World crude oil resources : evidence from estimating supply functions for 41 countries

Evidence to support or deny expectations of future scarcity or abundance of crude oil must show whether crude oil supply functions are shifting and, if so, in what direction. The authors estimate oil supply functions for 41 countries for which suitable data are available. Because of the poor quality of data, especially for reserves, the model specification is simple. Their model relates reserve additions to the imputed"in situ"price of discovered but undeveloped reserves and to the passage of time. The passage of time is a surrogate for measuring the net impact on supply conditions of the chance of finding oil, resource depletion, cost efficiency, and technology. Time's impact could be expansionary or contractionary. They test two main versions of the model, one a straightforward linear function, the other nonlinear, assuming decreasing returns. Both models yield similar results. In most cases the models fit the data reasonably closely, after adjustment for outliers. The complete model results show 26 countries with statistically significant shifts in supply functions -in almost equal parts expansionary and contractionary. The shift is often contractionary in countries with a long production history (including Burma, Trinidad and Tobago, and the United States). Some are OPEC countries, to which a model specification involving market price response does not properly apply. Tests on a small sample of countries for differences between earlier and later periods reveal limited evidence of an expansionary shift from 1980 onward. There is partial evidence that lower oil prices stimulate productivity. The authors suggest that a gloomy outlook for non-OPEC supply is unwarranted. Several countries are still in an expansionary phase. Others show no evidence of entering a period of decline. And countries in a contractionary phase will continue to add to reserves. Further research requires improving the database rather than employing more elaborate models.Labor Policies,Economic Theory&Research,Environmental Economics&Policies,Markets and Market Access,Health Economics&Finance,Economic Theory&Research,Environmental Economics&Policies,Access to Markets,Markets and Market Access,Oil Refining&Gas Industry

Effect of bisphenol-A on neurodevelopment in Drosophila melanogaster larvae

This paper examines the effects of the chemical preservative bisphenol-A on the developing nervous systems of Drosophila melanogaster, or fruit fly, larvae. This study examines the effects of bisphenol-A using both behavioral as well as morphological paradigms. It was determined that bisphenol-A significantly increased the amount of time larvae spent in seeking behavior, the number of peristaltic contractions, and the distance traveled in a linear fashion. In the morphological analysis, indications of increased dendritic area in experimental larvae existed, but there was not enough data to determine significance. For future research, it is recommended that more data be gathered to determine bisphenol-A\u27s effect on both morphological anatomy of motor neurons as well as locomotive behavior

Controlling the Electronic Properties and Morphology of Semiconducting Polymers Through the Incorporation of 1,6-Methano[10]annulene

Conducting polymers have been known since polyacetylene was discovered in the 1970s. Since then, myriad new small molecules and polymeric structures have been synthesized to optimize the properties of conducting organic materials. These materials are characterized by their highly delocalized pi-orbitals and semiconductor-like band structure in their neutral state. The vast majority of these conjugated small molecules and structures are based around benzenoid Hückel 4n+2 structures where n=1. Common examples include poly-paraphenylene, polythiophene, polyaniline, and many others. These subunits perform well in certain applications and have been studied extensively, but much less attention has been focused on aromatics with larger pi-electron systems. 1,6-methano[10]annulene (M10A) is one such aromatic with a 10-pi electron system, a non-planar structure, and a bridging methylene carbon. The non-planarity of the ring leads to low resonance energy, offering significant polyolefin character and lower energy barriers to oxidation, electrophilic addition, and other processes that require breaking of aromaticity. This polyolefin character also extends the effective conjugation length of polymers, leading to reduced bandgap and more effective delocalization of charge. These electronic features of M10A allow it to stabilize reactive species under oxidative electrochemical polymerization conditions, as well as render furan containing polymers resistant to environmental degradation. The curved geometry of the annulene has the ability to prevent torsional strain arising from steric clashes between alkyl chains and aromatic subunits along the polymer backbone. This too leads to extended effective conjugation length and good materials properties. The bridging methylene prevents ordered aggregation, resulting in M10A-containing polymers being amorphous with a variety of comonomers. These highly disordered conducting materials are useful as transistor and thermoelectric materials, exhibiting reasonable hole mobilities (ca. 10^-4 cm^2/Vs) and high Seebeck coefficients (ca. 10^3 uV/K)

Acute peripheral immune activation alters cytokine expression and glial activation in the early postnatal rat brain.

