Spatial distribution of Chlorpyrifos and Endosulfan in USA coastal waters and the Great Lakes

Between 1994 and 1997, 258 tissue and 178 sediment samples were analyzed for chlorpyrifos throughout the coastal United States and the Great Lakes. Subsequently, 95 of the 1997 tissue samples were reanalyzed for endosulfan. Tissue chlorpyrifos concentrations, which exceeded the 90th percentile, were found in coastal regions known to have high agricultural use rates but also strongly correlated with sites near high population. The highest concentrations of endosulfans in contrast, were generally limited to agricultural regions of the country. Detections of chlorpyrifos at several Alaskan sites suggest an atmospheric transport mechanism. Many Great Lakes sites had chlorpyrifos tissue concentrations above the 90th percentile which decreased with increasing distance from the Corn Belt region (Iowa, Indiana, Illinois, and Wisconsin) where most agriculturally applied chlorpyrifos is used. Correlation analysis suggests that fluvial discharge is the primary transport pathway on the Atlantic and Gulf of Mexico coasts for chlorpyrifos but not necessarily for endosulfans. (PDF contains 28 pages)

Der Haftwasseranteil bei Heringsanlandungen über Bandwaagen

In 2004 the fish processing company Euro-Baltic Fischverarbeitungs GmbH Mukran, went into operation on the Isle of Rügen at the Baltic coast of Germany. About 20 % of the herring landed there is discharged from the cutters into the processing plant by pipes, driven by pumps, in case that the landed volume exceeds 10 t fresh weight. In such case the herring is transported in water suspension by means of a pressure-vacuum suction pump system into containers and further transported via conveyer belt to a flowscale. During this process most of the water runs off. It is however unknown how much water remains with the fish and is eventually weighted as fish. To estimate this proportion the mixture of water and fish was stored in special transport containers, which allow the measurement of the run-off. As a result the study shows that on average 2 % of weight measured by the tape scale is water. Along with this factors were determined which influence the variability of the proportion of water.

Survey of El Nino 1957-58 in its relation to tropical pacific meteorology

ENGLISH: The survey aims at demonstrating the close relationship between anomalies of sea temperature observed along the tropical Pacific coast of the Americas and those observed in the oceanwide tropical belt. The survey also covers the variations, from 1952 to the present, of the trade-wind circulations which prove to be responsible for the major part of the anomalies in sea surface temperature. Finally, the thermal feedback effects of the oceanic anomalies upon the large-scale circulation of the atmosphere are treated in a preliminary fashion. SPANISH: El estudio trata de demostrar la estrecha relación que existe entre las anomalías observadas de la temperatura del mar a lo largo de la costa tropical de las Américas y las observadas en la faja tropical de todo el océano. El estudio incluye también las variaciones, desde 1952 hasta el presente, de la circulación de los vientos alisios que demuestra ser responsable por la mayor parte de las anomalías de temperatura de la superficie del mar. Finalmente los efectos termales de las anomalías oceánicas sobre la circulación en gran escala de la atmósfera son tratados en forma preliminar. (PDF contains 62 pages.)

Die Fruchtbarkeit von Dorschen in der Ostsee - was verrät sie uns?

About 1500 ovaries of Baltic cod were prepared for estimating the potential absolute and relative individual fecundity. The female cod were sampled in the Belt Sea, ICES Subdivision (SD) 22, in the Arkona Sea, SD 24, and in the Bornholm Sea, SD 25. The investigations started in1992 and until 1999 cruises were carried out to catch female cod in the different sub-divisions every year. The results shows that the potential fecundity is not a stable biological parameter, and that significant changes are possible within a relative short period. It was demonstrated that the developments of the potential individual fecundity of the western (Gadus morhua morhua) and eastern Baltic cod stocks (Gadus morhua callarias) were different. In contrast to the stable individual fecundity of the western cod the absolute and relative fecundity of the eastern repeat spawners increased from 1993 to 1999, significantly. The reason of this development seems to be the dramatic decrease of the eastern cod stock and the more successful reproduction of individuals that produce oocytes with a lower dry weight in combination with a higher relative fecundity.

