Sediment Movement at LTER Sites: Mechanics, Measurement and Integration with Hydrology

published or submitted for publicationis peer reviewedOpe

Tropical-cyclone-driven erosion of the terrestrial biosphere from mountains

The transfer of organic carbon from the terrestrial biosphere to the oceans via erosion and riverine transport constitutes an important component of the global carbon cycle. More than one third of this organic carbon flux comes from sediment-laden rivers that drain the mountains in the western Pacific region. This region is prone to tropical cyclones, but their role in sourcing and transferring vegetation and soil is not well constrained. Here we measure particulate organic carbon load and composition in the LiWu River, Taiwan, during cyclone-triggered floods. We correct for fossil particulate organic carbon using radiocarbon, and find that the concentration of particulate organic carbon from vegetation and soils is positively correlated with water discharge. Floods have been shown to carry large amounts of clastic sediment. Non-fossil particulate organic carbon transported at the same time may be buried offshore under high rates of sediment accumulation. We estimate that on decadal timescales, 77–92% of non-fossil particulate organic carbon eroded from the LiWu catchment is transported during large, cyclone-induced floods. We suggest that tropical cyclones, which affect many forested mountains within the Intertropical Convergence Zone, may provide optimum conditions for the delivery and burial of non-fossil particulate organic carbon in the ocean. This carbon transfer is moderated by the frequency, intensity and duration of tropical cyclones

Economic and climatic models for estimating coffee supply

O objetivo deste trabalho foi estimar a oferta cafeeira por meio da calibração de modelos estatísticos, com variáveis econômicas e climáticas, das principais regiões produtoras do Estado de São Paulo. As regiões estudadas foram Batatais, Caconde, Cássia dos Coqueiros, Cristais Paulista, Espírito Santo do Pinhal, Marília, Mococa e Osvaldo Cruz. Foram utilizados dados de oferta cafeeira, variáveis econômicas (crédito rural, crédito rural na agricultura e valor da produção) e variáveis climáticas (temperatura do ar, precipitação pluvial, evapotranspiração potencial, deficiência e excedente hídrico) de cada região, para o período de 2000–2014. Os modelos foram calibrados com uso de técnicas de regressão linear múltipla, e todas as combinações possíveis foram testadas para a seleção das variáveis. A oferta cafeeira foi a variável dependente, e as demais, as independentes. A acurácia e a precisão dos modelos foram analisadas pelo erro percentual médio e pelo coeficiente de determinação ajustado, respectivamente. As variáveis que mais influenciam a oferta cafeeira são o valor de produção e a temperatura do ar. É possível estimar a oferta cafeeira com regressões lineares múltiplas por meio de variáveis econômicas e elementos climáticos. Os modelos mais acurados são os calibrados para estimar a oferta cafeeira das regiões de Cássia dos Coqueiros e Osvaldo Cruz.The objective of this work was to estimate the coffee supply by calibrating statistical models with economic and climatic variables for the main producing regions of the state of São Paulo, Brazil. The regions were Batatais, Caconde, Cássia dos Coqueiros, Cristais Paulista, Espírito Santo do Pinhal, Marília, Mococa, and Osvaldo Cruz. Data on coffee supply, economic variables (rural credit, rural agricultural credit, and production value), and climatic variables (air temperature, rainfall, potential evapotranspiration, water deficit, and water surplus) for each region, during the period from 2000–2014, were used. The models were calibrated using multiple linear regression, and all possible combinations were tested for selecting the variables. Coffee supply was the dependent variable, and the other ones were considered independent. The accuracy and precision of the models were assessed by the mean absolute percentage error and the adjusted coefficient of determination, respectively. The variables that most affect coffee supply are production value and air temperature. Coffee supply can be estimated with multiple linear regressions using economic and climatic variables. The most accurate models are those calibrated to estimate coffee supply for the regions of Cássia dos Coqueiros and Osvaldo Cruz

Differential Inhibitory Effects of CysLT1 Receptor Antagonists on P2Y6 Receptor-Mediated Signaling and Ion Transport in Human Bronchial Epithelia

