Breeding Ecology of Birds at Teshekpuk Lake: A Key Habitat Site on the Arctic Coastal Plain of Alaska

The Teshekpuk Lake Special Area in the National Petroleum Reserve – Alaska (NPR-A) currently has no long-term protection from oil development. In this study, we provide novel information on nest density, productivity, and habitat use at Teshekpuk relative to a developed oilfield site at Prudhoe Bay, Alaska, to assess the importance of Teshekpuk for tundra-nesting birds and to provide recommendations regarding potential oil development. Mean annual nest density of all bird species combined was significantly higher at Teshekpuk than at Prudhoe Bay and was higher than any of five other sites with comparable data on the Alaskan Arctic Coastal Plain. Nest densities were significantly higher at Teshekpuk than at Prudhoe Bay for Lapland longspurs (Calcarius lapponicus) and long-billed dowitchers (Limnodromus scolopaceus), although those for semipalmated sandpipers (Calidris pusilla) were higher at Prudhoe Bay. Total shorebird nest densities at Teshekpuk were among the highest of any sites in the region. At Teshekpuk, shorebirds nested preferentially in wet and emergent habitats, including flooded low-center polygons, non-patterned tundra, and Carex aquatilis-dominated habitats. Therefore, we recommend that future oil infrastructure placement in this region avoid these habitats. Using data collected at Teshekpuk and Prudhoe Bay from 2005 to 2008, we modeled nest survivorship for 11 shorebird species and for Lapland longspurs. For longspurs, the best-supported models based on AICc values indicated that nest survival was always higher at Teshekpuk, but it was also higher elsewhere in years of high lemming abundance and later in the nesting season. For shorebirds, the best-supported models indicated that nest survivorship was highly variable among years and sites. Uniparental-nesting shorebirds had lower nest survivorship shortly after nest initiation followed by a rapid increase, while biparental survivorship was consistently high throughout the nest lifetime. We recommend that disturbances to nesting habitat be minimized during early June, when vulnerability to nest failure is higher. Because of their high importance to Arctic breeding birds, we recommend that areas within the Teshekpuk Lake Special Area, including our study area and those that are currently under 10-year deferral, be considered for permanent protection.La zone spéciale du lac Teshekpuk située dans la réserve nationale de pétrole de l’Alaska (NPR-A) n’est dotée d’aucune protection à long terme en matière de mise en valeur pétrolière. Dans la présente étude, nous fournissons de nouveaux renseignements sur la densité des nids, la productivité et l’utilisation de l’habitat à Teshekpuk à la lumière d’un chantier de mise en valeur pétrolière à la baie Prudhoe, en Alaska et ce, dans le but d’évaluer l’importance de Teshekpuk pour les oiseaux qui nichent dans la toundra ainsi que de fournir des recommandations en matière de mise en valeur pétrolière future. La densité moyenne annuelle des nids de toutes les espèces d’oiseaux prises ensemble était considérablement supérieure à Teshekpuk qu’à la baie Prudhoe et était plus élevée que dans n’importe quel des cinq autres sites aux données comparables sur la plaine côtière arctique de l’Alaska. La densité des nids était considérablement supérieure à Teshekpuk qu’à la baie Prudhoe dans le cas du bruant lapon (Calcarius lapponicus) et du bécasseau à long bec (Limnodromus scolopaceus), tandis que les densités du bécasseau semipalmé (Calidris pusilla) étaient plus élevées à la baie Prudhoe. Les densités totales de nids d’oiseaux de rivage à Teshekpuk comptaient parmi les densités les plus élevées de n’importe quel des sites de la région. À Teshekpuk, les oiseaux de rivage nichaient, de préférence, dans des habitats humides et émergents, ce qui comprend les polygones concaves inondés et la toundra non réticulée de même que les habitats dominés par le Carex aquatilis. Nous recommandons donc que l’emplacement d’infrastructures pétrolières futures dans cette région évite ces habitats. À l’aide de données recueillies à Teshekpuk et à la baie Prudhoe de 2005 à 2008, nous avons modélisé la présomption de survie en nid de 11 espèces d’oiseaux de rivage et des bruants lapons. Dans le cas des bruants lapons, les modèles les mieux soutenus d’après les valeurs AICc laissent entrevoir que la survie en nid était constamment supérieure à Teshekpuk, mais qu’elle était également plus élevée ailleurs pendant les années de grande abondance de lemmings de même qu’à une période plus tardive de la saison de nidification. Dans le cas des oiseaux de rivage, les modèles les mieux soutenus indiquent que la survie en nid varie beaucoup d’une année à l’autre et d’un emplacement à l’autre. Les oiseaux de rivage en mode de nidification monoparental affichaient un taux de survie en nid moins élevé peu après l’initiation du nid, ce qui était suivi d’une augmentation rapide, tandis que le taux de survie des oiseaux en mode de nidification biparental était constamment élevé pendant toute la durée d’existence du nid. Nous recommandons donc que les perturbations à l’habitat de nidification soient réduites au minimum au début de juin car c’est à ce moment-là que la nidification est plus vulnérable. Compte tenu de leur grande importance pour les oiseaux nicheurs de l’Arctique, nous recommandons que les aires faisant partie de la zone spéciale du lac Teshekpuk, ce qui comprend l’aire visée par notre étude et les aires faisant couramment l’objet d’un report de 10 ans, soient considérées à titre de protection permanente

