BicaudalD actively regulates microtubule motor activity in lipid droplet transport.

PubMed

Larsen, Kristoffer S; Xu, Jing; Cermelli, Silvia; Shu, Zhanyong; Gross, Steven P

2008-01-01

A great deal of sub-cellular organelle positioning, and essentially all minus-ended organelle transport, depends on cytoplasmic dynein, but how dynein's function is regulated is not well understood. BicD is established to play a critical role in mediating dynein function-loss of BicD results in improperly localized nuclei, mRNA particles, and a dispersed Golgi apparatus-however exactly what BicD's role is remains unknown. Nonetheless, it is widely believed that BicD may act to tether dynein to cargos. Here we use a combination of biophysical and biochemical studies to investigate BicD's role in lipid droplet transport during Drosophila embryogenesis. Functional loss of BicD impairs the embryo's ability to control the net direction of droplet transport; the developmentally controlled reversal in transport is eliminated. We find that minimal BicD expression (near-BicD(null)) decreases the average run length of both plus and minus end directed microtubule (MT) based transport. A point mutation affecting the BicD N-terminus has very similar effects on transport during cellularization (phase II), but in phase III (gastrulation) motion actually appears better than in the wild-type. In contrast to a simple static tethering model of BicD function, or a role only in initial dynein recruitment to the cargo, our data uncovers a new dynamic role for BicD in actively regulating transport. Lipid droplets move bi-directionally, and our investigations demonstrate that BicD plays a critical-and temporally changing-role in balancing the relative contributions of plus-end and minus-end motors to control the net direction of transport. Our results suggest that while BicD might contribute to recruitment of dynein to the cargo it is not absolutely required for such dynein localization, and it clearly contributes to regulation, helping activation/inactivation of the motors.

Body Image Concern and its Correlates among Male and Female Undergraduate Students at Assuit University in Egypt

PubMed Central

Ansari, Walid El; Dibba, Emily; Labeeb, Shokria; Stock, Christiane

2014-01-01

Introduction: This cross-sectional study examined variables associated with body image concern (BIC) and whether these associations differed between female and male students in Egypt. During the period 2009-2010, 3271 undergraduate students (1663 females, 1504 males) at Assuit University in Egypt completed a self-administered questionnaire that assessed BIC and other socio-demographic and health related variables. Methods: Based on Cooper et al.’s Body Shape Questionnaire the authors categorized BIC into ‘no BIC’; ‘mild BIC’; and ‘moderate/marked BIC’. Multifactorial linear regression analysis examined the association between BIC and BMI, body image perception, lifestyle (physical activity, nutrition, smoking) and mental well-being variables (quality of life, finances-related stress, perceived stress, perceived health, depressive symptoms). Results: About 40% of the female students and 25.6% of male students reported having mild to marked BIC. The correlates of BIC did not exhibit striking differences between male and female students. For both genders, BIC was positively associated with BMI, body image perception as being too fat and with depressive symptoms. Self-rated health was inversely associated with BIC. Conclusion: These findings suggest that health promoting strategies should address the co-occurrence of depressive symptoms and BIC, and should furthermore pay due attention to higher prevalence of BIC among female students. PMID:25168990

No Evidence for Connectivity between the Bushveld Igneous Complex and the Molopo Farms Complex from Forward Modeling of Receiver Functions

NASA Astrophysics Data System (ADS)

Skryzalin, P. A.; Ramirez, C.; Durrheim, R. J.; Raveloson, A.; Nyblade, A.; Feineman, M. D.

2016-12-01

The Bushveld Igneous Complex contains one of the most studied and economically important layered mafic intrusions in the world. The Rustenburg Layered Suite outcrops in northern South Africa over an area of 65,000 km2, and has a volume of up to 1,000,000 km3. Both the Bushveld Igneous Complex and the Molopo Farms Complex in Botswana intruded the crust at 2.05 Ga. Despite being extensively exploited by the mining industry, many questions still exist regarding the structure of the Bushveld Igneous Complex, specifically the total size and connectivity of the different outcrops. In this study, we used receiver function analysis, a technique for determining the seismic velocity structure of the crust and upper mantle, to search for evidence of the Bushveld at station LBTB, which lies in Botswana, between the Far Western Limb of the Bushveld and the Molopo Farms Complex. The goal of our study was to determine whether a fast, high-density mafic body can be seen in the crust beneath this region using receiver functions. Observation of a high density layer would argue in favor of connectivity of the Bushveld between The Far Western Limb and the Molopo Farms Complex. We forward modeled stacks of receiver functions as well as sub-stacks that were split into azimuthal groups which share similar characteristics. We found that there was no evidence for a high velocity zone in the crust, and that the Moho in this region is located at a depth of 38 ± 3 km, about 8-9 km shallower than Moho depths determined beneath the Bushveld Complex. These two lines of evidence give no reason to assume connectivity between the Bushveld Igneous Complex and the Molopo Farms Complex, and rather suggest two separate intrusive suites.

Bound states in the continuum on periodic structures: perturbation theory and robustness.

PubMed

Yuan, Lijun; Lu, Ya Yan

2017-11-01

On periodic structures, a bound state in the continuum (BIC) is a standing or propagating Bloch wave with a frequency in the radiation continuum. Some BICs (e.g., antisymmetric standing waves) are symmetry protected, since they have incompatible symmetry with outgoing waves in the radiation channels. The propagating BICs do not have this symmetry mismatch, but they still crucially depend on the symmetry of the structure. In this Letter, a perturbation theory is developed for propagating BICs on two-dimensional periodic structures. The Letter shows that these BICs are robust against structural perturbations that preserve the symmetry, indicating that these BICs, in fact, are implicitly protected by symmetry.

Live-cell imaging of rice cytological changes reveals the importance of host vacuole maintenance for biotrophic invasion by blast fungus, Magnaporthe oryzae.

PubMed

Mochizuki, Susumu; Minami, Eiichi; Nishizawa, Yoko

2015-12-01

The rice blast fungus Magnaporthe oryzae grows inside living host cells. Cytological analyses by live-cell imaging have revealed characteristics of the biotrophic invasion, particularly the extrainvasive hyphal membrane (EIHM) originating from the host plasma membrane and a host membrane-rich structure, biotrophic interfacial complex (BIC). Here, we observed rice subcellular changes associated with invasive hyphal growth using various transformants expressing specifically localized fluorescent proteins. The invasive hyphae did not penetrate across but were surrounded by the host vacuolar membrane together with EIHM even after branching. High-resolution imaging of BICs revealed that the host cytosol was accumulated at BIC with aggregated EIHM and a symplastic effector, Pwl2, in a punctate form. The vacuolar membrane did not aggregate in but closely surrounded the BIC. A good correlation was observed between the early collapse of vacuoles and damage of invasive hyphae in the first-invaded cell. Furthermore, a newly developed, long-term imaging method has revealed that the central vacuole gradually shrank until collapse, which was caused by the hyphal invasion occurring earlier in the neighboring cells than in the first-invaded cells. These data suggest that M. oryzae may suppress host vacuole collapse during early infection stages for successful infection. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Bound states in the continuum on periodic structures surrounded by strong resonances

NASA Astrophysics Data System (ADS)

Yuan, Lijun; Lu, Ya Yan

2018-04-01

Bound states in the continuum (BICs) are trapped or guided modes with their frequencies in the frequency intervals of the radiation modes. On periodic structures, a BIC is surrounded by a family of resonant modes with their quality factors approaching infinity. Typically the quality factors are proportional to 1 /|β - β*|2 , where β and β* are the Bloch wave vectors of the resonant modes and the BIC, respectively. But for some special BICs, the quality factors are proportional to 1 /|β - β*|4 . In this paper, a general condition is derived for such special BICs on two-dimensional periodic structures. As a numerical example, we use the general condition to calculate special BICs, which are antisymmetric standing waves, on a periodic array of circular cylinders, and show their dependence on parameters. The special BICs are important for practical applications, because they produce resonances with large quality factors for a very large range of β .

[Protective effect of sodium bicarbonate on radiological contrast medium-induced nephropathy in rats].

PubMed

Vattimo, Maria deFátima Fernandes; dos Santos, Juliana Guareschi

2013-06-01

Radiological iodinated contrasts (IC) agents cause acute kidney injury (AKI). To evaluate the renoprotective effect of sodium bicarbonate (Bic) on renal function (creatinine clearance [Clcr], Jaffé, and Clcr mLmin -1 x100 g-1) and the oxidative profile (peroxide excretion, urinary peroxides, urinary malondialdehyde, FOX-2 expression, and thiobarbituric acid reactive substance [TBARS; nmol/mg Cr]) in rats treated with an IC agent. Adult male Wistar rats weighing 250-300 g were treated once daily for 5 days with one of the following treatments: saline (0.9%, 3 mL.kg-1xday-1 intraperitoneally [i.p.]), IC agent (sodium and meglumine ioxitalamate, 3 mL/kg, i.p.), Bic + Saline (3-mL/kg Bic, i.p., 1 h before and after saline treatment), and Bic + IC (3-ml/kg Bic, i.p., 1 h before and after the IC treatment). The IC agent induced AKI, and the antioxidant renoprotective effect of Bic was confirmed (Clcr/TBARS/urinary peroxide: saline group, 0.59+/- 0.03/0.11 +/-0.02/1.29+/- 0.24; Bic+Saline group, 0.58 +/-0.03/0.13+/- 0.02/1.32+/- 0.64; IC group, 0.22 +/- 0.02/0.19 +/- 0.02/4.77 +/- 0.24; Bic +Clgroup, 0.51+/- 0.04/0.13+/- 0.3/1.80+/- 0.04; p<0.05). The protective effect of Bic in the IC-induced AKI was confirmed; hence, Bic administration may be considered as a therapeutic option for patients undergoing IC-enhanced radiography.

Model selection with multiple regression on distance matrices leads to incorrect inferences.

PubMed

Franckowiak, Ryan P; Panasci, Michael; Jarvis, Karl J; Acuña-Rodriguez, Ian S; Landguth, Erin L; Fortin, Marie-Josée; Wagner, Helene H

2017-01-01

In landscape genetics, model selection procedures based on Information Theoretic and Bayesian principles have been used with multiple regression on distance matrices (MRM) to test the relationship between multiple vectors of pairwise genetic, geographic, and environmental distance. Using Monte Carlo simulations, we examined the ability of model selection criteria based on Akaike's information criterion (AIC), its small-sample correction (AICc), and the Bayesian information criterion (BIC) to reliably rank candidate models when applied with MRM while varying the sample size. The results showed a serious problem: all three criteria exhibit a systematic bias toward selecting unnecessarily complex models containing spurious random variables and erroneously suggest a high level of support for the incorrectly ranked best model. These problems effectively increased with increasing sample size. The failure of AIC, AICc, and BIC was likely driven by the inflated sample size and different sum-of-squares partitioned by MRM, and the resulting effect on delta values. Based on these findings, we strongly discourage the continued application of AIC, AICc, and BIC for model selection with MRM.

A CRY-BIC negative-feedback circuitry regulating blue light sensitivity of Arabidopsis.

PubMed

Wang, Xu; Wang, Qin; Han, Yun-Jeong; Liu, Qing; Gu, Lianfeng; Yang, Zhaohe; Su, Jun; Liu, Bobin; Zuo, Zecheng; He, Wenjin; Wang, Jian; Liu, Bin; Matsui, Minami; Kim, Jeong-Il; Oka, Yoshito; Lin, Chentao

2017-11-01

Cryptochromes are blue light receptors that regulate various light responses in plants. Arabidopsis cryptochrome 1 (CRY1) and cryptochrome 2 (CRY2) mediate blue light inhibition of hypocotyl elongation and long-day (LD) promotion of floral initiation. It has been reported recently that two negative regulators of Arabidopsis cryptochromes, Blue light Inhibitors of Cryptochromes 1 and 2 (BIC1 and BIC2), inhibit cryptochrome function by blocking blue light-dependent cryptochrome dimerization. However, it remained unclear how cryptochromes regulate the BIC gene activity. Here we show that cryptochromes mediate light activation of transcription of the BIC genes, by suppressing the activity of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), resulting in activation of the transcription activator ELONGATED HYPOCOTYL 5 (HY5) that is associated with chromatins of the BIC promoters. These results demonstrate a CRY-BIC negative-feedback circuitry that regulates the activity of each other. Surprisingly, phytochromes also mediate light activation of BIC transcription, suggesting a novel photoreceptor co-action mechanism to sustain blue light sensitivity of plants under the broad spectra of solar radiation in nature. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Bound states in the continuum and polarization singularities in periodic arrays of dielectric rods

NASA Astrophysics Data System (ADS)

Bulgakov, Evgeny N.; Maksimov, Dmitrii N.

2017-12-01

We consider optical bound states in the continuum (BICs) in periodic arrays of dielectric rods. The full classification of BICs in the above system is provided, including the modes propagating along the axes of the rods and bidirectional BICs propagating both along the axes of the rods and the axis of periodicity. It is shown that the leaky zones supporting the BICs generally have elliptically polarized far-field radiation patterns, with the polarization ellipses collapsing on approach to the BICs in momentum space. That allowed us to apply the concept of polarization singularities and demonstrate that the BICs possess a topological charge defined as the winding number of the polarization direction [Phys. Rev. Lett. 113, 257401 (2014), 10.1103/PhysRevLett.113.257401]. It is found that the evolution of the BICs, including their creation and annihilation, under variation of geometric parameters is controlled by the topological charge. Three scenarios of such evolution for different leaky zones are described. Finally, it is shown that the topological properties of the BICs can be extracted from transmission spectra when the system is illuminated by a plane wave of circular polarization.

NACSN, note 67--Application for revision of Articles 36 and 37, Lithodemic units of the North American stratigraphic code

USGS Publications Warehouse

Easton, Robert M.; Edwards, Lucy E.; Orndorff, Randall C.; Duguet, Manuel; Ferrusquia-Villafranca, Ismael

2015-01-01

Currently the North American Stratigraphic Code, (NACSN 2005, Article 37) sets restrictions on the use of the term “complex” for lithodemic units. With exceptions for “volcanic complex” and “structural complex,” a complex must consist of more than one genetic class of rock (i.e., sedimentary, igneous or metamorphic). Thus, the use of the term “complex” to describe masses of intrusive rocks is not allowed. Asimilar restriction is also included in a recent British Geological Survey proposal for using lithodemic units to classify igneous rocks (Gillespie et al. 2008).Currently the North American Stratigraphic Code, (NACSN 2005, Article 37) sets restrictions on the use of the term “complex” for lithodemic units. With exceptions for “volcanic complex” and “structural complex,” a complex must consist of more than one genetic class of rock (i.e., sedimentary, igneous or metamorphic). Thus, the use of the term “complex” to describe masses of intrusive rocks is not allowed. Asimilar restriction is also included in a recent British Geological Survey proposal for using lithodemic units to classify igneous rocks (Gillespie et al. 2008).

Correlating enzymatic browning inhibition and antioxidant ability of Maillard reaction products derived from different amino acids.

PubMed

Xu, Haining; Zhang, Xiaoming; Karangwa, Eric; Xia, Shuqin

2017-09-01

Up to now, only limited research on enzymatic browning inhibition capacity (BIC) of Maillard reaction products (MRPs) has been reported and there are still no overall and systematic researches on MRPs derived from different amino acids. In the present study, BIC and antioxidant capacity, including 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and Fe 2+ reducing power activity, of the MRPs derived from 12 different amino acids and three reducing sugars were investigated. The MRPs of cysteine (Cys), cystine, arginine (Arg) and histidine (His) showed higher BIC compared to other amino acids. Lysine (Lys)-MRPs showed the highest absorbance value at 420 nm (A 420 ) but very limited BIC, whereas Cys-MRPs, showed the highest BIC and the lowest A 420 . The A 420 can roughly reflect the trend of BIC of MRPs from different amino acids, except Cys and Lys. MRPs from tyrosine (Tyr) showed the most potent antioxidant capacity but very limited BIC, whereas Cys-MRPs showed both higher antioxidant capacity and BIC compared to other amino acids. Partial least squares regression analysis showed positive and significant correlation between BIC and Fe 2+ reducing power of MRPs from 12 amino acids with glucose or fructose, except Lys, Cys and Tyr. The suitable pH for generating efficient browning inhibition compounds varies depending on different amino acids: acidic pH was favorable for Cys, whereas neutral and alkaline pH were suitable for His and Arg, respectively. Increasing both heating temperature and time over a certain range could improve the BIC of MRPs of Cys, His and Arg, whereas any further increase deteriorates their browning inhibition efficiencies. The types of amino acid, initial pH, temperature and time of the Maillard reaction were found to greatly influence the BIC and antioxidant capacity of the resulting MRPs. There is no clear relationship between BIC and the antioxidant capacity of MRPs when reactant type and processing parameters of the Maillard reaction are considered as variables. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Nearly bound states in the radiation continuum in a circular array of dielectric rods

NASA Astrophysics Data System (ADS)

Bulgakov, Evgeny N.; Sadreev, Almas F.

2018-03-01

We consider E -polarized bound states in the radiation continuum (BICs) in circular periodical arrays of N infinitely long dielectric rods. We find that each true BIC which occurs in an infinite linear array has its counterpart in the circular array as a near-BIC with extremely large quality factor. We argue analytically as well as numerically that the quality factor of the symmetry-protected near-BICs diverges as eλ N, where λ is a material parameter dependent on the radius and the refraction index of the rods. By tuning of the radius of rods, we also find numerically non-symmetry-protected near-BICs. These near-BICs are localized with exponential accuracy outside the circular array, but fill the whole inner space of the array carrying orbital angular momentum.

Resonances and bound states in the continuum on periodic arrays of slightly noncircular cylinders

NASA Astrophysics Data System (ADS)

Hu, Zhen; Lu, Ya Yan

2018-02-01

Optical bound states in the continuum (BICs), especially those on periodic structures, have interesting properties and potentially important applications. Existing theoretical and numerical studies for optical BICs are mostly for idealized structures with simple and perfect geometric features, such as circular holes, rectangular cylinders and spheres. Since small distortions are always present in actual fabricated structures, we perform a high accuracy numerical study for BICs and resonances on a simple periodic structure with small distortions, i.e., periodic arrays of slightly noncircular cylinders. Our numerical results confirm that symmetries are important not only for the so-called symmetry-protected BICs, but also for the majority of propagating BICs which do not have a symmetry mismatch with the outgoing radiation waves. Typically, the BICs continue to exist if the small distortions keep the relevant symmetries, and they become resonant modes with finite quality factors if the small distortions break a required symmetry.

The validity of the Brain Injury Cognitive Screen (BICS) as a neuropsychological screening assessment for traumatic and non-traumatic brain injury.

PubMed

Vaughan, Frances L; Neal, Jo Anne; Mulla, Farzana Nizam; Edwards, Barbara; Coetzer, Rudi

2017-04-01

The Brain Injury Cognitive Screen (BICS) was developed as an in-service cognitive assessment battery for acquired brain injury patients entering community rehabilitation. The BICS focuses on domains that are particularly compromised following TBI, and provides a broader and more detailed assessment of executive function, attention and information processing than comparable screening assessments. The BICS also includes brief assessments of perception, naming, and construction, which were predicted to be more sensitive to impairments following non-traumatic brain injury. The studies reported here examine preliminary evidence for its validity in post-acute rehabilitation. In Study 1, TBI patients completed the BICS and were compared with matched controls. Patients with focal lesions and matched controls were compared in Study 2. Study 3 examined demographic effects in a sample of normative data. TBI and focal lesion patients obtained significantly lower composite memory, executive function and attention and information processing BICS scores than healthy controls. Injury severity effects were also obtained. Logistic regression analyses indicated that each group of BICS memory, executive function and attention measures reliably differentiated TBI and focal lesion participants from controls. Design Recall, Prospective Memory, Verbal Fluency, and Visual Search test scores showed significant independent regression effects. Other subtest measures showed evidence of sensitivity to brain injury. The study provides preliminary evidence of the BICS' sensitivity to cognitive impairment caused by acquired brain injury, and its potential clinical utility as a cognitive screen. Further validation based on a revised version of the BICS and more normative data are required.

Hearing with Two Ears: Evidence for Cortical Binaural Interaction during Auditory Processing.

PubMed

Henkin, Yael; Yaar-Soffer, Yifat; Givon, Lihi; Hildesheimer, Minka

2015-04-01

Integration of information presented to the two ears has been shown to manifest in binaural interaction components (BICs) that occur along the ascending auditory pathways. In humans, BICs have been studied predominantly at the brainstem and thalamocortical levels; however, understanding of higher cortically driven mechanisms of binaural hearing is limited. To explore whether BICs are evident in auditory event-related potentials (AERPs) during the advanced perceptual and postperceptual stages of cortical processing. The AERPs N1, P3, and a late negative component (LNC) were recorded from multiple site electrodes while participants performed an oddball discrimination task that consisted of natural speech syllables (/ka/ vs. /ta/) that differed by place-of-articulation. Participants were instructed to respond to the target stimulus (/ta/) while performing the task in three listening conditions: monaural right, monaural left, and binaural. Fifteen (21-32 yr) young adults (6 females) with normal hearing sensitivity. By subtracting the response to target stimuli elicited in the binaural condition from the sum of responses elicited in the monaural right and left conditions, the BIC waveform was derived and the latencies and amplitudes of the components were measured. The maximal interaction was calculated by dividing BIC amplitude by the summed right and left response amplitudes. In addition, the latencies and amplitudes of the AERPs to target stimuli elicited in the monaural right, monaural left, and binaural listening conditions were measured and subjected to analysis of variance with repeated measures testing the effect of listening condition and laterality. Three consecutive BICs were identified at a mean latency of 129, 406, and 554 msec, and were labeled N1-BIC, P3-BIC, and LNC-BIC, respectively. Maximal interaction increased significantly with progression of auditory processing from perceptual to postperceptual stages and amounted to 51%, 55%, and 75% of the sum of monaural responses for N1-BIC, P3-BIC, and LNC-BIC, respectively. Binaural interaction manifested in a decrease of the binaural response compared to the sum of monaural responses. Furthermore, listening condition affected P3 latency only, whereas laterality effects manifested in enhanced N1 amplitudes at the left (T3) vs. right (T4) scalp electrode and in a greater left-right amplitude difference in the right compared to left listening condition. The current AERP data provides evidence for the occurrence of cortical BICs during perceptual and postperceptual stages, presumably reflecting ongoing integration of information presented to the two ears at the final stages of auditory processing. Increasing binaural interaction with the progression of the auditory processing sequence (N1 to LNC) may support the notion that cortical BICs reflect inherited interactions from preceding stages of upstream processing together with discrete cortical neural activity involved in binaural processing. Clinically, an objective measure of cortical binaural processing has the potential of becoming an appealing neural correlate of binaural behavioral performance. American Academy of Audiology.

Geochemistry and mineralogy of the Dotson Zone HREE deposit in the Bokan Mountain peralkaline igneous complex, southeastern Alaska, USA

USGS Publications Warehouse

Taylor, Cliff D.; Lowers, Heather; Adams, David; Robinson, R. James

2017-01-01

The Bokan Mountain igneous complex (BMIC) is a typical example of a peralkaline intrusive system that has evolved to the point of developing late stage HFSE- and REE-rich silicic pegmatites and dikes. The Dotson Zone comprises a series of felsic dikes that extend from the southeast margin of the composite pluton and may represent an important resource of critical HREEs. Petrographically, the primary igneous mineral assemblage is altered by late-igneous and hydrothermal fluids resulting in redistribution and enrichment of REEs. An area of flexure in the southeastern end of the Dotson Zone was the primary locus of enrichment as shown by the pervasive alteration and consistently high REE+Y values. We favor a model in which the dikes were emplaced concurrently with the marginal intrusions, and then altered during emplacement of the inner, main intrusion in a relatively rapid series of overlapping intrusive and late magmatic fluid-high temperature hydrothermal events as the complex cooled. A much later sodic intrusive event focused on the BMIC may have resulted in additional silica-Na-Zr-rich alteration in proximity to the pluton.

Rainfall runoff modelling of the Upper Ganga and Brahmaputra basins using PERSiST.

