Ovarian growth and ovulation in the mature blue crab, Callinectes sapidus Rathbun

Introduction. Observations: structure of the ovary during the periods of growth and ovulation in the mature crab (stages 1-5). Discussion and conclusions

RECENT PUBLIC POLICIES AND THE SMALL FARMER

Agricultural and Food Policy,

An ecosystem model of San Pedro Bay, Leyte, Philippines: initial parameter estimates

A mass-balance model of the trophic structure of San Pedro Bay, Leyte Province, Philippines was constructed using the Ecopath modeling software. The model is composed of 16 ecological groups (13 consumer, 2 producers, 1 detritus groups). The input parameters were obtained from the resource assessments studies conducted in 1994 - 95 and the biomass of Leiognathidae, an important group of small demersal fishes was estimated from trawl survey data using the swept- area method. The model indicated that the average trophic level of the fishery catches is 3.25.Fishery resources, Demersal fisheries, Fishery surveys, Biomass, Population density, Shrimp fisheries, Catch/effort, Trawling, Mathematical models, Coastal fisheries, Marine fisheries, Ecosystems, Trophic structure, ISEW, Philippines, Leyte I., Leyte, Jaro,

Analysis of demersal fish assemblages in selected Philippine fishing grounds

This paper presents the results of analyses of demersal fish assemblages in various fishing grounds in the Philippines. Data from exploratory trawl surveys conducted in 1947 - 49 show that the 24 fishing grounds covered by the survey can be arranged along a gradient of substrate type (i.e. relative coral cover and sediment characteristics). These may be used to determine the species commonly caught in these grounds. A trend of increasing catch rates with decreasing water depth and increasing proportion of mud in the substrate was noted. Data from more recent systematic surveys in Samar Sea (1979 - 80), San Pedro Bay (1994 - 95) and Manila Bay (1992 - 93) were analyzed to examine spatio-temporal patterns in fish assemblages. In all 3 areas, the fish community was characterized by a large number of ubiquitous species, with Leiognathids comprising at least 28% of the total catch. In terms of habitat relations, depth was the primary factor in Samar Sea and San Pedro Bay, where transitions in fish assemblage composition were recognizable at certain depth ranges. In Manila Bay, however, species composition appears to be more related to location (inner versus outer portions of the bay). Analysis of data from five locations (Manila Bay, Tayabas Bay, Sorsogon Bay, Samar Sea and San Pedro Bay) extending from the western to the eastern portions of the country showed similar seasonality, with fish assemblage composition varying slightly during the monsoon season.Fishery resources, Demersal fisheries, Fishery surveys, Biomass, Population density, Shrimp fisheries, Catch/effort, Trawling, Population characteristics, ISEW, Philippines,

Characteristics of a production route for filamentary Nb3Sn superconductors based on a reaction between niobium and Nb6Sn5

Monofilamentary Nb3Sn superconductors have been made by application of a reaction between Nb6Sn5 powder and niobium. The layer thickness of Nb3Sn shows a parabolic time dependence, implying diffusion-controlled layer growth. The activation energy for diffusion is 268 kJ mol−1. The critical temperature Tc is about 17.5 K and the overall critical current density Jc is about 5 × 108 A m−2at 8 T, both after annealing at 675 °C. These values are comparable with those obtained for so-called ECN-type superconductors, which are based on a reaction between NbSn2 powder and niobium. An advantage of the use of Nb6Sn5 powder in comparison with NbSn2 is the kinetics of growth of Nb3Sn, which allows a lowering of the reaction temperature to 600–625 °C for filament diameters of about 30 μm

Economic Impacts and Implications of Foreign-Born Labor Reductions in Agriculture - Emphasis on Dairy Farms

Giving consideration to the bills and laws being discussed in Congress during the last few years regarding immigration reform, the need has arisen to study the effects of immigrant labor on the dairy industry. The objective of this study is to consider the economic impacts of reducing the availability of immigrant workers in the United States. This analysis utilizes the IMPLAN model, developed and maintained by the Minnesota IMPLAN Group, for analyzing the effects of 20 percent, 50 percent and 100 percent reductions in immigrant labor within the dairy industry. IMPLAN maps the economy using an input/output structure that “describes commodity flows from producers to intermediate and final consumers”. The employment and production data used as inputs into the model were gathered using a national survey of 5,005 dairy farms with respondents from 47 states and a response rate of 41.4 percent. Approximately 50 percent of the 5,005 dairy farms surveyed use immigrant labor. Results of the analysis estimate baseline nationwide economic activity, employment, and total value added impacts attributable to dairy farming to be $48.1 billion, 301,300 jobs, and$19.6 billion, respectively. With a 20 percent reduction in immigrant labor, the values fall to $43.6 billion, 274,800 jobs, and$17.8 billion. Under a 50 percent reduction in immigrant labor the values are $36.9 billion, 235,000 jobs, and$15.1 billion. Under a 100 percent reduction in immigrant labor scenario, the values fall to an estimated $25.7 billion, 168,700 jobs, and$10.5 billion. These reported figures include the impacts directly linked to the dairy industry as well as those to the rest of the economy. This analysis reports both intra- and inter-industry impacts but gives special attention to the inter-industry impacts within the economy.impact analysis, dairy, immigrant labor, Agricultural and Food Policy, International Relations/Trade,

Disposable carrier for retrograde fillings

Commercially available retrograde filling carriers are delicate and easily damaged by pressure. In addition, they are difficult to clean and keep free from blockage. This report describes a simple and easy technique for transforming a standard disposable hypodermic syringe and needle into a disposable carrier for retrograde fillings. {\^A}{\copyright} 2006 Asian Association of Oral and Maxillofacial Surgeons

Making your own retrograde carrier

One of the problems faced by manufacturers is the difficulty in constructing a robust and reliable, angled applicator tip. This can be overcome by handmaking your own retrograde carrier. The applicator tip may be bent to about 50 degrees and, if a kink occurs while bending the tip, it can be replaced easily by a new modified needle. Because the wire used is flexible, it can adapt to the bend without a problem. Narrower carriers can also be made using a 20-G needle, perhaps more suitable for retrograde fillings of molar apices. Because the carrier is designed to be used once only, the problems of it being difficult to load and liable to blockages should not arise

Styrene-divinylbenzene copolymers. Construction of porosity in styrene divinylbenzene matrices

Experimental data are presented describing the formation of porosity in styrene-divinylbenzene copolymers as a function of the organic components present during the suspension polymerization. The reaction system contains a mixture of diluents such as toluene and hexane, which results in matrices that differ significantly in pore structure from the porous resins so far known. From these data a model of the physical structure is proposed

Estimating obsolescence risk from demand data - a case study

In this paper obsolescence of service parts is analyzed in a practical environment. Basedon the analysis, we propose a method that can be used to estimate the risk of obsolescenceof service parts. The method distinguishes groups of service parts. For these groups, therisk of obsolescence is estimated using the behavior of similar groups of service parts inthe past. The method uses demand data as main information source, and can therefore beapplied without the use of an expert's opinion. We will give numerical values for the risk ofobsolescence obtained with the method, and the e®ects of these values on inventory controlwill be examined.inventory;forecasting;obsolescence;spare parts