Hydrogeology, Chemical Characteristics, and Transport Processes in the Zone of Contribution of a Public-Supply Well in York, Nebraska

In 2001, the U.S. Geological Survey, as part of the National Water Quality Assessment (NAWQA) Program, initiated a topical study of Transport of Anthropogenic and Natural Contaminants (TANC) to PSW (public-supply wells). Local-scale and regional-scale TANC study areas were delineated within selected NAWQA study units for intensive study of processes effecting transport of contaminants to PSWs. This report describes results from a local-scale TANC study area at York, Nebraska, within the High Plains aquifer, including the hydrogeology and geochemistry of a 108-square-kilometer study area that contains the zone of contribution to a PSW selected for study (study PSW), and describes factors controlling the transport of selected anthropogenic and natural contaminants to PSWs.

Well-Defined Poly(4-vinylbenzocyclobutene): Synthesis by Living Anionic Polymerization and Characterization

Living anionic polymerization of 4-vinylbenzocylobutene was performed in benzene at room temperature using sec-butyllithium as the initiator. Results of the kinetic studies indicated the termination- and transfer-free nature of the polymerization. Homopolymers with predictable molecular weights and narrow molecular weight distributions were produced, excluding the interference of the cyclobutene rings during initiation and propagation. Thermogravimetric analysis of poly(4-vinylbenzocyclobutene) in air showed a small weight gain at ~200 °C, a rapid decomposition at ~455 °C, and a gradual decomposition at ~566 °C. This behavior was attributed to the formation of radicals from the pendent benzocyclobutene functionality through o-quinodimethane intermediates and simultaneous decomposition/cross-linking reactions at high temperature. The living nature of the polymerization was also examined via sequential copolymerization with butadiene to form diblock copolymers.

An Artesian Well System in Beaver Crossing, Nebraska- It's Development and Demise

ABSTRACT Nebraska has a veritable wealth of groundwater. The High Plains Aquifer underlies most of the state, and within its sand and gravel deposits, many interconnected aquifers provide fresh water for a variety of uses. One of the most spectacular examples of this resource is the artesian well. Beaver Crossing, Nebraska was once home to one of the most prolific artesian systems in the state before its demise. Founded in the 1880’s, Beaver Crossing soon became known for its many artesian wells, that provided leisure activities and supported profitable business ventures such as small farming, ice production and aquiculture. Eventually these wells would dry up and the town of Beaver Crossing would never see the level of commerce and activity that it saw during its early years. I decided to research this subject because I lived in Beaver Crossing for twelve years. While I lived there I heard stories about the artesian wells, the nationally recognized lily pond, and the large public pool fed by underground water that was plentiful around town. I was interested in knowing what happened to the water, the wells, the pool and businesses. . . And, in the wake of their disappearance, what happened to the town. To research this topic I looked at accounts of the history of Seward County and Beaver Crossing. I also studied the basic geology underlying the Great Plains, as well as local geology and issues pertaining to groundwater levels, such as rainfall amounts, drought and irrigation. As irrigation became a factor in rural Nebraska and through several documented droughts, groundwater levels all over the state declined. At the same time the artesian system in Beaver Crossing all but disappeared.

Propriedades físicas e mecânicas de cimentos de ionômero de vidro encapsulados e não encapsulados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Numerical analysis of different methods to calculate residual stresses in thin films based on instrumented indentation data

In this work, different methods to estimate the value of thin film residual stresses using instrumented indentation data were analyzed. This study considered procedures proposed in the literature, as well as a modification on one of these methods and a new approach based on the effect of residual stress on the value of hardness calculated via the Oliver and Pharr method. The analysis of these methods was centered on an axisymmetric two-dimensional finite element model, which was developed to simulate instrumented indentation testing of thin ceramic films deposited onto hard steel substrates. Simulations were conducted varying the level of film residual stress, film strain hardening exponent, film yield strength, and film Poisson's ratio. Different ratios of maximum penetration depth h(max) over film thickness t were also considered, including h/t = 0.04, for which the contribution of the substrate in the mechanical response of the system is not significant. Residual stresses were then calculated following the procedures mentioned above and compared with the values used as input in the numerical simulations. In general, results indicate the difference that each method provides with respect to the input values depends on the conditions studied. The method by Suresh and Giannakopoulos consistently overestimated the values when stresses were compressive. The method provided by Wang et al. has shown less dependence on h/t than the others.

