Social odours, conspecific chemical signals, have been demonstrated in every class of vertebrate except birds. The apparent absence is surprising, as every bird examined has a functional olfactory system and many produce odours. The crested auklet (Aethia cristatella), a monogamous seabird, exhibits a distinctive tangerine-like scent closely associated with courtship. Using T-maze experiments, ...

M crested wheatgrass stands in western North Dakota were established 15 to 20 years ago. These fields are still used for hay and pasture, and many are still in excellent condition. One field at the Dickinson Experiment Station, seeded in 1938, has produced an average of 1,262 pounds of forage per acre (dry weight) over the past 12 years. However, there is good evidence that the productivity of ...

Increasing available Mg in crested wheatgrass (Agropyron spp•) could reduce the incidence of grass tetany (hyponsagnesemia) in ruminants glazing this forage. Raisins the Mg levels might be done through genetic processes if enough variation in ion concentration existed in the Agropyrons. The purpose of this study was to determine the genetic variation in Mg, Ca, and K concentrations in 2 crested...

Head crests are important display structures in wild bird species and are also common in domesticated lineages. Many breeds of domestic rock pigeon (Columba livia) have crests of reversed occipital feathers, and this recessive trait is associated with a nonsynonymous coding mutation in the intracellular kinase domain of EphB2 (Ephrin receptor B2). The domestic ringneck dove (Streptopelia risori...

Although it is well established that wild birds, such as cormorants, carry virulent avian paramyxovirus serotype 1 (APMV-1; causative agent of Newcastle disease) and avian influenza virus (AIV), the prevalence of these viruses among Double-crested Cormorants (Phalacrocorax auritus) in the Great Lakes region of North America has not been rigorously studied. We determined the prevalences of APMV-...

Labyrinth weirs have not a straight crest in the perpendicular direction to the flow. The plan view of the weir consists of multiple and broken linear crests that cause the increase of its effective length. The advantages of this type of weirs are higher discharge capacity, easy aeration as well as low fluctuations of water surface at the weir upstream. This paper deals with the simulation of t...

Introduction Piano Key weirs (PKWs) are a hydraulically attractive alternative to linear overflow weirs, increasing the unit discharge at the unregulated spillway inlet for similar heads and spillway widths. This advantage, allowing for operation of dam reservoirs on elevated supply levels thus providing an increased retention volume, is a result of the non-linear nature of PKWs being folded ba...

throughout history dams have been important structures in water storage. to avoid overtopping, damage, and or failure of a dam, adequate spillway is needed to release excess water from upstream floods. researchers found that spillways have to be made nonlinear in order to reach an economic structure with high performance. a piano key weir is one of the best solutions. piano key weirs are the mo...

Side weirs are used in open channels to control flood and the flow passing through it. Discharge capacity is one of the crucial hydraulic parameters of side weirs. The aim of this study is to determine the effect of the intended dimensionless parameters on predicting the discharge coefficient of triangular labyrinth side weir. MAPE, RMSE, and R2 statistic indexes have been used to assess the ac...