2 resultados para Small fish community

em DigitalCommons@University of Nebraska - Lincoln


Relevância:

30.00% 30.00%

Publicador:

Resumo:

The gill monogene communities of Pimephales promelas (fathead minnow) in three distinct sites on converging streams were investigated from 2004 to 2006 in three different seasons. Thirty collections of P. promelas were made in southeastern Nebraska along three converging tributaries: Elk Creek (40.88534°N, 96.83366°W), West Oak Creek (40.9082°N, 96.81432°W), and Oak Creek (40.91402°N, 96.770583°W), Lancaster County, Nebraska. In all, 103 P. promelas were collected from Elk Creek, 115 from West Oak Creek, and 78 from Oak Creek and examined for gill monogenes. Among the P. promelas collected, 93.5% were infected with up to three species of Dactylogyrus, including Dactylogyrus simplex Mizelle, 1937, Dactylogyrus bychowskyi Mizelle, 1937, and Dactylogyrus pectenatus Mayes, 1977. Mean intensities at Elk Creek, West Oak Creek, and Oak Creek were 17.6, 22.8, and 25.1, and prevalences 88, 95, and 97%, respectively. At these three sites: (1) P. promelas does not share Dactylogyrus species with Semotilus atromaculatus (creek chub) or Notropis stramineus (sand shiner); (2) fish size and sex are not predictive of Dactylogyrus infection; (3) Dactylogyrus spp. vary (not always predictably) in their seasonal occurrence; (4) populations of Dactylogyrus spp. respond to environmental differences among sites; and (5) the community structure of Dactylogyrus spp. (order of abundance) is independent of environment.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Small businesses are considered important engines for job growth and economic development by policy makers worldwide. One of the most commonly cited constraints of small businesses is a lack of access to capital. To address this constraint, small business loan guarantee programs have been established in over 100 countries. There are a variety of types of guarantee funds, with the most significant differences being which borrowers are eligible for guarantees, and how borrowers are approved for guarantees. There is currently no clear delineation between types of programs and the economic conditions they operate in, though some trends are becoming apparent. However, these trends may not be leading to the best economic outcomes possible. By better matching the structure of the guarantee fund to the economic conditions it operates in, the program’s success in meeting economic development goals may be greatly improved. Many programs in developing countries may not be taking advantage of bank expertise and may be limiting the scope of their effectiveness. At the same time, programs in developed countries may be wasting resources by scattering their efforts too thinly and subsidizing less competitive firms to the detriment of local economic development.