Plasmodium vivax Duffy binding protein: baseline antibody responses and parasite polymorphisms in a well-consolidated settlement of the Amazon Region

Objective To investigate risk factors associated with the acquisition of antibodies against Plasmodium vivax Duffy binding protein (PvDBP) a leading malaria vaccine candidate in a well-consolidated agricultural settlement of the Brazilian Amazon Region and to determine the sequence diversity of the PvDBP ligand domain (DBPII) within the local malaria parasite population. Methods Demographic, epidemiological and clinical data were collected from 541 volunteers using a structured questionnaire. Malaria parasites were detected by conventional microscopy and PCR, and blood collection was used for antibody assays and molecular characterisation of DBPII. Results The frequency of malaria infection was 7% (6% for P. vivax and 1% for P. falciparum), with malaria cases clustered near mosquito breeding sites. Nearly 50% of settlers had anti-PvDBP IgG antibodies, as detected by enzyme-linked immunosorbent assay (ELISA) with subjects age being the only strong predictor of seropositivity to PvDBP. Unexpectedly, low levels of DBPII diversity were found within the local malaria parasites, suggesting the existence of low gene flow between P. vivax populations, probably due to the relative isolation of the studied settlement. Conclusion The recognition of PvDBP by a significant proportion of the community, associated with low levels of DBPII diversity among local P. vivax, reinforces the variety of malaria transmission patterns in communities from frontier settlements. Such studies should provide baseline information for antimalarial vaccines now in development.

The Effects of Processing Non-Timber Forest Products and Trade Partnerships on People's Well-Being and Forest Conservation in Amazonian Societies

This study evaluated whether processing non-timber forest products (NTFPs) and establishing trade partnerships between forest communities and companies enhance the outcomes of NTFP commercialization. In particular, we evaluated whether product processing, partnerships, or their combination was associated with a number of outcomes related to the well-being of forest inhabitants and forest conservation. We based our analyses on ethnographic and quantitative data (i.e., survey and systematic observations) gathered at seven communities from five societies of the Brazilian and Bolivian Amazon. Our results indicated that product processing and partnerships do not represent a silver bullet able to improve the results of NTFP commercialization in terms of well-being and conservation indicators. Compared with cases without interventions, households adopting partnerships but not product processing were most often associated with improved economic proxies of well-being (total income, NTFP income, food consumption and gender equality in income). In comparison, the combination of product processing and partnerships was associated with similar outcomes. Unexpectedly, product processing alone was associated with negative outcomes in the economic indicators of well-being. All of the investigated strategies were associated with less time spent in social and cultural activities. With respect to forest conservation, the strategies that included a partnership with or without processing produced similar results: while household deforestation tended to decrease, the hunting impact increased. Processing alone was also associated with higher levels of hunting, though it did not reduce deforestation. Our results indicate that establishing partnerships may enhance the outcomes of NTFP trade in terms of the financial outcomes of local communities, but practitioners need to use caution when adopting the processing strategy and they need to evaluate potential negative results for indicators of social and cultural activities. With respect to conservation, the three strategies are promising for reducing deforestation, but more pervasive impacts, such as hunting, might increase.

Positive Affection Measurement: Subjective Well-Being in Married People

The study analyzed the correlations among the different factors of subjective well-being (SWB) using a sample of 106 married people with an average of 16.11 years of marriage. The following instruments were used: Sociodemographic Questionnaire, Socioeconomic Questionnaire, and Subjective Well-being Scale (SWBS). Data analyses were conducted using the Software R and a multivariate model to understand the correlations among the factors of the SWBS. All factors of the SWBS were significantly inter-correlated, which confirm the results of the scale validation study. Future studies are necessary to evaluate the SWB in couples (dyads), which can help to understand whether this concept is influenced by the spouse or only by the marital status.