PubMed

Futter, M N; Whitehead, P G; Sarkar, S; Rodda, H; Crossman, J

2015-06-01

There are ongoing discussions about the appropriate level of complexity and sources of uncertainty in rainfall runoff models. Simulations for operational hydrology, flood forecasting or nutrient transport all warrant different levels of complexity in the modelling approach. More complex model structures are appropriate for simulations of land-cover dependent nutrient transport while more parsimonious model structures may be adequate for runoff simulation. The appropriate level of complexity is also dependent on data availability. Here, we use PERSiST; a simple, semi-distributed dynamic rainfall-runoff modelling toolkit to simulate flows in the Upper Ganges and Brahmaputra rivers. We present two sets of simulations driven by single time series of daily precipitation and temperature using simple (A) and complex (B) model structures based on uniform and hydrochemically relevant land covers respectively. Models were compared based on ensembles of Bayesian Information Criterion (BIC) statistics. Equifinality was observed for parameters but not for model structures. Model performance was better for the more complex (B) structural representations than for parsimonious model structures. The results show that structural uncertainty is more important than parameter uncertainty. The ensembles of BIC statistics suggested that neither structural representation was preferable in a statistical sense. Simulations presented here confirm that relatively simple models with limited data requirements can be used to credibly simulate flows and water balance components needed for nutrient flux modelling in large, data-poor basins.

Formation mechanism of guided resonances and bound states in the continuum in photonic crystal slabs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Xingwei; Hsu, Chia Wei; Zhen, Bo

2016-08-25

We develop a formalism, based on the mode expansion method, to describe the guided resonances and bound states in the continuum (BICs) in photonic crystal slabs with one-dimensional periodicity. This approach provides analytic insights to the formation mechanisms of these states: the guided resonances arise from the transverse Fabry–Pérot condition, and the divergence of the resonance lifetimes at the BICs is explained by a destructive interference of radiation from different propagating components inside the slab. As a result, we show BICs at the center and on the edge of the Brillouin zone protected by symmetry, BICs at generic wave vectorsmore » not protected by symmetry, and the annihilation of BICs at low-symmetry wave vectors.« less

School staff, parent and student perceptions of a Breakfast in the Classroom model during initial implementation.

PubMed

Folta, Sara C; Carmichael Djang, Holly; Halmo, Megan; Metayer, Nesly; Blondin, Stacy A; Smith, Kathleen S; Economos, Christina D

2016-06-01

To understand perspectives of stakeholders during initial district-wide implementation of a Breakfast in the Classroom (BIC) model of the School Breakfast Program. Qualitative data were collected from twenty-nine focus groups and twenty interviews with stakeholders in a school district early in the process of implementing a BIC model of the School Breakfast Program. Ten elementary schools within a large, urban school district in the USA that served predominantly low-income, racial/ethnic minority students. Purposively selected stakeholders in elementary schools that had implemented BIC for 3-6 months: students (n 85), parents/guardians (n 86), classroom teachers (n 44), cafeteria managers (n 10) and principals (n 10). Four primary themes emerged, which were interpreted based on the Diffusion of Innovations model. School staff had changed their perceptions of both the relative disadvantages and costs related to time and effort of BIC over time; the majority of each stakeholder group expressed an appreciation for BIC; student breakfast consumption varied from day to day, related to compatibility of foods with child preferences; and stakeholders held mixed and various impressions of BIC's potential impacts. The study underscores the importance of engaging school staff and parents in discussions of BIC programming prior to its initiation to pre-emptively address concerns related to cost, relative disadvantages and compatibility with child preferences and school routines/workflow. Effectively communicating with stakeholders about positive impacts and nutritional value of the meals may improve support for BIC. These findings provide new information to policy makers, districts and practitioners that can be used to improve implementation efforts, model delivery and outcomes.

The Physiological Basis and Clinical Use of the Binaural Interaction Component of the Auditory Brainstem Response

PubMed Central

Klump, Georg M.; Tollin, Daniel J.

2016-01-01

The auditory brainstem response (ABR) is a sound-evoked non-invasively measured electrical potential representing the sum of neuronal activity in the auditory brainstem and midbrain. ABR peak amplitudes and latencies are widely used in human and animal auditory research and for clinical screening. The binaural interaction component (BIC) of the ABR stands for the difference between the sum of the monaural ABRs and the ABR obtained with binaural stimulation. The BIC comprises a series of distinct waves, the largest of which (DN1) has been used for evaluating binaural hearing in both normal hearing and hearing-impaired listeners. Based on data from animal and human studies, we discuss the possible anatomical and physiological bases of the BIC (DN1 in particular). The effects of electrode placement and stimulus characteristics on the binaurally evoked ABR are evaluated. We review how inter-aural time and intensity differences affect the BIC and, analyzing these dependencies, draw conclusion about the mechanism underlying the generation of the BIC. Finally, the utility of the BIC for clinical diagnoses are summarized. PMID:27232077

The Effect of Breakfast in the Classroom on Obesity and Academic Performance: Evidence from New York City.

PubMed

Corcoran, Sean P; Elbel, Brian; Schwartz, Amy Ellen

2016-01-01

Participation in the federally subsidized school breakfast program often falls well below its lunchtime counterpart. To increase take-up, many districts have implemented Breakfast in the Classroom (BIC), offering breakfast directly to students at the start of the school day. Beyond increasing participation, advocates claim BIC improves academic performance, attendance, and engagement. Others caution BIC has deleterious effects on child weight. We use the implementation of BIC in New York City (NYC) to estimate its impact on meals program participation, body mass index (BMI), achievement, and attendance. While we find large effects on participation, our findings provide no evidence of hoped-for gains in academic performance, or of feared increases in obesity. The policy case for BIC will depend upon reductions in hunger and food insecurity for disadvantaged children, or its longer-term effects.

The Binaural Interaction Component in Barn Owl (Tyto alba) Presents few Differences to Mammalian Data.

PubMed

Palanca-Castan, Nicolas; Laumen, Geneviève; Reed, Darrin; Köppl, Christine

2016-12-01

The auditory brainstem response (ABR) is an evoked potential that reflects the responses to sound by brainstem neural centers. The binaural interaction component (BIC) is obtained by subtracting the sum of the monaural ABR responses from the binaural response. Its latency and amplitude change in response to variations in binaural cues. The BIC is thus thought to reflect the activity of binaural nuclei and is used to non-invasively test binaural processing. However, any conclusions are limited by a lack of knowledge of the relevant processes at the level of individual neurons. The aim of this study was to characterize the ABR and BIC in the barn owl, an animal where the ITD-processing neural circuits are known in great detail. We recorded ABR responses to chirps and to 1 and 4 kHz tones from anesthetized barn owls. General characteristics of the barn owl ABR were similar to those observed in other bird species. The most prominent peak of the BIC was associated with nucleus laminaris and is thus likely to reflect the known processes of ITD computation in this nucleus. However, the properties of the BIC were very similar to previously published mammalian data and did not reveal any specific diagnostic features. For example, the polarity of the BIC was negative, which indicates a smaller response to binaural stimulation than predicted by the sum of monaural responses. This is contrary to previous predictions for an excitatory-excitatory system such as nucleus laminaris. Similarly, the change in BIC latency with varying ITD was not distinguishable from mammalian data. Contrary to previous predictions, this behavior appears unrelated to the known underlying neural delay-line circuitry. In conclusion, the generation of the BIC is currently inadequately understood and common assumptions about the BIC need to be reconsidered when interpreting such measurements.

The Effect of Breakfast in the Classroom on Obesity and Academic Performance: Evidence from New York City

PubMed Central

Corcoran, Sean P.; Elbel, Brian; Schwartz, Amy Ellen

2016-01-01

Participation in the federally subsidized school breakfast program often falls well below its lunchtime counterpart. To increase take-up, many districts have implemented Breakfast in the Classroom (BIC), offering breakfast directly to students at the start of the school day. Beyond increasing participation, advocates claim BIC improves academic performance, attendance, and engagement. Others caution BIC has deleterious effects on child weight. We use the implementation of BIC in New York City (NYC) to estimate its impact on meals program participation, body mass index (BMI), achievement, and attendance. While we find large effects on participation, our findings provide no evidence of hoped-for gains in academic performance, or of feared increases in obesity. The policy case for BIC will depend upon reductions in hunger and food insecurity for disadvantaged children, or its longer-term effects. PMID:27314139

Deciphering igneous and metamorphic events in high-grade rocks of the Wilmington complex, Delaware: Morphology, cathodoluminescence and backscattered electron zoning, and SHRIMP U-Pb geochronology of zircon and monazite

USGS Publications Warehouse

Aleinikoff, J.N.; Schenck, W.S.; Plank, M.O.; Srogi, L.A.; Fanning, C.M.; Kamo, S.L.; Bosbyshell, H.

2006-01-01

High-grade rocks of the Wilmington Complex, northern Delaware and adjacent Maryland and Pennsylvania, contain morphologically complex zircons that formed through both igneous and metamorphic processes during the development of an island-arc complex and suturing of the arc to Laurentia. The arc complex has been divided into several members, the protoliths of which include both intrusive and extrusive rocks. Metasedimentary rocks are interlayered with the complex and are believed to be the infrastructure upon which the arc was built. In the Wilmingto n Complex rocks, both igneous and metamorphic zircons occur as elongate and equant forms. Chemical zoning, shown by cathodoluminescence (CL), includes both concentric, oscillatory patterns, indicative of igneous origin, and patchwork and sector patterns, suggestive of metamorphic growth. Metamorphic monazites are chemically homogeneous, or show oscillatory or spotted chemical zoning in backscattered electron images. U-Pb geochronology by sensitive high resolution ion microprobe (SHRIMP) was used to date complexly zoned zircon and monazite. All but one member of the Wilmington Complex crystallized in the Ordovician between ca. 475 and 485 Ma; these rocks were intruded by a suite of gabbro-to-granite plutonic rocks at 434 ?? Ma. Detrital zircons in metavolcanic and metasedimentary units were derived predominantly from 0.9 to 1.4 Ga (Grenvillian) basement, presumably of Laurentian origin. Amphibolite to granulite facies metamorphism of the Wilmington Complex, recorded by ages of metamorphic zircon (428 ?? 4 and 432 ?? 6 Ma) and monazite (429 ?? 2 and 426 ?? 3 Ma), occurred contemporaneously with emplacement of the younger plutonic rocks. On the basis of varying CL zoning patterns and external morphologies, metamorphic zircons formed by different processes (presumably controlled by rock chemistry) at slightly different times and temperatures during prograde metamorphism. In addition, at least three other thermal episodes are recorded by monazite growth at 447 ?? 4, 411 ?? 3, and 398 ?? 3 Ma. ?? 2006 Geological Society of America.

Zircon U-Pb ages and petrogenesis of a tonalite-trondhjemite-granodiorite (TTG) complex in the northern Sanandaj-Sirjan zone, northwest Iran: Evidence for Late Jurassic arc-continent collision

NASA Astrophysics Data System (ADS)

Azizi, Hossein; Zanjefili-Beiranvand, Mina; Asahara, Yoshihiro

2015-02-01

The Ghalaylan Igneous Complex is located in the northern part of the Sanandaj-Sirjan zone (SSZ) in northwest Iran. At the surface, the complex is ellipsoidal or ring-shaped. The igneous rocks, which are medium- to fine-grained, were intruded into a Jurassic metamorphic complex and are cut by younger dikes. Zircon U-Pb ages indicate that the crystallization of the main body occurred from 157.9 ± 1.6 to 155.6 ± 5.6 Ma. The igneous complex includes granodiorite, tonalite, and quartz monzonite, as well as subvolcanic to volcanic rocks such as dacite and rhyolite. The rocks have high concentrations of Al2O3 (15-19 wt.%), SiO2 (65-70 wt.%), and Sr (700-1100 ppm), high (La/Yb)N ratios (15-40), and very low concentrations of MgO (< 0.83 wt.%), Ni (< 7 ppm), and Cr (usually < 50 ppm). There is a lack of negative Eu anomalies. These geochemical features show that the rocks are similar to high-silica adakites and Archaean tonalite-trondhjemite-granodiorite (TTG) rocks. The initial ratios of 87Sr/86Sr and 143Nd/144Nd vary from 0.70430 to 0.70476 and from 0.51240 to 0.51261, respectively, values that are similar to those of primitive mantle and the bulk Earth. The chemical compositions of the igneous rocks of the complex, and their isotope ratios, differ from those of neighboring granitic bodies in the northern SSZ. Based on our results, we suggest a new geodynamic model for the development of this complex, as follows. During the generation of the Songhor-Ghorveh island arc in the Neotethys Ocean, an extensional basin, such as a back-arc, developed between the island arc and the Sanandaj-Sirjan zone (SSZ). As a consequence, basaltic magma was injected from the asthenosphere without the development of a mature oceanic crust. During arc-continent collision in the Late Jurassic, hot basaltic rocks were present beneath the SSZ at depths of 30-50 km, and the partial melting of these rocks led to the development of TTG-type magmas, forming the source of the Ghalaylan Igneous Complex.

bicaudal-C is required for the formation of anterior neurogenic ectoderm in the sea urchin embryo.

PubMed

Yaguchi, Shunsuke; Yaguchi, Junko; Inaba, Kazuo

2014-10-31

bicaudal-C (bicC) mRNA encodes a protein containing RNA-binding domains that is reported to be maternally present with deflection in the oocytes/eggs of some species. The translated protein plays a critical role in the regulation of cell fate specification along the body axis during early embryogenesis in flies and frogs. However, it is unclear how it functions in eggs in which bicC mRNA is uniformly distributed, for instance, sea urchin eggs. Here, we show the function of BicC in the formation of neurogenic ectoderm of the sea urchin embryo. Loss-of-function experiments reveal that BicC is required for serotonergic neurogenesis and for expression of ankAT-1 gene, which is essential for the formation of apical tuft cilia in the neurogenic ectoderm of the sea urchin embryo. In contrast, the expression of FoxQ2, the neurogenic ectoderm specification transcription factor, is invariant in BicC morphants. Because FoxQ2 is an upstream factor of serotonergic neurogenesis and ankAT-1 expression, these data indicate that BicC functions in regulating the events that are coordinated by FoxQ2 during sea urchin embryogenesis.

Antibacterial, antibiofilm and antioxidant screening of copper(II)-complexes with some S-alkyl derivatives of thiosalicylic acid. Crystal structure of the binuclear copper(II)-complex with S-propyl derivative of thiosalicylic acid

NASA Astrophysics Data System (ADS)

Bukonjić, Andriana M.; Tomović, Dušan Lj.; Nikolić, Miloš V.; Mijajlović, Marina Ž.; Jevtić, Verica V.; Ratković, Zoran R.; Novaković, Slađana B.; Bogdanović, Goran A.; Radojević, Ivana D.; Maksimović, Jovana Z.; Vasić, Sava M.; Čomić, Ljiljana R.; Trifunović, Srećko R.; Radić, Gordana P.

2017-01-01

The spectroscopically predicted structure of the obtained copper(II)-complex with S-propyl derivative of thiosalicylic acid was confirmed by X-ray structural study. The binuclear copper(II)-complex with S-propyl derivative of thiosalicylic acid crystallized in two polymorphic forms with main structural difference in the orientation of phenyl rings relative to corresponding carboxylate groups. The antibacterial activity was tested determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) by using microdilution method. The influence on bacterial biofilm formation was determined by tissue culture plate method. In general, the copper(II)-complexes manifested a selective and moderate activity. The most sensitive bacteria to the effects of Cu(II)-complexes was a clinical isolate of Pseudomonas aeruginosa. For this bacteria MIC and biofilm inhibitory concentration (BIC) values for all tested complexes were in the range or better than the positive control, doxycycline. Also, for the established biofilm of clinical isolate Staphylococcus aureus, BIC values for the copper(II)-complex with S-ethyl derivative of thiosalicylic acid,[Cu2(S-et-thiosal)4(H2O)2] (C3) and copper(II)-complex with S-butyl derivative of thiosalicylic acid, [Cu2(S-bu-thiosal)4(H2O)2] (C5) were in range or better than the positive control. All the complexes acted better against Gram-positive bacteria (Staphylococcus aureus and Staphylococcus aureus ATCC 25923) than Gram-negative bacteria (Proteus mirabilis ATCC 12453, Pseudomonas aeruginosa, and P. aeruginosa ATCC 27855). The complexes showed weak antioxidative properties tested by two methods (1,1-diphenyl-2-picrylhydrazyl (DPPH) and reducing power assay).

Regional investigations of tectonic and igneous geology, Iran, Pakistan, and Turkey

NASA Technical Reports Server (NTRS)

1978-01-01

The author has identified the following significant results. An extension of the trace of the Chaman-Nushki fault was detected and delineated for 42 km, as was the Ornach-Nal fault for 170 km. Two structural intersections responsible for restricted movements in particular segments of the Chaman-Nushki fault were detected and interpreted. The newest and youngest fault named the Quetta-Mustung-Surab system was delineated for 580 km. The igneous complex of the Lasbela area was interpreted and differentiation was made between ultramafic complex, mafic complex, and basaltic lava flows. One oblong feature was also found which was interpreted as a porphyritic basalt plug.

Magnaporthe oryzae Glycine-Rich Secretion Protein, Rbf1 Critically Participates in Pathogenicity through the Focal Formation of the Biotrophic Interfacial Complex

PubMed Central

Ishii-Minami, Naoko; Kawahara, Yoshihiro; Yoshida, Yuri; Okada, Kazunori; Ando, Sugihiro; Matsumura, Hideo; Terauchi, Ryohei; Minami, Eiichi; Nishizawa, Yoko

2016-01-01

Magnaporthe oryzae, the fungus causing rice blast disease, should contend with host innate immunity to develop invasive hyphae (IH) within living host cells. However, molecular strategies to establish the biotrophic interactions are largely unknown. Here, we report the biological function of a M. oryzae-specific gene, R equired-for-Focal- B IC- F ormation 1 (RBF1). RBF1 expression was induced in appressoria and IH only when the fungus was inoculated to living plant tissues. Long-term successive imaging of live cell fluorescence revealed that the expression of RBF1 was upregulated each time the fungus crossed a host cell wall. Like other symplastic effector proteins of the rice blast fungus, Rbf1 accumulated in the biotrophic interfacial complex (BIC) and was translocated into the rice cytoplasm. RBF1-knockout mutants (Δrbf1) were severely deficient in their virulence to rice leaves, but were capable of proliferating in abscisic acid-treated or salicylic acid-deficient rice plants. In rice leaves, Δrbf1 inoculation caused necrosis and induced defense-related gene expression, which led to a higher level of diterpenoid phytoalexin accumulation than the wild-type fungus did. Δrbf1 showed unusual differentiation of IH and dispersal of the normally BIC-focused effectors around the short primary hypha and the first bulbous cell. In the Δrbf1-invaded cells, symplastic effectors were still translocated into rice cells but with a lower efficiency. These data indicate that RBF1 is a virulence gene essential for the focal BIC formation, which is critical for the rice blast fungus to suppress host immune responses. PMID:27711180

Geology is the Key to Explain Igneous Activity in the Mediterranean Area

NASA Astrophysics Data System (ADS)

Lustrino, M.

2014-12-01

Igneous activity in tectonically complex areas can be interpreted in many different ways, producing completely different petrogenetic models. Processes such as oceanic and continental subduction, lithospheric delamination, changes in subduction polarity, slab break-off and mantle plumes have all been advocated as causes for changes in plate boundaries and magma production, including rate and temporal distribution, in the circum-Mediterranean area. This region thus provides a natural laboratory to investigate a range of geodynamic and magmatic processes. Although many petrologic and tectonic models have been proposed, a number of highly controversial questions still remain. No consensus has yet been reached about the capacity of plate-tectonic processes to explain the origin and style of the magmatism. Similarly, there is still not consensus on the ability of geochemical and petrological arguments to reveal the geodynamic evolution of the area. The wide range of chemical and mineralogical magma compositions produced within and around the Mediterranean, from carbonatites to strongly silica-undersaturated silico-carbonatites and melilitites to strongly silica-oversaturated rhyolites, complicate models and usually require a large number of unconstrained assumptions. Can the calcalkaline-sodic alkaline transition be related to any common petrogenetic point? Is igneous activity plate-tectonic- (top-down) or deep-mantle-controlled (bottom-up)? Do the rare carbonatites and carbonate-rich igneous rocks derive from the deep mantle or a normal, CO2-bearing upper mantle? Do ultrapotassic compositions require continental subduction? Understanding chemically complex magmas emplaced in tectonically complex areas require open minds, and avoiding dogma and assumptions. Studying the geology and shallow dynamics, not speculating about the deep lower mantle, is the key to understanding the igneous activity.

[Effect of anti-cancer drugs on the expression of BIC/miR-155 in human pancreatic cancer PANC-1 cells].

PubMed

Xia, Qi-sheng; Ishigaki, Yasuhito; Sun, Li; Chen, Rui; Motoo, Yoshiharu

2010-01-12

To investigate the effect of anti-cancer drugs on the expression of B-cell integration cluster (BIC) RNA/miRNA-155 in human pancreatic cancer PANC-1 cells. PANC-1 cells were treated with different concentrations of anti-cancer drugs. Total RNA of the treated cells were harvested and the expression levels of BIC RNA and mature miR-155 were quantified by using Taqman FAM/MGB probes on a real-time PCR system. Relative quantification was carried out using the DeltaDeltaCt method. A PI3K-related kinases inhibitor was used to determine whether these kinases were involved in the regulation of BIC RNA. The expression of BIC RNA was strongly induced by anti-cancer drugs. When PANC-1 cells were treated by gemcitabine with concentrations of 1.0, 2.5, 5.0, 10.0 mg/L for 48 h and 72 h, the level of BIC RNA (48 h: 37.1 +/- 4.1, 29.0 +/- 5.7, 21.0 +/- 7.6, 40.4 +/- 9.0, 72 h: 27.7 +/- 3.1, 43.1 +/- 1.2, 31.8 +/- 5.4, 23.1 +/- 1.4) were significantly higher than that of the control (48 h: 1.6 +/- 1.1, 72 h: 1.0 +/- 0.1, all P < 0.05). 5-FU (10 mg/L, 48 h) and bleomycin (100 mg/L, 48 h) also induced BIC RNA up-regulation (5.2 +/- 1.1 vs 1.7 +/- 0.7, 11.5 +/- 0.7 vs 1.7 +/- 0.7, both P < 0.05). When PANC-1 cells treated with 1.0, 2.5, 5.0, 10.0 mg/L gemcitabine for 72 h, the level of miR-155 (2.21 +/- 0.40, 1.86 +/- 0.03, 2.47 +/- 0.04, 3.24 +/- 0.05) also higher than that of the control (1.11 +/- 0.09, P < 0.05), while no change was observed when the cells only treated for 48 h. Further study showed gemcitabine-induced BIC RNA up-regulation was inhibited by wortmannin, a specific PI3K inhibitor, the expression levels of BIC RNA of 1 micromol/L wortmannin + 5 mg/L gemcitabine group and 10 micromol/L wortmannin + 5 mg/L gemcitabine group were 5.34 +/- 1.11 and 1.26 +/- 0.07, lower than that of 5 mg/L gemcitabine group (11.82 +/- 3.11, P < 0.05). BIC RNA is strongly induced by anti-cancer drugs in PANC-1 cells and the levels of miR-155 also slightly increase. PI3K pathway is involved in gemcitabine-induced BIC RNA up-regulation.

Osseoconductivity of a Specific Streptavidin-Biotin-Fibronectin Surface Coating of Biotinylated Titanium Implants - A Rabbit Animal Study.

PubMed

Kämmerer, Peer W; Lehnert, Michael; Al-Nawas, Bilal; Kumar, Vinay V; Hagmann, Sebastien; Alshihri, Abdulmonem; Frerich, Bernhard; Veith, Michael

2015-10-01

Biofunctionalized implant surfaces may accelerate bony integration and increase long-term stability. The aim of the study was to evaluate the osseous reaction toward biomimetic titanium implants surfaces coated with quasicovalent immobilized fibronectin in an in vivo animal model. A total of 84 implants (uncoated [control 1, n = 36], streptavidin-biotin coated [test 1, n = 24], streptavidin-biotin-fibronectin coated [test 2, n = 24]) were inserted 1 mm supracortically in the proximal tibia of 12 rabbits. The samples were examined after 3 and 6 weeks. Total bone-implant contact (tBIC; %), bone-implant contact in the cortical (cBIC; %) and in the spongious bone (sBIC; %) as well as the percentage of linear bone fill (PLF; %) were evaluated. After 3 weeks, streptavidin-biotin-fibronectin implants had a significant higher sBIC (p = .043) and PLF (p = .007) compared with the uncoated samples. After 6 weeks, this difference was significant for tBIC (p = .016) and cBIC (p < .001). Additionally, uncoated screws showed a significant higher sBIC when compared with the fibronectin coating (p < .001). Streptavidin-biotin-coated implants showed less bone growth at both time points of all examined parameters when compared with their counterparts (all p < .001). Quasicovalent immobilization of biotinylated fibronectin with the streptavidin-biotin-fibronectin system on smooth surface titanium shows a beneficial faster osseous healing in vivo. Besides, an antifouling effect of the streptavidin-biotin coating was proven. © 2015 Wiley Periodicals, Inc.