BACKGROUND:Neuroinflammation can modulate brain development; however, the influence of an acute peripheral immune challenge on neuroinflammatory responses in the early postnatal brain is not well characterized. To address this gap in knowledge, we evaluated the peripheral and central nervous system (CNS) immune responses to a mixed immune challenge in early postnatal rats of varying strains and sex. METHODS:On postnatal day 10 (P10), male and female Lewis and Brown Norway rats were injected intramuscularly with either a mix of bacterial and viral components in adjuvant, adjuvant-only, or saline. Immune responses were evaluated at 2 and 5 days post-challenge. Cytokine and chemokine levels were evaluated in serum and in multiple brain regions using a Luminex multiplex assay. Multi-factor ANOVAs were used to compare analyte levels across treatment groups within strain, sex, and day of sample collection. Numbers and activation status of astrocytes and microglia were also analyzed in the cortex and hippocampus by quantifying immunoreactivity for GFAP, IBA-1, and CD68 in fixed brain slices. Immunohistochemical data were analyzed using a mixed-model regression analysis. RESULTS:Acute peripheral immune challenge differentially altered cytokine and chemokine levels in the serum versus the brain. Within the brain, the cytokine and chemokine response varied between strains, sexes, and days post-challenge. Main findings included differences in T helper (Th) type cytokine responses in various brain regions, particularly the cortex, with respect to IL-4, IL-10, and IL-17 levels. Additionally, peripheral immune challenge altered GFAP and IBA-1 immunoreactivity in the brain in a strain- and sex-dependent manner. CONCLUSIONS:These findings indicate that genetic background and sex influence the CNS response to an acute peripheral immune challenge during early postnatal development. Additionally, these data reinforce that the developmental time point during which the challenge occurs has a distinct effect on the activation of CNS-resident cells

The Airborne Metagenome in an Indoor Urban Environment

The indoor atmosphere is an ecological unit that impacts on public health. To investigate the composition of organisms in this space, we applied culture-independent approaches to microbes harvested from the air of two densely populated urban buildings, from which we analyzed 80 megabases genomic DNA sequence and 6000 16S rDNA clones. The air microbiota is primarily bacteria, including potential opportunistic pathogens commonly isolated from human-inhabited environments such as hospitals, but none of the data contain matches to virulent pathogens or bioterror agents. Comparison of air samples with each other and nearby environments suggested that the indoor air microbes are not random transients from surrounding outdoor environments, but rather originate from indoor niches. Sequence annotation by gene function revealed specific adaptive capabilities enriched in the air environment, including genes potentially involved in resistance to desiccation and oxidative damage. This baseline index of air microbiota will be valuable for improving designs of surveillance for natural or man-made release of virulent pathogens

Is Chinese Competition Causing Deindustrialization in Brazil?

There has been a lively debate in Brazil in recent years, involving sectors of business, the labor movement, and academics, over deindustrialization and the future of the manufacturing sector. This is often linked to the growing relation between Brazil and China, which is now the country’s most significant trade partner. Brazil has experienced relative deindustrialization in the sense of a declining share of the manufacturing sector in gross domestic product that is mainly attributable to the changes in the country’s trade balance in manufactures. The direct and indirect impacts of China on Brazilian manufacturing have contributed to this relative deindustrialization

Sulfur-density differentials of crude oil: a linear programming analysis

Bibliography: p. 176-178