Laichgebiete des Dorschs in der westlichen Ostsee

Analyses of the previous years showed that the reproduction of the Belt Sea cod stock (Gadus morhua morhua) is also very important for the cod stock of the central Baltic Sea (Gadus morhua calarias). Oeberst (1999, 2000) proved, that between 20 % and 50 % of the cods caught in the Bornholm Sea at the age of 2 or 3 years between 1994 and 1998, were spawned in the Belt Sea. On account of this large significance of the Belt Sea cod stock, information regarding the reproduction process are important. The goal of the article presented is the description of the actual spawning areas of the Belt Sea cod stock by means of the spatial distribution of the spawners based on characteristic parameters as the maturity stages and the proportion of the sexes. The basis for these analyses are data sampled between 1992 and 1999. The analyses showed that the actual main spawning areas in the western Baltic Sea were the deeper regions of the Kiel Bay, of the Fehmarn Bay and of the western Mecklenburg Bay. In these regions spawning cods were regularly observed with high intensity. Furthermore, the deeper basin of the Arkona Sea is an important spawning area.

Culturable fish seeds in Nigerian waters: A research survey (1978-1985)

The desired species identified in this survey include mullets, catfishes, fast growing fish predators, species for control of weeds and grass it, ponds, cichlids and shrimps. Five coastal states: Lagos, Ondo, Bendel, Rivers, and Cross River were covered in the studies. Investigations were also carried into the major rivers and their tributaries. A combination of the estimation methods of Le Cren, (1962) and Pitcher and Mac Donald (1973) was employed in the analysis of data. From the detailed data collected from (1978-1985), the survey indicated that about 100 million fish seeds can be collected annually from Nigerian waters using appropriate gear-seine nets, cast nets, and fish traps. Of this number, 60% is available along the coastal belt of the country while 40% is in the major rivers, their tributaries and swamps. At the present level of fish culture development in Nigeria, this is more than enough, even after allowing for 50% mortality due to handling and transportation stress

Geological evolution of two crustal scale shear zones. Part I. The Rand thrust complex, northwestern Mojave Desert, California. Part II. The Magdalena metamorphic core complex, north central Sonora, Mexico

The geology and structure of two crustal scale shear zones were studied to understand the partitioning of strain within intracontinental orogenic belts. Movement histories and regional tectonic implications are deduced from observational data. The two widely separated study areas bear the imprint of intense Late Mesozoic through Middle Cenozoic tectonic activity. A regional transition from Late Cretaceous-Early Tertiary plutonism, metamorphism, and shortening strain to Middle Tertiary extension and magmatism is preserved in each area, with contrasting environments and mechanisms. Compressional phases of this tectonic history are better displayed in the Rand Mountains, whereas younger extensional structures dominate rock fabrics in the Magdalena area.

In the northwestern Mojave desert, the Rand Thrust Complex reveals a stack of four distinctive tectonic plates offset along the Garlock Fault. The lowermost plate, Rand Schist, is composed of greenschist facies metagraywacke, metachert, and metabasalt. Rand Schist is structurally overlain by Johannesburg Gneiss (= garnet-amphibolite grade orthogneisses, marbles and quartzites), which in turn is overlain by a Late Cretaceous hornblende-biotite granodiorite. Biotite granite forms the fourth and highest plate. Initial assembly of the tectonic stack involved a Late Cretaceous? south or southwest vergent overthrusting event in which Johannesburg Gneiss was imbricated and attenuated between Rand Schist and hornblende-biotite granodiorite. Thrusting postdated metamorphism and deformation of the lower two plates in separate environments. A post-kinematic stock, the Late Cretaceous Randsburg Granodiorite, intrudes deep levels of the complex and contains xenoliths of both Rand Schist and mylonitized Johannesburg? gneiss. Minimum shortening implied by the map patterns is 20 kilometers.