Quantum oscillations of spin polarization in a GaAs/AlGaAs double quantum well

5 We employ the circular-polarization-resolved magnetophotoluminescence technique to probe the spin character of electron and hole states in a GaAs/AlGaAs strongly coupled double-quantum-well system. The photoluminescence (PL) intensities of the lines associated with symmetric and antisymmetric electron states present clear out-of-phase oscillations between integer values of the filling factor. and are caused by magnetic-field-induced changes in the population of occupied Landau levels near to the Fermi level of the system. Moreover, the degree of circular polarization of these emissions also exhibits the oscillatory behavior with increasing magnetic field. Both quantum oscillations observed in the PL intensities and in the degree of polarizations may be understood in terms of a simple single-particle approach model. The k . p method was used to calculate the photoluminescence peak energies and the degree of circular polarizations in the double-quantum-well structure as a function of the magnetic field. These calculations prove that the character of valence band states plays an important role in the determination of the degree of circular polarization and, thus, resulting in a magnetic-field-induced change of the polarization sign.

Deformation of Implant Abutments After Framework Connection Using Strain Gauges

When a cylinder is connected to an abutment it is expected that abutment and cylinder will be subjected to compression forces throughout their periphery because of the clamping force exerted by the screw. The deformation resultant of this compression should be measurable and uniform along the periphery of the abutment. Considering that multiple retainers connected to each other can affect the fit of a framework, as well as the use of different alloys, it is expected that the abutments will present different levels of deformation as a result of framework connection. The aim of this study was to evaluate the deformation of implant abutments after frameworks, cast either in cobalt-chromium (CoCr) or silver-palladium (AgPd) alloys, were connected. Samples (n = 5) simulating a typical mandibular cantilevered implant-supported prosthesis framework were fabricated in cobalt-chromium and silver-palladium alloys and screwed onto standard abutments positioned on a master-cast containing 5 implant replicas. Two linear strain gauges were fixed on the mesial and distal aspects of each abutment to capture deformation as the retention screws were tightened. A combination of compressive and tensile forces was observed on the abutments for both CoCr and AgPd frameworks. There was no evidence of significant differences in median abutment deformation levels for 9 of the 10 abutment aspects. Visually well-fit frameworks do not necessarily transmit load uniformly to abutments. The use of CoCr alloy for implant-supported prostheses frameworks may be as clinically acceptable as AgPd alloy.

Retinal nerve fiber evaluation in neuro-ophthalmic diseases of the anterior visual pathway

Retinal nerve fiber evaluation is important in the diagnosis and management of several diseases of the anterior visual pathway. In this report we review the clinical findings and the current techonologies avalilable to analyse the retinal nerve fiber layer. We furthermore review the main findings in several disease of the anterior visual pathways including inflammatory, ischemic, toxics, hereditary, compressive and traumatic optic neuropathies as well as lesion of the optic chiasm, optic tract and lateral geniculate body.

Correlates of change in self-perceived oral health among older adults in Brazil Findings from the Health, Well-Being and Aging Study

