Flow alteration-ecology relationships in Ozark Highland streams: Consequences for fish, crayfish and macroinvertebrate assemblages

We examined flowalteration-ecology relationships in benthic macroinvertebrate, fish, and crayfish assemblages in Ozark Highland streams, USA, over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We hypothesized that: 1) there would be temporal variation in flow alteration-ecology relationships between the two years, 2) flow alteration-ecology relationshipswould be stronger during the drought year vs the flood year, and 3) fish assemblages would show the strongest relationships with flow alteration. We used a quantitative richest-targeted habitat (RTH) method and a qualitative multihabitat (QMH) method to collect macroinvertebrates at 16 USGS gaged sites during both years. We used backpack electrofishing to sample fish and crayfish at 17 sites in 2012 and 11 sites in 2013.Weused redundancy analysis to relate biological response metrics, including richness, diversity, density, and community-based metrics, to flow alteration.We found temporal variation in flow alteration-ecology relationships for all taxa, and that relationships differed greatly between assemblages. We found relationships were stronger for macroinvertebrates during the drought year but not for other assemblages, and that fish assemblage relationships were not stronger than the invertebrate taxa. Magnitude of average flow, frequency of high flow, magnitude of high flow, and duration of high flow were the most important categories of flow alteration metrics across taxa. Alteration of high and average flows was more important than alteration of low flows. Of 32 important flow alteration metrics across years and assemblages, 19 were significantly altered relative to expected values. Ecological responses differed substantially between drought and flood years, and this is likely to be exacerbated with predicted climate change scenarios. Differences in flow alteration-ecology relationships among taxonomic groups and temporal variation in relationships illustrate that a complex suite of variables should be considered for effective conservation of stream communities related to flow alteration

A model of an optical biosensor detecting environment

Heller et. Al. (Science 311, 508 (2006)) demonstrated the first DNA-CN optical sensor by wrapping a piece of double-stranded DNA around the surface of single-walled carbon nanotubes (CN). This new type of optical device can be placed inside living cells and detect trace amounts of harmful contaminants by means of near infrared light. Using a simple exciton theory in nanostructures and the phenomena of B-Z structural phase transition of DNA, we investigate the working principle of this new class of optical biosensor from DNA by using the nanostructure surface as a sensor to detect the property change of DNA as it responds to the presence of target ions. We also propose some new design models by replacing carbon nanotubes with graphene ribbon semiconductors.Comment: 4 pages, 4 figures, Accepte

Nonlinear Zeeman Effects in the Cavity-Enhanced Emission of Polarised Photons

We theoretically and experimentally investigate nonlinear Zeeman effects within a polarised single-photon source that uses a single 87Rb atom strongly coupled to a high finesse optical cavity. The breakdown of the atomic hyperfine structure in the D2 transition manifold for intermediate strength magnetic fields is shown to result in asymmetric and, ultimately, inhibited operation of the polarised atom-photon interface. The coherence of the system is considered using Hong-Ou-Mandel interference of the emitted photons. This informs the next steps to be taken and the modelling of future implementations, based on feasible cavity designs operated in regimes minimising nonlinear Zeeman effects, is presented and shown to provide improved performance.Comment: 12 pages, 8 figure

Islamic Fundamentalism: A Quantitative Analysis

Islamic fundamentalist movements are inherently anti-system social movements. An anti-system social movement is designed to criticize governmental institutions and the political mainstream while mobilizing disaffected individuals against the existing sociopolitical and socioeconomic institutions. What is lacking in the mindset of many Western politicians, practitioners, the media, and the general public is a basic understanding of Islamic fundamentalism; specifically, the causes. This is the first quantitative analysis of potential causes of Islamic fundamentalism. I have created a unique data set that contains every Islamic fundamentalist group that is or has been in operation from 1970 through 2008. This fundamentalist data set has a total number of 16,072 fundamentalist movements. I will utilize the negative binomial fixed effects regression model and a comparison of each independent variable’s effect on the number of fundamentalist movements by looking at each independent variable’s minimum, mean, and maximum score