Some low angle faults of the Rand Thrust Complex formed or were reactivated between Late Cretaceous and Early Miocene time. South-southwest directed mylonites derived from Johannesburg Gneiss are commonly overprinted by less penetrative north-northeast vergent structures. Available kinematic information at shallower structural levels indicates that late disturbance(s) culminated in northward transport of the uppermost plate. Persistence of brittle fabrics along certain structural horizons suggests a possible association of late movement(s) with regionally known detachment faults. The four plates were juxtaposed and significant intraplate movements had ceased prior to Early Miocene emplacement of rhyolite porphyry dikes.

In the Magdalena region of north central Sonora, components of a pre-Middle Cretaceous stratigraphy are used as strain markers in tracking the evolution of a long lived orogenic belt. Important elements of the tectonic history include: (1) Compression during the Late Cretaceous and Early Tertiary, accompanied by plutonism, metamorphism, and ductile strain at depth, and thrust driven? syntectonic sedimentation at the surface. (2) Middle Tertiary transition to crustal extension, initially recorded by intrusion of leucogranites, inflation of the previously shortened middle and upper crustal section, and surface volcanism. (3) Gravity induced development of a normal sense ductile shear zone at mid crustal levels, with eventual detachment and southwestward displacement of the upper crustal stratigraphy by Early Miocene time.

Elucidation of the metamorphic core complex evolution just described was facilitated by fortuitous preservation of a unique assemblage of rocks and structures. The "type" stratigraphy utilized for regional correlation and strain analysis includes a Jurassic volcanic arc assemblage overlain by an Upper Jurassic-Lower Cretaceous quartz pebble conglomerate, in turn overlain by marine strata with fossiliferous Aptian-Albian limestones. The Jurassic strata, comprised of (a) rhyolite porphyries interstratified with quartz arenites, (b) rhyolite cobble conglomerate, and (c) intrusive granite porphyries, are known to rest on Precambrian basement north and east of the study area. The quartz pebble conglomerate is correlated with the Glance Conglomerate of southeastern Arizona and northeastern Sonora. The marine sequence represents part of an isolated arm? of the Bisbee Basin.

Crosscutting structural relationships between the pre-Middle Cretaceous supracrustal section, younger plutons, and deformational fabrics allow the tectonic sequence to be determined. Earliest phases of a Late Cretaceous-Early Tertiary orogeny are marked by emplacement of the 78 ± 3 Ma Guacomea Granodiorite (U/Pb zircon, Anderson et al., 1980) as a sill into deep levels of the layered Jurassic series. Subsequent regional metamorphism and ductile strain is recorded by a penetrative schistosity and lineation, and east-west trending folds. These fabrics are intruded by post-kinematic Early Tertiary? two mica granites. At shallower crustal levels, the orogeny is represented by north directed thrust faulting, formation of a large intermontane basin, and development of a pronounced unconformity. A second important phase of ductile strain followed Middle Tertiary? emplacement of leucogranites as sills and northwest trending dikes into intermediate levels of the deformed section (surficial volcanism was also active during this transitional period to regional extension). Gravitational instabilities resulting from crustal swelling via intrusion and thermal expansion led to development of a ductile shear zone within the stratigraphic horizon occupied by a laterally extensive leucogranite sill. With continued extension, upper crustal brittle normal faults (detachment faults) enhanced the uplift and tectonic denudation of this mylonite zone, ultimately resulting in southwestward displacement of the upper crustal stratigraphy.

Strains associated with the two ductile deformation events have been successfully partitioned through a multifaceted analysis. R_f/Ø measurements on various markers from the "type" stratigraphy allow a gradient representing cumulative strain since Middle Cretaceous time to be determined. From this gradient, noncoaxial strains accrued since emplacement of the leucogranites may be removed. Irrotational components of the postleucogranite strain are measured from quartz grain shapes in deformed granites; rotational components (shear strains) are determined from S-C fabrics and from restoration of rotated dike and vein networks. Structural observations and strain data are compatable with a deformation path of: (1) coaxial strain (pure shear?), followed by (2) injection of leucogranites as dikes (perpendicular to the minimum principle stress) and sills (parallel to the minimum principle stress), then (3) southwest directed simple shear. Modeling the late strain gradient as a simple shear zone permits a minimum displacement of 10 kilometers on the Magdalena mylonite zone/detachment fault system. Removal of the Middle Tertiary noncoaxial strains yields a residual (or pre-existing) strain gradient representative of the Late Cretaceous-Early Tertiary deformation. Several partially destrained cross sections, restored to the time of leucogranite emplacement, illustrate the idea that the upper plate of the core complex bas been detached from a region of significant topographic relief. 50% to 100% bulk extension across a 50 kilometer wide corridor is demonstrated.

