increased with increasing concentration of AgNO3 and aging time. Gelatin nanofibers containing Ag NPs were fabricated by electrospinning. The average diameters of gelatin nanofibers were 166.52 ± 32.72 nm, but these decreased with the addition of AgNO3. The average diameters of the Ag NPs in gelatin nanofibers ranged between 13 and 25 nm, which was confirmed by transmission electron microscopy (TEM).
Systemic Immune Effects of Titanium Dioxide Nanoparticles after Repeated Intratracheal Instillation in Rat
Authors: Fu Yanyun , Zhang Yanqiu , Chang Xuhong , Zhang Yingjian , Ma Shumei , Sui Jing , Yin Lihong , Pu Yuepu , Liang Geyu
Published: April 2014

The potential immune effects of titanium dioxide nanoparticles (nano-TiO2) are raising concern. Our previous study verified that nano-TiO2 induce local immune response in lung tissue followed by intratracheal instillation administration. In this study, we aim to evaluate the systemic immune effects of nano-TiO2. Sprague Dawley rats were treated by intratracheal instillation with nano-TiO2 at doses of 0.5, 4, and 32 mg/kg body weight, micro-TiO2 with 32 mg/kg body weight and 0.9% NaCl, respectively. The exposure was conducted twice a week, for four consecutive weeks. Histopathological immune organs from exposed animals showed slight congestion in spleen, generally brown particulate deposition in cervical and axillary lymph node. Furthermore, immune function response was characterized by increased proliferation of T cells and B cells following mitogen stimulation and enhanced natural killer (NK) cell killing activity in spleen, accompanying by increased number of B cells in blood. No significant changes of Th1-type cytokines (IL-2 and INF-γ) and Th2-type cytokines (TNF-α and IL-6) were observed. Intratracheal exposure to nano-TiO2 may be one of triggers to be responsible for the systemic immune response. Further study is needed to confirm long-lasting lymphocyte responses and the potential mechanisms.
Anodic Fabrication of Ti-Ni-O Nanotube Arrays on Shape Memory Alloy
Authors: Liu Qiang , Ding Dongyan , Ning Congqin
Published: April 2014

Surface modification with oxide nanostructures is one of the efficient ways to improve physical or biomedical properties of shape memory alloys. This work reports a fabrication of highly ordered Ti-Ni-O nanotube arrays on Ti-Ni alloy substrates through pulse anodization in glycerol-based electrolytes. The effects of anodization parameters and the annealing process on the microstructures and surface morphology of Ti-Ni-O were studied using scanning electron microscope and Raman spectroscopy. The electrolyte type greatly affected the formation of nanotube arrays. A formation of anatase phase was found with the Ti-Ni-O nanotube arrays annealed at 450 °C. The oxide nanotubes could be crystallized to rutile phase after annealing treatment at 650 °C. The Ti-Ni-O nanotube arrays demonstrated an excellent thermal stability by keeping their nanotubular structures up to 650 °C.
Donor-Acceptor Block Copolymers: Synthesis and Solar Cell Applications
Authors: Nakabayashi Kazuhiro , Mori Hideharu
Published: April 2014

Fullerene derivatives have been widely used for conventional acceptor materials in organic photovoltaics (OPVs) because of their high electron mobility. However, there are also considerable drawbacks for use in OPVs, such as negligible light absorption in the visible-near-IR regions, less compatibility with donor polymeric materials and high cost for synthesis and purification. Therefore, the investigation of non-fullerene acceptor materials that can potentially replace fullerene derivatives in OPVs is increasingly necessary, which gives rise to the possibility of fabricating all-polymer (polymer/polymer) solar cells that can deliver higher performance and that are potentially cheaper than fullerene-based OPVs. Recently, considerable attention has been paid to donor-acceptor (D-A) block copolymers, because of their promising applications as fullerene alternative materials in all-polymer solar cells. However, the synthesis of D-A block copolymers is still a challenge, and therefore, the establishment of an efficient synthetic method is now essential. This review highlights the recent advances in D-A block copolymers synthesis and their applications in all-polymer solar cells.
Xanthan Gum Removal for 1H-NMR Analysis of the Intracellular Metabolome of the Bacteria Xanthomonas axonopodis pv. citri 306
Authors: Pegos Vanessa , Canevarolo Rafael , Sampaio Aline , Balan Andrea , Zeri Ana
Published: April 2014