Determining Kinetics for Simulated Sunlight-Exposed Oil Compounds

Understanding of the fate of oil in the environment is of utmost importance; however, accurate, predictive models are still in very early stages. To aid in the development of these models, photodegradation of selected polycyclic aromatic hydrocarbons (PAHs) in an n-alkane hydrocarbon matrix was followed for individual PAHs and mixtures of PAHs similar to that found in the Deepwater Horizon spill. Tetracene in tetradecane photodegraded quickest of all observed PAHs, with a loss of 99% after only one hour of irradiation. Binary mixtures of PAHs showed different degradation amounts, including changes in PAH kinetics. These results suggest that the formation of dimers or aggregates as well as photosensitization reaction is important in the degradation of PAHs in oil. Kinetics of PAH photodegradation and PAH sensitized photodegradation will be presented. This information will provide a better understanding of the fate of oil in environmental systems

Polarisation oscillations in birefringent emitter-cavity systems

We present the effects of resonator birefringence on the cavity-enhanced interfacing of quantum states of light and matter, including the first observation of single photons with a time-dependent polarisation state that evolves within their coherence time. A theoretical model is introduced and experimentally verified by the modified polarisation of temporally-long single photons emitted from a $^{87}$Rb atom coupled to a high-finesse optical cavity by a vacuum-stimulated Raman adiabatic passage (V-STIRAP) process. Further theoretical investigation shows how a change in cavity birefringence can both impact the atom-cavity coupling and engender starkly different polarisation behaviour in the emitted photons. With polarisation a key resource for encoding quantum states of light and modern micron-scale cavities particularly prone to birefringence, the consideration of these effects is vital to the faithful realisation of efficient and coherent emitter-photon interfaces for distributed quantum networking and communications.Comment: 9 pages, 5 figures including Supplemental Materia

Production of Bangla stops by native English speakers learning Bangla: An acoustic analysis

Differences in the phonetic and phonological systems of Bangla and English result in negative transfer in the Bangla stop productions of native English speakers. The phonetic realizations of Voice and Aspiration and their interactions with each other are the key factors in this. A production study was carried out focusing on sixteen of the twenty Bangla stops that are distinguished by a four-way voice/aspiration contrast at four different places of articulation, providing a contrastive acoustic analysis of the pronunciation of L1 and L2 adult speakers. Data containing these stops in an intervocalic environment in word-initial, word-medial, and word-final positions was elicited by digital recording from twelve native Bangla speakers and twelve native English speakers. The data from the L1 speakers was analyzed to investigate production characteristics related to the following acoustic variables: vowel voicing onset time, closure duration, closure voicing, preceding vowel duration, and duration of aspiration noise. The data from the L2 speakers was then analyzed using the same variables. The primary acoustic correlates of Voice and Aspiration in Bangla were found to be closure voicing and vowel voicing onset time, respectively, and the interaction of these two variables made a clear distinction between the four stop classes of Bangla: voiceless unaspirated, voiceless aspirated, voiced unaspirated, and voiced aspirated. Evidence was found supporting the work of various researchers who have suggested that a [breathy voice] feature is not necessary for a phonological description of the Indo-Aryan languages. The stop productions of the native English speakers indicated a conceptual awareness of the four stop classes, but it was also clear that they lacked a native-like control of the Voice and Aspiration features and their specific interactions with each other. The degree to which the L2 productions of the four stop classes were different from those of the L1 was directly correlated to each class’s similarity to English phonological patterns, providing evidence of certain predictable aspects of L1 transfer. In order to fully apply the results of this study in a pronunciation acquisition context, perceptual studies will need to be done to identify the salience of these acoustic variables for both L1 and L2 speakers. Perceptual studies involving L1 speakers may also give a greater understanding to the ongoing discussion on the best phonological description of the four-way stop systems of the Indo-Aryan languages