COMMODITY POLICY, PRICE INCENTIVES, AND THE GROWTH IN PER-ACRE YIELDS

We estimate the influence of policy-induced price changes and of technology supply on North Carolina flue-cured tobacco yields. The decline in land rent and effective output price that accompanied a 1965 policy change from acreage allotments to poundage quotas caused a 12 percent decrease in yields. Farmer yields were more responsive to yield-increasing technologies under acreage allotments than under poundage quotas. Annual yield growth was 0.5 percent under poundage quotas and 4.32 percent under acreage allotments. The growth rate decline is attributable to changes in relative prices and to a slowdown in the supply of available technologies.Commodity policy, Endogenous yield growth, Flue-cured tobacco, Technical change, Agricultural and Food Policy, Demand and Price Analysis, Research and Development/Tech Change/Emerging Technologies,

The Effect of the Cold Soda Pulping Process on the Various Constituents of Aspen Wood

Literature Survey The commercial Gold Soda Process for wood is relatively new pulping process developed at the United States Forest Products Laboratory in Madison, Wisconsin, for high-yield pulping for hardwoods. The development of this process has been due to the increasing shortage of softwood fibers has made necessary the need for a suitable process for pulping hardwoods. The Gold Soda process is thought to meet some of the economic and strength requirements of this need. Most of the research done on this subject has been done in the 65 to 95 yield range at the Forest Products Laboratory. This naturally follows from the fact the the Gold Soda process is a high-yield process and almost all interest to date has been in this range. It should be noted that the few articles published have been concerned almost wholly with strength and economic characteristics, which are of primary concern to industry. Only one article has shown the effect of the process on chemical composition of the pulp

Alien Registration- Foster, William A. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/23907/thumbnail.jp

Alien Registration- Foster, William A. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/23907/thumbnail.jp

Alien Registration- Foster, William A. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/23907/thumbnail.jp

Reinforcer magnitude and demand under fixed-ratio schedules with domestic hens

This study compared three methods of normalizing demand functions to allow comparison of demand for different commodities and examined how varying reinforcer magnitudes affected these analyses. Hens responded under fixed-ratio schedules in 40-min sessions with response requirement doubling each session and with 2-s, 8-s, and 12-s access to wheat. Over the smaller fixed ratios overall response rates generally increased and were higher the shorter the magazine duration. The logarithms of the number of reinforcers obtained (consumption) and the fixed ratio (price) were well fitted by curvilinear demand functions (Hursh et al., 1988. Journal of the Experimental Analysis of Behavior 50, 419–440) that were inelastic (b negative) over small fixed-ratios. The fixed ratio with maximal response rate (Pmax) increased, and the rate of change of elasticity (a) and initial consumption (L) decreased with increased magazine duration. Normalizing consumption using measures of preference for various magazine durations (3-s vs. 3-s, 2-s vs. 8-s, and 2-s vs. 12-s), obtained using concurrent schedules, gave useful results as it removed the differences in L. Normalizing consumption and price (Hursh and Winger, 1995. Journal of the Experimental Analysis of Behavior 64, 373–384) unified the data functions as intended by that analysis. The exponential function (Hursh and Silberberg, 2008. Psychological Review, 115, 186–198) gave an essential value that increased (i.e., α decreased significantly) as magazine duration decreased. This was not as predicted, since α should be constant over variations in magazine duration, but is similar to previous findings using a similar procedure with different food qualities (hens) and food quantities (rats)

Crozier's Effect and the Acceptance of Intraspecific Brood Parasites.

Organisms can often benefit by distinguishing between different classes of individuals. An example is kin recognition, whereby individuals preferentially associate with or aid genetic relatives that bear matching recognition cues but reject others. Despite its potential benefits, however, kin recognition using genetically based cues is often weak or absent [1-4]. A general explanation, termed "Crozier's effect," is that when individuals interact randomly, rarer cue alleles less often match cues of other individuals, and so are involved predominantly in "reject"-type interactions. If such interactions are more costly, positive frequency-dependent selection will erode the cue diversity upon which discrimination depends [4, 5]. Although widely cited [1, 2, 4, 6-9], this idea lacks rigorous testing in the field. Here, we show how Crozier's effect applies to interactions between hosts and conspecific parasites, and measure it using field data. In the wasp we studied, conspecific parasitism fits a key assumption of Crozier's model: the same females act as both hosts and parasites. By exchanging offspring between nests experimentally, we find no evidence that females respond to genetically based cues associated with foreign offspring. Through measuring costs and benefits, however, we demonstrate a strong Crozier effect: because more parental investment is wasted when foreign offspring are rejected, interactions involving rejection have substantially lower payoffs than interactions involving acceptance. Costly rejection can thus eliminate cue diversity by causing selection against rare cue alleles, consistent with the absence of genetically based recognition that we observe. Females instead appear to rely on non-genetic cues that enable them to detect less than half of parasitic offspring

Ant mosaics in Bornean primary rain forest high canopy depend on spatial scale, time of day, and sampling method.

Background: Competitive interactions in biological communities can be thought of as giving rise to "assembly rules" that dictate the species that are able to co-exist. Ant communities in tropical canopies often display a particular pattern, an "ant mosaic", in which competition between dominant ant species results in a patchwork of mutually exclusive territories. Although ant mosaics have been well-documented in plantation landscapes, their presence in pristine tropical forests remained contentious until recently. Here we assess presence of ant mosaics in a hitherto under-investigated forest stratum, the emergent trees of the high canopy in primary tropical rain forest, and explore how the strength of any ant mosaics is affected by spatial scale, time of day, and sampling method. Methods: To test whether these factors might impact the detection of ant mosaics in pristine habitats, we sampled ant communities from emergent trees, which rise above the highest canopy layers in lowland dipterocarp rain forests in North Borneo (38.8-60.2 m), using both baiting and insecticide fogging. Critically, we restricted sampling to only the canopy of each focal tree. For baiting, we carried out sampling during both the day and the night. We used null models of species co-occurrence to assess patterns of segregation at within-tree and between-tree scales. Results: The numerically dominant ant species on the emergent trees sampled formed a diverse community, with differences in the identity of dominant species between times of day and sampling methods. Between trees, we found patterns of ant species segregation consistent with the existence of ant mosaics using both methods. Within trees, fogged ants were segregated, while baited ants were segregated only at night. Discussion: We conclude that ant mosaics are present within the emergent trees of the high canopy of tropical rain forest in Malaysian Borneo, and that sampling technique, spatial scale, and time of day interact to determine observed patterns of segregation. Restricting sampling to only emergent trees reveals segregatory patterns not observed in ground-based studies, confirming previous observations of stronger segregation with increasing height in the canopy.Kalsum M. Yusah was funded by the South East Asia Rainforest Research Partnership (SEARRP), a Malaysian Ministry of Higher Education Fundamental Research Grant (FRG0373- STWN- 1/ 2014), and a Universiti Malaysia Sabah New Lecturer Grant Scheme grant (SLB0071- STWN- 2013). Tom M. Fayle was funded by a Czech Science Foundation standard grant (16-09427S)