Growing-Degree Units For Selected Agricultural Locations In Alaska

Paper copies in Archives, Acc #:2013-0059It is well known that the rate at which a plant grows is influenced by air temperature. The problem is to define this relationship in a quantitative manner so that the information can be applied to agricultural problems. In places where growth of a particular crop is limited by the length of the growing season, an evaluation of the "heat-units" available is particularly important. Many heat-unit systems have evolved over the years, with certain advantages claimed for each. In crop production, heat unit systems are used to estimate the time required for a crop to go from one stage of development to another, usually from planting to harvest. Each heat-unit system produces a particular set of values, the values being determined by the relationship between temperature and growth that is assumed in the calculations. This paper lists heat-units available in six areas in Alaska, all having agricultural potential. The system used measures temperature in "growing-degree units" and is described in detail. Recent comparative studies of growing season and growing degree days leads to the conclusion that the temperature records taken at Big Delta may have been favorably affected by the nearness of the weather recording station to an extensive coated runway. The "flywheel" effect of this large heat sink appear to have reduced the occurrence of 32°F. night temperatures in both the spring and fall, making the growing degree accumulation unrealistic.Introduction and general comments -- Description of Stations -- Results and discussion -- Summary -- References -- Appendix -- Figures: Fig. 1 Average weekly growing degree units for Matanuska Experiment Station; Big Delta; University Experiment Station, Fairbanks; Homer; Kasilof; and Kodiak. Fig. 2 Seasonal growing degree unites (May 15 to 1st 30°F or lower temperature in fall) which will be equaled or exceeded for varying probability levels at Big Delta, Matanuska Experiment Station and University Experiment Station, Fairbanks. Fig. 3 Seasonal growing degree units (May 15 to 1st 30°F or lower temperature in fall) which will be equaled or exceeded for varying probability levels ta Homer, Kasilof, and Kodiak. Tables: Table 1 Comparison of growing-degree units (GDU) for Clearwater and Big Delta for the period 1965-70. Table 2 Highest, lowest and average weekly GDU values for Big Delta, and values which will be equaled or exceeded for given probabilities. Table 3 Highest, lowest and average weekly GDU values for Homer and values which will be equaled or exceeded for given probabilities. Table 4 Highest, lowest and average weekly GDU values for Kasilof and values which will be equaled or exceeded for given probabilities. Table 5 Highest, lowest and average weekly GDU values for Kodiak and values which will be equaled or exceeded for given probabilities. Highest, lowest and average weekly GDU values for the Matanuska Experiment Station, and values which will be equaled or exceeded for given probabilities. Table 7 Highest, lowest and average weekly GDU values for the University Experiment Station, Fairbanks and values which will be equaled or exceeded for given probabilities at 6 Alaska locations. Table 8 Highest, lowest and average monthly GDU values and values which will be equaled or exceeded for given probabilities at 6 Alaska locations. Table 9 Highest, lowest and average seasonal GDU values and values which will be equaled or exceeded for given probabilities for the period May 15 to date of first 30°F or lower temperature in the fall at 6 Alaska locations

Using nonequilibrium fluctuation theorems to understand and correct errors in equilibrium and nonequilibrium discrete Langevin dynamics simulations

Common algorithms for computationally simulating Langevin dynamics must discretize the stochastic differential equations of motion. These resulting finite time step integrators necessarily have several practical issues in common: Microscopic reversibility is violated, the sampled stationary distribution differs from the desired equilibrium distribution, and the work accumulated in nonequilibrium simulations is not directly usable in estimators based on nonequilibrium work theorems. Here, we show that even with a time-independent Hamiltonian, finite time step Langevin integrators can be thought of as a driven, nonequilibrium physical process. Once an appropriate work-like quantity is defined -- here called the shadow work -- recently developed nonequilibrium fluctuation theorems can be used to measure or correct for the errors introduced by the use of finite time steps. In particular, we demonstrate that amending estimators based on nonequilibrium work theorems to include this shadow work removes the time step dependent error from estimates of free energies. We also quantify, for the first time, the magnitude of deviations between the sampled stationary distribution and the desired equilibrium distribution for equilibrium Langevin simulations of solvated systems of varying size. While these deviations can be large, they can be eliminated altogether by Metropolization or greatly diminished by small reductions in the time step. Through this connection with driven processes, further developments in nonequilibrium fluctuation theorems can provide additional analytical tools for dealing with errors in finite time step integrators.Comment: 11 pages, 4 figure

A multibeam bathymetric survey of Bay of Islands, Newfoundland: new evidence of late-glacial and Holocene geological processes