Xanthomonas is a genus of phytopathogenic bacteria, which produces a slimy, polysaccharide matrix known as xanthan gum, which involves, protects and helps the bacteria during host colonization. Although broadly used as a stabilizer and thickener in the cosmetic and food industries, xanthan gum can be a troubling artifact in molecular investigations due to its rheological properties. In particular, a cross-reaction between reference compounds and the xanthan gum could compromise metabolic quantification by NMR spectroscopy. Aiming at an efficient gum extraction protocol, for a 1H-NMR-based metabolic profiling study of Xanthomonas, we tested four different interventions on the broadly used methanol-chloroform extraction protocol for the intracellular metabolic contents observation. Lower limits for bacterial pellet volumes for extraction were also probed, and a strategy is illustrated with an initial analysis of X. citri’s metabolism by 1H-NMR spectroscopy.
Effects of Inorganic Carbon Limitation on the Metabolome of the Synechocystis sp. PCC 6803 Mutant Defective in glnB Encoding the Central Regulator PII of Cyanobacterial C/N Acclimation
Authors: Schwarz Doreen , Orf Isabel , Kopka Joachim , Hagemann Martin
Published: April 2014

Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis. Non-diazotrophic strains such as the model Synechocystis sp. PCC 6803 depend on a balanced uptake and assimilation of inorganic carbon and nitrogen sources. The internal C/N ratio is sensed via the PII protein (GlnB). We analyzed metabolic changes of the DglnB mutant of Synechocystis sp. PCC 6803 under different CO2 availability. The identified metabolites provided a snapshot of the central C/N metabolism. Cells of the DglnB mutant shifted to carbon-limiting conditions, i.e. a decreased C/N ratio, showed changes in intermediates of the sugar storage and particularly of the tricarboxylic acid cycle, arginine, and glutamate metabolism. The changes of the metabolome support the notion that the PII protein is primarily regulating the N-metabolism whereas the changes in C-metabolism are probably secondary effects of the PII deletion.
Characterization of Green Liquor Dregs, Potentially Useful for Prevention of the Formation of Acid Rock Drainage
Authors: Mäkitalo Maria , Maurice Christian , Jia Yu , Öhlander Björn
Published: April 2014

Using alternative materials such as residual products from other industries to mitigate the negative effects of acid rock drainage would simultaneously solve two environmental problems. The main residual product still landfilled by sulphate paper mills is the alkaline material green liquor dregs (GLD). A physical, mineralogical and chemical characterization of four batches of GLD was carried out to evaluate the potential to use it as a sealing layer in the construction of dry covers on sulphide-bearing mine waste. GLD has relatively low hydraulic conductivity (10−8 to 10−9 m/s), a high water retention capacity (WRC) and small particle size. Whilst the chemical and mineralogical composition varied between the different batches, these variations were not reflected in properties such as hydraulic conductivity and WRC. Due to relatively low trace element concentrations, leaching of contaminants from the GLD is not a concern for the environment. However, GLD is a sticky material, difficult to apply on mine waste deposits and the shear strength is insufficient for engineering applications. Therefore, improving the mechanical properties is necessary. In addition, GLD has a high buffering capacity indicating that it could act as an alkaline barrier. Once engineering technicalities have been overcome, the long-term effectiveness of GLD should be studied, especially the effect of aging and how the sealing layer would be engineered in respect to topography and climatic conditions.
Anti-Amoebic Properties of Carbonyl Thiourea Derivatives
Authors: Ibrahim Maizatul , Mohd Yusof Mohd , Amin Nakisah
Published: April 2014