Depth-charge static and time-dependence perturbation/sensitivity system for nuclear reactor core analysis. [LMFBR]

This report provides the background theory, user input, and sample problems required for the efficient application of the DEPTH-CHARGE system - a code block for both static and time-dependence perturbation theory and data sensitivity analyses. The DEPTH-CHARGE system is of modular construction and has been implemented within the VENTURE-BURNER computational system at Oak Ridge National Labortary. The DEPTH-CHARGE system provides, for the first time, a complete generalized first-order perturbation/sensitivity theory capability for both static and time-dependent analysis of realistic multidimensional reactor models

An inquiry into minimalist phrase structure

This thesis takes as its starting point the proposal in Kayne (1994) that all syntactic structures are underlyingly spec-head-complement, and that they are right-branching. I will investigate this proposal taking data from English degree constructions, namely result clauses and comparatives. A comparison will be made between these constructions and English VPs, on which the majority of the phrase structure debate in the literature has been based. The evidence for left-branching and for right-branching in VPs will be considered, and similar evidence sought for degree constructions. We will see that VPs have a mostly right-branching structure, although left-branching structures are required in restricted circumstances. Also reason and manner adjuncts are argued to be right-adjoined to the VP node, a conclusion that is re-inforced by considering the constituency of VP adjuncts and some PP sequences noted by Jackendoff (1973). In degree constructions too, we argue that both left-branching and right-branching structures are necessary. My conclusion will be that Kayne's proposal is too strong, even though it is ideal from the perspective of a minimalist approach to syntax

Equivalence of two approaches for the inhomogeneous density in the canonical ensemble

In this article we show that the inhomogeneous density obtained from a density-functional theory of classical fluids in the canonical ensemble (CE), recently presented by White et al [Phys. Rev. Lett. 84 (2000) 1220], is equivalent to first order to the result of the series expansion of the CE inhomogeneous density introduced by Gonzalez et al [Phys. Rev. Lett. 79 (1997) 2466].Comment: 6 pages, RevTe

Electronic damping of molecular motion at metal surfaces

A method for the calculation of the damping rate due to electron-hole pair excitation for atomic and molecular motion at metal surfaces is presented. The theoretical basis is provided by Time Dependent Density Functional Theory (TDDFT) in the quasi-static limit and calculations are performed within a standard plane-wave, pseudopotential framework. The artificial periodicity introduced by using a super-cell geometry is removed to derive results for the motion of an isolated atom or molecule, rather than for the coherent motion of an ordered over-layer. The algorithm is implemented in parallel, distributed across both ${\bf k}$ and ${\bf g}$ space, and in a form compatible with the CASTEP code. Test results for the damping of the motion of hydrogen atoms above the Cu(111) surface are presented.Comment: 10 pages, 3 figure

An InGaAlAs-InGaAs two-color photodetector for ratio thermometry

We report the evaluation of a molecular-beam epitaxy grown two-color photodetector for radiation thermometry. This two-color photodetector consists of two p+in+ diodes, an In0.53Ga0.25Al0.22As (hereafter InGaAlAs) p+in+ diode, which has a cutoff wavelength of 1180 nm, and an In0.53Ga0.47As (hereafter InGaAs) p+in+ diode with a cutoff wavelength of 1700 nm. Our simple monolithic integrated two-color photodetector achieved comparable output signal and signal-to-noise (SNR) ratio to that of a commercial two-color Si-InGaAs photodetector. The InGaAlAs and InGaAs diodes detect blackbody temperature as low as 275°C and 125°C, respectively, with an SNR above 10. The temperature errors extracted from our data are 4°C at 275°C for the InGaAlAs diode and 2.3°C at 125°C for the InGaAs diode. As a ratio thermometer, our two-color photodetector achieves a temperature error of 12.8°C at 275°C, but this improves with temperature to 0.1°C at 450°C. These results demonstrated the potential of InGaAlAs-InGaAs two-color photodetector for the development of high performance two-color array detectors for radiation thermometry and thermal imaging of hot objects