Multibeam bathymetric imagery of Ray of Islands, Newfoundland, is interpreted within the context of late-glacial and post-glacial processes- West of Humber Arm, the fiord floor is irregular and deep. Humber Arm has steep sidewalls and a flat floor. It contains glaciomarine mud. capped by a layer of red mud probably derived from the Deer Lake Basin, which was connected to the ocean ca. 12.2 ka. In the early postglacial period, sediments on the fiord sidewalls slid into deep water, forming erosional channels. Depositional lobes, stacked in many areas, overlie glaciomarine sediments in deep water. The glaciomarine and submarine slide sediments are overlain by postglacial mud that is imprinted by elongate, ovoid, and circular fluid-escape trenches, and sedimentary furrows. The natural morphology of the fiord has been modified by anthropogenic activity at Comer Brook. Effects include an apron of bark offshore from the paper mill, dredge spoil, and a sunken vessel at the mouth of Humber River. Large submarine slides, probably triggered by wharf construction at Seal Head, formed deep channels on the fiord sidewalls and overlapping depositional lobes on the fiord floor. They are morphologically similar to the lateglacial slide failures in the fund. RÉSUMÉ Les images bathymétriques multifaisceaux de Bay of Islands, Terre-Neuve, sont interprétées dans le contexte des processus tardiglaciaires et post-glaciaires. À I'ouest de Humber Arm. Ie fond du l’jord est irrégulier et profond. Humber Arm est doté de parois abruptes et d'un fond plat. Il renferme de la boue glaciomarine recouverte d'une couche de boue rouge provenant probablemenl du bassin du lac Deer, qui était relié à l'océan il y a environ 12.2 millies d'années avant nos jours. Au début de la période post-glaciaire, Ies sediments sur Ies parois du l’jord ont glissé a l’intérieur de I'eau profonde en formant des chenaux d'érosion. Des lobes sédimentaires s'empilant en de nombreux endroits recouvrent les sédiments glaciomarins en eaux profondes. Les sédiments de glissement glaciomarins et sous-marins sont recouverts d'une boue post-glaciaire marquée de tranchées allongées, ovoides et circulaires d'évacuation des liquides et de silions sédimentaires. L'activité anthropique a modi fié la morphologic naturelle du l’jord a Corner Brook. Les effets de cette activité comprennent un tablier d'écorce au large de la papeterie, des matériaux de dragage et un navire ayant coulé à I'embouchure dc la riviére Humber. D'importants éboulements sous-marins, probablement causés par la construction du quai de Seal Head, ont formé des chenaux profonds dans les parois du l’jord et des lobes sédimentaires qui se superposcnt sur Ic fond du l’jord Ceux-ci sont morphologiquemcnt analogues aux fractures de glissement tardiglaciaires dans le l’jord. Traduit par la rédactio

Occurrence rate of delirium in acute stroke settings

Background and Purpose— Delirium is associated with increased mortality, length of stay, and poor functional outcome following critical illness. The epidemiology of delirium in stroke is poorly described. We sought to collate evidence around occurrence (incidence or prevalence) of delirium in acute stroke. Methods— We searched multiple cross-disciplinary electronic databases using a prespecified search strategy, complemented by hand searching. Eligible studies described delirium in acute (first 6 weeks) stroke. We compared delirium occurrence using random-effects models to describe summary estimates. We assessed risk of bias using the Newcastle-Ottawa tool, incorporating this in sensitivity analyses. We performed subgroup analyses for delirium diagnostic method (confusion assessment method scoring, clinical diagnosis, other), duration and timing of delirium assessment (>1 or <1 week), and performed meta-regression based on the year of publication. Results— Of 8822 titles, we included 32 papers (6718 participants) in the quantitative analysis. Summary estimate for occurrence of delirium was 25% (95% CI, 20%–30%; moderate quality evidence). Limiting to studies at low risk of bias (22 studies, 4422 participants), the occurrence rate was 23% (95% CI, 17%–28%). Subgroup summary estimates suggest that delirium occurrence may vary with assessment method: confusion assessment method, 21% (95% CI, 16%–27%); clinical diagnosis, 27% (95% CI, 19%–38%); other, 32% (95% CI, 22%–43%) but not with duration and timing of assessment. Meta-regression suggested decline in occurrence of delirium comparing historical to more recent studies (slope, 0.03 [SE, 0.004]; P<0.0001). Conclusions— Delirium is common, affecting 1 in 4 acute stroke patients. Reported rates of delirium may be dependent on assessment method. Our estimate of delirium occurrence could be used for audit, to plan intervention studies, and inform clinical practice. Clinical Trial Registration— URL: http://www.crd.york.ac.uk/PROSPERO/. Unique identifier: CRD42015029251

The value placed on everyday professionalism

This special issue is focusing on the 'extraordinary ordinary' of everyday life in residential care. This is appropriate as daily life is not only the bread and butter but also the meat of the work. It is its main strength but also its main weakness. The residential care profession does not have its own distinct body of knowledge, and its status in the UK, unlike much of continental Europe, is low. The key to successful care lies primarily with the values and motivation of the workers

Quantifying the stratigraphic completeness of delta shoreline trajectories

Understanding the incomplete nature of the stratigraphic record is fundamental for interpreting stratigraphic sequences. Methods for quantifying stratigraphic completeness for one-dimensional stratigraphic columns, defined as the proportion of time intervals of some length that contain stratigraphy, are commonplace; however, quantitative assessments of completeness in higher dimensions are lacking. Here we present a metric for defining stratigraphic completeness of two-dimensional shoreline trajectories using topset-foreset rollover positions in dip-parallel sections and describe the preservation potential of a shoreline trajectory derived from the geometry of the delta surface profile and the kinematics of the geomorphic shoreline trajectory. Two end-member forward models are required to fully constrain the preservation potential of the shoreline dependent on whether or not a topset is eroded during base level fall. A laboratory fan-delta was constructed under nonsteady boundary conditions, and one-dimensional stratigraphic column and two-dimensional shoreline completeness curves were calculated. Results are consistent with the hypothesis derived from conservation of sediment mass that completeness over all timescales should increase given increasing dimensions of analysis. Stratigraphic trajectories and completeness curves determined from forward models using experimental geomorphic trajectories compare well to values from transects when subsampled to the equivalent stratigraphic resolution as observed in the actual preserved sequence. The concept of stratigraphic completeness applied to two-dimensional trajectory analysis and the end-member forward models presented here provide novel tools for a conceptual understanding of the nature of stratigraphic preservation at basin scales

Court Strategy

This session focuses on the following issues: (1) access to the courts, (2) secrecy of court documents and settlements, (3) court bias, and (4) public education and tools. The panelists present possible solutions for the issues discussed

Relative Impact of Highway Construction on Wetland Hydrology in Environmentally Sensitive Areas in Southeast Louisiana

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv