Whooping Crane Sightings in Nebraska, August 1994-January 1995

The first arrival at Aransas National Wildlife Refuge in southern Texas was on October 5, 1994, and the last arrivals (a family group) were on January 12, 1995, the latest date that an adult pair had ever arrived at Aransas. A total of 132 (125 adult/subadult and 7 young) Whooping Cranes are wintering at Aransas, including 3 birds that spent the summer at Aransas. A solitary chick sighted with Sandhill Cranes in Oklahoma on January 2, 1995 is the 133rd crane in the flock. Since, under optimum conditions, 148 cranes were expected to reach Aransas during the fall migration, the location and cause of summer and migrational losses are not known. The first dates for confirmed observations of migrating Whooping Cranes were August 16 in Canada and September 7 in the United States. The last sighting date was January 5 in Oklahoma. Sightings were reported from Alberta, Canada (1); Saskatchewan, Canada (18); Montana (1); North Dakota (5); South Dakota (2); Nebraska (5); Kansas (13); Oklahoma (4); and Texas (1). The migration progressed slowly, perhaps due to the mild weather during September and October. There were two or more Whooping Cranes present at Cheyenne Bottoms State Wildlife Area, Kansas, between October 13 and November 29, with a peak of 18 birds on November 1. A group of five Whooping Cranes was present at Cheyenne Bottoms between October 25 and November 29 (36 days), which is a record migration stopover time for the United States

Whooping Crane Sightings during March-May 1997 Migration

During the 1996-97 winter, 158 (143 adult/subadult and 15 juvenile) Whooping Cranes stayed at the Aransas National Wildlife Refuge in Texas. Two early migrants in Nebraska were an adult-plumaged bird first observed on 9 March, and a juvenile confirmed on 19 March. Neither of these birds wintered at Aransas, so the total population was therefore 160 (144 adult/subadult and 16 juvenile). All 158 cranes wintering at Aransas were present 3 April, but by 10 April, about 103 cranes had begun to migrate, and by 24 April, only 13 cranes were still at Aransas. All cranes had migrated by 6 May

Whooping Crane Sightings in Nebraska, August 1994-January 1995

The first arrival at Aransas National Wildlife Refuge in southern Texas was on October 5, 1994, and the last arrivals (a family group) were on January 12, 1995, the latest date that an adult pair had ever arrived at Aransas. A total of 132 (125 adult/subadult and 7 young) Whooping Cranes are wintering at Aransas, including 3 birds that spent the summer at Aransas. A solitary chick sighted with Sandhill Cranes in Oklahoma on January 2, 1995 is the 133rd crane in the flock. Since, under optimum conditions, 148 cranes were expected to reach Aransas during the fall migration, the location and cause of summer and migrational losses are not known. The first dates for confirmed observations of migrating Whooping Cranes were August 16 in Canada and September 7 in the United States. The last sighting date was January 5 in Oklahoma. Sightings were reported from Alberta, Canada (1); Saskatchewan, Canada (18); Montana (1); North Dakota (5); South Dakota (2); Nebraska (5); Kansas (13); Oklahoma (4); and Texas (1). The migration progressed slowly, perhaps due to the mild weather during September and October. There were two or more Whooping Cranes present at Cheyenne Bottoms State Wildlife Area, Kansas, between October 13 and November 29, with a peak of 18 birds on November 1. A group of five Whooping Cranes was present at Cheyenne Bottoms between October 25 and November 29 (36 days), which is a record migration stopover time for the United States

The ontological argument

The thesis of this essay is that the pursuit of a reality in general or appearance in general is barren. The only reality there can be, it is held, is the reality of this or that appearance. There is no reality in general because there is no appearance in general. Any reality is real only in its relation to a given appearance. Apart from that appearance, it may and will be equally well regarded as the appearance of another reality. Hence any attempt to establish an absolute reality, that is, such a reality as is the reality of all appearance and the appearance of no reality, ends in self- contradiction.The absolute reality, during the greater part of the development of European philosophy, has been envisaged as God. Even when this has not been so, still the arguments by which it has been upheld have been borrowed from Christian theology. Thus, for example,even when Hegelian absolutism has diverged from Christianity, its basis has always been the Christian arguments for the existence of God. And the same may be said of Spinoza, who, although certainly not a Christian, is yet a Scholastic. Thus any examination of the tenability of the concept of an absolute reality must centre round the Christian proofs of the existence of God. And since, as it will be argued, the final form of these proofs is the Ontological argument, it is through a detailed consideration of the thought of Anselm - the first and greatest of the exponents of that argument - that the thesis of this essay is to be made out

Reduction of crystalline iron(III) oxyhydroxides using hydroquinone: Influence of phase and particle size

