Establishment of Shoshone sculpin ( Cottus greenei ) in a spring inhabited by mottled sculpin ( C. bairdi )

The Shoshone sculpin ( Cottus greenei ) is found only in springs of the Thousand Springs formation along the Snake River in Idaho. In 1983 a small population of Shoshone sculpin was introduced into an unnamed spring in the Thousand Springs formation in an attempt to increase the range of the species. Previously, the only sculpin in that spring was the mottled sculpin ( Cottus bairdi ). The Shoshone sculpin was able to establish itself and become the predominant fish within 8 years.     

Association of black-tailed prairie dog colonies with cattle point attractants in the Northern Great Plains

In October 1991 we recorded all black-tailed prairie dog ( Cynomys ludovicianus ) colonies and cattle points in a 1248-km 2 study area in southwest North Dakota and southeast Montana. Cattle point attractants were defined as fabricated water tanks and long-term supplemental feed sites. We found that a signivicant number of prairie dog colonies encompassed or adjoined cattle point attractants ( p < .001). Prairie dog colonies associated with cattle point attractants were a mean distance of 1.0 km from the next nearest town. The existence of cattle point attractants may encourage prairie dog colonization. Conversely, refraining from using long-term cattle point attractants can discourage prairie dog colonization.     

North American types of Oxytropis DC. (Leguminosae) at The Natural History Museum and Royal Botanic Garden, England, with nomenclatural comments and a new variety

Specimens of Oxytropis in the herbaria of The Natural History Museum and Royal Botanic Garden were examined to interpret their role in nomenclature. This is the first attempt at a systematic overview of specimens so important in understanding the genus as it occurs in North America. The review of specimens at BM and K during the present research has resulted in realignment of names of some of the taxa. Oxytropis campestris var. gracils (A. Nelson) Barneby is recognized herein as being predated by O. campestris var. spicata Hook., O. sericea var. spicata (Hook.) Barneby is replaced by O. sericea var. speciosa (Torr. & A. Gray) Welsh comb. nov., and O. campestris var. terrae-novae (Fern.) Barneby is superseded by O. campestris var. minor (Hook.) Welsh comb. nov. One new taxon is proposed: Oxytropis deflexa (Pall.) DC. var. pulcherrima Welsh & A. Huber, var. nov. Lectotypes are designated for the following taxa: Astragalus retroflexus Pall. Oxytropis artica R. Br., O. artica var. α subumbellata Hook., O. arctica var. β uniflora Hook. O. campestris var. β sepciosa Torr & A. Gray, O. campestris var. ξ melanocephala Hook., O. campestris var. δ spincata Hook., O. multiceps var. minor A. Gray, O. splendens Douglas ex Hook., O. splendens β richardsonii Hook., O. uralensis β subsucculenta Hook., and O. uralensis γ minor Hook.     

Testing for the usefulness of forecasts

Ashley (Journal of Forecasting 1983; 2 (3): 211–223) proposes a criterion (known as Ashley's index) to judge whether the external macroeconomic variables are well forecast to serve as explanatory variables in forecasting models, which is crucial for policy makers. In this article, we try to extend Ashley's work by providing three testing procedures, including a ratio‐based test, a difference‐based test, and the Bayesian approach. The Bayesian approach has the advantage of allowing the flexibility of adapting all possible information content within a decision‐making environment such as the change of variable's definition due to the evolving system of national accounts. We demonstrate the proposed methods by applying six macroeconomic forecasts in the Survey of Professional Forecasters. Researchers or practitioners can thus formally test whether the external information is helpful. Copyright © 2010 John Wiley & Sons, Ltd.     

Deep levels,transport and THz emission properties of SiGe/Si quantum-well structures

In coal mines in such countries as China and Russia,most of the coal mine methane(CMM) generated during mining is emitted to the atmosphere without any effective usage,because the methane concentration of CMM is relatively low and not allowed to be used as fuel for safety reasons.Methane is one of the greenhouse gases.Therefore,if it becomes possible to concentrate CMM to an acceptable level for use as fuel,this will greatly contribute to reduction of greenhouse gas emissions.With the aim of gaining approva...