Efficacies of Cabotegravir and Bictegravir against drug-resistant HIV-1 integrase mutants.

PubMed

Smith, Steven J; Zhao, Xue Zhi; Burke, Terrence R; Hughes, Stephen H

2018-05-16

Integrase strand transfer inhibitors (INSTIs) are the class of antiretroviral (ARV) drugs most recently approved by the FDA for the treatment of HIV-1 infections. INSTIs block the strand transfer reaction catalyzed by HIV-1 integrase (IN) and have been shown to potently inhibit infection by wild-type HIV-1. Of the three current FDA-approved INSTIs, Dolutegravir (DTG), has been the most effective, in part because treatment does not readily select for resistant mutants. However, recent studies showed that when INSTI-experienced patients are put on a DTG-salvage therapy, they have reduced response rates. Two new INSTIs, Cabotegravir (CAB) and Bictegravir (BIC), are currently in late-stage clinical trials. Both CAB and BIC had much broader antiviral profiles than RAL and EVG against the INSTI-resistant single, double, and triple HIV-1 mutants used in this study. BIC was more effective than DTG against several INSTI-resistant mutants. Overall, in terms of their ability to inhibit a broad range of INSTI-resistant IN mutants, BIC was superior to DTG, and DTG was superior to CAB. Modeling the binding of CAB, BIC, and DTG within the active site of IN suggested that the "left side" of the INSTI pharmacophore (the side away from the viral DNA) was important in determining the ability of the compound to inhibit the IN mutants we tested. Of the two INSTIs in late stage clinical trials, BIC appears to be better able to inhibit the replication of a broad range of IN mutants. BIC retained potency against several of the INSTI-resistant mutants that caused a decrease in susceptibility to DTG.

MULTIPLE EPISODES OF IGNEOUS ACTIVITY, MINERALIZATION, AND ALTERATION IN THE WESTERN TUSHAR MOUNTAINS, UTAH.

USGS Publications Warehouse

Cunningham, Charles G.; Steven, Thomas A.; Campbell, David L.; Naeser, Charles W.; Pitkin, James A.; Duval, Joseph S.

1984-01-01

The report outlines the complex history of igneous activity and associated alteration and mineralization in the western Tushar Mountains, Utah and pointss out implciations for minerals exploration. The area has been subjected to recurrent episodes of igneous intrusion, hydrothermal alteration, and mineralization, and the mineral-resource potential of the different mineralized areas is directly related to local geologic history. The mineral commodities to be expected vary from one hydrothermal system to another, and from one depth to another within any given system. Uranium and molybdenum seem likely to have the greatest economic potential, although significant concentrations of gold may also exist.

Magmatic Complexes of the Vetlovaya Marginal Sea Paleobasin (Kamchatka): Composition and Geodynamic Setting

NASA Astrophysics Data System (ADS)

Tsukanov, N. V.; Saveliev, D. P.; Kovalenko, D. V.

2018-01-01

This study presents new geochemical and isotope data on igneous rocks of the Vetlovaya marginal sea paleobasin (part of the Late Mesozoic-Cenozoic margin of the northwestern Pacific). The results show that the rock complexes of this marginal sea basin comprise igneous rocks with geochemical compositions similar to those of normal oceanic tholeiites, enriched transitional tholeiites, and ocean island and back-arc basin basalts. Island-arc tholeiitic basalts are present only rarely. The specific geochemical signatures of these rocks are interpreted as being related to mantle heterogeneity and the geodynamic conditions in the basin.

Intrusive origin of the Sudbury Igneous Complex: Structural and sedimentological evidence

NASA Technical Reports Server (NTRS)

Cowan, E. J.; Schwerdtner, W. M.

1992-01-01

In recent years, many geoscientists have come to believe that the Sudbury event was exogenic rather than endogenic. Critical to a recent exogenic hypothesis is the impact melt origin of the Sudbury Igneous Complex (SIC). Such origin implies that the SIC was emplaced before deposition of the Whitewater Group, in contrast to origins in which the SIC postdates the lithification of the Onaping Formation. Structural and sedimentological evidence is summarized herein that supports an intrusion of the SIC after lithification of all Whitewater Group strata, and conflicts with the hypothesis advanced by other researchers.

Comparative 3D micro-CT and 2D histomorphometry analysis of dental implant osseointegration in the maxilla of minipigs.

PubMed

Bissinger, Oliver; Probst, Florian Andreas; Wolff, Klaus-Dietrich; Jeschke, Anke; Weitz, Jochen; Deppe, Herbert; Kolk, Andreas

2017-04-01

The bone implant contact (BIC) has traditionally been evaluated with histological methods. Thereupon, strong correlations of two-dimensional (2D) BIC have been detected between μCT and destructive histology. However, due to the high intra-sample variability in BIC values, one histological slice is not sufficient to represent 3D BIC. Therefore, our aim has been to correlate the averaged values of 3-4 histological sections to 3D μCT. Fifty-four implants inserted into the maxilla of 14 minipigs were evaluated. Two different time points were selected to assess the 3D BIC (distance to implant: 2-5 voxels), an inner ring (6-30 voxels) and an outer ring (55-100 voxels) using μCT (voxel size: 10 μm) and to correlate the values to histomorphometry. Strong correlations (p < 0.0001; 28 days, 56 days, total) were seen between μCT and histomorphometry concerning BIC (r = 0.84, r = 0.85, r = 0.83), the inner ring (r = 0.87, r = 0.87, r = 0.88) and the outer ring (r = 0.85, r = 0.85, r = 0.88). Closer to the implant, μCT values were higher compared with histomorphometry. Although 3-4 histological slices per implant seem to predict the 3D BIC, μCT might be advantageous because of its non-destructive 3D character. The healing time may not impact on the comparability. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Controlling 212Bi to 212Pb activity concentration ratio in thoron chambers.

PubMed

He, Zhengzhong; Xiao, Detao; Lv, Lidan; Zhou, Qingzhi; Shan, Jian; Qiu, Shoukang; Wu, Xijun

2017-11-01

It is necessary to establish a reference atmosphere in a thoron chamber containing various ratios of 212 Bi to 212 Pb activity concentrations (C( 212 Bi)/C( 212 Pb)) to simulate typical environmental conditions (e.g., indoor or underground atmospheres). In this study, a novel method was developed for establishing and controlling C( 212 Bi)/C( 212 Pb) in a thoron chamber system based on an aging chamber and air recirculation loops which alter the ventilation rate. The effects of main factors on the C( 212 Bi)/C( 212 Pb) were explored, and a steady-state theoretical model was derived to calculate the ratio. The results show that the C( 212 Bi)/C( 212 Pb) inside the chamber is mainly dependent on ventilation rate. Ratios ranging from 0.33 to 0.83 are available under various ventilation. The stability coefficient of the ratios is better than 7%. The experimental results are close to the theoretical calculated results, which indicates that the model can serve as a guideline for the quantitative control of C( 212 Bi)/C( 212 Pb). Copyright © 2017 Elsevier Ltd. All rights reserved.

A new audience segmentation tool for African Americans: the black identity classification scale.

PubMed

Davis, Rachel E; Alexander, Gwen; Calvi, Josephine; Wiese, Cheryl; Greene, Sarah; Nowak, Mike; Cross, William E; Resnicow, Ken

2010-07-01

Many health communications target African Americans in an attempt to remediate race-based health disparities. Such materials often assume that African Americans are culturally homogeneous; however, research indicates that African Americans are heterogeneous in their attitudes, behaviors, and beliefs. The Black Identity Classification Scale (BICS) was designed as a telephone-administered tool to segment African American audiences into 16 ethnic identity types. The BICS was pretested using focus groups, telephone pretests, and a pilot study (n = 306). The final scale then was administered to 625 Black adults participating in a dietary intervention study, where it generally demonstrated good internal consistency reliability. The construct validity of the BICS also was explored by comparing participants' responses to culturally associated survey items. The distribution of the 16 BICS identity types in the intervention study is presented, as well as select characteristics for participants with core identity components. Although additional research is warranted, these findings suggest that the BICS has good psychometric properties and may be an effective tool for identifying African American audience segments.

A New Audience Segmentation Tool for African Americans: The Black Identity Classification Scale

PubMed Central

DAVIS, RACHEL E.; ALEXANDER, GWEN; CALVI, JOSEPHINE; WIESE, CHERYL; GREENE, SARAH; NOWAK, MIKE; CROSS, WILLIAM E.; RESNICOW, KEN

2011-01-01

Many health communications target African Americans in an attempt to remediate race-based health disparities. Such materials often assume that African Americans are culturally homogeneous; however, research indicates that African Americans are heterogeneous in their attitudes, behaviors, and beliefs. The Black Identity Classification Scale (BICS) was designed as a telephone-administered tool to segment African American audiences into 16 ethnic identity types. The BICS was pretested using focus groups, telephone pretests, and a pilot study (n=306). The final scale was then administered to 625 Black adults participating in a dietary intervention study, where it generally demonstrated good internal consistency reliability. The construct validity of the BICS was also explored by comparing participants’ responses to culturally associated survey items. The distribution of the 16 BICS identity types in the intervention study is presented, as well as select characteristics for participants with core identity components. Although additional research is warranted, these findings suggest that the BICS has good psychometric properties and may be an effective tool for identifying African American audience segments. PMID:20677057

Controlling Directionality and Dimensionality of Radiation by Perturbing Separable Bound States in the Continuum

DOE PAGES

Rivera, Nicholas; Hsu, Chia Wei; Zhen, Bo; ...

2016-09-19

Here, a bound state in the continuum (BIC) is an unusual localized state that is embedded in a continuum of extended states. Here, we present the general condition for BICs to arise from wave equation separability. Then we show that by exploiting perturbations of certain symmetry such BICs can be turned into resonances that radiate with a tailorable directionality and dimensionality. Using this general framework, we construct new examples of separable BICs and resonances that can exist in optical potentials for ultracold atoms, photonic systems, and systems described by tight binding. Such resonances with easily reconfigurable radiation allow for applicationsmore » such as the storage and release of waves at a controllable rate and direction, as well systems that switch between different dimensions of confinement.« less

Nuclear pore complex tethers to the cytoskeleton.

PubMed

Goldberg, Martin W

2017-08-01

The nuclear envelope is tethered to the cytoskeleton. The best known attachments of all elements of the cytoskeleton are via the so-called LINC complex. However, the nuclear pore complexes, which mediate the transport of soluble and membrane bound molecules, are also linked to the microtubule network, primarily via motor proteins (dynein and kinesins) which are linked, most importantly, to the cytoplasmic filament protein of the nuclear pore complex, Nup358, by the adaptor BicD2. The evidence for such linkages and possible roles in nuclear migration, cell cycle control, nuclear transport and cell architecture are discussed. Copyright © 2017. Published by Elsevier Ltd.

Network models provide insights into how oriens–lacunosum-moleculare and bistratified cell interactions influence the power of local hippocampal CA1 theta oscillations

PubMed Central

Ferguson, Katie A.; Huh, Carey Y. L.; Amilhon, Bénédicte; Manseau, Frédéric; Williams, Sylvain; Skinner, Frances K.

2015-01-01

Hippocampal theta is a 4–12 Hz rhythm associated with episodic memory, and although it has been studied extensively, the cellular mechanisms underlying its generation are unclear. The complex interactions between different interneuron types, such as those between oriens–lacunosum-moleculare (OLM) interneurons and bistratified cells (BiCs), make their contribution to network rhythms difficult to determine experimentally. We created network models that are tied to experimental work at both cellular and network levels to explore how these interneuron interactions affect the power of local oscillations. Our cellular models were constrained with properties from patch clamp recordings in the CA1 region of an intact hippocampus preparation in vitro. Our network models are composed of three different types of interneurons: parvalbumin-positive (PV+) basket and axo-axonic cells (BC/AACs), PV+ BiCs, and somatostatin-positive OLM cells. Also included is a spatially extended pyramidal cell model to allow for a simplified local field potential representation, as well as experimentally-constrained, theta frequency synaptic inputs to the interneurons. The network size, connectivity, and synaptic properties were constrained with experimental data. To determine how the interactions between OLM cells and BiCs could affect local theta power, we explored how the number of OLM-BiC connections and connection strength affected local theta power. We found that our models operate in regimes that could be distinguished by whether OLM cells minimally or strongly affected the power of network theta oscillations due to balances that, respectively, allow compensatory effects or not. Inactivation of OLM cells could result in no change or even an increase in theta power. We predict that the dis-inhibitory effect of OLM cells to BiCs to pyramidal cell interactions plays a critical role in the resulting power of network theta oscillations. Overall, our network models reveal a dynamic interplay between different classes of interneurons in influencing local theta power. PMID:26300744

Evaluating the effects of caffeine and sodium bicarbonate, ingested individually or in combination, and a taste-matched placebo on high-intensity cycling capacity in healthy males.

PubMed

Higgins, Matthew F; Wilson, Susie; Hill, Cameron; Price, Mike J; Duncan, Mike; Tallis, Jason

2016-04-01

This study evaluated the effects of ingesting sodium bicarbonate (NaHCO3) or caffeine individually or in combination on high-intensity cycling capacity. In a counterbalanced, crossover design, 13 healthy, noncycling trained males (age: 21 ± 3 years, height: 178 ± 6 cm, body mass: 76 ± 12 kg, peak power output (Wpeak): 230 ± 34 W, peak oxygen uptake: 46 ± 8 mL·kg(-1)·min(-1)) performed a graded incremental exercise test, 2 familiarisation trials, and 4 experimental trials. Trials consisted of cycling to volitional exhaustion at 100% Wpeak (TLIM) 60 min after ingesting a solution containing either (i) 0.3 g·kg(-1) body mass sodium bicarbonate (BIC), (ii) 5 mg·kg(-1) body mass caffeine plus 0.1 g·kg(-1) body mass sodium chloride (CAF), (iii) 0.3 g·kg(-1) body mass sodium bicarbonate plus 5 mg·kg(-1) body mass caffeine (BIC-CAF), or (iv) 0.1 g·kg(-1) body mass sodium chloride (PLA). Experimental solutions were administered double-blind. Pre-exercise, at the end of exercise, and 5-min postexercise blood pH, base excess, and bicarbonate ion concentration ([HCO3(-)]) were significantly elevated for BIC and BIC-CAF compared with CAF and PLA. TLIM (median; interquartile range) was significantly greater for CAF (399; 350-415 s; P = 0.039; r = 0.6) and BIC-CAF (367; 333-402 s; P = 0.028; r = 0.6) compared with BIC (313: 284-448 s) although not compared with PLA (358; 290-433 s; P = 0.249, r = 0.3 and P = 0.099 and r = 0.5, respectively). There were no differences between PLA and BIC (P = 0.196; r = 0.4) or between CAF and BIC-CAF (P = 0.753; r = 0.1). Relatively large inter- and intra-individual variation was observed when comparing treatments and therefore an individual approach to supplementation appears warranted.

Generation of TNFalpha and interleukin-6 by peritoneal macrophages after overnight dwells with bicarbonate- or lactate-buffered dialysis fluid.

PubMed

Liberek, Tomasz; Lichodziejewska-Niemierko, Monika; Knopinska-Posluszny, Wanda; Schaub, Thomas P; Kirchgessner, Judith; Passlick-Deetjen, Jutta; Rutkowski, Boleslaw

2002-01-01

In order to evaluate the biocompatibility profile of a newly designed peritoneal dialysis fluid (PDF), we evaluated peritoneal leukocyte (PMphi) cytokine release following overnight in vivo dwells using standard, lactate-buffered, single-chamber bag PDF (Lac-PDF) and purely bicarbonate-buffered, double-chamber bag PDF containing 34 (Bic-PDF) or 39 (Bic Hi-PDF) mmol/L bicarbonate. A randomized, open, crossover clinical trial with single weekly test dwells was performed in stable, long-term continuous ambulatory PD patients (n = 8). During 8-hour overnight dwells, PMphi were exposed to different PDF containing 1.5% glucose. After drainage, peritoneal cells were isolated and incubated with RPMI 1640 medium for 2 or 3 hours, with and without stimulation by lipopolysaccharide (LPS). Ex vivo release of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 was measured by specific ELISA technique. After pre-exposure to Lac-PDF, PMphi generated 242 +/- 279 pg TNFalpha/10(6) cells and 157 +/- 105 pg IL-6/10(6) cells. When pre-exposed to Bic-PDF and Bic Hi-PDF, TNFa and IL-6 production of PMphi was not significantly different from Lac-PDF. After LPS stimulation (100 ng/mL), PMD secretion of TNFalpha and IL-6 pre-exposed to three PDF revealed no significant differences between groups: TNFalpha was 2,864 +/- 1,216, 2,910 +/- 1,202, and 3,291 +/- 558 pg/10(6) cells after overnight dwells with Lac-PDF, Bic-PDF, and Bic Hi-PDF, respectively. Comparably, LPS-stimulated (100 pg/ mL) PMphi showed IL-6 secretion of 891 +/- 335, 1,380 +/- 1,149, and 1,442 +/- 966 pg/10(6) cells for Lac-PDF, Bic-PDF, and Bic Hi-PDF. After long-term overnight dwells, initial pH, the different buffers, and varying glucose degradation product levels of PDF do not strongly affect PMphi function with respect to cytokine release. The lack of significant differences between fluids may result from the complete dialysate equilibration achieved during the overnight intraperitoneal dwell.

U–Pb geochronology documents out-of-sequence emplacement of ultramafic layers in the Bushveld Igneous Complex of South Africa

PubMed Central

Mungall, James E.; Kamo, Sandra L.; McQuade, Stewart

2016-01-01

Layered intrusions represent part of the plumbing systems that deliver vast quantities of magma through the Earth's crust during the formation of large igneous provinces, which disrupt global ecosystems and host most of the Earth's endowment of Pt, Ni and Cr deposits. The Rustenburg Layered Suite of the enormous Bushveld Igneous Complex of South Africa has been presumed to have formed by deposition of crystals at the floor of a subterranean sea of magma several km deep and hundreds of km wide called a magma chamber. Here we show, using U–Pb isotopic dating of zircon and baddeleyite, that individual chromitite layers of the Rustenburg Layered Suite formed within a stack of discrete sheet-like intrusions emplaced and solidified as separate bodies beneath older layers. Our U–Pb ages and modelling necessitate reassessment of the genesis of layered intrusions and their ore deposits, and challenge even the venerable concept of the magma chamber itself. PMID:27841347

U-Pb geochronology documents out-of-sequence emplacement of ultramafic layers in the Bushveld Igneous Complex of South Africa.

PubMed

Mungall, James E; Kamo, Sandra L; McQuade, Stewart

2016-11-14

Layered intrusions represent part of the plumbing systems that deliver vast quantities of magma through the Earth's crust during the formation of large igneous provinces, which disrupt global ecosystems and host most of the Earth's endowment of Pt, Ni and Cr deposits. The Rustenburg Layered Suite of the enormous Bushveld Igneous Complex of South Africa has been presumed to have formed by deposition of crystals at the floor of a subterranean sea of magma several km deep and hundreds of km wide called a magma chamber. Here we show, using U-Pb isotopic dating of zircon and baddeleyite, that individual chromitite layers of the Rustenburg Layered Suite formed within a stack of discrete sheet-like intrusions emplaced and solidified as separate bodies beneath older layers. Our U-Pb ages and modelling necessitate reassessment of the genesis of layered intrusions and their ore deposits, and challenge even the venerable concept of the magma chamber itself.

Competitive chiral induction in a 2D molecular assembly: Intrinsic chirality versus coadsorber-induced chirality.

PubMed

Chen, Ting; Li, Shu-Ying; Wang, Dong; Wan, Li-Jun

2017-11-01

Noncovalently introducing stereogenic information is a promising approach to embed chirality in achiral molecular systems. However, the interplay of the noncovalently introduced chirality with the intrinsic chirality of molecules or molecular aggregations has rarely been addressed. We report a competitive chiral expression of the noncovalent interaction-mediated chirality induction and the intrinsic stereogenic center-controlled chirality induction in a two-dimensional (2D) molecular assembly at the liquid/solid interface. Two enantiomorphous honeycomb networks are formed by the coassembly of an achiral 5-(benzyloxy)isophthalic acid (BIC) derivative and 1-octanol at the liquid/solid interface. The preferential formation of the globally homochiral assembly can be achieved either by using the chiral analog of 1-octanol, ( S )-6-methyl-1-octanol, as a chiral coadsorber to induce chirality to the BIC assembly via noncovalent hydrogen bonding or by covalently linking a chiral center in the side chain of BIC. Both the chiral coadsorber and the intrinsically chiral BIC derivative can act as a chiral seeds to induce a preferred handedness in the assembly of the achiral BIC derivatives. Furthermore, the noncovalent interaction-mediated chirality induction can restrain or even overrule the manifestation of the intrinsic chirality of the BIC molecule and dominate the handedness of the 2D molecular coassembly. This study provides insight into the interplay of intrinsically chiral centers and external chiral coadsorbers in the chiral induction, transfer, and amplification processes of 2D molecular assembly.

Competitive chiral induction in a 2D molecular assembly: Intrinsic chirality versus coadsorber-induced chirality

PubMed Central

Chen, Ting; Li, Shu-Ying; Wang, Dong; Wan, Li-Jun

2017-01-01

Noncovalently introducing stereogenic information is a promising approach to embed chirality in achiral molecular systems. However, the interplay of the noncovalently introduced chirality with the intrinsic chirality of molecules or molecular aggregations has rarely been addressed. We report a competitive chiral expression of the noncovalent interaction–mediated chirality induction and the intrinsic stereogenic center–controlled chirality induction in a two-dimensional (2D) molecular assembly at the liquid/solid interface. Two enantiomorphous honeycomb networks are formed by the coassembly of an achiral 5-(benzyloxy)isophthalic acid (BIC) derivative and 1-octanol at the liquid/solid interface. The preferential formation of the globally homochiral assembly can be achieved either by using the chiral analog of 1-octanol, (S)-6-methyl-1-octanol, as a chiral coadsorber to induce chirality to the BIC assembly via noncovalent hydrogen bonding or by covalently linking a chiral center in the side chain of BIC. Both the chiral coadsorber and the intrinsically chiral BIC derivative can act as a chiral seeds to induce a preferred handedness in the assembly of the achiral BIC derivatives. Furthermore, the noncovalent interaction–mediated chirality induction can restrain or even overrule the manifestation of the intrinsic chirality of the BIC molecule and dominate the handedness of the 2D molecular coassembly. This study provides insight into the interplay of intrinsically chiral centers and external chiral coadsorbers in the chiral induction, transfer, and amplification processes of 2D molecular assembly. PMID:29119137

GABAergic regulation of REM sleep in reticularis pontis oralis and caudalis in rats.

PubMed

Sanford, Larry D; Tang, Xiangdong; Xiao, Jihua; Ross, Richard J; Morrison, Adrian R

2003-08-01

The nucleus reticularis pontis oralis (RPO) and nucleus reticularis pontis caudalis (RPC) are implicated in the generation of rapid eye movement sleep (REM). Work in cats has indicated that GABA in RPO plays a role in the regulation of REM. We assessed REM after local microinjections into RPO and RPC of the gamma-aminobutyric acid-A (GABA(A)) agonist, muscimol (MUS), and the GABA(A) antagonist, bicuculline (BIC). Rats (90-day-old male Sprague-Dawley) were implanted with electrodes for recording electroencephalographs (EEG) and electromyographs (EMG). Guide cannulae were aimed into RPO (n = 9) and RPC (n = 8) for microinjecting MUS (200, 1,000.0 microM) and BIC (0.056, 0.333, 1.0, 1,000.0, and 10,000.0 microM). Animals received bilateral microinjections of saline, MUS, and BIC (0.2 microl microinjected at 0.1 microl/min) into each region followed by 6-h sleep recordings. In RPO, MUS (1,000.0 microM) suppressed REM and BIC (1,000.0 microM) enhanced REM. In RPC, MUS (200, 1,000.0 microM) suppressed REM, but BIC (1,000.0 microM and less) did not significantly affect REM. Higher concentrations of BIC (10,000.0 microM) injected into RPO (n = 9) and RPC (n = 4) produced wakefulness and escape behavior. The results indicate that GABA in RPO/RPC is involved in the regulation of REM and suggest site-specific differences in this regulation.