Late Cenozoic tectonics of the Magdalena region are dominated by Basin and Range style faulting. Northeast and north-northwest trending high angle normal faults have interacted to extend the crust in an east-west direction. Net extension for this period is minor (10% to 15%) in comparison to the Middle Tertiary detachment related extensional episode.

Evolução geológica do Complexo Quirino, Terreno Paraíba do Sul, Setor Central da Faixa Ribeira, com base em dados isotópicos de Sm-Nd e Sr

A área estudada está inserida na Faixa Ribeira, Segmento Central da Província Mantiqueira (Almeida et al., 1973, 1977, 1981), que representa um cinturão de dobramentos e empurrões gerado no Neo-proterozóico/Cambriano, durante a Orogênese Brasiliana, na borda sul/sudeste do Cráton do São Francisco (Almeida, 1971, 1977; Cordani et al., 1967, 1973; Cordani & Brito Neves, 1982; Teixeira & Figueiredo, 1991). Neste contexto, o Complexo Quirino é o embasamento retrabalhado do Terreno Paraíba do Sul (Heilbron et al., 2004). O Complexo Quirino é formado por extensos corpos de ortognaisses foliados a homogêneos, leuco a mesocráticos, de granulometria média à grossa, composicionalmente variando entre granitóides tonalíticos/granodioríticos a graníticos, e apresentando enclaves de rochas ultramáficas, máficas e cálcio-silicáticas (ricas em tremolita). Os ortognaisses tonalíticos/granodioríticos apresentam porfiroblastos de plagioclásio e a hornblenda como máfico principal, contrastando com os de composição granítica que apresentam porfiroblastos de K-feldspato e biotita predominante. Como acessórios aparecem zircão, titanita, apatita e epidoto. Também estão associados a estes ortognaisses, granitóides neoproterozóicos que formam corpos individualizados ou lentes anatéticas no conjunto paleoproterozóico. Estes são compostos predominantemente por biotita gnaisse e hornblenda-biotita gnaisse. A análise litogeoquímicas dos ortognaisses do Complexo Quirino demonstrou a existência de duas séries magmáticas distintas. A primeira pertencente à série cálcio-alcalina de alto-K apresenta uma composição mais expandida granítica-adamelítica/granodioritica/tonalítica e é correlacionável aos bt-ortognaisses e alguns hb-bt-ortognaisses. Os ortognaisses da série médio-K apresentam composição predominantemente tonalítica, sendo correlacionáveis à maioria dos hornblenda-biotita gnaisses. Enclaves lenticulares de metapiroxeníticos e anfibolíticos ocorrem em muitos afloramentos. Também ocorrem granitóides neoproterozóicos de composição graníticas a quartzo-monzoníticas O estudo isotópico de Sm-Nd e Sr demonstrou que os ortognaisses da série cálcio-alcalina de alto-K e aqueles da série cálcio-alcalina de médio-K possuem idades modelo TDM variando entre paleoproterozóicas a arqueanas, consistentes com dados U-Pb em zircão publicados na literatura. A série cálcio-alcalina de alto-K é mais antiga (2308 9,2 Ma a 2185 8 Ma) do que a série calcio-alcalina de médio-K (2169 3 a 2136 14 Ma) e a existência de zircões herdados com idades mínimas de 2846 Ma e 2981 Ma para série de médio-K e 3388 16 para série de alto-K. Os granitóides brasilianos possuem idades de cristalização neoproterozóica correlacionada a Orogênese Brasiliana (602 a 627 Ma) (Viana, 2008; Valladares et al., 2002)./Com base nos dados de Sr e Sm-Nd foi possível caracterizar 4 grupos distintos. Os grupos 1 e 2 são formados por rochas de idade paleoproterozóica (2,1 a 2,3 Ga) com idades modelo TDM variando de 2,9 e 3,4 Ga, εNd entre -8,1 e -5,8 e 87Sr/86Sr(t) = 0,694707 (Grupo 1) e TDM variando de 2,5 a 2,7 Ga, εNd entre -5,8 e -3,1 e 87Sr/86Sr(t) = 0,680824 (Grupo 2), formados no paleoproterozóico com contribuição de uma crosta arqueana. O grupo 3 é formado por rochas juvenis de idade paleoproterozóica, com idades de cristalização variando entre 2,0 e 2,2 Ga e com idades modelo TDM variando de 2,1 a 2,2 Ga e εNd entre + 1,5 e + 1,2. O grupo 4 é formado durante o neoproterozóico (645 Ma) por rochas possivelmente de idade paleoproterozóico com idades modelo TDM igual a 1,7 Ga e εNd igual a -8,3.