Thiourea derivatives display a broad spectrum of applications in chemistry, various industries, medicines and various other fields. Recently, different thiourea derivatives have been synthesized and explored for their anti-microbial properties. In this study, four carbonyl thiourea derivatives were synthesized and characterized, and then further tested for their anti-amoebic properties on two potential pathogenic species of Acanthamoeba, namely A. castellanii (CCAP 1501/2A) and A. polyphaga (CCAP 1501/3A). The results indicate that these newly-synthesized thiourea derivatives are active against both Acanthamoeba species. The IC50 values obtained were in the range of 2.39–8.77 µg·mL‑1 (9.47–30.46 µM) for A. castellanii and 3.74–9.30 µg·mL‑1 (14.84–31.91 µM) for A. polyphaga. Observations on the amoeba morphology indicated that the compounds caused the reduction of the amoeba size, shortening of their acanthopodia structures, and gave no distinct vacuolar and nuclear structures in the amoeba cells. Meanwhile, fluorescence microscopic observation using acridine orange and propidium iodide (AOPI) staining revealed that the synthesized compounds induced compromised-membrane in the amoeba cells. The results of this study proved that these new carbonyl thiourea derivatives, especially compounds M1 and M2 provide potent cytotoxic properties toward pathogenic Acanthamoeba to suggest that they can be developed as new anti-amoebic agents for the treatment of Acanthamoeba keratitis.
Does Electrical Conductivity of Linear Polyelectrolytes in Aqueous Solutions Follow the Dynamic Scaling Laws? A Critical Review and a Summary of the Key Relations
Authors: Cametti Cesare
Published: April 2014

In this review, we focus on the electrical conductivity of aqueous polyelectrolyte solutions in the light of the dynamic scaling laws, recently proposed by Dobrynin and Rubinstein, to take into account the polymer conformations in different concentration regimes, both in good and poor solvent conditions. This approach allows us to separate contributions due to polymer conformation from those due to the ionic character of the chain, and offers the possibility to extend the validity of the Manning conductivity model to dilute and semidilute regimes. The electrical conductivity in the light of the scaling approach compares reasonably well with the observed values for different polyelectrolytes in aqueous solutions, over an extended concentration range, from the dilute to the semidilute regime.
Quorum Sensing Activity of Aeromonas Caviae Strain YL12, A Bacterium Isolated from Compost
Authors: Lim Yan-Lue , Ee Robson , Yin Wai-Fong , Chan Kok-Gan
Published: April 2014

Quorum sensing is a well-studied cell-to-cell communication method that involves a cell-density dependent regulation of genes expression mediated by signalling molecules. In this study, a bacterium isolated from a plant material compost pile was found to possess quorum sensing activity based on bioassay screening. Isolate YL12 was identified using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and molecular typing using rpoD gene which identified the isolate as Aeromonas caviae. High resolution tandem mass spectrometry was subsequently employed to identify the N-acyl homoserine lactone profile of Aeromonas caviae YL12 and confirmed that this isolate produced two short chain N-acyl homoserine lactones, namely C4-HSL and C6, and the production was observed to be cell density-dependent. Using the thin layer chromatography (TLC) bioassay, both AHLs were found to activate C. violaceum CV026, whereas only C6-HSL was revealed to induce bioluminescence expression of E. coli [pSB401]. The data presented in this study will be the leading steps in understanding the role of quorum sensing in Aeromonas caviae strain YL12.
Effect of Angular Velocity on Sensors Based on Morphology Dependent Resonances
Authors: Ali Amir , Ioppolo Tindaro
Published: April 2014

We carried out an analysis to investigate the morphology dependent optical resonances shift (MDR) of a rotating spherical resonator. The spinning resonator experiences an elastic deformation due to the centrifugal force acting on it, leading to a shift in its MDR. Experiments are also carried out to demonstrate the MDR shifts of a spinning polydimethylsiloxane (PDMS) microsphere. The experimental results agree well with the analytical prediction. These studies demonstrated that spinning sensor based on MDR may experience sufficient shift in the optical resonances, therefore interfering with its desirable operational sensor design. Also the results show that angular velocity sensors could be designed using this principle.
An Affordable Open-Source Turbidimeter
Authors: Kelley Christopher , Krolick Alexander , Brunner Logan , Burklund Alison , Kahn Daniel , Ball William , Weber-Shirk Monroe
Published: April 2014