Antibody-Mediated Complement C3b/iC3b Binding to Group B Streptococcus in Paired Mother and Baby Serum Samples in a Refugee Population on the Thailand-Myanmar Border

PubMed Central

Herbert, Jenny; Thomas, Stephen; Brookes, Charlotte; Turner, Claudia; Turner, Paul; Nosten, Francois; Le Doare, Kirsty; Hudson, Michael; Heath, Paul T.; Gorringe, Andrew

2015-01-01

Streptococcus agalactiae (group B streptococcus [GBS]) is the leading cause of neonatal sepsis and meningitis. In this study, we determined antibody-mediated deposition of complement C3b/iC3b onto the bacterial cell surface of GBS serotypes Ia, Ib, II, III, and V. This was determined for 520 mother and umbilical cord serum sample pairs obtained at the time of birth from a population on the Thailand-Myanmar border. Antibody-mediated deposition of complement C3b/iC3b was detected to at least one serotype in 91% of mothers, despite a known carriage rate in this population of only 12%. Antibody-mediated C3b/iC3b deposition corresponded to known carriage rates, with the highest levels of complement deposition observed onto the most prevalent serotype (serotype II) followed by serotypes Ia, III, V, and Ib. Finally, neonates born to mothers carrying serotype II GBS at the time of birth showed higher antibody-mediated C3b/iC3b deposition against serotype II GBS than neonates born to mothers with no serotype II carriage. Assessment of antibody-mediated C3b/iC3b deposition against GBS may provide insights into the seroepidemiology of anti-GBS antibodies in mothers and infants in different populations. PMID:25589553

Synthetic Nanovaccines Against Respiratory Pathogens (SYNARP). Addendum

DTIC Science & Technology

2014-09-01

and c) block ionomer complexes (BIC) for targeted delivery of DNA (or protein) antigen to the antigen presenting cells (APCs) (Platform C). The...immune cells to elicit most efficient immune response. The proposal was focusing on achieving the following specific technical objectives: 1) Develop...muscle in a mouse (Platform B & C). ACCOMPLISHED YEAR 3 Task 1: Determine optimal antigen-containing BPN that activate dendritic cells (DCs

Pre-Elsonian mafic magmatism in the Nain Igneous Complex, Labrador: the bridges layered intrusion

USGS Publications Warehouse

Ashwal, L.D.; Wiebe, R.A.; Wooden, J.L.; Whitehouse, M.J.; Snyder, Diane

1992-01-01

Decades of work on the pristine, unmetamorphosed, and well exposed anorthositic, mafic and granitic rocks of the Nain igneous complex, Labrador, have led to the conclusion that all plutonic rocks in that area were emplaced in a short time intercal at about 1300 ?? 10 Ma). We report here new isotopic data for mafic intrusive rocks that appear to have crystallized several hundred Ma earlier than the bulk of the plutonic activity in the Nain complex. The Bridges layered intrusion (BLI) is a small (15-20 km2) lens of layered mafic rocks about 1.5 km thick, surrounded and intruded by anorthositic, leuconoritic and leucotroctolitic plutons in the middle of the coastal section of the Nain igneous complex. BLI shows very well developed magmatic structures, including channel scours, slump structures, and ubiquitous modally graded layering. Most rocks, however, show granular textures indicative of recrystallization, presumably caused by emplacement of younger anorthositic rocks. BLI contains cumulate rocks with slightly more primitive mineral compositions (An60-83, Fo66-71) than those of other mafic intrusions in the Nain igneous complex, including Kiglapait. SmNd isotopic data for 7 BLI whole-rocks ranging in composition between olivine melagabbro and olivine leucogabbro yield an age of 1667 ?? 75 Ma, which we interpret as the time of primary crystallization. The internal isotopic systematics of the BLI have been reset, probably by intrusion of adjacent anorthositic plutons. A SmNd mineral isochron (plag, whole-rock, mafics) for a BLI olivine melagabbro gives an age of 1283 ?? 22 Ma, equivalent within error of a mineral array (plag, whole-rock, opx, cpx) for an adjacent, igneous-textured, leuconorite vein (1266 ?? 152 Ma). The initial Nd ratio for BLI corresponds to ??{lunate}Nd = -3.18 ?? 0.44. Other whole-rock samples, however, some with vein-like alteration (Chlorite, serpentine, amphiboles), show ??{lunate}Nd values as low as -9.1, suggesting variable contamination by direct assimilation of early Archean crustal rocks and/or by fluids that have interacted with such crust. Adjacent anorthositic rocks also show variable ??{lunate}Nd some as low as -14.7, implying larger degrees if crustal assimilation, perhaps by parental magmas during lower crustal ponding prior to emplacement. These contamination effects preclude straightforward determination of the isotopic character of mantle sources for both BLI and the anorthositic rocks. ?? 1992.

Polynomial order selection in random regression models via penalizing adaptively the likelihood.

PubMed

Corrales, J D; Munilla, S; Cantet, R J C

2015-08-01

Orthogonal Legendre polynomials (LP) are used to model the shape of additive genetic and permanent environmental effects in random regression models (RRM). Frequently, the Akaike (AIC) and the Bayesian (BIC) information criteria are employed to select LP order. However, it has been theoretically shown that neither AIC nor BIC is simultaneously optimal in terms of consistency and efficiency. Thus, the goal was to introduce a method, 'penalizing adaptively the likelihood' (PAL), as a criterion to select LP order in RRM. Four simulated data sets and real data (60,513 records, 6675 Colombian Holstein cows) were employed. Nested models were fitted to the data, and AIC, BIC and PAL were calculated for all of them. Results showed that PAL and BIC identified with probability of one the true LP order for the additive genetic and permanent environmental effects, but AIC tended to favour over parameterized models. Conversely, when the true model was unknown, PAL selected the best model with higher probability than AIC. In the latter case, BIC never favoured the best model. To summarize, PAL selected a correct model order regardless of whether the 'true' model was within the set of candidates. © 2015 Blackwell Verlag GmbH.

Detrital zircon and igneous protolith ages of high-grade metamorphic rocks in the Highland and Wanni Complexes, Sri Lanka: Their geochronological correlation with southern India and East Antarctica

NASA Astrophysics Data System (ADS)

Kitano, Ippei; Osanai, Yasuhito; Nakano, Nobuhiko; Adachi, Tatsuro; Fitzsimons, Ian C. W.

2018-05-01

The high-grade metamorphic rocks of Sri Lanka place valuable constraints on the assembly of central parts of the Gondwana supercontinent. They are subdivided into the Wanni Complex (WC), Highland Complex (HC) and Vijayan Complex (VC), but their correlation with neighbouring Gondwana terranes is hindered by a poor understanding of the contact between the HC and WC. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb dating of remnant zircon cores from 45 high-grade metamorphic rocks in Sri Lanka reveals two domains with different age characteristics that correlate with the HC and WC and which help constrain the location of the boundary between them. The HC is dominated by detrital zircon ages of ca. 3500-1500 Ma from garnet-biotite gneiss, garnet-cordierite-biotite gneiss, some samples of garnet-orthopyroxene-biotite gneiss and siliceous gneiss (interpreted as paragneisses) and igneous protolith ages of ca. 2000-1800 Ma from garnet-hornblende-biotite gneiss, other samples of garnet-orthopyroxene-biotite gneiss, garnet-two-pyroxene granulite, two-pyroxene granulite and charnockite (interpreted as orthogneisses). In contrast, the WC is dominated by detrital zircon ages of ca. 1100-700 Ma from paragneisses and igneous protolith ages of ca. 1100-800 Ma from orthogneisses. This clearly suggests the HC and WC have different origins, but some of our results and previous data indicate their spatial distribution does not correspond exactly to the unit boundary proposed in earlier studies using Nd model ages. Detrital zircon and igneous protolith ages in the HC suggest that sedimentary protoliths were eroded from local 2000-1800 Ma igneous rocks and an older Paleoproterozoic to Archean craton. In contrast, the WC sedimentary protoliths were mainly eroded from local late Mesoproterozoic to Neoproterozoic igneous rocks with very minor components from an older 2500-1500 Ma craton, and in the case of the WC precursor sediments there was possibly additional detritus derived from early to middle Neoproterozoic metamorphic rocks. The relic zircon core ages in the HC are comparable with those of the Trivandrum Block and Nagercoil Block of southern India. In contrast, those ages in the WC match the Achankovil Shear Zone and Southern Madurai Block of southern India. These comparisons are also supported by Th/U ratios of detrital zircon cores from paragneisses (Th/U ratios of >0.10 for the former and not only >0.10 but also ≤0.10 for the latter). Comparisons with the Lützow-Holm Complex of East Antarctica indicate that the geochronological characteristics of the HC and WC broadly match those of the Skallen Group, and the Ongul and Okuiwa Groups, respectively.

Ca. 890 Ma magmatism in the northwest Yangtze block, South China: SIMS U-Pb dating, in-situ Hf-O isotopes, and tectonic implications

NASA Astrophysics Data System (ADS)

Zhou, Jiu-Long; Li, Xian-Hua; Tang, Guo-Qiang; Gao, Bing-Yu; Bao, Zhi-An; Ling, Xiao-Xiao; Wu, Li-Guang; Lu, Kai; Zhu, Yu-Sheng; Liao, Xin

2018-01-01

Early Neoproterozoic tectonics of the Yangtze block remains poorly understood because very limited igneous records are available from the time interval of ∼1000-870 Ma. In this paper, our new SIMS U-Pb dating results demonstrate that the Liushudian mafic intrusion and Pinghe alkaline complex in the northwest Yangtze block were emplaced at 888 ± 6 Ma and 891 ± 7 Ma, respectively, representing the products of a ∼890 Ma igneous event. Gabbros from the Liushudian intrusion have rather depleted zircon ɛHf(t) (mean = 10.4) and normal mantle-like zircon δ18O (mean = 5.97‰). Their parental magma was thus probably derived from asthenospheric mantle. Geochemically, these mafic rocks have an affinity to continental flood tholeiitic basalts rather than ocean island basalts, as previously thought. In contrast, an ijolite sample from the Pinghe complex has less depleted zircon ɛHf(t) (mean = 5.7) and anomalously high zircon and apatite δ18O (mean = 13.76‰ and 13.80‰, respectively). Such a characteristic δ18O signal, among the highest yet known for igneous zircons, could be either inherited from a magma source in metasomatized lithospheric mantle or acquired by assimilation of high-δ18O supracrustal materials (e.g., limestone, chert) during magma evolution. An intra-plate extensional environment is suggested for the ∼890 Ma igneous event in the northwest Yangtze block, although it is as yet unclear whether this igneous event is related to a mantle plume or not. It could be concluded that magmatism on the western periphery of the Yangtze block was not shut down between ∼1000 and ∼870 Ma, and the ∼890 Ma intra-plate igneous event may mark either the onset of Neoproterozoic continental rifting or the ending of Late Mesoproterozoic to Early Neoproterozoic lithospheric extension.

The idea of magma mixing: History of a struggle for acceptance

USGS Publications Warehouse

Wilcox, R.E.

1999-01-01

In 1851, chemist Robert Bunsen suggested that the mixing of two magmas, one mafic and the other felsic, in various proportions might account for the wide range of chemical compositions of igneous rocks. Based on flaws in several of its secondary provisions, the whole hypothesis was rejected by a succession of influential critics and remained in disrepute for a hundred years. Meanwhile, studies of composite dikes and sills indicated that, indeed, mafic and felsic magmas had coexisted at close quarters and had been emplaced in quick succession. This interpretation was also used by some investigators to explain the intimate association of mafic and felsic rock types in the commonly occurring igneous complexes. Others believed that the mafic components of these complexes were derived from geologically older mafic formations. By the early 1900s it had become apparent that mafic magmas crystallized at higher temperatures than felsic magmas. This knowledge was not immediately applied to the problem of magma mixing, however, due in part to the popularity of the newly validated process of fractional crystallization and to the implication that the diversity of igneous rocks could be accounted for by that process alone. Not until the 1950s was the attention of the geological community drawn to the fact that disparate magmas mix in a special manner: they mingle, the mafic magma being quenched to a fracturable solid upon contact with the cooler felsic magma. This explanation set in motion a series of studies of other igneous complexes, confirming the concept and adding other identifying features of the process.

Origin of the South Atlantic igneous province

NASA Astrophysics Data System (ADS)

Foulger, Gillian R.

2018-04-01

The South Atlantic Igneous Province comprises the Paraná Basalts, Rio Grande Rise, Tristan archipelago and surrounding guyot province, Walvis Ridge, Etendeka basalts and, in some models, the alkaline igneous lineament in the Lucapa corridor, Angola. Although these volcanics are often considered to have a single generic origin, complexities that suggest otherwise are observed. The Paraná Basalts erupted 5 Ma before sea-floor spreading started in the neighborhood, and far more voluminous volcanic margins were emplaced later. A continental microcontinent likely forms much of the Rio Grande Rise, and variable styles of volcanism built the Walvis Ridge and the Tristan da Cunha archipelago and guyot province. Such complexities, coupled with the northward-propagating mid-ocean ridge crossing a major transverse transtensional intracontinental structure, suggest that fragmentation of Pangaea was complex at this latitude and that the volcanism may have occurred in response to distributed extension. The alternative model, a deep mantle plume, is less able to account for many observations and no model variant can account for all the primary features that include eruption of the Paraná Basalts in a subsiding basin, continental breakup by rift propagation that originated far to the south, the absence of a time-progressive volcanic chain between the Paraná Basalts and the Rio Grande Rise, derivation of the lavas from different sources, and the lack of evidence for a plume conduit in seismic-tomography- and magnetotelluric images. The region shares many common features with the North Atlantic Igneous Province which also features persistent, widespread volcanism where a propagating mid-ocean ridge crossed a transverse structural discontinuity in the disintegrating supercontinent.

Differences in crestal bone-to-implant contact following an under-drilling compared to an over-drilling protocol. A study in the rabbit tibia.

PubMed

Cohen, Omer; Ormianer, Zeev; Tal, Haim; Rothamel, Daniel; Weinreb, Miron; Moses, Ofer

2016-12-01

The objective of this study is to compare bone-to-implant contact (BIC) between implants inserted at high torque due to under-drilling of the crestal bone to those inserted at low torque due to over-drilling of the crestal bone. Forty implants with diameters of 3.75 mm (group A) or 3.55 mm (group B) were inserted in the proximal tibiae of NZW rabbits in two separate surgeries on day 0 or 21. Osteotomy of the crestal bone was finalized with a 3.65-mm drill. In group A, implants were inserted at torque ≥35 Ncm (under-drilling) and in group B with torque <10 Ncm (over-drilling). Implants and their surrounding bone were retrieved on day 42, thus creating 3- and 6-week observation periods, processed for non-decalcified histology and stained with toluidine blue. Crestal BIC (c-BIC) and total BIC (t-BIC) were measured. Wilcoxon test was used to evaluate differences between groups. Three weeks post-surgery, the mean c-BIC in group A was 16.3 ± 3.3 vs 31.5 ± 3.4 % in group B (P < 0.05). At 6 weeks, a similar trend was observed (group A: 28.7 ± 3.6 %; group B: 38.4 ± 4.9 %) (P > 0.05). No differences in t-BIC were noted at 3 weeks and at 6 weeks between the groups. Insertion of implants with an over-drilling protocol of the crestal aspect of the osteotomy resulted in increased short-term crestal bone-to-implant contact. Insertion of implants with a high torque following an under-drilling protocol, commonly used for immediate loading, may reduce crestal bone-to-implant contact at early healing stages.

Effect of insertion torque on titanium implant osseointegration: an animal experimental study.

PubMed

Duyck, Joke; Roesems, Rutger; Cardoso, Marcio V; Ogawa, Toru; De Villa Camargos, Germana; Vandamme, Katleen

2015-02-01

To evaluate the effect of implant insertion torque on the peri-implant bone healing and implant osseointegration. Bilaterally in the tibia of five adult New Zealand white rabbits, 20 implants were installed, subdivided into four groups, corresponding to two insertion torque conditions (low, < 10 Ncm vs. high > 50 Ncm) and 2 experimental periods (2 weeks vs. 4 weeks of healing). The implant insertion torque was determined by the surgical drill diameter relative to the implant diameter. Implant osseointegration was evaluated by quantitative histology (bone-to-implant contact with host bone [BIC-host], with neoformed bone [BIC-de novo], with both bone types [BIC-total], and peri-implant bone [BA/TA]). Every response was modelled over time using GEE (general estimation equation) with an unstructured variance-covariance matrix to correct for dependency between the measurements from one animal. The statistical significance level of α = 0.05 was applied. Significantly, more BIC-host and BIC-total were recorded for H implants compared with L implants after 2 week of healing (P = 0.010 and P = 0.0001, respectively). However, this result was no longer found for the extended healing period. Furthermore, BIC-total significantly increased over time for L implants (P < 0.00001). In contrast, the significant increase in BA/TA over time was found for H implants (P < 0.01). Finally, H insertion torque led to an increased BA/TA after 4 week of healing (P < 0.02) compared with the L insertion protocol. L insertion torque implants installed in the rabbit tibial bone osseointegrate with considerable de novo bone formation. This bone neoformation enables L implants to catch up, already during the early osseointegration stage, the initial inferior amount BIC contact compared with that of H implants. A negative impact of the created strain environment accompanying H insertion torque implant installation on the biological process of osseointegration could not be observed, at least not at tissue level. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lead isotope compositions of Late Cretaceous and early Tertiary igneous rocks and sulfide minerals in Arizona: Implications for the sources of plutons and metals in porphyry copper deposits

USGS Publications Warehouse

Bouse, R.M.; Ruiz, J.; Titley, S.R.; Tosdal, R.M.; Wooden, J.L.

1999-01-01

Porphyry copper deposits in Arizona are genetically associated with Late Cretaceous and early Tertiary igneous complexes that consist of older intermediate volcanic rocks and younger intermediate to felsic intrusions. The igneous complexes and their associated porphyry copper deposits were emplaced into an Early Proterozoic basement characterized by different rocks, geologic histories, and isotopic compositions. Lead isotope compositions of the Proterozoic basement rocks define, from northwest to southeast, the Mojave, central Arizona, and southeastern Arizona provinces. Porphyry copper deposits are present in each Pb isotope province. Lead isotope compositions of Late Cretaceous and early Tertiary plutons, together with those of sulfide minerals in porphyry copper deposits and of Proterozoic country rocks, place important constraints on genesis of the magmatic suites and the porphyry copper deposits themselves. The range of age-corrected Pb isotope compositions of plutons in 12 Late Cretaceous and early Tertiary igneous complexes is 206Pb/204Pb = 17.34 to 22.66, 207Pb/204Pb = 15.43 to 15.96, and 208Pb/204Pb = 37.19 to 40.33. These Pb isotope compositions and calculated model Th/U are similar to those of the Proterozoic rocks in which the plutons were emplaced, thereby indicating that Pb in the younger rocks and ore deposits was inherited from the basement rocks and their sources. No Pb isotope differences distinguish Late Cretaceous and early Tertiary igneous complexes that contain large economic porphyry copper deposits from less rich or smaller deposits that have not been considered economic for mining. Lead isotope compositions of Late Cretaceous and early Tertiary plutons and sulfide minerals from 30 metallic mineral districts, furthermore, require that the southeastern Arizona Pb province be divided into two subprovinces. The northern subprovince has generally lower 206Pb/204Pb and higher model Th/U, and the southern subprovince has higher 206Pb/204Pb and lower model Th/U. These Pb isotope differences are inferred to result from differences in their respective post-1.7 Ga magmatic histories. Throughout Arizona, Pb isotope compositions of Late Cretaceous and early Tertiary plutons and associated sulfide minerals are distinct from those of Jurassic plutons and also middle Tertiary igneous rocks and sulfide minerals. These differences most likely reflect changes in tectonic setting and magmatic sources. Within Late Cretaceous and early Tertiary igneous complexes that host economic porphyry copper deposits, there is commonly a decrease in Pb isotope composition from older to younger plutons. This decrease in Pb isotope values with time suggests an increasing involvement of crust with lower U/Pb than average crust in the source(s) of Late Cretaceous and early Tertiary magmas. Lead isotope compositions of the youngest porphyries in the igneous complexes are similar to those in most sulfide minerals within the associated porphyry copper deposit. This Pb isotope similarity argues for a genetic link between them. However, not all Pb in the sulfide minerals in porphyry copper deposits is magmatically derived. Some sulfide minerals, particularly those that are late stage, or distal to the main orebody, or in Proterozoic or Paleozoic rocks, have elevated Pb isotope compositions displaced toward the gross average Pb isotope composition of the local country rocks. The more radiogenic isotopic compositions argue for a contribution of Pb from those rocks at the site of ore deposition. Combining the Pb isotope data with available geochemical, isotopic, and petrologic data suggests derivation of the young porphyry copper-related plutons, most of their Pb, and other metals from a hybridized lower continental crustal source. Because of the likely involvement of subduction-related mantle-derived basaltic magma in the hybridized lower crustal source, an indiscernible mantle contribution is probable in the porphyry magmas. Clearly, in addition

Marrow-isolated adult multilineage inducible cells embedded within a biologically-inspired construct promote recovery in a mouse model of peripheral vascular disease.

PubMed

Grau-Monge, Cristina; Delcroix, Gaëtan J-R; Bonnin-Marquez, Andrea; Valdes, Mike; Awadallah, Ead Lewis Mazen; Quevedo, Daniel F; Armour, Maxime R; Montero, Ramon B; Schiller, Paul C; Andreopoulos, Fotios M; D'Ippolito, Gianluca

2017-02-17

Peripheral vascular disease is one of the major vascular complications in individuals suffering from diabetes and in the elderly that is associated with significant burden in terms of morbidity and mortality. Stem cell therapy is being tested as an attractive alternative to traditional surgery to prevent and treat this disorder. The goal of this study was to enhance the protective and reparative potential of marrow-isolated adult multilineage inducible (MIAMI) cells by incorporating them within a bio-inspired construct (BIC) made of two layers of gelatin B electrospun nanofibers. We hypothesized that the BIC would enhance MIAMI cell survival and engraftment, ultimately leading to a better functional recovery of the injured limb in our mouse model of critical limb ischemia compared to MIAMI cells used alone. Our study demonstrated that MIAMI cell-seeded BIC resulted in a wide range of positive outcomes with an almost full recovery of blood flow in the injured limb, thereby limiting the extent of ischemia and necrosis. Functional recovery was also the greatest when MIAMI cells were combined with BICs, compared to MIAMI cells alone or BICs in the absence of cells. Histology was performed 28 days after grafting the animals to explore the mechanisms at the source of these positive outcomes. We observed that our critical limb ischemia model induces an extensive loss of muscular fibers that are replaced by intermuscular adipose tissue (IMAT), together with a highly disorganized vascular structure. The use of MIAMI cells-seeded BIC prevented IMAT infiltration with some clear evidence of muscular fibers regeneration.