Understanding planet formation through high precision photometry and spectroscopy

From studies of protoplanetary disks to extrasolar planets and planetary debris, we aim to understand the full evolution of a planetary system. Observational constraints from ground- and space-based instrumentation allows us to measure the properties of objects near and far and are central to developing this understanding. We present here three observational campaigns that, when combined with theoretical models, reveal characteristics of different stages and remnants of planet formation. The Kuiper Belt provides evidence of chemical and dynamical activity that reveals clues to its primordial environment and subsequent evolution. Large samples of this population can only be assembled at optical wavelengths, with thermal measurements at infrared and sub-mm wavelengths currently available for only the largest and closest bodies. We measure the size and shape of one particular object precisely here, in hopes of better understanding its unique dynamical history and layered composition.

Molecular organic chemistry is one of the most fundamental and widespread facets of the universe, and plays a key role in planet formation. A host of carbon-containing molecules vibrationally emit in the near-infrared when excited by warm gas, T~1000 K. The NIRSPEC instrument at the W.M. Keck Observatory is uniquely configured to study large ranges of this wavelength region at high spectral resolution. Using this facility we present studies of warm CO gas in protoplanetary disks, with a new code for precise excitation modeling. A parameterized suite of models demonstrates the abilities of the code and matches observational constraints such as line strength and shape. We use the models to probe various disk parameters as well, which are easily extensible to others with known disk emission spectra such as water, carbon dioxide, acetylene, and hydrogen cyanide.

Lastly, the existence of molecules in extrasolar planets can also be studied with NIRSPEC and reveals a great deal about the evolution of the protoplanetary gas. The species we observe in protoplanetary disks are also often present in exoplanet atmospheres, and are abundant in Earth's atmosphere as well. Thus, a sophisticated telluric removal code is necessary to analyze these high dynamic range, high-resolution spectra. We present observations of a hot Jupiter, revealing water in its atmosphere and demonstrating a new technique for exoplanet mass determination and atmospheric characterization. We will also be applying this atmospheric removal code to the aforementioned disk observations, to improve our data analysis and probe less abundant species. Guiding models using observations is the only way to develop an accurate understanding of the timescales and processes involved. The futures of the modeling and of the observations are bright, and the end goal of realizing a unified model of planet formation will require both theory and data, from a diverse collection of sources.

Seismic structure along transitions from flat to normal subduction: central Mexico, southern Peru, and southwest Japan

The fine-scale seismic structure of the central Mexico, southern Peru, and southwest Japan subduction zones is studied using intraslab earthquakes recorded by temporary and permanent regional seismic arrays. The morphology of the transition from flat to normal subduction is explored in central Mexico and southern Peru, while in southwest Japan the spatial coincidence of a thin ultra-slow velocity layer (USL) atop the flat slab with locations of slow slip events (SSEs) is explored. This USL is also observed in central Mexico and southern Peru, where its lateral extent is used as one constraint on the nature of the flat-to-normal transitions.