BACKGROUND: Cysteinyl leukotriene (CysLT) is one of the proinflammatory mediators released by the bronchi during inflammation. CysLTs exert their biological effects via specific G-protein-coupled receptors. CysLT(1) receptor antagonists are available for clinical use for the treatment of asthma. Recently, crosstalk between CysLT(1) and P2Y(6) receptors has been delineated. P2Y receptors are expressed in apical and/or basolateral membranes of virtually all polarized epithelia to control the transport of fluid and electrolytes. Previous research suggests that CysLT(1) receptor antagonists inhibit the effects of nucleotides acting at P2Y receptors. However, the detailed molecular mechanism underlying the inhibition remains unresolved. METHODOLOGY/PRINCIPAL FINDINGS: In this study, western blot analysis confirmed that both CysLT(1) and P2Y(6) receptors were expressed in the human bronchial epithelial cell line 16HBE14o-. All three CysLT(1) antagonists inhibited the uridine diphosphate (UDP)-evoked I(SC), but only montelukast inhibited the UDP-evoked [Ca(2+)](i) increase. In the presence of forskolin or 8-bromoadenosine 3'5' cyclic monophosphate (8-Br-cAMP), the UDP-induced I(SC) was potentiated but was reduced by pranlukast and zafirlukast but not montelukast. Pranlukast inhibited the UDP-evoked I(SC) potentiated by an Epac activator, 8-(4-Chlorophenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (8-CPT-2'-O-Me-cAMP), while montelukast and zafirlukast had no such effect. Pranlukast inhibited the real-time increase in cAMP changes activated by 8-CPT-2'-O-Me-cAMP as monitored by fluorescence resonance energy transfer imaging. Zafirlukast inhibited the UDP-induced I(SC) potentiated by N(6)-Phenyladenosine-3',5'-cyclic monophosphorothioate, Sp-isomer (Sp-6-Phe-cAMP; a PKA activator) and UDP-activated PKA activity. CONCLUSIONS/SIGNIFICANCE: In summary, our data strongly suggest for the first time that in human airway epithelia, the three specific CysLT(1) receptor antagonists exert differential inhibitory effects on P2Y(6) receptor-coupled Ca(2+) signaling pathways and the potentiating effect on I(SC) mediated by cAMP and Epac, leading to the modulation of ion transport activities across the epithelia

Tapping a Foreign Subsidiarys Competence: An Empirical Test of Subsidiaries of Multinational Corporations in South Korea

This study examined the conditions under which a foreign subsidiary becomes the competence center within the multinational corporation (MNC)s network. We developed an integrated framework by investigating effects of both subsidiary-level factors and headquarter (HQ)-level factors on subsidiarys competence development. Survey data from 76 foreign subsidiaries of MNCs in South Korea largely supported our hypotheses. We found that subsidiaries with high management autonomy and high network embeddedness in the local market (South Korea) tend to build superior capabilities that would be useful throughout the entire MNC network. Concerning an MNCs management system, our results suggested that technological and managerial knowledge transfer from HQ to subsidiaries plays important roles in helping a subsidiary evolve into a competence center in the MNCs global network

Inovatyvus požiūris į socialinės atsakomybės ugdymo(si) prielaidas

Straipsnyje nagrinėjama socialinio ugdymo(si) problematika mokytojų rengimo ir didaktiniu požiūriais. Autoriai kelia ir siekia atsakyti į pagrindinį tyrimo klausimą: kokios socialinio ugdymos(si) metodinės prieigos gali būti efektyviausios globaliame pasaulyje? Pristatomi tarptautinių tyrimų duomenys, rodantys, kad švietimo politikų, praktikų pastangos ne visada yra adekvačios pačių mokinių aktyvumo rodikliams. Todėl straipsnio autoriai daro prielaidą, kad edukacinėje praktikoje taikomos metodologinės ugdymo(si) prieigos ne visada atspindi mokinių lūkečius, interesus ir poreikius. Galbūt todėl mažėja mokinių motyvacija aktyviems pilietiškumo veiksmams. Pasitelkus mokslinės literatūros šaltinių aprašomąją ir turinio analizę, pateikiamos įžvalgos apie inovatyvias ugdymo(si) metodikas, jas klasifikuojant į keturias pagrindines kryptis: svarstomąją, tinklaveikos, socialinių inovacijų didaktikos ir aktyvaus pilietiškumo. Kiekvienai iš šių krypčių apibūdinti autoriai pasitelkia švietimo politikų ir įvairių šalių tyrėjų atliktas analizes. Įžvalgų ir analizės pagrindu daromos išvados apie tikėtinai efektyviausius socialinės atsakomybės ugdymo (si) metodusThe authors of the article deals with the problem of education for social responsibility from teacher training and didactical perspectives. The authors stress that every society has a need to perpetuate itself, and establishes supports and promotes institutions which do so. And the role of educational communities is discussed because schools need to provide learning / teaching settings for students awareness of their responsibilities to the society. That knowledge, those skills and dispositions in a globalized context are different from traditional ones and they have to be researchedVytauto Didžiojo universitetasŠvietimo akademij