MIAMI cells embedded within a biologically-inspired construct promote recovery in a mouse model of peripheral vascular disease

PubMed Central

Grau-Monge, Cristina; Delcroix, Gaëtan J.-R; Bonnin-Marquez, Andrea; Valdes, Mike; Awadallah, Ead Lewis Mazen; Quevedo, Daniel F.; Armour, Maxime R.; Montero, Ramon B.; Schiller, Paul C.; Andreopoulos, Fotios M.; D’Ippolito, Gianluca

2017-01-01

Peripheral vascular disease is one of the major vascular complications in individuals suffering from diabetes and in the elderly that is associated with significant burden in terms of morbidity and mortality. Stem cell therapy is being tested as an attractive alternative to traditional surgery to prevent and treat this disorder. The goal of this study was to enhance the protective and reparative potential of marrow-isolated adult multilineage inducible (MIAMI) cells by incorporating them within a bio-inspired construct (BIC) made of 2 layers of gelatin B electrospun nanofibers. We hypothesized that the BIC would enhance MIAMI cell survival and engraftment, ultimately leading to a better functional recovery of the injured limb in our mouse model of critical limb ischemia compared to MIAMI cells used alone. Our study demonstrated that MIAMI cell-seeded BIC resulted in a wide range of positive outcomes with an almost full recovery of blood flow in the injured limb, thereby limiting the extent of ischemia and necrosis. Functional recovery was also the greatest when MIAMI cells were combined with BICs, compared to MIAMI cells alone or BICs in the absence of cells. Histology was performed 28 days after grafting the animals to explore the mechanisms at the source of these positive outcomes. We observed that our critical limb ischemia model induces an extensive loss of muscular fibers that are replaced by intermuscular adipose tissue (IMAT), together with a highly disorganized vascular structure. The use of MIAMI cells-seeded BIC prevented IMAT infiltration with some clear evidence of muscular fibers regeneration. PMID:28211362

Characterization of Arctic Highly Magnetic Domains - the Geophysical Expression of Inferred Large Igneous Province(s)

NASA Astrophysics Data System (ADS)

Saltus, R. W.; Oakey, G.; Miller, E. L.; Jackson, R.

2012-12-01

The magnetic anomalies of the high arctic are dominated by a large domain (1000 x 1700 km; the High Arctic Magnetic High, HAMH) consisting of numerous high-amplitude magnetic high ridges with a complex set of orientations and by other smaller, but still fundamentally highly magnetic, domains. The magnetic potential anomaly field (also known as pseudogravity) of the HAMH shows a single large intensity high and underscores the crustal-scale thickness of this geophysical feature (which also forms a prominent anomaly on satellite magnetic maps). The seafloor morphology of this region includes the complex linear trends of the Alpha and Mendeleev ridges, but the magnetic expression of this domain extends beyond the complex bathymetry to include areas where Canada Basin sediments have covered the complex basement topography. The calculated magnetic effect of the bathymetric ridges matches some of the observed magnetic anomalies, but not others. We have analyzed and modeled the distinctive HAMH and other smaller magnetic high domains to generate estimates of their volume and to characterize the directionality of their component features. Complimentary processing and modeling of high arctic gravity anomalies allows characterization of the density component of these geophysical features. Spatially, the HAMH encompasses the Alpha and Mendeleev "ridges," that are considered to represent a major mafic igneous province. The term "Alpha-Mendeleev Large Igneous Province" is given to a domain mapped by tracing magnetic anomalies in a recent map published by AAPG (Grantz and others, 2009). On this map the province is described as "alkali basalt with ages between 120 and 90 Ma". New seismic and bathymetric data, collected as part of on-going research efforts for definition of extended continental shelf, are revealing new details about the Alpha ridge. One interesting development is the possible identification of a supervolcano that may represent a major locus of igneous activity. In the broader Arctic region, the term High Arctic Large Igneous Province (HALIP) refers to (now) scattered parts of a major plume-type basaltic eruption, many of which also show as magnetic highs on the current data compilation. Rocks that contribute to this province have been mapped in Arctic Canada, Greenland, Svalbard, Franz Josef Land and the DeLong Islands. Most HALIP volcanic rocks do not have reliable reported radiometric ages but seem to indicate two pulses of magmatism of around 130-120 Ma and 90-80 Ma. There are many fundamental open questions regarding the evolution of the Arctic, particularly for the opening and development of the Amerasian side. The mafic igneous rocks and their roots that make up large igneous provinces are a good target for regional magnetic interpretation. Our goal is to use a data-driven approach to characterize the geometries and volumes these features as the expression of major mafic (basaltic) elements to aid in tectonic reconstruction and understanding.

School Suspension Alternatives.

ERIC Educational Resources Information Center

Ewashen, George, Jr.; And Others

1988-01-01

Describes Calgary's Behavior Intervention Centre (BIC), which provides short and long term counseling and teaching services to disruptive elementary and junior high school students and their parents. Discusses psychological assessment, family counseling, and school reintegration strategies contributing to BIC's 81 percent success rate. (SV)

Riftogenic magmatism of western part of the Early Mesozoic Mongolian-Transbaikalian igneous province: Results of geochronological studies

NASA Astrophysics Data System (ADS)

Yarmolyuk, V. V.; Kozlovsky, A. M.; Salnikova, E. B.; Travin, A. V.; Kudryashova, E. A.

2017-08-01

Geochronological studies of rocks from a bimodal high-alkali volcanic-plutonic complex collected in the area of Kharkhorin zone of the Early Mesozoic Mongolian-Transbaikalian igneous province (MTIP) are made. The age of alkali granites from Olziit sum is 211 ± 1 Ma (U-Pb ID-TIMS on zircon) to 209 ± 2 and 217 ± 4 Ma (40Ar/39Ar on alkali amphibole); the age of alkali granite-porphyries from the area of Sant sum is 206 ± 1 Ma (U-Pb ID-TIMS on zircon). These rock series formed syncronously to the analogous magmatism episode in the Northern Gobi and Western Transbaikalian rift zones of the MTIP. The similarity of the age and composition of igneous associations of the MTIP suggests a common mechanism of its formation related to the effect of a mantle plume on the continental lithosphere at the base of the entire igneous zone having a zonal structure.

Model weights and the foundations of multimodel inference

USGS Publications Warehouse

Link, W.A.; Barker, R.J.

2006-01-01

Statistical thinking in wildlife biology and ecology has been profoundly influenced by the introduction of AIC (Akaike?s information criterion) as a tool for model selection and as a basis for model averaging. In this paper, we advocate the Bayesian paradigm as a broader framework for multimodel inference, one in which model averaging and model selection are naturally linked, and in which the performance of AIC-based tools is naturally evaluated. Prior model weights implicitly associated with the use of AIC are seen to highly favor complex models: in some cases, all but the most highly parameterized models in the model set are virtually ignored a priori. We suggest the usefulness of the weighted BIC (Bayesian information criterion) as a computationally simple alternative to AIC, based on explicit selection of prior model probabilities rather than acceptance of default priors associated with AIC. We note, however, that both procedures are only approximate to the use of exact Bayes factors. We discuss and illustrate technical difficulties associated with Bayes factors, and suggest approaches to avoiding these difficulties in the context of model selection for a logistic regression. Our example highlights the predisposition of AIC weighting to favor complex models and suggests a need for caution in using the BIC for computing approximate posterior model weights.

Geometric consequences of ductile fabric development from brittle shear faults in mafic melt sheets: Evidence from the Sudbury Igneous Complex, Canada

NASA Astrophysics Data System (ADS)

Lenauer, Iris; Riller, Ulrich

2012-02-01

Compared to felsic igneous rocks the genetic relationship between brittle and ductile fabric development and its influence on the geometry of deformed mafic melt sheets has received little attention in structural analyses. We explore these relationships using the Sudbury Igneous Complex (SIC) as an example. The SIC is the relic of a layered impact melt sheet that was transformed into a fold basin, the Sudbury Basin, during Paleoproterozoic deformation at the southern margin of the Archean Superior Province. We studied brittle and ductile strain fabrics on the outcrop and map scales in the southern Sudbury Basin, notably in the Norite and Quartz Gabbro layers of the SIC. Here, deformation is heterogeneous and occurred under variable rheological conditions, evident by the development of brittle shear fractures, brittle-ductile shear zones and pervasive ductile strain. The mineral fabrics formed under low- to middle greenschist-facies metamorphism, whereby brittle deformation caused hydrolytic weakening and ductile fabric development. Principal strain axes inferred from all structural elements are collinear and point to a single deformation regime that led to thinning of SIC layers during progressive deformation. Ductile fabric development profoundly influenced the orientation of SIC material planes, such as lithological contacts and magmatic mineral fabrics. More specifically, these planar structural elements are steep where the SIC underwent large magnitudes of thinning, i.e., in the south limb of the Sudbury Basin. Here, the actual tilt component of material planes is likely smaller than its maximum total rotation (60°) inferred from inclined igneous layering in the Norite. Our field-based study shows that ductile fabric development from brittle faults can have a profound influence on the rotational components of primary material planes in deformed igneous melt sheets.

Modeling of Diffuse-Diffuse Photon Coupling via a Nonscattering Region: a Comparative Study

NASA Astrophysics Data System (ADS)

Lee, Jae Hoon; Kim, Seunghwan; Kim, Youn Tae

2004-06-01

It is well established that diffusion approximation is valid for light propagation in highly scattering media, but it breaks down in nonscattering regions. The previous methods that manipulate nonscattering regions are essentially boundary-to-boundary coupling (BBC) methods through a nonscattering void region based on the radiosity theory. We present a boundary-to-interior coupling (BIC) method. BIC is based on the fact that the collimated pencil beam incident on the medium can be replaced by an isotropic point source positioned at one reduced scattering length inside the medium from an illuminated point. A similar replacement is possible for the nondiffuse lights that enter the diffuse medium through the void, and it is formulated as the BIC method. We implemented both coupling methods using the finite element method (FEM) and tested for the circle with a void gap and for a four-layer adult head model. For mean time of flight, the BIC shows better agreement with Monte Carlo (MC) simulation results than BBC. For intensity, BIC shows a comparable match with MC data compared with that of BBC. The effect of absorption of the clear layer in the adult head model was investigated. Both mean time and intensity decrease as absorption of the clear layer increases.

Modeling of diffuse-diffuse photon coupling via a nonscattering region: a comparative study.

PubMed

Lee, Jae Hoon; Kim, Seunghwan; Kim, Youn Tae

2004-06-20

It is well established that diffusion approximation is valid for light propagation in highly scattering media, but it breaks down in nonscattering regions. The previous methods that manipulate nonscattering regions are essentially boundary-to-boundary coupling (BBC) methods through a nonscattering void region based on the radiosity theory. We present a boundary-to-interior coupling (BIC) method. BIC is based on the fact that the collimated pencil beam incident on the medium can be replaced by an isotropic point source positioned at one reduced scattering length inside the medium from an illuminated point. A similar replacement is possible for the nondiffuse lights that enter the diffuse medium through the void, and it is formulated as the BIC method. We implemented both coupling methods using the finite element method (FEM) and tested for the circle with a void gap and for a four-layer adult head model. For mean time of flight, the BIC shows better agreement with Monte Carlo (MC) simulation results than BBC. For intensity, BIC shows a comparable match with MC data compared with that of BBC. The effect of absorption of the clear layer in the adult head model was investigated. Both mean time and intensity decrease as absorption of the clear layer increases.

Synergistic effect of PEGylated resveratrol on delivery of anticancer drugs.

PubMed

Wang, Wenlong; Zhang, Liang; Le, Yuan; Chen, Jian-Feng; Wang, Jiexin; Yun, Jimmy

2016-02-10

Resveratrol (RES) is a natural polyphenol which can be considered as a nutraceutical because of its benefits such as anticancer and antioxidant activity. In this paper, we designed polymer-RES conjugates as anticancer drug carrier for synergistic therapeutic effect in cancer treatment. Bicalutamide (BIC) was used as a model drug to investigate the drug release behaviors and in vitro anticancer performance. PEG-RES and PEG-Glycine-RES nanoparticles were prepared and characterized. The size of the prepared particles was around 50 nm with RES content of 17.2 and 16.3 wt% for PEG-RES and PEG-Glycine-RES, respectively, and BIC loading efficiency were of 81.6% and 84.5%, separately. Release rate of RES from conjugates depended on the stability of ester group against hydrolysis. BIC release was much faster than RES release. The anticancer activity of BIC loaded PEGylated RES nanoparticles was much better than that of free BIC, indicating the conjugates provided a synergetic cytotoxicity to cancer cells. Confocal laser scanning microscopy observation and flow cytometry analyses indicated that PEGylated RES conjugates were more efficiently internalized into cells, released drug into cytoplasm. These results suggest that PEGylated RES conjugates show great potential for cancer therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimizing a micro-computed tomography-based surrogate measurement of bone-implant contact.

PubMed

Meagher, Matthew J; Parwani, Rachna N; Virdi, Amarjit S; Sumner, Dale R

2018-03-01

Histology and backscatter scanning electron microscopy (bSEM) are the current gold standard methods for quantifying bone-implant contact (BIC), but are inherently destructive. Microcomputed tomography (μCT) is a non-destructive alternative, but attempts to validate μCT-based assessment of BIC in animal models have produced conflicting results. We previously showed in a rat model using a 1.5 mm diameter titanium implant that the extent of the metal-induced artefact precluded accurate measurement of bone sufficiently close to the interface to assess BIC. Recently introduced commercial laboratory μCT scanners have smaller voxels and improved imaging capabilities, possibly overcoming this limitation. The goals of the present study were to establish an approach for optimizing μCT imaging parameters and to validate μCT-based assessment of BIC. In an empirical parametric study using a 1.5 mm diameter titanium implant, we determined 90 kVp, 88 µA, 1.5 μm isotropic voxel size, 1600 projections/180°, and 750 ms integration time to be optimal. Using specimens from an in vivo rat experiment, we found significant correlations between bSEM and μCT for BIC with the manufacturer's automated analysis routine (r = 0.716, p = 0.003) or a line-intercept method (r = 0.797, p = 0.010). Thus, this newer generation scanner's improved imaging capability reduced the extent of the metal-induced artefact zone enough to permit assessment of BIC. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:979-986, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Utilising symptom dimensions with diagnostic categories improves prediction of time to first remission in first-episode psychosis.

PubMed

Ajnakina, Olesya; Lally, John; Di Forti, Marta; Stilo, Simona A; Kolliakou, Anna; Gardner-Sood, Poonam; Dazzan, Paola; Pariante, Carmine; Reis Marques, Tiago; Mondelli, Valeria; MacCabe, James; Gaughran, Fiona; David, Anthony S; Stamate, Daniel; Murray, Robin M; Fisher, Helen L

2018-03-01

There has been much recent debate concerning the relative clinical utility of symptom dimensions versus conventional diagnostic categories in patients with psychosis. We investigated whether symptom dimensions rated at presentation for first-episode psychosis (FEP) better predicted time to first remission than categorical diagnosis over a four-year follow-up. The sample comprised 193 FEP patients aged 18-65years who presented to psychiatric services in South London, UK, between 2006 and 2010. Psychopathology was assessed at baseline with the Positive and Negative Syndrome Scale and five symptom dimensions were derived using Wallwork/Fortgang's model; baseline diagnoses were grouped using DSM-IV codes. Time to start of first remission was ascertained from clinical records. The Bayesian Information Criterion (BIC) was used to find the best fitting accelerated failure time model of dimensions, diagnoses and time to first remission. Sixty percent of patients remitted over the four years following first presentation to psychiatric services, and the average time to start of first remission was 18.3weeks (SD=26.0, median=8). The positive (BIC=166.26), excited (BIC=167.30) and disorganised/concrete (BIC=168.77) symptom dimensions, and a diagnosis of schizophrenia (BIC=166.91) predicted time to first remission. However, a combination of the DSM-IV diagnosis of schizophrenia with all five symptom dimensions led to the best fitting model (BIC=164.35). Combining categorical diagnosis with symptom dimension scores in FEP patients improved the accuracy of predicting time to first remission. Thus our data suggest that the decision to consign symptom dimensions to an annexe in DSM-5 should be reconsidered at the earliest opportunity. Copyright © 2017 Elsevier B.V. All rights reserved.

A systematic review of studies comparing body image concerns among female college athletes and non-athletes, 1997-2012.

PubMed

Varnes, Julia R; Stellefson, Michael L; Janelle, Christopher M; Dorman, Steven M; Dodd, Virginia; Miller, M David

2013-09-01

Research prior to 2001 indicated that athletes experienced better body image than non-athletes, with no differences among sport types. Since then, female athletes have become increasingly sexually objectified in the media, and the sociocultural beauty ideal has shifted to emphasize appearing both athletic and thin. Part I of this paper explores the literature describing these changes. Part II presents a systematic and comprehensive literature review of 10 recent studies comparing body image concerns (BIC) among collegiate female athletes and non-athletes to identify the current status of BIC in female athletes. Findings indicate that involvement in collegiate athletics provides some protection from BIC; however, this protection appears attenuated for athletes in more feminine sports (e.g., gymnastics), and higher level athletes (Division I). Researchers should examine how sociocultural pressures unrelated to competition predict female athletes' BIC using measures that focus on objectification, positive body image, body functionality, and thin- and athletic-ideal internalization. Copyright © 2013 Elsevier Ltd. All rights reserved.

The cyanobacterial bicarbonate transporter BicA: its physiological role and the implications of structural similarities with human SLC26 transporters.

PubMed

Price, G Dean; Howitt, Susan M

2011-04-01

The cyanobacterial Na+-dependent HCO3- transporter BicA is a member of the ubiquitous and important SulP/SLC26 family of anion transporters found in eukaryotes and prokaryotes. BicA is an important component of the cyanobacterial CO2 concentrating mechanism, an adaptation that contributes to cyanobacteria being able to achieve an estimated 25% of global primary productivity, largely in the oceans. The human SLC26 members are involved in a range of key cellular functions involving a diverse range of anion transport activities including Cl-/HCO3-, I-/HCO3-, and SO42-/HCO3- exchange; mutations in SLC26 members are known to be associated with debilitating diseases such as Pendred syndrome, chondrodysplasias, and congenital chloride diarrhoea. We have recently experimentally determined the membrane topology of BicA using the phoA-lacZ reporter system and here consider some of the extrapolated implications for topology of the human SLC26 family and the Sultr plant sulphate transporters.

Comparison of a new simplified acid-base tool to the original Stewart-Figge approach: a study on cardiac surgical patients.

PubMed

Agrafiotis, Michalis; Mpliamplias, Dimitrios; Papathanassiou, Maria; Ampatzidou, Fotini; Drossos, Georgios

2018-05-03

To suggest a simplified method for strong ion gap ([SIG]) calculation. To simplify [SIG] calculation, we used the following assumptions: (1) the major determinants of apparent strong ion difference ([SID a ]) are [Na + ], [K + ] and [Cl - ] (2) [Ca 2+ ] and [Mg 2+ ] do not contribute significantly to [SID a ] variation and can be replaced by their reference concentrations (3) physiologically relevant pH variation is at the order of 10 -2 and therefore we can assume a standard value of 7.4. In the new model, [SID a ] is replaced by its adjusted form, i.e. [SID a,adj ] = [Na + ] + [K + ] - [Cl - ] + 6.5 and [SIG] is replaced by "bicarbonate gap", i.e. [BIC gap ] = [SID a,adj ] - (0.25·[Albumin]) - (2·[Phosphate]) - [HCO 3 - ]. The model was tested in 224 postoperative cardiac surgical patients. Strong correlations were observed between [SID a,adj ] and [SID a ] (r = 0.93, p < 0.0001) and between [BIC gap ] and [SIG] (r = 0.95, p < 0.0001). The mean bias (limits of agreement) of [SID a,adj ] - [SID a ] and of [BIC gap ]-[SIG] was - 0.6 meq/l (- 2.7 to 1.5) and 0.2 meq/l (- 2 to 2.4), respectively. The intraclass correlation coefficients between [SID a,adj ] and [SID a ] and between [BIC gap ] and [SIG] were 0.90 and 0.95, respectively. The sensitivities and specificities for the prediction of a [lactate - ] > 4 meq/l were 73.4 and 82.3% for a [BIC gap ] > 12.2 meq/l and 74.5 and 83.1% for a [SIG] > 12 meq/l, respectively. The [BIC gap ] model bears a very good agreement with the [SIG] model while being simpler and easier to apply at the bedside. [BIC gap ] could be used as an alternative tool for the diagnosis of unmeasured ion acidosis.

Sudbury Breccia (Canada): a product of the 1850 Ma Sudbury Event and host to footwall Cu Ni PGE deposits

NASA Astrophysics Data System (ADS)

Rousell, Don H.; Fedorowich, John S.; Dressler, Burkhard O.

2003-02-01

The Sudbury Structure, formed by meteorite impact at 1850 Ma, consists of three major components: (1) the Sudbury Basin; (2) the Sudbury Igneous Complex, which surrounds the basin as an elliptical collar; and (3) breccia bodies in the footwall known as Sudbury Breccia. In general, the breccia consists of subrounded fragments set in a dark, fine-grained to aphanitic matrix. A comparison of the chemical composition of host rocks, clasts and matrices indicates that brecciation was essentially an in-situ process. Sudbury Breccia forms irregular-shaped bodies or dikes that range in size from mm to km scale. Contacts with the host rocks are commonly sharp. The aspect ratio of most clasts is approximately 2 with the long axes parallel to dike walls. The fractal dimension (Dr)=1.55. Although there appears to be some concentration of brecciation within concentric zones, small Sudbury Breccia bodies within and outside these zones have more or less random strikes and steep dips. Sudbury Breccia bodies near an embayment structure tend to be subparallel to the base of the Sudbury Igneous Complex. Sudbury Breccia occurs as much as 80 km from the outer margin of the Sudbury Igneous Complex. In an inner zone, 5 to 15 km wide, breccia comprises 5% of exposed bedrock with an increase in brecciation intensity in embayment structures. Sudbury Breccia may be classified into three types based on the nature of the matrix: clastic, pseudotachylite and microcrystalline. Clastic Sudbury Breccia, the dominant type in the Southern Province, is characterized by flow-surface structures. Possibly, a sudden rise in pore pressure caused explosive dilation and fragmentation, followed by fluidization and flowage into extension fractures. Pseudotachylite Sudbury Breccia, mainly confined to Archean rocks, apparently formed by comminution and frictional melting. Microcrystalline Sudbury Breccia formed as a result of the thermal metamorphism, of the North Range footwall, by the Sudbury Igneous Complex. This produced a zone, approximately 1.2 km wide, wherein the matrix of the breccia either recrystallized or, locally, melted. An overprint of regional metamorphism obliterated contact effects in the South Range footwall. The Ni-Cu-PGE magmatic sulphide deposits may be classified into four types based on structural setting: Sudbury Igneous Complex-footwall contact, footwall, offset, and sheared deposits. Sudbury Breccia is the main host for footwall deposits (e.g., McCreedy East, Victor, Lindsley). Sudbury Breccia locally hosts mineralization in radial (e.g., Parkin and Copper Cliff) and concentric (e.g., Frood-Stobie) offset dikes.

Novel ambler class A carbapenem-hydrolyzing beta-lactamase from a Pseudomonas fluorescens isolate from the Seine River, Paris, France.

PubMed

Girlich, Delphine; Poirel, Laurent; Nordmann, Patrice

2010-01-01

A Pseudomonas fluorescens isolate (PF-1) resistant to carbapenems was recovered during an environmental survey performed with water from the Seine River (Paris). It expressed a novel Ambler class A carbapenemase, BIC-1, sharing 68 and 59% amino acid identities with beta-lactamases SFC-1 from Serratia fonticola and the plasmid-encoded KPC-2, respectively. beta-Lactamase BIC-1 hydrolyzed penicillins, carbapenems, and cephalosporins except ceftazidime and monobactams. The bla(BIC-1) gene was chromosomally located and was also identified in two other P. fluorescens strains isolated from the Seine River 3 months later.

Influence of peri-implant artifacts on bone morphometric analysis with micro-computed tomography.

PubMed

Song, Jin Wook; Cha, Jung Yul; Bechtold, Till Edward; Park, Young Chel

2013-01-01

To determine the optimal dilation pixel size distance from the mini-implant interface needed to compensate for the metal artifact on micro-computed tomography (micro-CT) for bone morphometric analysis. A total of 72 self-drilling mini-implants were placed into the buccal alveolar bone of six male beagle dogs. After 12 weeks of orthodontic loading, specimens were harvested and scanned with micro-CT (Skyscan 1076) at a resolution of 9 μm. Using the reload plug-in and dilation procedure of CTAn, the percentage of bone-implant contact (BIC) and bone volume density (BV/TV, bone volume/total volume), respectively, were measured from one to seven pixels from the metal implant surface. Each pixel size of dilation (PSD) were compared with that of a ground histologic section, and the optimal PSD for bone morphometric analysis using micro-CT was determined. BIC values from micro-CT analysis decreased when the PSD increased (P < .05). BIC from micro-CT showed the highest correlation coefficient with BIC from histologic slides when the PSD was 5 to 7 (P < .05), whereas BV/TV from micro-CT showed a very high correlation with BV/TV from histologic slides in all ranges (P < .0001). To measure BIC and BV/TV using micro-CT, at least 5 PSD from the metal implant surface is needed.