In western central Mexico, I find an edge to this USL which is coincident with the western boundary of the projected Orozco Fracture Zone (OFZ) region. Forward modeling of the 2D structure of the subducted Cocos plate using a finite-difference algorithm provides constraints on the velocity and geometry of the slab’s seismic structure in this region and confirms the location of the USL edge. I propose that the Cocos slab is currently fragmenting into a North Cocos plate and a South Cocos plate along the projection of the OFZ, by a process analogous to that which occurred when the Rivera plate separated from the proto-Cocos plate 10 Ma.

In eastern central Mexico, observations of a sharp transition in slab dip near the abrupt end of the Trans Mexican Volcanic Belt (TMVB) suggest a possible slab tear located within the subducted South Cocos plate. The eastern lateral extent of the USL is found to be coincident with these features and with the western boundary of a zone of decreased seismicity, indicating a change in structure which I interpret as evidence of a possible tear. Analysis of intraslab seismicity patterns and focal mechanism orientations and faulting types provides further support for a possible tear in the South Cocos slab. This potential tear, together with the tear along the projection of the OFZ to the northwest, indicates a slab rollback mechanism in which separate slab segments move independently, allowing for mantle flow between the segments.

In southern Peru, observations of a gradual increase in slab dip coupled with a lack of any gaps or vertical offsets in the intraslab seismicity suggest a smooth contortion of the slab. Concentrations of focal mechanisms at orientations which are indicative of slab bending are also observed along the change in slab geometry. The lateral extent of the USL atop the horizontal Nazca slab is found to be coincident with the margin of the projected linear continuation of the subducting Nazca Ridge, implying a causal relationship, but not a slab tear. Waveform modeling of the 2D structure in southern Peru provides constraints on the velocity and geometry of the slab’s seismic structure and confirms the absence of any tears in the slab.

In southwest Japan, I estimate the location of a possible USL along the Philippine Sea slab surface and find this region of low velocity to be coincident with locations of SSEs that have occurred in this region. I interpret the source of the possible USL in this region as fluids dehydrated from the subducting plate, forming a high pore-fluid pressure layer, which would be expected to decrease the coupling on the plate interface and promote SSEs.

Mapeamento geológico em áreas graníticas intemperizadas em regiões montanhosas tropicais: o granito Conselheiro Paulino (Faixa Ribeira)

Neste trabalho foram integrados o mapeamento geológico de campo, os dados regionais aerogeofísicos e as imagens orbitais de alta resolução (1 m) para fornecer um mapa geológico detalhado do Pluton granítico Conselheiro Paulino, na Faixa Ribeira, Brasil. A área estudada possui poucos afloramentos e outras questões que dificultam o mapeamento geológico tradicional. Escorregamentos de terra são comuns na porção mais intemperizada do granito. A utilização de imagens orbitais de alta resolução permitiu a identificação dos poucos afloramentos existentes, além de outros elementos, como ravinas, planícies aluviais, eluviões, vegetação e estradas. Isso foi importante para orientar e otimizar as pesquisas de campo. A disponibilidade de dados aerogeofísicos magnéticos e radiométricos corroboraram nos trabalhos de campo e na petrografia do Pluton granítico Conselheiro Paulino. O pluton pode ser dividido em duas facies distintas, sendo uma de composição microgranítica e outra de composição microgranodiorítica

Solar System Small-Body Demographics with the Palomar Transient Factory Survey

Observational studies of our solar system's small-body populations (asteroids and comets) offer insight into the history of our planetary system, as these minor planets represent the left-over building blocks from its formation. The Palomar Transient Factory (PTF) survey began in 2009 as the latest wide-field sky-survey program to be conducted on the 1.2-meter Samuel Oschin telescope at Palomar Observatory. Though its main science program has been the discovery of high-energy extragalactic sources (such as supernovae), during its first five years PTF has collected nearly five million observations of over half a million unique solar system small bodies. This thesis begins to analyze this vast data set to address key population-level science topics, including: the detection rates of rare main-belt comets and small near-Earth asteroids, the spin and shape properties of asteroids as inferred from their lightcurves, the applicability of this visible light data to the interpretation of ultraviolet asteroid observations, and a comparison of the physical properties of main-belt and Jovian Trojan asteroids. Future sky-surveys would benefit from application of the analytical techniques presented herein, which include novel modeling methods and unique applications of machine-learning classification. The PTF asteroid small-body data produced in the course of this thesis work should remain a fertile source of solar system science and discovery for years to come.