Background. Identifying changes in the oral health status of older populations, and their predictors and explanations, is necessary for public health planning. The authors assessed patterns of change in oral health-related quality of life in a large cohort of older adults in Brazil during a five-year period and evaluated associations between baseline characteristics and those changes. Methods. The sample consisted of 747 older people enrolled in a Brazilian cohort study called the Health, Well-Being and Aging (Saude, Bem-estar e Envelhecimento [SABE]) Study. Trained examiners measured participants' self-perceived oral health by using the General Oral Health Assessment Index (GOHAI). The authors calculated changes in the overall GOHAI score and in the scores for each of the GOHAI's three dimensions individually by subtracting the baseline score from the score at follow-up. A positive difference indicated improvement in oral health, a negative difference indicated a decline and a difference of zero indicated no change. Results. The authors found that 48.56 percent of the participants experienced a decline in oral health and 33.48 percent experienced an improvement. Participants with 16 or more missing teeth and eight or more years of education were more likely to have an improvement in total GOHAI score. Deterioration was more likely to occur among those with two or more diseases. Improvement and decline in GOHAI functional scores were related to the number of missing teeth. The authors found no significant model for the change in the psychosocial score, and Self-rated general health was the only variable related to both improvement and decline in pain or discomfort scores. Conclusions. The authors observed a bidirectional change in self-perceived oral health, with deterioration predominating. The strongest predictor of improvement in the total GOHAI score was the number of missing teeth, whereas the number of diseases was the strongest predictor of deterioration. Clinical Implications. Dental professionals and policymakers need to know the directions of change in older adults' oral health to establish treatment priorities and evaluate the impact of services directed at this population.

Treatment of severe forms of paracoccidioidomycosis: is there a role for corticosteroids?

Despite their immunosuppressive effects, corticosteroids have long been used as adjunct therapy (aCST) in the treatment of infectious diseases. The rationale is that in certain infections it is necessary to decrease the exacerbated host's inflammatory response, which can otherwise result in tissue damage and organ dysfunction. In fact, a major concern in treating paracoccidioidomycosis (PCM) is the host's intense inflammatory response to Paracoccidioides brasiliensis, which can be further intensified by antifungal therapy. Depending on its localization, this immunological phenomenon may be life threatening or result in permanent sequels, as is the case for some patients with cerebral or laryngeal involvement. However, the literature on aCST in paracoccidioidomycosis treatment is scarce and as a result we present our recent experience in the management of four patients with severe PCM manifestations, i.e., cerebral paracoccidioidal granuloma, laryngeal stenosis, compressive abdominal mass, and exacerbated inflammatory response with tissue destruction. In addition to the antifungal therapy, these patients required aCST, which probably promoted their clinical improvement and/or prevented serious complications. We suggest that aCST: (a) can potentially help in the management of selected cases of severe forms of PCM, particularly when there is a risk of acute complications, and (b) that it can be used safely provided that the risk-benefit ratio is carefully weighed. Well-controlled, prospective studies of aCST in the treatment of severe cases of paracoccidioidomycosis are needed to better define its role in the management of PCM.

Magneto-optical probe of quantum Hall states in a wide parabolic well modulated by random potential

Polarized photoluminescence from weakly coupled random multiple well quasi-three-dimensional electron system is studied in the regime of the integer quantum Hall effect. Two quantum Hall ferromagnetic ground states assigned to the uncorrelated miniband quantum Hall state and to the spontaneous interwell phase coherent dimer quantum Hall state are observed. Photoluminescence associated with these states exhibits features caused by finite-size skyrmions: dramatic reduction of the electron spin polarization when the magnetic field is increased past the filling factor nu = 1. The effective skyrmion size is larger than in two-dimensional electron systems.

Valence band tail states in disordered superlattices embedded in wide parabolic AlGaAs well

Optical properties of intentionally disordered multiple quantum well (QW) system embedded in a wide AlGaAs parabolic well were investigated by photoluminescence (PL) measurements as functions of the laser excitation power and the temperature. The characterization of the carriers localized in the individual wells was allowed due to the artificial disorder that caused spectral separation of the photoluminescence lines emitted by different wells. We observed that the photoluminescence peak intensity from each quantum well shifted to high energy as the excitation power was increased. This blue-shift is associated with the filling of localized states in the valence band tail. We also found that the dependence of the peak intensity on the temperature is very sensitive to the excitation power. The temperature dependence of the photoluminescence peak energy from each QW was well fitted using a model that takes into account the thermal redistribution of the localized carriers. Our results demonstrate that the band tails in the studied structures are caused by alloy potential fluctuations and the band tail states dominate the emission from the peripheral wells. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4730769]