Topology mapping to characterize cyanobacterial bicarbonate transporters: BicA (SulP/SLC26 family) and SbtA.

PubMed

Price, G Dean; Howitt, Susan M

2014-09-01

This mini-review addresses advances in understanding the transmembrane topologies of two unrelated, single-subunit bicarbonate transporters from cyanobacteria, namely BicA and SbtA. BicA is a Na(+)-dependent bicarbonate transporter that belongs to the SulP/SLC26 family that is widespread in both eukaryotes and prokaryotes. Topology mapping of BicA via the phoA/lacZ fusion reporter method identified 12 transmembrane helices with an unresolved hydrophobic region just beyond helix 8. Re-interpreting this data in the light of a recent topology study on rat prestin leads to a consensus topology of 14 transmembrane domains with a 7+7 inverted repeat structure. SbtA is also a Na(+)-dependent bicarbonate transporter, but of considerably higher affinity (Km 2-5 μM versus >100 μM for BicA). Whilst SbtA is widespread in cyanobacteria and a few bacteria, it appears to be absent from eukaryotes. Topology mapping of SbtA via the phoA/lacZ fusion reporter method identified 10 transmembrane helices. The topology consists of a 5+5 inverted repeat, with the two repeats separated by a large intracellular loop. The unusual location of the N and C-termini outside the cell raises the possibility that SbtA forms a novel fold, not so far identified by structural and topological studies on transport proteins.

Subduction history of the Paleo-Pacific plate beneath the Eurasian continent: Evidence from Mesozoic igneous rocks and accretionary complex in NE Asia

NASA Astrophysics Data System (ADS)

Xu, W.

2015-12-01

Mesozoic magmatisms in NE China can be subdivided into seven stages, i.e., Late Triassic, Early Jurassic, Middle Jurassic, Late Jurassic, early Early Cretaceous, late Early Cretaceous, and Late Cretaceous. Late Triassic magmatisms consist of calc-alkaline igneous rocks in the Erguna Massif, and bimodal igneous rocks in eastern margin of Eurasian continent. The former reveals southward subduction of the Mongol-Okhotsk oceanic plate, the latter reveals an extensional environment (Xu et al., 2013). Early Jurassic magmatisms are composed of calc-alkaline igneous rocks in the eastern margin of the Eurasian continent and the Erguna Massif, revealing westward subduction of the Paleo-pacific plate and southward subduction of the Mongol-Okhotsk oceanic plate (Tang et al., 2015), respectively. Middle Jurassic magmatism only occur in the Great Xing'an Range and the northern margin of the NCC, and consists of adakitic rocks that formed in crustal thickening, reflecting the closure of the Mongol-Okhotsk ocean (Li et al., 2015). Late Jurassic and early Early Cretaceous magmatisms only occur to the west of the Songliao Basin, and consist of trackyandesite and A-type of rhyolites, revealing an extensional environment related to delamination of thickened crust. The late Early Cretaceous magmatisms are widespread in NE China, and consist of calc-alkaline volcanics in eastern margin and bimodal volcanics in intracontinent, revealing westward subduction of the Paleo-pacific plate. Late Cretaceous magmatisms mainly occur to the east of the Songliao Basin, and consist of calc-alkaline volcanics in eastern margin and alkaline basalts in intracontinent (Xu et al., 2013), revealing westward subduction of the Paleo-pacific plate. The Heilongjiang complex with Early Jurassic deformation, together with Jurassic Khabarovsk complex in Russia Far East and Mino-Tamba complex in Japan, reveal Early Jurassic accretionary history. Additionally, the Raohe complex with the age of ca. 169 Ma was intruded by the 110-130 Ma massive granitoids, suggesting late Early Cretaceous accretionary event. From late Early Cretaceous to Late Cretaceous, the spatial extent of magmatisms was reduced from west to east, revealing roll-back of subducted slab. This research was financially supported by the NSFC (41330206).

Large scale magmatic event, magnetic anomalies and ore exploration in northern Norway

NASA Astrophysics Data System (ADS)

Pastore, Z.; Church, N. S.; ter Maat, G. W.; Michels, A.; McEnroe, S. A.; Fichler, C.; Larsen, R. B.

2016-12-01

More than 17000 km3of igneous melts intruded into the deep crust at ca. 560-580 Ma and formed the Seiland Igneous Province (SIP), the largest complex of mafic and ultramafic intrusions in northern Fennoscandia. The original emplacement of the SIP is matter of current discussion. The SIP is now located within the Kalak Nappe Complex (KNC), a part of the Middle Allochthon of the North Norwegian Caledonides. The province is believed to represent a cross section of the deep plumbing system of a large igneous province and it is known for its layered intrusions sharing geological features with large ore-forming exploration provinces. In this study we investigate one of the four major ultramafic complexes of the province, the Reinfjord Complex. This was emplaced during three magmatic events in a time span of 4 Ma, and consists in a cylindrically zoned complex with a slightly younger dunite core (Central Series) surrounded by wehrlite and lherzolite dominated series (Upper and Lower Layered Series). Sulphides are present throughout the complex, and an electromagnetic survey identified a Ni-Cu-and a PGE reef deposit within the dunite, 100 meters below the surface. This discovery increased the ore potential of the complex and subsequently 4 deep drill cores were made. High-resolution magnetic helicopter survey was later followed up with ground magnetic and gravity surveys. Extensive sampling of surface rocks and drill cores were made to measure the rock-magnetic and physical properties of the samples and to explore the subsurface structure of the complex. Here, we developed a magnetic model for the Reinfjord complex integrating petrophysical data from both oriented surface samples and from the deep drill cores, with the new ground magnetic, and helicopter data (SkyTEM survey). A 3D model of the geometry of the ultramafic intrusion is presented and a refinement of the geological interpretation of the Reinfjord ultramafic intrusion.

Feeder systems of acidic lava flows from the Paraná-Etendeka Igneous Province in southern Brazil and their implications for eruption style

NASA Astrophysics Data System (ADS)

de Lima, Evandro Fernandes; Waichel, Breno Leitão; Rossetti, Lucas De Magalhães May; Sommer, Carlos Augusto; Simões, Matheus Silva

2018-01-01

In the Rio Grande do Sul State, southern Brazil, the volcanic sequence of the Paraná-Etendeka Igneous Province consists of pahoehoe and rubbly pahoehoe lava flows with basaltic and basaltic andesitic composition respectively, overlaid by acidic volcanic rocks. The acidic volcanic rocks of the Paraná-Etendeka Igneous Province exhibit textures and structures that can be related to effusive and/or explosive eruptions generating predominantly rheoignimbrites. The huge lava volume related to the emplacement of large igneous provinces implicates on efficient feeder systems that are more commonly observed in continental environments. In the Paraná-Etendeka Igneous Province, feeders of basaltic rocks are exposed in several dyke swarms (Ponta Grossa NW trending, Florianópolis/Skeleton Coast (NW Namibia) N-S trending, Serra do Mar NE trending and Henties Bay/Outjo NE trending). In contrast, the only feeder system proposed to the acidic rocks of the Paraná-Etendeka Igneous Province is the Messum complex in Namibia (Milner et al. 1995). In the study area, the opening of three quarries for the extraction of dimension stones has exposed impressive structures/textures that show the effusive emplacement and the ductile to fragile-ductile magma transition along the acidic feeder dykes. Besides that, magma mixing/mingling processes between two acidic magmas are observed along the dykes. Here we describe new occurrences of acidic feeder dykes, correlate the dykes with acidic flows and discuss their importance to understand the emplacement of the Palmas type acid units in southern Brazil.

76 FR 37404 - Identification of Nine Entities Pursuant to Executive Order 13566 and Amendment of General...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-27

...: 13-14, 27090 Sehitkamil, Gaziantep, Turkey; Registration ID 146103 (Turkey); SWIFT/BIC ATUBTRIS... 30199 (Lebanon) issued 13 Oct 1973; SWIFT/BIC NACBLBBE (Lebanon); Telephone No. (961 1) [[Page 37406... Street, Taksim Al Nassim, 1002, Tunis, Tunisia; Boulevard 7 Novembre, Route El Kantaoui, 4011, Hammam...

Web-Based Intervention for Nutritional Management in Cystic Fibrosis: Development, Usability, and Pilot Trial.

PubMed

Stark, Lori J; Opipari-Arrigan, Lisa; Filigno, Stephanie S; Simon, Stacey L; Leonard, Amanda; Mogayzel, Peter J; Rausch, Joseph; Zion, Cynthia; Powers, Scott W

2016-06-01

Usability and pilot testing of a web intervention (BeInCharge.org [BIC]) of behavior plus nutrition intervention for children with cystic fibrosis (CF) ages 4-9 years. Think Aloud methodology was used with five mothers to assess usability and refine the intervention. A pilot trial was then conducted with 10 mothers of children with CF ages 4-9 years randomized to the web-based BIC or a Standard Care Control (STC). Change in weight gain for each group was compared in a pre-to-post design. Mothers rated the usability and clarity of BIC highly. The pilot trial showed children of mothers who received BIC had a significant change in weight pre-to-post-treatment (0.67 kg, p = .04). Change for the STC was not significant (0.41 kg, p = .10). A web-based behavior plus nutrition intervention appears promising in increasing weight gain in children with CF. © The Author 2015. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

PubMed

Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

2016-02-12

Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Concurrent Chemotherapy of Malignant Glioma in Rats by Using Multidrug-Loaded Biodegradable Nanofibrous Membranes

NASA Astrophysics Data System (ADS)

Tseng, Yuan-Yun; Huang, Yin-Chen; Yang, Tao-Chieh; Yang, Shun-Tai; Liu, Shou-Cheng; Chang, Tzu-Min; Kau, Yi-Chuan; Liu, Shih-Jung

2016-07-01

Glioblastoma multiforme has a poor prognosis and is highly chemoresistant. In this study, we implanted biodegradable 1,3-bis[2-chloroethyl]-1-nitroso-urea-, irinotecan-, and cisplatin-eluting poly[(d,l)-lactide-co-glycolide] (BIC/PLGA) and virgin nanofibrous membranes on the brain surface of C6 glioma-bearing rats in concurrent and virgin groups, respectively. The concentrations of all applied drugs were significantly higher in the brain than in the blood for more than 8 weeks in all studied rats. Tumor growth was more rapid in the vehicle-treated group, and tumor volumes were significantly higher in the vehicle-treated group. Moreover, the average survival time was significantly shorter in the vehicle-treated group (P = 0.026), and the BIC/PLGA nanofibrous membranes significantly reduced the risk of mortality (P < 0.001). Furthermore, the results suggested that the BIC/PLGA nanofibers reduced the malignancy of C6 glioma. The experimental findings indicate that the multianticancer drug (i.e., BIC)-eluting PLGA nanofibers are favorable candidates for treating malignant glioma.

Concurrent Chemotherapy of Malignant Glioma in Rats by Using Multidrug-Loaded Biodegradable Nanofibrous Membranes

PubMed Central

Tseng, Yuan-Yun; Huang, Yin-Chen; Yang, Tao-Chieh; Yang, Shun-Tai; Liu, Shou-Cheng; Chang, Tzu-Min; Kau, Yi-Chuan; Liu, Shih-Jung

2016-01-01

Glioblastoma multiforme has a poor prognosis and is highly chemoresistant. In this study, we implanted biodegradable 1,3-bis[2-chloroethyl]-1-nitroso-urea-, irinotecan-, and cisplatin-eluting poly[(d,l)-lactide-co-glycolide] (BIC/PLGA) and virgin nanofibrous membranes on the brain surface of C6 glioma-bearing rats in concurrent and virgin groups, respectively. The concentrations of all applied drugs were significantly higher in the brain than in the blood for more than 8 weeks in all studied rats. Tumor growth was more rapid in the vehicle-treated group, and tumor volumes were significantly higher in the vehicle-treated group. Moreover, the average survival time was significantly shorter in the vehicle-treated group (P = 0.026), and the BIC/PLGA nanofibrous membranes significantly reduced the risk of mortality (P < 0.001). Furthermore, the results suggested that the BIC/PLGA nanofibers reduced the malignancy of C6 glioma. The experimental findings indicate that the multianticancer drug (i.e., BIC)-eluting PLGA nanofibers are favorable candidates for treating malignant glioma. PMID:27471070

Synchrotron radiation μCT and histology evaluation of bone-to-implant contact.

PubMed

Neldam, Camilla Albeck; Sporring, Jon; Rack, Alexander; Lauridsen, Torsten; Hauge, Ellen-Margrethe; Jørgensen, Henrik L; Jørgensen, Niklas Rye; Feidenhansl, Robert; Pinholt, Else Marie

2017-09-01

The purpose of this study was to evaluate bone-to-implant contact (BIC) in two-dimensional (2D) histology compared to high-resolution three-dimensional (3D) synchrotron radiation micro computed tomography (SR micro-CT). High spatial resolution, excellent signal-to-noise ratio, and contrast establish SR micro-CT as the leading imaging modality for hard X-ray microtomography. Using SR micro-CT at voxel size 5 μm in an experimental goat mandible model, no statistically significant difference was found between the different treatment modalities nor between recipient and reconstructed bone. The histological evaluation showed a statistically significant difference between BIC in reconstructed and recipient bone (p < 0.0001). Further, no statistically significant difference was found between the different treatment modalities which we found was due to large variation and subsequently due to low power. Comparing histology and SR micro-CT evaluation a bias of 5.2% was found in reconstructed area, and 15.3% in recipient bone. We conclude that for evaluation of BIC with histology and SR micro-CT, SR micro-CT cannot be proven more precise than histology for evaluation of BIC, however, with this SR micro-CT method, one histologic bone section is comparable to the 3D evaluation. Further, the two methods complement each other with knowledge on BIC in 2D and 3D. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Breakup magmatism style on the North Atlantic Igneous Province: insight from Mid-Norwegian volcanic margin

NASA Astrophysics Data System (ADS)

Mansour Abdelmalak, Mohamed; Faleide, Jan Inge; Planke, Sverre; Theissen-Krah, Sonja; Zastrozhnov, Dmitrii; Breivik, Asbjørn Johan; Gernigon, Laurent; Myklebust, Reidun

2014-05-01

The distribution of breakup-related igneous rocks on rifted margins provide important constraints on the magmatic processes during continental extension and lithosphere separation which lead to a better understanding of the melt supply from the upper mantle and the relationship between tectonic setting and volcanism. The results can lead to a better understanding of the processes forming volcanic margins and thermal evolution of associated prospective basins. We present a revised mapping of the breakup-related igneous rocks in the NE Atlantic area, which are mainly based on the Mid-Norwegian (case example) margin. We divided the breakup related igneous rocks into (1) extrusive complexes, (2) shallow intrusive complexes (sills/dykes) and (3) deep intrusive complexes (Lower Crustal Body: LCB). The extrusive complex has been mapped using the seismic volcanostratigraphic method. Several distinct volcanic seismic facies units have been identified. The top basalt reflection is easily identified because of the high impedance contrast between the sedimentary and volcanic rocks resulting in a major reflector. The basal sequence boundary is frequently difficult to identify but it lies usually over the intruded sedimentary basin. Then the base is usually picked above the shallow sill intrusions identified on seismic profile. The mapping of the top and the base of the basaltic sequences allows us to determine the basalt thickness and estimate the volume of the magma production on the Mid- Norwegian margin. The thicker part of the basalt corresponds to the seaward dipping reflector (SDR). The magma feeder system, mainly formed by dyke and sill intrusions, represents the shallow intrusive complex. Deeper interconnected high-velocity sills are also mappable in the margin. Interconnected sill complexes can define continuous magma network >10 km in vertical ascent. The large-scale sill complexes, in addition to dyke swarm intrusions, represent a mode of vertical long-range magma transport through the upper crust. The deep intrusive complex represents the Lower Crustal Body (LCB) which is observed along the margin and characterized by high P-wave velocity bodies (Vp> 7km/s). On the Vøring margin a strong amplitude dome-shaped reflection (the so-called T-Reflection) has been identified and interpreted as the top LCB. In the sedimentary part of the margin, sill intrusions are the major feeder system and seem to be connected with LCB. In the volcanic part of the margin, dykes represent the main feeder system and lie above the thicker part of the LCB.

Effect of microthreads on removal torque and bone-to-implant contact: an experimental study in miniature pigs

PubMed Central

Kwon, Yee-Seo; Namgoong, Hee; Kim, Jung-Hoon; Cho, In Hee; Kim, Myung Duk; Eom, Tae Gwan

2013-01-01

Purpose The objective of this study was to evaluate the effect of microthreads on removal torque and bone-to-implant contact (BIC). Methods Twelve miniature pigs for each experiment, a total of 24 animals, were used. In the removal torque analysis, each animal received 2 types of implants in each tibia, which were treated with sandblasting and acid etching but with or without microthreads at the marginal portion. The animals were sacrificed after 4, 8, or 12 weeks of healing. Each subgroup consisted of 4 animals, and the tibias were extracted and removal torque was measured. In the BIC analysis, each animal received 3 types of implants. Two types of implants were used for the removal torque test and another type of implant served as the control. The BIC experiment was conducted in the mandible of the animals. The P1-M1 teeth were extracted, and after a 4-month healing period, 3 each of the 2 types of implants were placed, with one type on each side of the mandible, for a total of 6 implants per animal. The animals were sacrificed after a 2-, 4-, or 8-week healing period. Each subgroup consisted of 4 animals. The mandibles were extracted, specimens were processed, and BIC was analyzed. Results No significant difference in removal torque value or BIC was found between implants with and without microthreads. The removal torque value increased between 4 and 8 weeks of healing for both types of implants, but there was no significant difference between 8 and 12 weeks. The percentage of BIC increased between 2 and 4 weeks for all types of implants, but there was no significant difference between 4 and 8 weeks. Conclusions The existence of microthreads was not a significant factor in mechanical and histological stability. PMID:23508085

Psychrobacter glaciei sp. nov., isolated from the ice core of an Arctic glacier.

PubMed

Zeng, Yin-Xin; Yu, Yong; Liu, Yang; Li, Hui-Rong

2016-04-01

A Gram-stain-negative, non-motile, non-spore-forming, non-pigmented, oxidase- and catalase-positive bacterial strain, designated BIc20019T, was isolated from the ice core of Austre Lovénbreen in Ny-Ålesund, Svalbard. The temperature and NaCl ranges for growth were 4-34 °C (optimum, 25-29 °C) and 0-8% (w/v) (optimum, 2-4%). Analysis of the 16S rRNA gene sequence indicated that strain BIc20019T belonged to the genus Psychrobacter and was closely related to Psychrobacter arcticus 273-4T, Psychrobacter cryohalolentis K5T, 'Psychrobacter fjordensis' BSw21516B, Psychrobacter fozii LMG 21280T, Psychrobacter luti LMG 21276T and Pyschrobacter okhotskensis MD17T at greater than 99% similarity. Phylogenetic analysis based on gyrB gene sequences revealed highest similarity (93.6%) to P. okhotskensis MD17T. However, DNA hybridization experiments revealed a low level of DNA-DNA relatedness (<59%) between strain BIc20019T and its closest relatives. Strain BIc20019T contained ubiquinone-8 (Q-8) as the predominant respiratory quinone, and C18:1ω9c and summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH) as the major fatty acids. It had a DNA G+C content of 46.3 mol%. The polar lipid profile of strain BIc20019T was mainly composed of phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Owing to the differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene and gyrB gene sequences, and DNA-DNA relatedness data, the isolate merits classification within a novel species for which the name Psychrobacter glaciei sp. nov. is proposed. The type strain is BIc20019T (=KCTC 42280T = CCTCC AB 2014019T).

Correlation between Initial BIC and the Insertion Torque/Depth Integral Recorded with an Instantaneous Torque-Measuring Implant Motor: An in vivo Study.

PubMed

Capparé, Paolo; Vinci, Raffaele; Di Stefano, Danilo Alessio; Traini, Tonino; Pantaleo, Giuseppe; Gherlone, Enrico Felice; Gastaldi, Giorgio

2015-10-01

Quantitative intraoperative evaluation of bone quality at implant placement site and postinsertion implant primary stability assessment are two key parameters to perform implant-supported rehabilitation properly. A novel micromotor has been recently introduced allowing to measure bone density at implant placement site and to record implant insertion-related parameters, such as the instantaneous, average and peak insertion torque values, and the insertion torque/depth integral. The aim of this study was to investigate in vivo if any correlation existed between initial bone-to-implant contact (BIC) and bone density and integral values recorded with the instrument. Twenty-five patients seeking for implant-supported rehabilitation of edentulous areas were consecutively treated. Before implant placement, bone density at the insertion site was measured. For each patient, an undersized 3.3 × 8-mm implant was placed, recording the insertion torque/depth integral values. After 15 minutes, the undersized implant was retrieved with a 0.5 mm-thick layer of bone surrounding it. Standard implants were consequently placed. Retrieved implants were analyzed for initial BIC quantification after fixation, dehydration, acrylic resin embedment, sections cutting and grinding, and toluidine-blue and acid fuchsine staining. Correlation between initial BIC values, bone density at the insertion site, and the torque/depth integral values was investigated by linear regression analysis. A significant linear correlation was found to exist between initial BIC and (a) bone density at the insertion site (R = 0.96, explained variance R(2)  = 0.92) and (b) torque/depth integral at placement (R = 0.81, explained variance R(2)  = 0.66). The system provided quantitative, reliable data correlating significantly with immediate postinsertion initial BIC, and could therefore represent a valuable tool both for clinical research and for the oral implantologist in his/her daily clinical practice. © 2015 Wiley Periodicals, Inc.

Early and Late Alkali Igneous Pulses and a High-3He Plume Origin for the Deccan Flood Basalts.

PubMed

Basu, A R; Renne, P R; Dasgupta, D K; Teichmann, F; Poreda, R J

1993-08-13

Several alkalic igneous complexes of nephelinite-carbonatite affinities occur in extensional zones around a region of high heat flow and positive gravity anomaly within the continental flood basalt (CFB) province of Deccan, India. Biotites from two of the complexes yield (40)Ar/(39)Ar dates of 68.53 +/- 0.16 and 68.57 +/- 0.08 million years. Biotite from a third complex, which intrudes the flood basalts, yields an (40)Ar/(39)Ar date of 64.96 +/- 0.1 1 million years. The complexes thus represent early and late magmatism with respect to the main pulse of CFB volcanism 65 million years ago. Rocks from the older complexes show a (3)He/(4)He ratio of 14.0 times the air ratio, an initial (87)Sr/(86)Sr ratio of 0.70483, and other geochemical characteristics similar to ocean island basalts; the later alkalic pulse shows isotopic evidence of crustal contamination. The data document 3.5 million years of incubation of a primitive, high-(3)He mantle plume before the rapid eruption of the Deccan CFB.

Four-Channel PC/104 MIL-STD-1553 Circuit Board

NASA Technical Reports Server (NTRS)

Cox, Gary L.

2004-01-01

The mini bus interface card (miniBIC) is the first four-channel electronic circuit board that conforms to MIL-STD-1553 and to the electrical-footprint portion of PC/104. [MIL-STD-1553 is a military standard that encompasses a method of communication and electrical- interface requirements for digital electronic subsystems connected to a data bus. PC/104 is an industry standard for compact, stackable modules that are fully compatible (in architecture, hardware, and software) with personal-computer data- and power-bus circuitry.] Prior to the development of the miniBIC, only one- and two-channel PC/104 MIL-STD-1553 boards were available. To obtain four channels, it was necessary to include at least two boards in a PC/104 stack. In comparison with such a two-board stack, the miniBIC takes up less space, consumes less power, and is more reliable. In addition, the miniBIC includes 32 digital input/output channels. The miniBIC (see figure) contains four MIL-STD-1553B hybrid integrated circuits (ICs), four transformers, a field-programmable gate array (FPGA), and an Industry Standard Architecture (ISA) interface. Each hybrid IC includes a MILSTD-1553 dual transceiver, memory-management circuitry, processor interface logic circuitry, and 64Kx16 bits of shared static random access memory. The memory is used to configure message and data blocks. In addition, 23 16-bit registers are available for (1) configuring the hybrid IC for, and starting it in, various modes of operation; (2) reading the status of the functionality of the hybrid IC; and (3) resetting the hybrid IC to a known state. The miniBIC can operate as a remote terminal, bus controller, or bus monitor. The FPGA provides the chip-select and data-strobe signals needed for operation of the hybrid ICs. The FPGA also receives interruption signals and forwards them to the ISA bus. The ISA interface connects the address, data, and control interfaces of the hybrid ICs to the ISA backplane. Each channel is, in effect, a MIL-STD-1553 interface that can operate either independently of the others or else as a redundant version of one of the others. The transformer in each channel provides electrical isolation between the rest of the miniBIC circuitry and the bus to which that channel is connected.