Turbidity is an internationally recognized criterion for assessing drinking water quality, because the colloidal particles in turbid water may harbor pathogens, chemically reduce oxidizing disinfectants, and hinder attempts to disinfect water with ultraviolet radiation. A turbidimeter is an electronic/optical instrument that assesses turbidity by measuring the scattering of light passing through a water sample containing such colloidal particles. Commercial turbidimeters cost hundreds or thousands of dollars, putting them beyond the reach of low-resource communities around the world. An affordable open-source turbidimeter based on a single light-to-frequency sensor was designed and constructed, and evaluated against a portable commercial turbidimeter. The final product, which builds on extensive published research, is intended to catalyze further developments in affordable water and sanitation monitoring.
Smartphone-Based Solutions for Fall Detection and Prevention: Challenges and Open Issues
Authors: Habib Mohammad , Mohktar Mas , Kamaruzzaman Shahrul , Lim Kheng , Pin Tan , Ibrahim Fatimah
Published: April 2014

This paper presents a state-of-the-art survey of smartphone (SP)-based solutions for fall detection and prevention. Falls are considered as major health hazards for both the elderly and people with neurodegenerative diseases. To mitigate the adverse consequences of falling, a great deal of research has been conducted, mainly focused on two different approaches, namely, fall detection and fall prevention. Required hardware for both fall detection and prevention are also available in SPs. Consequently, researchers’ interest in finding SP-based solutions has increased dramatically over recent years. To the best of our knowledge, there has been no published review on SP-based fall detection and prevention. Thus in this paper, we present the taxonomy for SP-based fall detection and prevention solutions and systematic comparisons of existing studies. We have also identified three challenges and three open issues for future research, after reviewing the existing articles. Our time series analysis demonstrates a trend towards the integration of external sensing units with SPs for improvement in usability of the systems.
Sexual Motivations and Ideals Distinguish Sexual Identities within the Self-Concept: A Multidimensional Scaling Analysis
Authors: Sangiorgio Celeste , Reich Warren , Vial Andrea , Savone Mirko
Published: April 2014

Many studies explore when and how young people make sexual choices but few empirical investigations link their sexual motivations with their inner conceptions about their sexual identities. We used multidimensional scaling (MDS) analysis to connect young adult participants’ (N = 128) self-descriptions of twelve identities to their sexual motivations and ideals. Identities clustered along two semantically distinct dimensions: Dimension 1 was anchored by family identities on one side and non-family identities on the other; Dimension 2 was anchored on one side by friend/romantic relationships and achievement-based social identities on the other. Those who cited intimacy (e.g., sex as an expression of love) and enhancement (e.g., gratification; to feel good) sexual motivations were more likely to describe their sexual identities and gender identities as distinct from other identities, especially for women. Idealizing physically passionate relationships was positively linked to a higher distinction between sexual and non-sexual identities, and between gender and personal identities and family identities. The mental structuring of identities may inform sexual relationship motives, ideals, and expectations.
HIV-1 Latency in Monocytes/Macrophages
Authors: Kumar Amit , Abbas Wasim , Herbein Georges
Published: April 2014

Human immunodeficiency virus type 1 (HIV-1) targets CD4+ T cells and cells of the monocyte/macrophage lineage. HIV pathogenesis is characterized by the depletion of T lymphocytes and by the presence of a population of cells in which latency has been established called the HIV-1 reservoir. Highly active antiretroviral therapy (HAART) has significantly improved the life of HIV-1 infected patients. However, complete eradication of HIV-1 from infected individuals is not possible without targeting latent sources of infection. HIV-1 establishes latent infection in resting CD4+ T cells and findings indicate that latency can also be established in the cells of monocyte/macrophage lineage. Monocyte/macrophage lineage includes among others, monocytes, macrophages and brain resident macrophages. These cells are relatively more resistant to apoptosis induced by HIV-1, thus are important stable hideouts of the virus. Much effort has been made in the direction of eliminating HIV-1 resting CD4+ T-cell reservoirs. However, it is impossible to achieve a cure for HIV-1 without considering these neglected latent reservoirs, the cells of monocyte/macrophage lineage. In this review we will describe our current understanding of the mechanism of latency in monocyte/macrophage lineage and how such cells can be specifically eliminated from the infected host.
The Prediction Methods for Potential Suspended Solids Clogging Types during Managed Aquifer Recharge
Authors: Du Xinqiang , Fang Yunqing , Wang Zijia , Hou Jiawei , Ye Xueyan
Published: April 2014