Iron oxides and oxyhydroxides are common and important materials in the environment, and they strongly impact the biogeochemical cycle of iron and other species at the Earth's surface. These materials commonly occur as nanoparticles in the 3–10 nm size range. This paper presents quantitative results demonstrating that iron oxide reactivity is particle size dependent. The rate and extent of the reductive dissolution of iron oxyhydroxide nanoparticles by hydroquinone in batch experiments were measured as a function of particle identity, particle loading, and hydroquinone concentration. Rates were normalized to surface areas determined by both transmission electron microscopy and Braunauer-Emmett-Teller surface. Results show that surface-area-normalized rates of reductive dissolution are fastest (by as much as 100 times) in experiments using six-line ferrihydrite versus goethite. Furthermore, the surface-area-normalized rates for 4 nm ferrihydrite nanoparticles are up to 20 times faster than the rates for 6 nm ferrihydrite nanoparticles, and the surface-area-normalized rates for 5 × 64 nm goethite nanoparticles are up to two times faster than the rates for 22 × 367 nm goethite nanoparticles

Anoxic nitrification in marine sediments

Nitrate peaks are found in pore-water profiles in marine sediments at depths considerably below the conventional zone of oxic nitrification. These have been interpreted to represent nonsteady- state effects produced by the activity of nitrifying bacteria, and suggest that nitrification occurs throughout the anoxic sediment region. In this study, ΣNO3 peaks and molecular analysis of DNA and RNA extracted from anoxic sediments of Loch Duich, an organic-rich marine fjord, are consistent with nitrification occurring in the anoxic zone. Analysis of ammonia oxidiser 16S rRNA gene fragments amplified from sediment DNA indicated the abundance of autotrophic ammonia-oxidising bacteria throughout the sediment depth sampled (40 cm), while RT-PCR analysis indicated their potential activity throughout this region. A large non-steady-state pore-water ΣNO3 peak at ~21 cm correlated with discontinuities in this ammonia-oxidiser community. In addition, a subsurface nitrate peak at ~8 cm below the oxygen penetration depth, correlated with the depth of a peak in nitrification rate, assessed by transformation of 15N-labelled ammonia. The source of the oxidant required to support nitrification within the anoxic region is uncertain. It is suggested that rapid recycling of N is occurring, based on a coupled reaction involving Mn oxides (or possibly highly labile Fe oxides) buried during small-scale slumping events. However, to fully investigate this coupling, advances in the capability of high-resolution pore-water techniques are required

Deep-sea benthic foraminifera faunas and stable isotopes from the Portugal margin

Abstrac

Modeling sensitivity of biodiffusion coefficient to seasonal bioturbation

Biodiffusion coefficient is the predominant parameter used to constrain biological activity in marine sediments. Bioturbation characterization is important because of the dominant role it plays on the flux determination through the sediment-water interface. Biological mixing is quantified through models of radionuclides diagenesis by both a biodiffusion coefficient (Db) and a mixed depth (L) under the basic steady-state assumption. Based on a new global compilation of radionuclide data in marine sediments and on previously published modeling results, we show that short-live radionu-clides are perfectly devoted to quantify biological mixing for sediments associated with L2/Db lower than 125, representing the decay constant of the radionuclide. 75 % of the 234Th-derived Db, and 79 % of the 7Be-derived Db are concerned by this result. However, as transient regimes prevail within marine sediments, especially at a seasonal time scale and within the coastal and shelf environment, it is necessary to model their impacts on Db calculations. A transient model of radionuclide decay and transport is therefore used to perform extensive sensitivity tests of Db calculations in respect to seasonal mixing. Numerical tests of seasonal sensitivity indicate that 234Th and 7Be are the most sensitive tracers to seasonal biological mixing: the steady-state assumptio

Modeling sensitivity of biodiffusion coefficient to seasonal bioturbation

Biodiffusion coefficient is the predominant parameter used to constrain biological activity in marine sediments. Bioturbation characterization is important because of the dominant role it plays on the flux determination through the sediment-water interface. Biological mixing is quantified through models of radionuclides diagenesis by both a biodiffusion coefficient (Db) and a mixed depth (L) under the basic steady-state assumption. Based on a new global compilation of radionuclide data in marine sediments and on previously published modeling results, we show that short-live radionuclides are perfectly devoted to quantify biological mixing for sediments associated with λL2/Db lower than 125, λ representing the decay constant of the radionuclide. 75 % of the234Th-derived Db, and 79 % of the 7Be-derived Db are concerned by this result. However, as transient regimes prevail within marine sediments, especially at a seasonal time scale and within the coastal and shelf environment, it is necessary to model their impacts on Db calculations. A transient model of radionuclide decay and transport is therefore used to perform extensive sensitivity tests of Db calculations in respect to seasonal mixing. Numerical tests of seasonal sensitivity indicate that 234Th and 7Be are the most sensitive tracers to seasonal biological mixing: the steady-state assumption remains valid and applicable for most of natural marine environments. However, systematic tests reveal that incorrect seasonal sensitivity of 234Th is detected for marine environments with λL2/Db lower than 10 and greater than 1000. In these cases, the apparent seasonal variations of the biological activity need to be corrected. The main parameter in selecting the appropriate radionuclide for field analyses is the dimensionless pulse, which defines the relative importance of decay time scale relative to the seasonal time scale. This pulse controls the relative extension of the domain of satisfactory sensitivity. Consequently, long-lived radionuclides (210Pb and 228Th) are not appropriate for predicting seasonal mixing, except for specific environments which display an unexpected sensitivity to seasonal mixing. These marine environments are characterized by a moderate biological mixing and a deep mixed-layer