78 FR 25256 - Petition Requesting Exception From Lead Content Limits: BIC USA Inc.

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-30

... Exception From Lead Content Limits: BIC USA Inc. AGENCY: Consumer Product Safety Commission. ACTION: Notice... exception from the 100 ppm lead content limit under section 101(b) of the Consumer Product Safety... intended primarily for children 12 years old and younger that contain lead content in excess of 100 ppm are...

The Impact of Various Class-Distinction Features on Model Selection in the Mixture Rasch Model

ERIC Educational Resources Information Center

Choi, In-Hee; Paek, Insu; Cho, Sun-Joo

2017-01-01

The purpose of the current study is to examine the performance of four information criteria (Akaike's information criterion [AIC], corrected AIC [AICC] Bayesian information criterion [BIC], sample-size adjusted BIC [SABIC]) for detecting the correct number of latent classes in the mixture Rasch model through simulations. The simulation study…

The Effect of Breakfast in the Classroom on Obesity and Academic Performance: Evidence from New York City

ERIC Educational Resources Information Center

Corcoran, Sean P.; Elbel, Brian; Schwartz, Amy Ellen

2016-01-01

Participation in the federally subsidized school breakfast program often falls well below its lunchtime counterpart. To increase take-up, many districts have implemented Breakfast in the Classroom (BIC), offering breakfast directly to students at the start of the school day. Beyond increasing participation, advocates claim BIC improves academic…

What do conscientious people do? Development and validation of the Behavioral Indicators of Conscientiousness (BIC).

PubMed

Jackson, Joshua J; Wood, Dustin; Bogg, Tim; Walton, Kate E; Harms, Peter D; Roberts, Brent W

2010-08-01

Typical assessments of personality traits collapse behaviors, thoughts, and feelings into a single measure without distinguishing between these different manifestations. To address this lack of specification, the current study develops and validates a measure that assesses a number of broad behaviors associated with the personality trait of conscientiousness (the Behavioral Indicators of Conscientiousness; BIC). Findings suggest that the lower-order structure of conscientious behaviors is mostly similar to the lower-order structure in extant trait measures. Furthermore, a daily diary method was used to validate the BIC against frequency counts of conscientious behavior. Overall, the results identify specific behaviors that conscientious individuals tend to perform and highlight possible advantages of this approach over broad trait assessment.

Histologic analysis of resorbable blasting media surface implants retrieved from humans: a report of two cases

PubMed Central

2016-01-01

The purpose of this study is to evaluate the degree of osseointegration of resorbable blasting media (RBM) surface implants retrieved from humans. Three implants in the mandibular molar region that were surface-treated with RBM were retrieved from two patients. The implants were used to manufacture specimens in order to measure the bone-implant contact (BIC) ratio. The BIC ratios of the three implants were found to be an average of 69.0%±9.1%. In conclusion, that RBM surface implants are integrated into the host environment with histological significance and the BIC ratio of the RBM surface-treated implant was not significantly different from that of other surface-treated implants. PMID:26904493

Forward Modeling of Receiver Functions to Determine Crustal Structure of the Eastern Limb in TheBushveld Complex, South Africa

NASA Astrophysics Data System (ADS)

Loza, E.; Ramirez, C.; Nyblade, A.; Durrheim, R. J.; Raveloson, A.

2016-12-01

The Bushveld Igneous Complex contains the largest layered mafic intrusion on Earth, about the size of England, and has been exploited for metals such as platinum since the 1950s. Several igneous bodies within and around the complex have been dated from 2.06 Ga, possibly representing a single massive magmatic event. The Rustenburg Layered Suite of the Bushveld Igneous Complex intruded into the Transvaal sedimentary sequence, with associated volcanic rocks of the Rooiberg Group forming the roof and part of the floor. The purpose of this study is to determine whether the Rustenburg Layered Suite is a continuous bowl-shaped formation or if it is made up of two separate dipping sheets that crop out in the western and eastern limbs. If the intrusion is connected at depth, then the Moho (crust-mantle boundary) would most likely be depressed due to the weight of the 7-8km of mafic material injected into the crust. Seismic stations were installed in the eastern and northern Bushveld in 2015 to collect teleseismic data. The use of receiver functions derived from seismic data collected since 2015 has helped determine the subsurface crustal structure of the Bushveld. Receiver functions have been used to trace the contact between the high-density mafic lower zone and the low-density Transvaal sediments. The new data gathered show the Moho boundary at about 47 km, and a 5.0 Gaussian width shows a backswing consistent with a mafic-sedimentary boundary at 8km.

Neodymium isotopic study of rare earth element sources and mobility in hydrothermal Fe-oxide (Fe-P-REE) systems

NASA Astrophysics Data System (ADS)

Gleason, James D.; Marikos, Mark A.; Barton, Mark D.; Johnson, David A.

2000-03-01

Rare earth element (REE)-enriched, igneous-related hydrothermal Fe-oxide hosted (Fe-P-REE) systems from four areas in North America have been analyzed for their neodymium isotopic composition to constrain REE sources and mobility in these systems. The Nd isotopic results evidence a common pattern of REE concentration from igneous sources despite large differences in age (Proterozoic to Tertiary), tectonic setting (subduction vs. intraplate), and magmatic style (mafic vs. felsic). In the Middle Proterozoic St. Francois Mountains terrane of southeastern Missouri, ɛ Nd for Fe-P-REE (apatite, monazite, xenotime) deposits ranges from +3.5 to +5.1, similar to associated felsic to intermediate igneous rocks of the same age (ɛ Nd = +2.6 to +6.2). At the mid-Jurassic Humboldt mafic complex in western Nevada, ɛ Nd for Fe-P-REE (apatite) mineralization varies between +1.1 and +2.4, similar to associated mafic igneous rocks (-1.0 to +3.5). In the nearby Cortez Mountains in central Nevada, mid-Jurassic felsic volcanic and plutonic rocks (ɛ Nd = -2.0 to -4.4) are associated with Fe-P-REE (apatite-monazite) mineralization having similar ɛ Nd (-1.7 to -2.4). At Cerro de Mercado, Durango, Mexico, all assemblages analyzed in this Tertiary rhyolite-hosted Fe oxide deposit have identical isotopic compositions with ɛ Nd = -2.5. These data are consistent with coeval igneous host rocks being the primary source of REE in all four regions, and are inconsistent with a significant contribution of REE from other sources. Interpretations of the origin of these hydrothermal systems and their concomitant REE mobility must account for nonspecialized igneous sources and varied tectonic settings.

Neodymium isotopic study of rare earth element sources and mobility in hydrothermal Fe oxide (Fe-P-REE) systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gleason, J.D.; Marikos, M.A.; Barton, M.D.

2000-03-01

Rare earth element (REE)-enriched, igneous-related hydrothermal Fe-oxide hosted (Fe-P-REE) systems from four areas in North America have been analyzed for their neodymium iosotopic composition to constrain REE sources and mobility in these systems. The Nd isotopic results evidence a common pattern of REE concentration from igneous sources despite large differences in age (Proterozoic to Tertiary), tectonic setting (subduction vs. intraplate), and magmatic style (mafic vs. felsic). In the Middle Proterozoic St. Francois Mountains terrane of southeastern Missouri, {epsilon}{sub Nd} for Fe-P-REE (apatite, monazite, xenotime) deposits ranges from +3.5 to +5.1, similar to associated felsic to intermediate igneous rocks of themore » same age ({epsilon}{sub Nd} = +2.6 to +6.2). At the mid-Jurassic Humboldt mafic complex in western Nevada, {epsilon}{sub Nd} for Fe-P-REE (apatite) mineralization varies between +1.1 and +2.4, similar to associated mafic igneous rocks ({minus}1.0 to +3.5). In the nearby Cortez Mountains in central Nevada, mid-Jurassic felsic volcanic and plutonic rocks ({epsilon}{sub Nd} = {minus}2.0 to {minus}4.4) are associated with Fe-P-REE (apatite-monazite) mineralization having similar {epsilon}{sub Nd}({minus}1.7 to {minus}2.4). At Cerro de Mercado, Durango, Mexico, all assemblages analyzed in this Tertiary rhyolite-hosted Fe oxide deposit have identical isotopic compositions with {epsilon}{sub Nd} = {minus}2.5. These data are consistent with coeval igneous host rocks being the primary source of REE in all four regions, and are inconsistent with a significant contribution of REE from other sources. Interpretations of the origin of these hydrothermal systems and their concomitant REE mobility must account for nonspecialized igneous sources and varied tectonic settings.« less

Query-based biclustering of gene expression data using Probabilistic Relational Models.

PubMed

Zhao, Hui; Cloots, Lore; Van den Bulcke, Tim; Wu, Yan; De Smet, Riet; Storms, Valerie; Meysman, Pieter; Engelen, Kristof; Marchal, Kathleen

2011-02-15

With the availability of large scale expression compendia it is now possible to view own findings in the light of what is already available and retrieve genes with an expression profile similar to a set of genes of interest (i.e., a query or seed set) for a subset of conditions. To that end, a query-based strategy is needed that maximally exploits the coexpression behaviour of the seed genes to guide the biclustering, but that at the same time is robust against the presence of noisy genes in the seed set as seed genes are often assumed, but not guaranteed to be coexpressed in the queried compendium. Therefore, we developed ProBic, a query-based biclustering strategy based on Probabilistic Relational Models (PRMs) that exploits the use of prior distributions to extract the information contained within the seed set. We applied ProBic on a large scale Escherichia coli compendium to extend partially described regulons with potentially novel members. We compared ProBic's performance with previously published query-based biclustering algorithms, namely ISA and QDB, from the perspective of bicluster expression quality, robustness of the outcome against noisy seed sets and biological relevance.This comparison learns that ProBic is able to retrieve biologically relevant, high quality biclusters that retain their seed genes and that it is particularly strong in handling noisy seeds. ProBic is a query-based biclustering algorithm developed in a flexible framework, designed to detect biologically relevant, high quality biclusters that retain relevant seed genes even in the presence of noise or when dealing with low quality seed sets.

A Comparison of Two Objective Measures of Binaural Processing: The Interaural Phase Modulation Following Response and the Binaural Interaction Component.

PubMed

Haywood, Nicholas R; Undurraga, Jaime A; Marquardt, Torsten; McAlpine, David

2015-12-30

There has been continued interest in clinical objective measures of binaural processing. One commonly proposed measure is the binaural interaction component (BIC), which is obtained typically by recording auditory brainstem responses (ABRs)-the BIC reflects the difference between the binaural ABR and the sum of the monaural ABRs (i.e., binaural - (left + right)). We have recently developed an alternative, direct measure of sensitivity to interaural time differences, namely, a following response to modulations in interaural phase difference (the interaural phase modulation following response; IPM-FR). To obtain this measure, an ongoing diotically amplitude-modulated signal is presented, and the interaural phase difference of the carrier is switched periodically at minima in the modulation cycle. Such periodic modulations to interaural phase difference can evoke a steady state following response. BIC and IPM-FR measurements were compared from 10 normal-hearing subjects using a 16-channel electroencephalographic system. Both ABRs and IPM-FRs were observed most clearly from similar electrode locations-differential recordings taken from electrodes near the ear (e.g., mastoid) in reference to a vertex electrode (Cz). Although all subjects displayed clear ABRs, the BIC was not reliably observed. In contrast, the IPM-FR typically elicited a robust and significant response. In addition, the IPM-FR measure required a considerably shorter recording session. As the IPM-FR magnitude varied with interaural phase difference modulation depth, it could potentially serve as a correlate of perceptual salience. Overall, the IPM-FR appears a more suitable clinical measure than the BIC. © The Author(s) 2015.

Model Selection and Psychological Theory: A Discussion of the Differences between the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC)

ERIC Educational Resources Information Center

Vrieze, Scott I.

2012-01-01

This article reviews the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) in model selection and the appraisal of psychological theory. The focus is on latent variable models, given their growing use in theory testing and construction. Theoretical statistical results in regression are discussed, and more important…

Stylizing Genderlect Online for Social Action: A Corpus Analysis of "BIC Cristal for Her" Reviews

ERIC Educational Resources Information Center

Ray, Brian

2016-01-01

This article introduces the concept of stylization and illustrates its usefulness for studying online discourse by examining how writers have employed it in order to parody sexist products such as BIC Cristal for Her, using genderlect in order to introduce dissonance into and reframe patriarchal discourse. A corpus analysis of 671 reviews, written…

The Effect of Breakfast in the Classroom on Obesity and Academic Performance: Evidence from New York City. Working Paper #04-14

ERIC Educational Resources Information Center

Corcoran, Sean P.; Elbel, Brian; Schwartz, Amy Ellen

2014-01-01

Participation in the federally-subsidized school breakfast program often falls well below its lunchtime counterpart. To increase take-up, many districts have implemented Breakfast in the Classroom (BIC), offering breakfast directly to students at the start of the school day. Beyond increasing participation, advocates claim BIC improves academic…

Chemically stable Au nanorods as probes for sensitive surface enhanced scattering (SERS) analysis of blue BIC ballpoint pens

NASA Astrophysics Data System (ADS)

Alyami, Abeer; Saviello, Daniela; McAuliffe, Micheal A. P.; Cucciniello, Raffaele; Mirabile, Antonio; Proto, Antonio; Lewis, Liam; Iacopino, Daniela

2017-08-01

Au nanorods were used as an alternative to commonly used Ag nanoparticles as Surface Enhanced Raman Scattering (SERS) probes for identification of dye composition of blue BIC ballpoint pens. When used in combination with Thin Layer Chromatography (TLC), Au nanorod colloids allowed identification of the major dye components of the BIC pen ink, otherwise not identifiable by normal Raman spectroscopy. Thanks to their enhanced chemical stability compared to Ag colloids, Au nanorods provided stable and reproducible SERS signals and allowed easy identification of phthalocyanine and triarylene dyes in the pen ink mixture. These findings were supported by FTIR and MALDI analyses, also performed on the pen ink. Furthermore, the self-assembly of Au nanorods into large area ordered superstructures allowed identification of BIC pen traces. SERS spectra of good intensity and high reproducibility were obtained using Au nanorod vertical arrays, due to the high density of hot spots and morphological reproducibility of these superstructures. These results open the way to the employment of SERS for fast screening analysis and for quantitative analysis of pens and faded pens which are relevant for the fields of forensic and art conservation sciences.

Petrology, geochemistry and zircon U-Pb geochronology of a layered igneous complex from Akarui Point in the Lützow-Holm Complex, East Antarctica: Implications for Antarctica-Sri Lanka correlation

NASA Astrophysics Data System (ADS)

Kazami, Sou; Tsunogae, Toshiaki; Santosh, M.; Tsutsumi, Yukiyasu; Takamura, Yusuke

2016-11-01

The Lützow-Holm Complex (LHC) of East Antarctica forms part of a complex subduction-collision orogen related to the amalgamation of the Neoproterozoic supercontinent Gondwana. Here we report new petrological, geochemical, and geochronological data from a metamorphosed and disrupted layered igneous complex from Akarui Point in the LHC which provide new insights into the evolution of the complex. The complex is composed of mafic orthogneiss (edenite/pargasite + plagioclase ± clinopyroxene ± orthopyroxene ± spinel ± sapphirine ± K-feldspar), meta-ultramafic rock (pargasite + olivine + spinel + orthopyroxene), and felsic orthogneiss (plagioclase + quartz + pargasite + biotite ± garnet). The rocks show obvious compositional layering reflecting the chemical variation possibly through magmatic differentiation. The metamorphic conditions of the rocks were estimated using hornblende-plagioclase geothermometry which yielded temperatures of 720-840 °C. The geochemical data of the orthogneisses indicate fractional crystallization possibly related to differentiation within a magma chamber. Most of the mafic-ultramafic samples show enrichment of LILE, negative Nb, Ta, P and Ti anomalies, and constant HFSE contents in primitive-mantle normalized trace element plots suggesting volcanic arc affinity probably related to subduction. The enrichment of LREE and flat HREE patterns in chondrite-normalized REE plot, with the Nb-Zr-Y, Y-La-Nb, and Th/Yb-Nb/Yb plots also suggest volcanic arc affinity. The felsic orthogneiss plotted on Nb/Zr-Zr diagram (low Nb/Zr ratio) and spider diagrams (enrichment of LILE, negative Nb, Ta, P and Ti anomalies) also show magmatic arc origin. The morphology, internal structure, and high Th/U ratio of zircon grains in felsic orthogneiss are consistent with magmatic origin for most of these grains. Zircon U-Pb analyses suggest Early Neoproterozoic (847.4 ± 8.0 Ma) magmatism and protolith formation. Some older grains (1026-882 Ma) are regarded as xenocrysts from basement entrained in the magma through limited crustal reworking. The younger ages (807-667 Ma) might represent subsequent thermal events. The results of this study suggest that the ca. 850 Ma layered igneous complex in Akarui Point was derived from a magma chamber constructed through arc-related magmatism which included components from ca. 1.0 Ga felsic continental crustal basement. The geochemical characteristics and the timing of protolith emplacement from this complex are broadly identical to those of similar orthogneisses from Kasumi Rock and Tama Point in the LHC and the Kadugannawa Complex in Sri Lanka, which record Early Neoproterozoic (ca. 1.0 Ga) arc magmatism. Although the magmatic event in Akarui Point is slightly younger, the thermal event probably continued from ca. 1.0 Ga to ca. 850 Ma or even to ca. 670 Ma. We therefore correlate the Akarui Point igneous complex with those in the LHC and Kadugannawa Complex formed under similar Early Neoproterozoic arc magmatic events during the convergent margin processes prior to the assembly of the Gondwana supercontinent.

Mapping Phyllic and Argillic-Altered Rocks in Southeastern Afghanistan using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Data

USGS Publications Warehouse

Mars, John L.; Rowan, Lawrence C.

2007-01-01

Introduction: ASTER data and logical operators were successfully used to map phyllic and argillic-altered rocks in the southeastern part of Afghanistan. Hyperion data were used to correct ASTER band 5 and ASTER data were georegistered to orthorectified Landsat TM data. Logical operator algorithms produced argillic and phyllic byte ASTER images that were converted to vector data and overlain on ASTER and Landsat TM images. Alteration and fault patterns indicated that two areas, the Argandab igneous complex, and the Katawaz basin may contain potential polymetallic vein and porphyry copper deposits. ASTER alteration mapping in the Chagai Hills indicates less extensive phyllic and argillic-altered rocks than mapped in the Argandab igneous complex and the Katawaz basin and patterns of alteration are inconclusive to predict potential deposit types.

Intraterrestrial life in igneous ocean crust: advances, technologies, and the future (Invited)

NASA Astrophysics Data System (ADS)

Edwards, K. J.; Wheat, C. G.

2010-12-01

The “next frontier” of scientific investigation in the deep sub-seafloor microbial biosphere lies in a realm that has been a completely unexplored until just the past decade: the igneous oceanic crust. Problems that have hampered exploration of the “hard rock” marine deep biosphere have revolved around sample access (hard rock drilling is technologically complex), contamination (a major hurdle), momentum (why take on this challenge when the relatively “easier” marine muds also have been a frontier) and suspicion that microbes in more readily accessed using (simpler) non-drilling technologies - like vents - are truly are endemic of subsurface clades/activities. Since the late 1990’s, however, technologies and resultant studies on microbes in the igneous ocean crust deep biosphere have risen sharply, and offer a new and distinct view on this biome. Moreover, microbiologists are now taking leading roles in technological developments that are critically required to address this biosphere - interfacing and collaborating closely with engineers, genomic biologists, geologists, seismologists, and geochemists to accomplish logistically complex and long-term studies that bring observatory research to this deep realm. The future of this field for the least decade is rich - opportunities abound for microbiologists to play new roles in how we study microbiology in the deep subsurface in an oceanographic and Earth system science perspective.

Analyzing Genome-Wide Association Studies with an FDR Controlling Modification of the Bayesian Information Criterion

PubMed Central

Dolejsi, Erich; Bodenstorfer, Bernhard; Frommlet, Florian

2014-01-01

The prevailing method of analyzing GWAS data is still to test each marker individually, although from a statistical point of view it is quite obvious that in case of complex traits such single marker tests are not ideal. Recently several model selection approaches for GWAS have been suggested, most of them based on LASSO-type procedures. Here we will discuss an alternative model selection approach which is based on a modification of the Bayesian Information Criterion (mBIC2) which was previously shown to have certain asymptotic optimality properties in terms of minimizing the misclassification error. Heuristic search strategies are introduced which attempt to find the model which minimizes mBIC2, and which are efficient enough to allow the analysis of GWAS data. Our approach is implemented in a software package called MOSGWA. Its performance in case control GWAS is compared with the two algorithms HLASSO and d-GWASelect, as well as with single marker tests, where we performed a simulation study based on real SNP data from the POPRES sample. Our results show that MOSGWA performs slightly better than HLASSO, where specifically for more complex models MOSGWA is more powerful with only a slight increase in Type I error. On the other hand according to our simulations GWASelect does not at all control the type I error when used to automatically determine the number of important SNPs. We also reanalyze the GWAS data from the Wellcome Trust Case-Control Consortium and compare the findings of the different procedures, where MOSGWA detects for complex diseases a number of interesting SNPs which are not found by other methods. PMID:25061809

Geostatistical Interplay Between Geophysical and Geochemical Data: Mapping Litho-Structural Assemblages of Mesozoic Igneous Activities in the Parnaíba Basin (NE Brazil)

NASA Astrophysics Data System (ADS)

de Castro, David L.; Oliveira, Diógenes C.; Hollanda, Maria Helena B. M.

2018-07-01

Two widespread magmatic events are recorded in the Parnaíba basin (NE Brazil) during the Jurassic/Cretaceous opening of the Central and South Atlantic Oceans. The Early Jurassic ( 200 Ma) lava flows of the Mosquito Formation occur essentially in the western and southern basin segments, representing one of the largest expressions of the Central Atlantic Magmatic Province in the South American Plate. In contrast, sill complexes and dike swarms of the Early Cretaceous (129-124 Ma) Sardinha Formation occur in the eastern part of the basin and are chrono-correlated to the large Paraná-Etendeka igneous province and to the Rio Ceará-Mirim Dike Swarm. We gathered geophysical, well logging, outcrop analogs and geochemical data to recognize geometrical shapes and areal distribution patterns of igneous-related constructions. Seismic and well data reveal hundreds of km wide multilayered sill complexes and dikes, which are widespread across vast regions of the basin without evident structural control from either the Precambrian basement grain or the basin internal architecture. Anomaly enhancement techniques and self-organizing maps (SOM) procedure were applied on airborne magnetic data, unraveling near-surface magmatic features in four distinct magnetic domains. Using SOM analysis, the basaltic rocks were divided into six groups based on magnetic susceptibility and major elements composition. These results suggest common origin for both magmatic episodes, probably a combination of effects of edge-driven convection and large-scale mantle warming under the westward moving West Gondwana during the Central and South Atlantic opening, which caused a shifted emplacement to the east of the igneous rocks in the Parnaíba basin.

Geostatistical Interplay Between Geophysical and Geochemical Data: Mapping Litho-Structural Assemblages of Mesozoic Igneous Activities in the Parnaíba Basin (NE Brazil)

NASA Astrophysics Data System (ADS)

de Castro, David L.; Oliveira, Diógenes C.; Hollanda, Maria Helena B. M.