Are viruses associated with disc herniation? A clinical case series

Background There is some limited evidence for the presence of viruses in herniated disc material including a previous case series that claimed to provide “unequivocal evidence of the presence of herpes virus DNA in intervertebral disc specimens of patients with lumbar disc herniation suggesting the potential role of herpes viruses as a contributing factor to the pathogenesis of degenerative disc disease”. This study has not been replicated. The objective of our study was to determine if viruses were present in herniated disc fragments in participants with a prior history of back pain. Methods We recruited fifteen participants with a history of prior low-back pain prior to undergoing disc herniation surgery in the lumbar spine. Harvested disc samples were subject to next generation sequencing for detection of both RNA and DNA viral pathogens. Additionally, samples were analysed by a broadly reactive PCR targeting herpesviral DNA. Ethics approval was granted by the Human Research Ethics Committees of both Murdoch University, and St John of God Hospital, Western Australia. Results Of the fifteen research participants, 8 were female. Mean age was 49.4 years (SD 14.5 yrs) with a range of 24–70 years. All participants had prior back pain with mean time since first ever attack being 8.8 years (SD 8.8 yrs). No samples contained significant DNA sequences relating to known human viral agents. Inconsequential retroviral sequences were commonly found and were a mixture of putative animal and human retroviral protein coding segments. All samples were negative for herpesvirus DNA when analysed by pan-herpesvirus PCR. Conclusions This study found no viral pathogens in any intervertebral disc fragments of patients who had previous back pain and underwent discectomy for disc herniation and thus it is unlikely that viruses are associated with disc herniation, however given the contradiction between key studies enhanced replication of this experiment is recommended

Detection of pairing correlation in the two-dimensional Hubbard model

Quantum Monte Carlo method is used to re-examine superconductivity in the single-band Hubbard model in two dimensions. Instead of the conventional pairing, we consider a `correlated pairing', \langle \tilde{c}_{i\uparrow} \tilde{c}_{i'\downarrow} %\tilde{c}_{j'\downarrow}^\dagger \tilde{c}_{j \uparrow}^\dagger \rangle with $\tilde{c}_{i\sigma} \equiv c_{i\sigma}(1-n_{i-\sigma})$, which is inferred from the $t$-$J$ model, the strong-coupling limit of the Hubbard model. The pairing in the $d$-wave channel is found to possess both a divergence like $1/T$ in the pairing susceptibility and a growth of the ground-state pairing correlation with sample size, indicating an off-diagonal long-range order near (but not exactly at) half-filling.Comment: 3 pages, revtex, 6 figures available on request from [email protected]

Ultraviolet Imaging with Low Cost Smartphone Sensors: Development and Application of a Raspberry Pi-Based UV Camera

Here, we report, for what we believe to be the first time, on the modification of a low cost sensor, designed for the smartphone camera market, to develop an ultraviolet (UV) camera system. This was achieved via adaptation of Raspberry Pi cameras, which are based on back-illuminated complementary metal-oxide semiconductor (CMOS) sensors, and we demonstrated the utility of these devices for applications at wavelengths as low as 310 nm, by remotely sensing power station smokestack emissions in this spectral region. Given the very low cost of these units, ≈ USD 25, they are suitable for widespread proliferation in a variety of UV imaging applications, e.g., in atmospheric science, volcanology, forensics and surface smoothness measurements

Computationally Efficient Implementation of Convolution-based Locally Adaptive Binarization Techniques

One of the most important steps of document image processing is binarization. The computational requirements of locally adaptive binarization techniques make them unsuitable for devices with limited computing facilities. In this paper, we have presented a computationally efficient implementation of convolution based locally adaptive binarization techniques keeping the performance comparable to the original implementation. The computational complexity has been reduced from O(W2N2) to O(WN2) where WxW is the window size and NxN is the image size. Experiments over benchmark datasets show that the computation time has been reduced by 5 to 15 times depending on the window size while memory consumption remains the same with respect to the state-of-the-art algorithmic implementation