Proton-Coupled Reduction of N2 Facilitated by Molecular Fe Complexes

The activation of Fe-coordinated N₂ via the formal addition of hydrogen atom equivalents is explored in this thesis. These reactions may occur in nitrogenase enzymes during the biological conversion of N₂ to NH₃. To understand these reactions, the N₂ reactivity of a series of molecular Fe(N₂) platforms is investigated. A trigonal pyramidal, carbon-ligated Fe^I complex was prepared that displays a similar geometry to that of the resting state 'belt' Fe atoms of nitrogenase. Upon reduction, this species was shown to coordinate N₂, concomitant with significant weakening of the C-Fe interaction. This hemilability of the axial ligand may play a critical role in mediating the interconversion of Fe(N_xH_y) species during N₂ conversion to NH₃. In fact, a trigonal pyramidal borane-ligated Fe complex was shown to catalyze this transformation, generating up to 8.49 equivalents of NH₃. To shed light on the mechanistic details of this reaction, protonation of a borane-ligated Fe(N₂) complex was investigated and found to give rise to a mixture of species that contains an iron hydrazido(2-) [Fe(NNH₂)] complex. The identification of this species is suggestive of an early N-N bond cleavage event en route to NH₃ production, but the highly-reactive nature of this complex frustrated direct attempts to probe this possibility. A structurally-analogous silyl-ligated Fe(N₂) complex was found to react productively with hydrogen atom equivalents, giving rise to an isolable Fe(NNH₂) species. Spectroscopic and crystallographic studies benefited from the enhanced stability of this complex relative to the borane analogue. One-electron reduction of this species initiates a spontaneous disproportionation reaction with an iron hydrazine [Fe(NH₂NH₂)] complex as the predominant reaction product. This transformation provides support for an Fe-mediated N₂ activation mechanism that proceeds via a late N-N bond cleavage. In hopes of gaining more fundamental insight into these reactions, a series of Fe(CN) complexes were prepared and reacted with hydrogen-atom equivalents. Significant quantities of CH₄ and NH₃ are generated in these reactions as a result of complete C-N bond activation. A series of Fe(CNH_x) were found to be exceptionally stable and may be intermediates in these reactions. The stability of these compounds permitted collection of thermodynamic parameters pertinent to the unique N-H bonds. This data is comparatively discussed with the theoretically-predicted data of the N₂-derived Fe(NNH_x) species. Exceptionally-weak N-H bond enthalpies are found for many of these compounds, and sheds light on their short-lived nature and tendency to evolve H₂. As a whole, these works both establish and provide a means to understand Fe-mediated N₂ activation via the addition of hydrogen atom equivalents.

Metallogenic Provinces of the Southwestern United States and Northern Mexico

Some of the metallogenic provinces of the southwestern United States and northern Mexico are defined by the geographic distribution of trace elements in the primary sulfide minerals chalcopyrite and sphalerite. The elements investigated include antimony, arsenic, bismuth, cadmium, cobalt, gallium, germanium, indium, manganese, molybdenum, nickel, silver, tellurium, thallium, and tin. Of these elements, cobalt, gallium, germanium, indium, nickel, silver, and tin exhibit the best defined geographic distribution.

The data indicate that chalcopyrite is the preferred host for tin and perhaps molybdenum; sphalerite is the preferred host for cadmium, gallium, germanium, indium, and manganese; galena is the preferred host for antimony, bismuth, silver, tellurium, and thallium; and pyrite is the preferred host for cobalt, nickel, and perhaps arsenic. With respect to the two minerals chalcopyrite and sphalerite, antimony, arsenic, molybdenum, nickel, silver, and tin prefer chalcopyrite; and bismuth, cadmium, cobalt, gallium, germanium, indium, manganese, and thallium prefer sphalerite. This distribution probably is the result of the interaction of several factors, among which are these: the various radii of the elements, the association due to chemical similarities of the major and trace elements, and the degree of ionic versus covalent and metallic character of the metal-sulfur bonds in chalcopyrite and sphalerite. The type of deposit, according to a temperature classification, appears to be of minor importance in determining the trace element content of chalcopyrite and sphalerite.