The implementation and development of managed aquifer recharge (MAR) have been limited by the clogging attributed to physical, chemical, and biological reactions. In application field of MAR, physical clogging is usually the dominant type. Although numerous studies on the physical clogging mechanism during MAR are available, studies on the more detailed suspended clogging types and its prediction methods still remain few. In this study, a series of column experiments were inducted to show the process of suspended solids clogging process. The suspended solids clogging was divided into three types of surface clogging, inner clogging and mixed clogging based on the different clogging characteristics. Surface clogging indicates that the suspended solids are intercepted by the medium surface when suspended solids grain diameter is larger than pore diameter of infiltration medium. Inner clogging indicates that the suspended solids particles could transport through the infiltration medium. Mixed clogging refers to the comprehensive performance of surface clogging and inner clogging. Each suspended solids clogging type has the different clogging position, different changing laws of hydraulic conductivity and different deposition profile of suspended solids. Based on the experiment data, the ratio of effective medium pore diameter (Dp) and median grain size of suspended solids (d50) was proposed as the judgment index for suspended solids clogging types. Surface clogging occurred while Dp/d50 was less than 5.5, inner clogging occurred while Dp/d50 was greater than 180, and mixed clogging occurred while Dp/d50 was between 5.5 and 180. In order to improve the judgment accuracy and applicability, Bayesian method, which considered more ratios of medium pore diameter (Dp) and different level of grain diameter of suspended solids (di), were developed to predict the potential suspended solids types.
Sur une galle foliaire d'un Wendlandia (Rubiacée) du Cambodge, en rapport avec la question des domaties
Authors: Schnell Raymond
Published: April 2014

Chez les limbes du Wendlatidia étudié, normalement dépourvus des do- maties en fossettes courantes chez de très nombreuses Rubiacées tropicales, peuvent exister des acarocécidies en poches, électivement localisées le long de la nervure principale et à l'aisselle des nervures secondaires, et présentant une pilosité abondante. Par leur structure histologique, et particulièrement par leur dédifférenciation et leur hyperplasie, ces poches cécidiennes se rattachent aux autres cécidies produites par des Acariens, et se différencient des domaties foliaires typiques des Rubiacées tropicales.
Propofol Inhibits Proliferation and Invasion of Osteosarcoma Cells by Regulation of MicroRNA-143 Expression
Authors: Ye Zhang , Jingzhong Li , Yangbo Liu , Lei Chen , Jiandong Yuan
Published: April 2014

Propofol is one of the extensively commonly used intravenous anesthetic agents. Previous studies have indicated that propofol has the ability to influence the biological behavior of several human cancer cells. However, the effect of propofol on osteosarcoma and its related molecular
mechanisms are still not clear. Here we found that propofol significantly elevated the expression of miR-143, inhibited cell proliferation and invasion, and promoted apoptosis in osteosarcoma cell line MG63. Propofol also efficiently decreased protein expression of matrix metalloproteinase
13 (MMP-13). Moreover, the overexpression of miR-143 decreased MMP-13 protein level. Finally, the neutralization of miR-143 by anti-miR-143 antibody reversed the effect of propofol on cell proliferation, apoptosis, and invasion and upregulated MMP-13 expression in MG63 cells. Taken together,
propofol may have antitumor potential in osteosarcoma, which is partly due to the downregulation of MMP-13 expression by miR-143.
Synergistic Antitumoral Effect of IL-12 Gene Cotransfected With Antiangiogenic Genes for Angiostatin, Endostatin, and Saxatilin
Authors: Kim Hong Sung , Jeong Hwa Yeon , Lee Yeon Kyung , Kim Keun Sik , Park Yong Serk
Published: April 2014

