Humans are capable of simply observing a correlation between cause and effect, and then producing a novel behavioural pattern in order to recreate the same outcome. However, it is unclear how the ability to create such causal interventions evolved. Here, we show that while 24-month-old children can produce an effective, novel action after observing a correlation, tool-making New Caledonian crow...

Research in population genetics theory has two main strands. The first is deterministic theory, where random changes in allelic frequencies are ignored and attention focuses on the evolutionary effects of selection and mutation. The second strand, stochastic theory, takes account of these random changes and thus is more complete than deterministic theory. This essay is one in the series of Pers...

Teuri Island, Hokkaido in Japan is an important place for seabirds breeding. We measured the concentrations of heavy metals (Hg, Cd, Cr, Co, Ni, Cu, Zn, and Pb) and a metalloid (As) in rhinoceros auklet (Cerorhinca monocerata) (n = 7), thick-billed murre (Uria lomvia) (n = 2), spectacled guillemot (Cepphus carbo) (n = 6), slaty-backed gull (Larus schistisagus) (n = 15), jungle crow (Corvus macr...

Danes Tie Maritime Fall To Montclair Face Columbia Next The Albany State grapple rs ran into two tough opponents this week. On Wednesday they battled to a 18-18 draw with Maritime, and then they bowed to Montclair by a 24-8 count. Outstanding wrestlers foi the Great Danes were Warren Crow and Randy Palmer at 130 and 14S re spectively. Crow remained undefeated as he pinned his Martlme _ # oppone...

The Crow Creek Member is one of several marl units recognized within the Upper Cretaceous Pierre Shale Formation of eastern South Dakota and northeastern Nebraska, but it is the only unit that contains shock-metamorphosed minerals. The shocked minerals represent impact ejecta from the 74-Ma Manson impact structure (MIS). This study was aimed at determining the bulk chemical compositions and ana...

In this paper, single machine scheduling problems with sequence dependent setup times are considered. The objective is to minimize the total weighted tardiness. The single machine total weighted tardiness (SMTWT) scheduling problems with sequence dependent setup times were proved to be strongly NP-hard. A recently developed meta-heuristic algorithm called as crow search algorithm is proposed to...

A 64-year-old woman was admitted with systemic edema and exertional dyspnea. High-output heart failure was diagnosed by right heart catheterization and she was treated with diuretics. After 3 weeks, her symptoms disappeared but a high cardiac output state persisted. A diagnosis of Crow-Fukase syndrome was made based on the presence of polyneuropathy, organomegaly, endocrinopathy, M-protein, and...

The risk of becoming a West Nile virus case in New York State, excluding New York City, was evaluated for persons whose town of residence was proximal to spatial clusters of dead American crows (Corvus brachyrhynchos). Weekly clusters were delineated for June-October 2002 by using both the binomial spatial scan statistic and kernel density smoothing. The relative risk of a human case was estima...

The importance of species richness in maintaining ecosystem function in the field remains unclear. Recent studies however have suggested that in some systems functionality is maintained by a few abundant species. Here we determine this relationship by quantifying the species responsible for a key ecosystem role, carcass removal by scavengers. We find that, unlike those within largely unaltered ...