Latitudinal and seasonal variation in reproductive effort of the eastern fence lizard (Sceloporus undulatus)

Geographic variation in life‐history traits among populations of wide‐ranging species is influenced by both spatial and temporal aspects of the environment. Rarely, however, are the effects of both aspects examined concurrently. We collected gravid female lizards (Sceloporus undulatus) from northern (Indiana), central (Mississippi) and southern (Florida) populations, spanning nearly the full latitudinal range of the species, to examine amongpopulation differences in strategies of reproductive energy allocation. Adult females from the southern population were smaller, and produced fewer and smaller eggs in their first clutches than did females from the more northern populations. Southern females were more likely to produce a second clutch, and second clutches were smaller than first clutches for females from the 2 northern populations. Together these trends eliminated population differences in overall reproductive output after accounting for body size. The trend for greater reproductive energy to be allocated to first clutches at higher latitudes, and to later clutches at lower latitudes is corroborated by published data from field studies on multiple populations. Distributing reproductive effort by producing more clutches of smaller eggs may be an adaptive response to the long season available for egg incubation and lizard activity in sub‐tropical southern environments. In contrast, allocating greater resources to early reproduction may enhance maternal fitness in the relatively short activity seasons that characterize more northern sites.     

长江流域侵蚀区“土壤水库”的调用是控制洪涝灾害的治本之策

The reasons for the Yangtze River flood calamity in 1998 are briefly introduced. The authors believe that using a “soil reservoir“ concept is an important means to help control flooding of the Yangtze River. A “soil reservoir“ has a large potential storage capacity and its water can be rapidly “discharged“ into the underground water in a timely fashion. The eroded, infertile soils of the Yangtze River Watershed are currently an obstacle to efficient operation of the “soil reservoir“. The storage capacity of this “soll reservoir“ has been severely hampered due to intensive soil erosion and the formation of soil crusts. Therefore, possible measures to control floods in the Yangtze River Watershed include: rehabilitating the vegetation to preserve soil and water on the eroded infertile soils, enhancing infiltration of the different soil types, and utilizing the large “soil reservoir“ of the upper reaches of the Yangtze River.     

Controlling microbial contamination on beef and lamb meat during processing

SUMMARY The microbiological quality of carcases, meat and environmental surfaces was evaluated in commercial boning rooms processing beef and lamb. There was considerable variation in the level of microbial contamination on both carcases and meat, with counts ranging from less than 20 to 10⁸/cm² on carcases and to 2 times 10⁷/cm² on meat. The level of microbial contamination on meat was influenced by the level of carcase contamination at boning and by the boning process itself. Carcase contamination was the major determinant of microbiological quality, as more than 70% of carcases had microbial counts greater than 10³/cm². Cutting boards were a major source for microbial dissemination during boning, particularly when carcase counts were less than 10³/cm². If carcases were heavily contaminated, the contamination of processing surfaces was irrelevant in determining microbial loads on meat. Where carcase contamination was at low to moderate levels, the contribution of the boning process to the contamination on meat assumed increased significance. Under these conditions, improved sanitation of cutting surfaces in the boning room resulted in a significant reduction in microbial contamination on the surface of meat. These results can form the basis for ensuring that improvements made in carcase management before boning, to improve microbiological quality, will be preserved through attention to cutting board hygiene during boning.     

Evaluation of fish-meal free diets for rainbow trout, Oncorhynchus mykiss

Eight experimental diets were formulated for rainbow trout using agricultural byproducts as major ingredients. Each experimental diet contained varying amounts of corn grain, corn gluten meal, corn gluten feed and one of the following: 200 g kg^?1 peanut meal, 200 or 400 g kg^?1 soybean meal (SBM), 390 g kg^?1 low-allergen soy flour, 310 g kg^?1 soy protein concentrate, 300 g kg^?1 low-allergen soy protein concentrate or 200 g kg^?1 SBM + 110 g kg^?1 blood meal. One diet contained 200 g kg^?1 SBM and canola oil as the main lipid source. The remaining diets contained 95 g kg^?1 menhaden oil. Fish fed a commercial trout diet exhibited significantly greater weight gain (322%), and a lower feed conversion ratio (0.89) but significantly lower protein efficiency ratio (2.18) than fish fed the experimental diets. Within the experimental diets, fish fed the 400 g kg^?1 soy flour diet and the 400 g kg^?1 soybean meal diet had significantly higher weight gains (276% and 268%) and protein efficiency ratios (2.58 and 2.52), and lower feed conversion ratios (1.02 and 1.03) than fish fed other experimental diets. Fillet flavour varied between treatments. Most notable was the lower fishy flavour and higher chicken flavour of fish fed the diet that contained canola oil rather than menhaden oil. Microscopic evaluation of the liver and five sections of the gastrointestinal tract failed to demonstrate any differences between treatment groups. The ingredient costs of several experimental diets were lower than the estimated cost of a standard commercial trout diet. However, the superior feed conversion ratios of fish fed the control diet resulted in lower feed costs per unit of fish produced.     

Role of Services in Regional Economy Growth

ABSTRACT Although the final demand‐oriented export base paradigm dominates economic development theory and practice, its usefulness is increasingly questioned because of the changing structure of modern economies, empirical critiques of export‐led growth strategies, and studies that decompose the actual sources of growth. The importance of service industries, especially local services and their role in inducing economic growth, requires a measure that includes both forward and backward linkages to empirically account for the complete role of an industry. Using data for New York State, we demonstrate how the input‐output‐based method of hypothetical extraction can more appropriately measure the economic linkage of a broader range of contemporary economic sectors (including services) than traditional, final demand‐induced, backward‐linkage multipliers. Our analysis provides empirical support for greater economic development attention to be directed toward local services.     

Set stocking, rotational grazing and forward rotational grazing by sheep on western Oregon hill pastures

Data on sheep live weights, herbage standing crop and herbage quality are presented from a 3-year grazing management study comparing set stocking, four-paddock rotational grazing and four-paddock forward rotational grazing systems. In both rotational grazing and forward rotational grazing systems, sheep were sequentially moved from one paddock to the next every 5 days. Lambs were weaned at 12–15 weeks of age in the forward rotationally grazed system and from then on grazed one paddock ahead of the ewes. Herbage mass was consistently greater on the rotationally grazed system than on the set-stocked system, averaging 38.4% more herbage in 1978. 32.8% more in 1979 and 52.7% more in 1980. No differences were observed in ewe live weights at the end of the grazing year between the rotationally grazed and the set stocked systems. Live weights of rotationally grazed lambs were superior to set-stocked lambs only when herbage allowance was low; otherwise no difference existed between these two systems. The forward rotationally grazed lambs generally had lower liveweights than did the rotationally grazed lambs, perhaps due to weaning stress.