Seasonal factors

It has been said that climate determines the crops that can be grown, and weather determines the yields. Seasonal factors such as weather patterns affect crop yields. There can also be a wide variation in yields between fields on one farm and even between different areas within fields. 

There can be no doubt that there is an important seasonal factor in LAS biodegradation in coastal areas, as other authors have indicated previously [4,7]. Temperature variations are only relevant in shallow coastal systems. In these areas, LAS will probably be efficiently removed from the water column in summer time, whereas degradation could be less extensive during winter months due to the lower kinetics of biodegradation under these conditions, which permits access to sediments of a higher proportion of the LAS present. 

Gomez-Moreno FJ, Pujadas M, Plaza J, Rodrfguez-Maroto JJ, Martmez-Lozano P, Artmano B (2011) Influence of seasonal factors on the atmospheric particle number concentration and size distribution in Madrid. Atmos Environ 45 3169-3180... 

Van den Hoek, J., Kirchmann, R.J., Colard, J. Sprietsma, J.E. (1969) Importance of some methods of pasture feeding, of pasture type and of seasonal factors on85 Sr and 134Cs transfer from grass to milk. Health Physics, 17, 691-700. 

The transfer factor Fm from feed to milk is defined in equation (2.11) as the activity per litre expressed as a fraction of the activity ingested daily by the cow. Numerous measurements of Fm have been made by dosing cows with iodine isotopes or by comparing radioactive or stable iodine in milk and in the herbage eaten by the cows. Table 3.6 shows a selection of the results. Fm depends on the yield of milk and on seasonal factors (Gamer, 1971), but it does not appear to depend on the chemical form of the iodine (Bretthauer et al., 1972). Gamer (1971) recommended Fm = 5 x 10 3 d l-1 for UK conditions, but noted that US results tended towards a higher value. 

Models for multiplicative effects are also available. Multiplicative seasonal factors are suitable if the variance, v2[a (/)J increases as the mean increases ... 

When calculating financial ratios at the end of each quarter, keep in mind seasonal factors that may distort the ratio. Firms use different, accepted accounting methods to prepare their balance sheet and income statement. Therefore, it is imperative to understand how the values used in calculating the ratios were obtained. 

The emission of SO from Europe in 1983 was about 638 Gmoles S yr1 (15). The mean seasonal factor for spring and summer is 0.67 and the area of Europe taken as 9.1 x lO m2, so the man-made emission rate is ... 

Life history models may be useful for considering age- or stage-specific variability in sensitivity in the extrapolation of response however, it should not be assumed that smaller or younger stages are always the most sensitive. The few studies that have addressed the impact of time of year on responses of aquatic communities to a stressor indicate that, in freshwater communities, threshold concentrations for direct toxic effects vary within a factor of 2 among seasons — well within the normal range of variation observed in laboratory toxicity tests. However, at greater exposures, the intensity and duration of direct and indirect responses may vary considerably between different periods of the year because of the influence of climatic and seasonal factors on recovery. 

The second metric used to assess the overall health of combinatorial chemistry as a business is related directly to the performance of participating companies in the public capital markets. Specifically, it plots the aggregate market capitalization of combinatorial chemistry companies over time. Ultimately, excluding seasonality factors and microconditions which affect the stock performance of individual companies, a good measure of relative success of a field is simply to look at market capitalization over time for as large a collection or representative companies as is possible. This is shown in Figure 24.2, for a total of nine companies that are combinatorial chemistry specific and are also publicly traded. With an aggregate market value of more... 

Under all conditions, the capability to provide simultaneous heat and power provides substantial advantage for the microgrid system relative to the conventional system. The ability to effectively manage an H-APS to efficiently match both heat and power demand, including seasonal factors and unexpected events, is also key to the success of these systems. Installing technologies appropriately sized to deliver necessary heat and power as efficiently as possible will maximise benefits relative to conventional alternatives. 

There are some seasonal factors so the linkage is not as direct for LPG as is the case for gasoline (these relationships are detailed in a later chapter). 

Ambler, J. W. (1985). Seasonal factors affecting egg production and viability of eggs of Acartia tonsa Dana from East Lagoon, Galveston, Texas. Estuar. Coast. Shelf Sd. 20, 743—760. 

The relationships between immune functions of the host and metastasis as a function of stress have been examined in mice bearing Lewis lung carcinoma subjected to rotational stress. Since some immune parameters were shown to display rhythmic variations, the occurrence of seasonal factors has been also taken into consideration. Indeed, the increase in metastasis number and volume caused by rotational stress varied in magnitude with a highly significant circannual rhythm, the acrophase coinciding with summer solstice. 

Oil yield, properties and ri-limonene content are affected by many aspects such as seasonal factors, ripening, soil types, climatic conditions, cultural practices, cultivar and varietal factors, scion and rootstock, etc. (Sinclair, 1984). Variation of oil content was also partially correlated with fruit size or peel thickness (Sinclair, 1984). Nitrogen fertilization increases the oil yield, while potassium fertilization had no significant effect on peel oil content (Sinclair, 1984). Limonene content of different kinds of citrus from different origins can be observed in Table 5.3. 

Young E Seasonal factors in atopic dermatitis and their relationship to allergy. Acta Derm Venereol (Stockh) 1980 92(suppl) lll-112. 

The chemical nature and the volume of PPP applied vary both on the basis of agricultural crops (for example the largest quantities of PPPs are used for grapes and cereal crops) and on a range of other factors, such as the weather trend, the seasonal factors and the prices of pesticides. 

In addition to seasonal factors, significant changes in the FA composition of milk fat can be achieved by manipulating the cow s diet. Milk fat composition is influenced more by dietary fat than by any other dietary component. The effects of fat supplementation on FA composition are dependent on the type and amount of dietary fat. In most cases, fat supplements decrease the proportions of 6 0 to 14 0 acids (de novo synthesized) and increase the proportion of long-chain (dietary) FA. Diets containing supplemental fat do not affect the proportion of C4 0 in milk fat. 

II. Toxic dose. The concentration of toxin varies widely depending on geographic and seasonal factors. The amount of toxin necessary to produce symptoms is unknown. Saxitoxin is extremely potent the estimated lethal dose in humans is 0.3-1 mg, and contaminated mussels may contain 15-20 mg. 

Factors affecting plant response. Plant response was found to be variable between exposure and appeared to be subjected to control by seasonal factors. Injury ranged from 0 to 257o necrosis of the exposed foliage on sensitive species between different exposures but with constant conditions of age, temperature, and pollutant concentration. The relative humidity varied between 50% and 707o but did not appear to influence plant respnse within this range. When injury did develop it appeared to be uniform among plants of the same species exposed at the same time. 

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