Previously, it was reported that the cotransfection of angiostatin K1-3, endostatin, and saxatilin genes using cationic liposomes significantly inhibited tumor progression. IL-12 is a well-known immune modulator that promotes Th1-type antitumor immune responses and also induces antiangiogenic effects. In this study, we have examined the antitumoral function of the IL-12 gene cotransfected with antiangiogenic genes for angiostatin K1-3, endostatin, and saxatilin byO,O′-dimyristyl-N-lysyl glutamate (DMKE) cationic liposomes in a mouse tumor model. According to our results, the administration of the IL-12 gene or the genes for angiostatin K1-3, endostatin, and saxatilin exhibited effective inhibition of B16BL6 melanoma growth in mice. In particular, intravenous administration of the IL-12 gene along with intratumoral administration of the three antiangiogenic genes synergistically inhibited the B16BL6 tumor growth. These results suggest that systemically expressed IL-12 enhances antitumoral efficacy of locally expressed antiangiogenic proteins.
Characterization of selenium and sulfur accumulation across the genus Stanleya (Brassicaceae): A field survey and common‐garden experiment
Authors: Cappa Jennifer J. , Cappa Patrick J. , El Mehdawi Ali F. , McAleer Jenna M. , Simmons Mark P. , Pilon‐Smits Elizabeth A. H.
Published: April 2014

• Premise of study: Selenium (Se) hyperaccumulation, the capacity to concentrate the toxic element Se above 1000 mg·kg−1·dry mass, is found in relatively few taxa native to seleniferous soils. While Se hyperaccumulation has been shown to likely be an adaptation that protects plants from herbivory, its evolutionary history remains unstudied. Stanleya (Brassicaceae) is a small genus comprising seven species endemic to the western United States. Stanleya pinnata is a hyperaccumulator of selenium (Se). In this study we investigated to what extent other Stanleya taxa accumulate Se both in the field and a greenhouse setting on seleniferous soil.

• Methods: We collected multiple populations of six of the seven species and all four varieties of S. pinnata. We tested leaves, fruit, and soil for in situ Se and sulfur (S) concentrations. The seeds collected in the field were used for a common garden study in a greenhouse.

• Key results: We found that S. pinnata var. pinnata is the only hyperaccumulator of Se. Within S. pinnata var. pinnata, we found a geographic pattern related to Se hyperaccumulation where the highest accumulating populations are found on the eastern side of the continental divide. We also found differences in genome size within the S. pinnata species complex.

• Conclusions: The S. pinnata species complex has a range of physiological properties making it an attractive system to study the evolution of Se hyperaccumulation. Beyond the basic scientific value of understanding the evolution of this fascinating trait, we can potentially use S. pinnata or its genes for environmental cleanup and/or nutrient‐enhanced dietary material.
DNA origami deposition on native and passivated molybdenum disulfide substrates
Authors: Zhang Xiaoning , Rahman Masudur , Neff David , Norton Michael Louis
Published: April 2014

Maintaining the structural fidelity of DNA origami structures on substrates is a prerequisite for the successful fabrication of hybrid DNA origami/semiconductor-based biomedical sensor devices. Molybdenum disulfide (MoS2) is an ideal substrate for such future sensors due to its exceptional electrical, mechanical and structural properties. In this work, we performed the first investigations into the interaction of DNA origami with the MoS2 surface. In contrast to the structure-preserving interaction of DNA origami with mica, another atomically flat surface, it was observed that DNA origami structures rapidly lose their structural integrity upon interaction with MoS2. In a further series of studies, pyrene and 1-pyrenemethylamine, were evaluated as surface modifications which might mitigate this effect. While both species were found to form adsorption layers on MoS2 via physisorption, 1-pyrenemethylamine serves as a better protective agent and preserves the structures for significantly longer times. These findings will be beneficial for the fabrication of future DNA origami/MoS2 hybrid electronic structures.
Biocompatible LDH-Alginate Composites for the Adsorption of Naphthalene Anionic Dye AG 120: Influence of Alginate Concentration on the Adsorption Characteristics
Authors: Sebastian Sanil , Mayadevi Suseeladevi , Mandal Sujata
Published: April 2014

