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

Getting a start in dairying in Alaska

Dairying in Alaska probably will always be confined to areas where milk can reach city markets readily. The demand £or fresh milk, even at present prices, exceeds the supply. Probably the dairy farmer always will be able to produce milk in competition with fluid mlik shipped in from the States if he is a good manager and has high producing cows. A farmer with low producing cows can show a profit at present prices, but if the price of milk dropped two dollars or more per hundred, he would have a tough time making both ends meet. It is doubtful if other dairy products can be produced in Alaska to compete with stateside prices

Precipitation Probabilities for Selected Sites in Alaska

Paper copies in Archives, Acc #:2013-0059This publication is the result of cooperation between many research entities whose separate contributions have made it possible to assemble this information concerning precipitation in the nation's largest state, Alaska. The program to extract precipitation probabilities from the raw data was developed by Drs. L. D. Bark and A. M. Feyerherm of Kansas State University of Agriculture and Applied Science as a contribution to the regional research of the North Central Committee NC-26 concerned with "Weather Information for Agriculture". The program was modified and adapted to a higher speed computer by Dr. G. L. Ashcroft of the Utah State University of Agriculture and Applied Science as a contribution of the Western regional Committee W-48, concerned with "Weather and its Relation to Agriculture. The final processing of Alaskan data was made possible by the close cooperation of the Western Data Processing Center of the University of California at Los Angeles and the personnel of the computer center of the University of Alaska at College.Foreword (with acknowledgement) -- Introduction and General Comments -- Figure 1: Chart of Mean Annual Precipitation -- Use of Precipitation Probabilities for Alaska -- Explanation and Discussion of Data Tabulations -- Table 1: Precipitation Means and Probabilities for 1, 2, and 3-Week Periods at: Adak, Anchorage, Bethel, Big Delta, Eagle, Fairbanks ( College Experiment Farm), Fort Yukon, Holy Cross, Homer, Iliamna, Kasilof, Ketchikan, Kodiak, McGrath, Matanuska (Matanuska Experiment Farm), Nome, Talkeetna -- Bibliography and Reference Materia

Identification of phenological stages and vegetative types for land use classification

There are no author-identified significant results in this report

Relationship between Temperament and Performance Traits in Yearling Cattle

To examine relationships between exit velocity (EV, objective measure of temperament) and performance traits, calves were weighed 14 days prior to weaning, at weaning, 128 days post weaning, and at time of carcass measurements. Exit velocity obtained on day -14 and carcass ultrasound measurements (n = 6) obtained on day 208 and carcass harvest measurements (n = 12) obtained on day 349 were used to determine correlations between EV, performance and carcass measurements. Exit velocity showed a tendency to be negatively correlated (P \u3c 0.15) with weaning weight (r = -0.40), but not correlated (P \u3e 0.05) with average daily gain post 128 days. Exit velocity was not correlated (P \u3e 0.05) with carcass ultrasound measurements or with yearling weight. Exit velocity was negatively correlated (P = 0.04) with carcass weight (r = -0.65). Although, EV was not correlated (P \u3c 0.05) with carcass harvest traits of back fat and longissimus muscle area, results indicated more excitable cattle could have less back fat and smaller longissimus muscle area. Results suggest with additional numbers EV may be useful as an objective measure of temperament to sort calves into specific outcome groups that differ in carcass quality traits

Unzipping Kinetics of Double-Stranded DNA in a Nanopore

We studied the unzipping kinetics of single molecules of double-stranded DNA by pulling one of their two strands through a narrow protein pore. PCR analysis yielded the first direct proof of DNA unzipping in such a system. The time to unzip each molecule was inferred from the ionic current signature of DNA traversal. The distribution of times to unzip under various experimental conditions fit a simple kinetic model. Using this model, we estimated the enthalpy barriers to unzipping and the effective charge of a nucleotide in the pore, which was considerably smaller than previously assumed.Comment: 10 pages, 5 figures, Accepted: Physics Review Letter

Chaperone-assisted translocation of a polymer through a nanopore

Using Langevin dynamics simulations, we investigate the dynamics of chaperone-assisted translocation of a flexible polymer through a nanopore. We find that increasing the binding energy $\epsilon$ between the chaperone and the chain and the chaperone concentration $N_c$ can greatly improve the translocation probability. Particularly, with increasing the chaperone concentration a maximum translocation probability is observed for weak binding. For a fixed chaperone concentration, the histogram of translocation time $\tau$ has a transition from long-tailed distribution to Gaussian distribution with increasing $\epsilon$. $\tau$ rapidly decreases and then almost saturates with increasing binding energy for short chain, however, it has a minimum for longer chains at lower chaperone concentration. We also show that $\tau$ has a minimum as a function of the chaperone concentration. For different $\epsilon$, a nonuniversal dependence of $\tau$ on the chain length $N$ is also observed. These results can be interpreted by characteristic entropic effects for flexible polymers induced by either crowding effect from high chaperone concentration or the intersegmental binding for the high binding energy.Comment: 10 pages, to appear in J. Am. Chem. So

Transverse Electronic Transport through DNA Nucleotides with Functionalized Graphene Electrodes

Graphene nanogaps and nanopores show potential for the purpose of electrical DNA sequencing, in particular because single-base resolution appears to be readily achievable. Here, we evaluated from first principles the advantages of a nanogap setup with functionalized graphene edges. To this end, we employed density functional theory and the non-equilibrium Green's function method to investigate the transverse conductance properties of the four nucleotides occurring in DNA when located between the opposing functionalized graphene electrodes. In particular, we determined the electrical tunneling current variation as a function of the applied bias and the associated differential conductance at a voltage which appears suitable to distinguish between the four nucleotides. Intriguingly, we observe for one of the nucleotides a negative differential resistance effect.Comment: 19 pages, 7 figure