A preliminary investigation of large single crystals of sphalerite and chalcopyrite indicates that the distribution within a single crystal of some elements such as cadmium in sphalerite and indium and silver in chalcopyrite is relatively uniform, whereas the distribution of some other elements such as cobalt and manganese in sphalerite is somewhat less uniform and the distribution of tin in sphalerite is extremely erratic. The variations in trace element content probably are due largely to variations in the composition of the fluids during the growth of the crystals, but the erratic behavior of tin in sphalerite perhaps is related to the presence of numerous cavities and inclusions in the crystal studied.

Maps of the geographic distribution of trace elements in chalcopyrite and sphalerite exhibit three main belts of greater than average trace element content, which are called the Eastern, Central, and Western belts. These belts are consistent in trend and position with a beltlike distribution of copper, gold, lead, zinc, silver, and tungsten deposits and with most of the major tectonic features. However, there appear to be no definite time relationships, for as many as four metallogenic epochs, from Precambrian to late Tertiary, are represented by ore deposits within the Central belt.

The evidence suggests that the beltlike features have a deep seated origin, perhaps in the sub-crust or outer parts of the mantle, and that the deposits within each belt might be genetically related through a beltlike compositional heterogeneity in the source regions of the ores. Hence, the belts are regarded as metallogenic provinces.

Crioterapia: tecnologia não-invasiva de cuidado da enfermeira obstétrica para alívio da dor em parturientes

Pesquisa piloto de intervenção com dados prospectivos, grupo único de intervenção, cujo desfecho é a medida da dor de mulheres em trabalho de parto. Apresenta como objetivo discutir os efeitos da crioterapia no alívio da dor das parturientes. Como referencial teórico este trabalho apresentou o descrito por Soares e Low, onde se encontra que os mecanismos de ação do gelo para alívio da dor propiciam o decréscimo da transmissão das fibras de dor, a diminuição da excitabilidade nas terminações livres, a redução no metabolismo tecidual aumentando o limiar das fibras de dor e a liberação de endorfinas. Baseou-se ainda nos princípios da desmedicalização e do emprego de tecnologias não-invasivas de cuidado de enfermagem obstétrica conforme descritos por Vargens e Progianti. A pesquisa foi realizada no Centro Obstétrico do Hospital Municipal Maternidade Carmela Dutra, no Rio de Janeiro de abril a agosto de 2011. O gelo foi aplicado, utilizando-se para tal uma bolsa-cinta ajustável à região tóraco-lombar de 36 gestantes. A bolsa/cinta é descartável, de tecido TNT, com abertura na parte superior para introdução de gelo picado envolto em plástico. As aplicações se deram aos cinco centímetros de dilatação do colo uterino; e/ou aos sete centímetros de dilatação do colo uterino; e/ou aos nove centímetros de dilatação uterina, totalizando ao final das três aplicações um tempo de 60 minutos, que corresponde ao somatório de 20 minutos para cada uma. O gelo foi produzido em fôrma exclusiva para o projeto, em freezer da unidade. Os dados referentes à avaliação da dor foram coletados através de entrevista estruturada guiada por formulário previamente elaborado. Os resultados evidenciaram que a crioterapia produziu extinção ou alívio da dor quando aplicada na região tóraco-lombar das parturientes aos cinco, sete ou nove centímetros de dilatação do colo uterino, dando-lhes maiores condições de vivenciar o seu trabalho de parto; produziu um relaxamento geral e local (na região lombar) das parturientes; não interferiu na dinâmica uterina e, não causou dano ao binômio mãe-filho. Concluiu-se que a crioterapia, na forma como descrita no presente estudo, pode ser considerada uma tecnologia não-invasiva de cuidado de enfermagem obstétrica para alivio da dor no trabalho de parto.