Effects of an Export Subsidy on the U.S. Cotton Industry

In this study, the effects of an export subsidy for cotton are analyzed using a linear elasticity model. The study explicitly addresses the interaction of current domestic policies with the proposed export subsidy. An export subsidy may be a succesful method of reducing the government costs of the cotton program if beginning price is low relative to the target price and if producer response to higher market prices is low

Decoration of carbohydrate nanocomposite with silver nanoparticles for highly efficient adsorption of methylene blue and antimicrobial against human pathogens

The current study aims to prepare carbohydrate nanocomposite based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized cellulose nanofibers (CNFs) /chitosan chloride (Ch) decorated with silver nanoparticles (Ag-NPs) and designed as (TEMPO/CNF/Ch/Ag-NPs) that was investigated as antimicrobial materials and applied as efficient sorbent. CNF was prepared from cellulose through TEMPO oxidation-mechanical defibrillation technique. Anionic CNF and Ch were ironically interacted to prepare novel sustainable ionic nanofibers films. Ag-NPs having approximately 20 nm were prepared in situ to decorate the ionic fibers. The effects of experimental parameters including media pH (3.0–8.0), contact time (10–120 min), and initial methylene blue (MB) concentration (50–800 ppm) on the adsorption behavior of MB onto nanocomposite films were evaluated. The results exhibited similar and fast adsorption kinetic, as illustrated by the pseudo-second-order model. The adsorption results were best suited by the Langmuir isotherm model, and the maximum adsorption capacity for the TEMPO/CNF/Ch and TEMPO/CNF/Ch/Ag-NPs nanocomposite was 369 and 432 mg/g, respectively, at the optimized media pH of 7 with a contact time of 60 min at 88 to 90 mg/g of MB. In kinetic studies, the pseudo-second-order model for nanocomposite films provided the best fit (R 2  = 0.98), than pseudo-first-order model (R 2  = 0.82 and 0.77). The TEMPO/CNF/Ch and TEMPO/CNF/Ch/Ag-NPs nanocomposite retains 73 and 69% of its initial adsorption performance towards MB after five consecutive runs. The formed nanocomposite showed excellent efficacy against Escherichia coli (14.3 ± 0.57 mm), followed by Candida albicans (12 ± 1 mm), Staphylococcus aureus (11.3 ± 1.15 mm), and Streptococcus mutans (10.6 ± 1.15 mm), and their antimicrobial activity was enhanced by the incorporation of Ag-NPs. The formed nanocomposite might find applications in industrial and biomedical fields

Laser Compton scattering gamma-ray generation for Delbrück scattering experiments

Delbrück scattering, in which a gamma-ray interacting with a Coulomb field creates an electron-position pair, which subsequently annihilates to generate a gamma-ray which energy is almost identical with the incident gamma-ray, is one of important phenomena to study non-linear effects by QED and vacuum polarization. Koga and Hayakawa [1] have presented that it is possible to measure selectively the amplitude of Delbrück scattering using linearly polarized gamma-ray beams. Furthermore, if one uses a linearly polarized beam with energies lower than 1.022 MeV, which is the threshold of the pair creation, it is possible to measure only the virtual process of Delbrück Scattering, namely vacuum polarization. For such a purpose, we have developed a laser Compton scattering (LCS) gamma-ray beam with a CO2 laser having a wavelength of 10 micro m at the UVSOR-III synchrotron radiation facility, in which the energy of the electron beam stored in top-up mode is approximately 750 MeV. We generated a 1-MeV LCS gamma-ray beam. We will also discuss future plans.Nuclear Photonics 201