Layered double hydroxide (MgAl LDH) and its composites containing different quantities of sodium alginate were synthesized. The adsorption characteristics of these materials were evaluated for the adsorption of Acid Blue 120 (AB 120). The adsorption capacity of the composites for the dye was higher than that of pristine LDH. The adsorption capacity varied with alginate concentration and was the highest when the alginate concentration was 5.9 wt%. The maximum adsorption capacity of the composite enhanced by 40%, compared to pristine MgAl LDH. The rate of adsorption of the dye on the composites was also higher than that of pristine MgAl LDH up to an alginate concentration of 11%. The results reveal that LDH composites are more efficient adsorbents compared to pure LDH. Sodium alginate, being a biopolymer can also improve the biocompatibility of the LDH for biological applications.
Epoxidation of Palm Kernel Oil-Based Crude Oleic Acid
Authors: Jalil Mohd Jumain , Mohamed Noorfazlida , Jamaludin Siti Khatijah , Som Ayub M. , Mohamad Daud Ahmad Rafizan
Published: April 2014

Most vegetable oils have high content of unsaturated bond and can be converted into epoxidized fatty acids. These days, epoxidized vegetable oils are great concern as they are obtained from sustainable, renewable natural resources and are environmental friendly. The epoxidation of palm oleic acid was carried out by using in situ generated performic acid (HCOOOH) to produce epoxidized oleic acid. The degree of temperature, the molar ratio of formic acid or hydrogen peroxide and types of catalyst was considered. Epoxidation results were based on complete conversion oxirane, rate of epoxidation and stability of the oxirane. It was found that a maximum relative conversion oxirane (RCO) of epoxide is 88% at optimal condition.
Effect of Pretreatment on Adsorption of Nickel by Oil Palm Mesocarp Fiber
Authors: Nor-Azemi Siti Nor Izuera , Fuadi Farah Aimi , Syed-Hassan Syed Shatir A.
Published: April 2014

In this study, the usage of abundantly available oil palm mesocarp fiber as biosorbent for nickel removal from aqueous solution is discussed. The effect of NaOH and HCl pretreatment on the nickel removal by oil palm mesocarp fiber is one of the objectives. Varieties of NaOH concentration were examined to determine the effect of concentration on nickel removal. Other than pretreatment, effect of initial nickel concentration is also determined. XRD analysis was done in order to proof the existence of nickel phase on the oil palm mesocarp fiber. From the result, oil palm mesocarp fiber treated with NaOH results in higher nickel adsorption compared with the treatment using HCl and the nickel nitrate phases was successfully attached on the oil palm mesocarp fiber with crystalline size between 28-52 nm.
Effect of Sisal Fiber Surface Treatments on Sisal Fiber Reinforced Polypropylene (PP) Composites
Authors: Gan Hou Lei , Tian Lei , Yi Chang Hai
Published: April 2014

Abstract: The Interface of sisal fiber which was treated by using alkali, potassium permanganate, atmospheric plasma and silane reinforced polypropylene composites were investigated by single fiber pull-out testes and surface morphology were studied. The results indicated that the morphological changes observed on the sisal fiber surface were obviously evident. Untreated, permanganate and plasma treated sisal fiber reinforced PP show a stable debonding process. Silane treated sisal fiber reinforced PP show an unstable debonding process. Single fiber pull-out tests indicated that the IFSS value was in the order of FIB < FIBKMnO4 < FIBP < FIBKH-550 < FIBKH-570. As can be seen from surface morphology of pull-out fiber, a little of PP resin was adhered to the pull-out FIB, FIBKMnO4, FIBP of sisal fiber. In contrast, PP resin at the surface of pull-out fiber was flaked off and sisal fibril was drawn out from sisal fiber were observed from pull-out fibers of FIBKH-550 and FIBKH-570.