2018-02-01

Two widespread magmatic events are recorded in the Parnaíba basin (NE Brazil) during the Jurassic/Cretaceous opening of the Central and South Atlantic Oceans. The Early Jurassic ( 200 Ma) lava flows of the Mosquito Formation occur essentially in the western and southern basin segments, representing one of the largest expressions of the Central Atlantic Magmatic Province in the South American Plate. In contrast, sill complexes and dike swarms of the Early Cretaceous (129-124 Ma) Sardinha Formation occur in the eastern part of the basin and are chrono-correlated to the large Paraná-Etendeka igneous province and to the Rio Ceará-Mirim Dike Swarm. We gathered geophysical, well logging, outcrop analogs and geochemical data to recognize geometrical shapes and areal distribution patterns of igneous-related constructions. Seismic and well data reveal hundreds of km wide multilayered sill complexes and dikes, which are widespread across vast regions of the basin without evident structural control from either the Precambrian basement grain or the basin internal architecture. Anomaly enhancement techniques and self-organizing maps (SOM) procedure were applied on airborne magnetic data, unraveling near-surface magmatic features in four distinct magnetic domains. Using SOM analysis, the basaltic rocks were divided into six groups based on magnetic susceptibility and major elements composition. These results suggest common origin for both magmatic episodes, probably a combination of effects of edge-driven convection and large-scale mantle warming under the westward moving West Gondwana during the Central and South Atlantic opening, which caused a shifted emplacement to the east of the igneous rocks in the Parnaíba basin.

Infection control and prevention practices implemented to reduce transmission risk of Middle East respiratory syndrome-coronavirus in a tertiary care institution in Saudi Arabia.

PubMed

Butt, Taimur S; Koutlakis-Barron, Irene; AlJumaah, Suliman; AlThawadi, Sahar; AlMofada, Saleh

2016-05-01

Transmission of Middle East respiratory syndrome-coronavirus (MERS-CoV) among health care workers (HCWs) and patients has been documented with mortality rate approximating 36%. We propose advanced infection control measures (A-IC) used in conjunction with basic infection control measures (B-IC) help reduce pathogen transmission. B-IC include standard and transmission-based precautions. A-IC are initiatives implemented within our center to enhance effectiveness of B-IC. Study effectiveness of combining B-IC and A-IC to prevent transmission of MERS-CoV to HCWs. A retrospective observational study was undertaken. A-IC measures include administrative support with daily rounds; infection control risk assessment; timely screening, isolation, and specimen analysis; collaboration; epidemic planning; stockpiling; implementation of contingency plans; full personal protective equipment use for advanced airway management; use of a real-time electronic isolation flagging system; infection prevention and control team on-call protocols; pretransfer MERS-CoV testing; and education. A total of 874 real-time polymerase chain reaction MERS-CoV tests were performed during the period beginning July 1, 2013, and ending January 31, 2015. Six hundred ninety-four non-HCWs were tested, of these 16 tested positive for MERS-CoV and their infection was community acquired. Sixty-nine percent of the confirmed MERS-CoV-positive cases were men, with an average age of 56 years (range, 19-84 years). Of the total tested for MERS-CoV, 180 individuals were HCWs with zero positivity. Adhering to a combination of B-IC and A-IC reduces the risk of MERS-CoV transmission to HCWs. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

The influence of micro and macro-geometry in term of bone-implant interface in two implant systems: an histomorphometrical study

PubMed Central

ROCCI, A.; CALCATERRA, R.; DI GIROLAMO, M.; ROCCI, M.; ROCCI, C.; BAGGI, L.

2015-01-01

SUMMARY Objective Many factors could affect the osseous healing of implants such as surface topography of biomaterial, the status of the bone/implant site, implant loading conditions, surgical technique and implant design. The aim of this study was to analyze the BIC of 2 different implants systems characterized by different micro and macrogeometry, that were placed in the posterior maxillary and mandibular jaws of humans, clinically unloaded and retrieved for histomorphometric analyses after 12 weeks. Material and method The patients were divided in two groups (Group I and II); group I was composed by 4 patients that each received in the posterior areas of mandible one type A implant [GTB-Plan1Health Amaro (UD) Italy] one type B implant (OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). Group II was composed by 3 patients that each received in the posterior areas of jawsbone one type A implant [GTB-Plan1Health Amaro (UD) Italy] one type B implant (OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). After 12 weeks of healing all the implants of both groups were harvested with the peri-implant bone tissues. Osseointegration process was evaluated throughout measurements of BIC. Results No statistical significance differences were found among the mean percentage of BIC of Group I – type A were 66,51% versus 49,96% in Group I – type B, as well as among the mean percentage of BIC of Group II – type A were 43.7% versus 60.02% in Group II – type B. Conclusions Our results highlight that the mean percentage of BIC after 12 weeks from the implants placement without functional loading is not influenced by the composition of the implant surface. PMID:28042421

The influence of micro and macro-geometry in term of bone-implant interface in two implant systems: an histomorphometrical study.

PubMed

Rocci, A; Calcaterra, R; DI Girolamo, M; Rocci, M; Rocci, C; Baggi, L

2015-01-01

Many factors could affect the osseous healing of implants such as surface topography of biomaterial, the status of the bone/implant site, implant loading conditions, surgical technique and implant design. The aim of this study was to analyze the BIC of 2 different implants systems characterized by different micro and macrogeometry, that were placed in the posterior maxillary and mandibular jaws of humans, clinically unloaded and retrieved for histomorphometric analyses after 12 weeks. The patients were divided in two groups (Group I and II); group I was composed by 4 patients that each received in the posterior areas of mandible one type A implant [GTB-Plan1Health Amaro (UD) Italy] one type B implant (OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). Group II was composed by 3 patients that each received in the posterior areas of jawsbone one type A implant [GTB-Plan1Health Amaro (UD) Italy] one type B implant (OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). After 12 weeks of healing all the implants of both groups were harvested with the peri-implant bone tissues. Osseointegration process was evaluated throughout measurements of BIC. No statistical significance differences were found among the mean percentage of BIC of Group I - type A were 66,51% versus 49,96% in Group I - type B, as well as among the mean percentage of BIC of Group II - type A were 43.7% versus 60.02% in Group II - type B. Our results highlight that the mean percentage of BIC after 12 weeks from the implants placement without functional loading is not influenced by the composition of the implant surface.

Comparison of two dental implant surface modifications on implants with same macrodesign: an experimental study in the pelvic sheep model.

PubMed

Ernst, Sabrina; Stübinger, Stefan; Schüpbach, Peter; Sidler, Michéle; Klein, Karina; Ferguson, Stephen J; von Rechenberg, Brigitte

2015-08-01

The aim of this study was to compare two different surfaces of one uniform macro-implant design in order to focus exclusively on the osseointegration properties after 2, 4 and 8 weeks and to discuss the animal model chosen. In six mature sheep, n = 36 implants with a highly crystalline and phosphate-enriched anodized titanium oxide surface (TiU) and n = 36 implants with a hydrophilic, sandblasted, large grit and acid-etched surface (SLA) were placed in the pelvic bone. TiU implants were custom-made to match the SLA implant design. The implant stability and bone-to-implant contact (BIC) were assessed by resonance frequency (ISQ), backscatter scanning electron microscopy (B-SEM), light microscopy (LM), micro-CT and intravital fluorochrome staining. Biomechanical removal torque testing was performed. Overall, no statistically significant differences in BIC total (trabecular + cortical) between TiU and SLA were found via LM and B-SEM. BIC values (B-SEM; LM) in both groups revealed a steady rise in trabecular bone attachment to the implant surface after 2, 4 and 8 weeks. In the 2- to 4-week time interval in the TiU group (P = 0.005) as well as in the SLA group (P = 0.01), a statistically significant increase in BIC trabecular could be observed via LM. B-SEM values confirmed the statistically significant increase for TiU (P = 0.001). In both groups, BIC trabecular values after 8 weeks were significantly higher (P ≤ 0.05) than after 2 weeks (B-SEM; LM). Biomechanical data confirmed the histological data. The two surfaces proved comparable osseointegration in this sheep model. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska

USGS Publications Warehouse

Bundtzen, Thomas K.; Miller, Marti L.; Goldfarb, Richard J.; Miller, Lance D.

1997-01-01

Placer gold and precious metal-bearing lode deposits of southwestern Alaska lie within a region 550 by 350 km, herein referred to as the Kuskokwim mineral belt. This mineral belt has yielded 100,240 kg (3.22 Moz) of gold, 12, 813 kg (412,000 oz) of silver, 1,377,412 kg (39,960 flasks) of mercury, and modest amounts of antimony and tungsten derived primarily from the late Cretaceous-early Tertiary igneous complexes of four major types: (1) alkali-calcic, comagmatic volcanic-plutonic complexes and isolated plutons, (2) calc-alkaline, meta-aluminous reduced plutons, (3) peraluminous alaskite or granite-porphyry sills and dike swarms, and (4) andesite-rhyolite subaerial volcanic rocks.About 80 percent of the 77 to 52 Ma intrusive and volcanic rocks intrude or overlie the middle to Upper Cretaceous Kuskokwim Group sedimentary and volcanic rocks, as well as the Paleozoic-Mesozoic rocks of the Nixon Fork, Innoko, Goodnews, and Ruby preaccretionary terranes.The major precious metal-bearing deposit types related to Late Cretaceous-early Tertiary igneous complexes of the Kuskokwim mineral belt are subdivided as follows: (1) plutonic-hosted copper-gold polymetallic stockwork, skarn, and vein deposits, (2) peraluminous granite-porphory-hosted gold polymetallic deposits, (3) plutonic-related, boron-enriched silver-tin polymetallic breccia pipes and replacement deposits, (4) gold and silver mineralization in epithermal systems, and (5) gold polymetallic heavy mineral placer deposits. Ten deposits genetically related to Late Cretaceous-early Tertiary intrusions contain minimum, inferred reserves amounting to 162,572 kg (5.23 Moz) of gold, 201,015 kg (6.46 Moz) silver, 12,160 metric tons (t) of tin, and 28,088 t of copper.The lodes occur in veins, stockworks, breccia pipes, and replacement deposits that formed in epithermal to mesothermal temperature-pressure conditions. Fluid inclusion, isotopic age, mineral assemblage, alteration assemblage, and structural data indicate that many of the mineral deposits associated with Late Cretaceous-early tertiary volcanic and plutonic rocks represent geologically and spatially related, vertically zoned hydrothermal systems now exposed at several erosional levels.Polymetallic gold deposits of the Kuskokwim mineral belt are probably related to 77 to 52 Ma plutonism and volcanism associated with a period of rapid, north-directed subduction of the Kula plate. The geologic interpretation suggests that igneous complexes of the Kuskokwim mineral belt formed in an intracontinental back-arc setting during a period of extensional, wrench fault tectonics.The Kuskokwim mineral belt has many geologic and metallogenic features similar to other precious metal-bearing systems associated with arc-related igneous rocks such as the Late Cretaceous-early Tertiary Rocky Mountain alkalic province, the Jurassic Mount Milligan district of central British Columbia, the Andean orogen of South America, and the Okhotsk-Chukotka belt of northeast Asia.

Corticomotor excitability of arm muscles modulates according to static position and orientation of the upper limb.

PubMed

Mogk, Jeremy P M; Rogers, Lynn M; Murray, Wendy M; Perreault, Eric J; Stinear, James W

2014-10-01

We investigated how multi-joint changes in static upper limb posture impact the corticomotor excitability of the posterior deltoid (PD) and biceps brachii (BIC), and evaluated whether postural variations in excitability related directly to changes in target muscle length. The amplitude of individual motor evoked potentials (MEPs) was evaluated in each of thirteen different static postures. Four functional postures were investigated that varied in shoulder and elbow angle, while the forearm was positioned in each of three orientations. Posture-related changes in muscle lengths were assessed using a biomechanical arm model. Additionally, M-waves were evoked in the BIC in each of three forearm orientations to assess the impact of posture on recorded signal characteristics. BIC-MEP amplitudes were altered by shoulder and elbow posture, and demonstrated robust changes according to forearm orientation. Observed changes in BIC-MEP amplitudes exceeded those of the M-waves. PD-MEP amplitudes changed predominantly with shoulder posture, but were not completely independent of influence from forearm orientation. Results provide evidence that overall corticomotor excitability can be modulated according to multi-joint upper limb posture. The ability to alter motor pathway excitability using static limb posture suggests the importance of posture selection during rehabilitation aimed at retraining individual muscle recruitment and/or overall coordination patterns. Published by Elsevier Ireland Ltd.

Robust backstepping control of an interlink converter in a hybrid AC/DC microgrid based on feedback linearisation method

NASA Astrophysics Data System (ADS)

Dehkordi, N. Mahdian; Sadati, N.; Hamzeh, M.

2017-09-01

This paper presents a robust dc-link voltage as well as a current control strategy for a bidirectional interlink converter (BIC) in a hybrid ac/dc microgrid. To enhance the dc-bus voltage control, conventional methods strive to measure and feedforward the load or source power in the dc-bus control scheme. However, the conventional feedforward-based approaches require remote measurement with communications. Moreover, conventional methods suffer from stability and performance issues, mainly due to the use of the small-signal-based control design method. To overcome these issues, in this paper, the power from DG units of the dc subgrid imposed on the BIC is considered an unmeasurable disturbance signal. In the proposed method, in contrast to existing methods, using the nonlinear model of BIC, a robust controller that does not need the remote measurement with communications effectively rejects the impact of the disturbance signal imposed on the BIC's dc-link voltage. To avoid communication links, the robust controller has a plug-and-play feature that makes it possible to add a DG/load to or remove it from the dc subgrid without distorting the hybrid microgrid stability. Finally, Monte Carlo simulations are conducted to confirm the effectiveness of the proposed control strategy in MATLAB/SimPowerSystems software environment.

Geochemical characteristics of charnockite and high grade gneisses from Southern Peninsular Shield and their significance in crustal evolution

NASA Technical Reports Server (NTRS)

Sugavanam, E. B.; Vidyadharan, K. T.

1988-01-01

Presented here are the results of detailed investigations encompassing externsive structural mapping in the charnockite-high grade gneiss terrain of North Arcot district and the type area in Pallavaram in Tamil Nadu supported by petrography, mineral chemistry, major, minor and REE distribution patterns in various lithounits. This has helped in understanding the evolutionary history of the southern peninsular shield. A possible tectonic model is also suggested. The results of these studies are compared with similar rock types from parts of Andhra Pradesh, Kerala, Sri Lanka, Lapland and Nigeria which has brought about a well defined correlation in geochemical characteristics. The area investigated has an interbanded sequence of thick pile of charnockite and a supracrustal succession of shelf type sediments, layered igneous complex, basic and ultrabasic rocks involved in a complex structural, tectonic, igneous and metamorphic events.

Portrait of a giant deep-seated magmatic conduit system: The Seiland Igneous Province

NASA Astrophysics Data System (ADS)

Larsen, Rune B.; Grant, Thomas; Sørensen, Bjørn E.; Tegner, Christian; McEnroe, Suzanne; Pastore, Zeudia; Fichler, Christine; Nikolaisen, Even; Grannes, Kim R.; Church, Nathan; ter Maat, Geertje W.; Michels, Alexander

2018-01-01

The Seiland Igneous Province (SIP), Northern Norway, contains > 5000 km2 of mafic and ultramafic intrusions with minor alkaline, carbonatite and felsic rocks that were intruded into the lower continental crust at a depth of 25 to as much as 35 km. The SIP can be geochemically and temporally correlated to numerous dyke swarms throughout Scandinavia at 560-610 Ma, and is linked to magmatic provinces in W-Greenland and NE-America that are collectively known as the Central Iapetus Magmatic Province (CIMP). Revised mapping show that the SIP exposes 85-90% layered tholeiitic- alkaline- and syeno-gabbros, 8-10% peridotitic complexes, 2-5% carbonatite, syenite and diorite that formed within a narrow (< 10 Ma) time frame in the Ediacaran (560-570 Ma). Large peridotite complexes were emplaced into the still hot and unconsolidated gabbro (no dating available) and are regarded as the main-conduit systems. Gravimetric data implies an average thickness of igneous rocks of 4-5 km and also features six deep lithospheric roots of ultramafic rocks extending min 9 km into the crust. Together, the root structures represent the main volcanic conduits conveying thousands of km3 of mafic-ultramafic melts from the asthenosphere to the lithosphere. The ultramafic complexes were predominantly emplaced into the layered gabbros at four major igneous centres, respectively, Nordre Brumandsfjord, Melkvann, Kvalfjord and Reinfjord. All complexes are situated in a right-way-up position and are steep sided forming large plugs. A marginal hybrid zone forms at the contact with country-rock and transitions gradually from olivine-mela-gabbro over pyroxenites that grades in to an olivine-clinopyroxenite zone, which is followed by a wehrlite zone and, finally, the centre of the complexes comprises pure dunite. From pyroxenite to dunite, olivine changes from Fo72 to Fo85 and clinopyroxene from Di80 to Di92 i.e. the complexes observe a reverse fractional crystallisation sequence with time. Parental melt compositions modelled from early dykes indicate komatiitic to picritic melts with 16-22 wt% MgO, Cr of 1594 ppm and Ni of 611 ppm, which were emplaced at 1450-1500 °C. Melt compositions calculated from clinopyroxene compositions from Reinfjord are OIB-like with LREE enriched over HREE. The high abundance of carbonatites and lamproites demonstrates the volatile-rich nature of the mantle source region and is further corroborated by the unusually high abundance of magmatic sulphides (0.5-1%) and carbonated and hydrous assemblages (c. 1%) throughout the region. In Reinfjord, they are also closely associated with PGE-Cu-Ni reef deposits. Essentially, the ultramafic complexes in the SIP comprises deep-seated transient magma chambers that facilitated mixing and homogenisation of a rich diversity of fertile asthenospheric melts en route to the upper parts of the continental crust.

Pore Distribution Characteristics of the Igneous Reservoirs in the Eastern Sag of the Liaohe Depression

NASA Astrophysics Data System (ADS)

Zongli, Liu; Zhuwen, Wang; Dapeng, Zhou; Shuqin, Zhao; Min, Xiang

2017-05-01

In the Es3 formation (third section of the Shahejie) of the Eastern sag section of the Liaohe Depression, basalt and trachyte are predominant in the igneous rock. The reservoir consists of complex reservoir space types. Based on the porosity bins of nuclear magnetic logging and the porosity distribution of electric imaging logging, the pores' sizes and distribution, as well as the mutual connectivity of the reservoir, were analyzed. Also, the characteristics of the different reservoirs were summarized. In regards to the oil reservoirs, large pores (PS>10) were found to account for the majority of the reservoir spaces, and the pore distribution was concentrated and well connected. However, for the poor oil reservoirs, the large and small pores were found to alternate, and the pore distribution was scattered and poorly connected. Within the dry layers, the smaller pores (PS<10) were predominant. The pore distributions were found to be influenced by lithology, facies, and tectonism. The reservoirs of the pyroclastic flow of the explosive facies had good connectivity, and the interlayer heterogeneity was relatively weak. This reservoir's pore distributions were found to be mainly dominated by the larger pores (PS10-PS13), which displayed a concentrated distribution mainly in one porosity bin. Therefore, it was taken as a favorable facie belt in the eastern sag of the Liaohe Depression. The examination of the pore distribution characteristics of the igneous rock was the key to the evaluation of the properties and effectiveness of the igneous reservoirs in this study, which potentially has great significance to the future exploration and development of igneous rock.

Mind Over Magma: The Story of Igneous Petrology

NASA Astrophysics Data System (ADS)

Snyder, Don

2004-01-01

In the centuries that enquiring minds have studied and theorized about igneous rocks, much progress has been made, both in accumulating observations and in developing theories. Yet, writing a history of this progress is a daunting undertaking. The volume of the literature is vast and in multiple languages; the various lines of inquiry are diverse and complex; and the nomenclature is sometimes abstruse. On top of these challenges, many of its principal issues have yet to find a definitive consensus. With the exception of a few topical studies, historians of science have virtually avoided the subject. In Mind Over Magma: The Story of Igneous Petrology, Davis Young has taken on the challenge of writing a comprehensive survey of the study of igneous rocks, and the result has been a remarkable book of meticulous scholarship. Igneous petrology is a vast subject, and it is not obvious how best to organize its history. Young takes a topical approach, generally grouping together various studies by either the problem being investigated or the method of attack. These topics span the earliest times to the present, with an emphasis on recurring themes, such as the causes of magmatic diversity and the origins of the granitic rocks. The range of topics includes most of the subjects central to the field over its history. As much as is practical, topics are discussed in chronological order, and along the way, the reader is treated to biographical sketches of many of the key contributors. This organization proves effective in dealing with the multitude of concepts.

Arc-continent collision and the formation of continental crust: A new geochemical and isotopic record from the Ordovician Tyrone Igneous Complex, Ireland

USGS Publications Warehouse

Draut, Amy E.; Clift, Peter D.; Amato, Jeffrey M.; Blusztajn, Jerzy; Schouten, Hans

2009-01-01

Collisions between oceanic island-arc terranes and passive continental margins are thought to have been important in the formation of continental crust throughout much of Earth's history. Magmatic evolution during this stage of the plate-tectonic cycle is evident in several areas of the Ordovician Grampian-Taconic orogen, as we demonstrate in the first detailed geochemical study of the Tyrone Igneous Complex, Ireland. New U-Pb zircon dating yields ages of 493 2 Ma from a primitive mafic intrusion, indicating intra-oceanic subduction in Tremadoc time, and 475 10 Ma from a light rare earth element (LREE)-enriched tonalite intrusion that incorporated Laurentian continental material by early Arenig time (Early Ordovician, Stage 2) during arc-continent collision. Notably, LREE enrichment in volcanism and silicic intrusions of the Tyrone Igneous Complex exceeds that of average Dalradian (Laurentian) continental material that would have been thrust under the colliding forearc and potentially recycled into arc magmatism. This implies that crystal fractionation, in addition to magmatic mixing and assimilation, was important to the formation of new crust in the Grampian-Taconic orogeny. Because similar super-enrichment of orogenic melts occurred elsewhere in the Caledonides in the British Isles and Newfoundland, the addition of new, highly enriched melt to this accreted arc terrane was apparently widespread spatially and temporally. Such super-enrichment of magmatism, especially if accompanied by loss of corresponding lower crustal residues, supports the theory that arc-continent collision plays an important role in altering bulk crustal composition toward typical values for ancient continental crust. ?? 2009 Geological Society of London.

Crustal structure of the northern Menderes Massif, western Turkey, imaged by joint gravity and magnetic inversion

NASA Astrophysics Data System (ADS)

Gessner, Klaus; Gallardo, Luis A.; Wedin, Francis; Sener, Kerim

2016-10-01

In western Anatolia, the Anatolide domain of the Tethyan orogen is exposed in one of the Earth's largest metamorphic core complexes, the Menderes Massif. The Menderes Massif experienced a two-stage exhumation: tectonic denudation in the footwall of a north-directed Miocene extensional detachment, followed by fragmentation by E-W and NW-SE-trending graben systems. Along the northern boundary of the core complex, the tectonic units of the Vardar-Izmir-Ankara suture zone overly the stage one footwall of the core complex, the northern Menderes Massif. In this study, we explore the structure of the upper crust in the northern Menderes Massif with cross-gradient joint inversion of gravity and aeromagnetic data along a series of 10-km-deep profiles. Our inversions, which are based on gravity and aeromagnetic measurements and require no geological and petrophysical constraints, reveal the salient features of the Earth's upper crust. We image the northern Menderes Massif as a relatively homogenous domain of low magnetization and medium to high density, with local anomalies related to the effect of interspersed igneous bodies and shallow basins. In contrast, both the northern and western boundaries of the northern Menderes Massif stand out as domains where dense mafic, metasedimentary and ultramafic domains with a weak magnetic signature alternate with low-density igneous complexes with high magnetization. With our technique, we are able to delineate Miocene basins and igneous complexes, and map the boundary between intermediate to mafic-dominated subduction-accretion units of the suture zone and the underlying felsic crust of the Menderes Massif. We demonstrate that joint gravity and magnetic inversion are not only capable of imaging local and regional changes in crustal composition, but can also be used to map discontinuities of geodynamic significance such as the Vardar-Izmir-Ankara suture and the West Anatolia Transfer Zone.

Best Interest of the Child and Parental Alienation: A Survey of State Statutes.

PubMed

Baker, Amy J L; Asayan, Mariann; LaCheen-Baker, Alianna

2016-07-01

State statutes regarding the best interests of the child (BIC) in deciding disputed custody were reviewed and independently coded with respect to three issues (i) the child's preference and any limits (ii) parental alienation and (iii) psychological maltreatment. Results revealed that many states allowed for the child's preferences to be considered and none qualified that preference when undue influence has occurred; parental alienation as a term was not found in any state statutes but 70% of the states included at least one BIC factor relevant to its core construct of the parent supporting the child's relationship to the other parent; and many states included a history of domestic violence or child abuse but only three states explicitly mentioned psychological maltreatment. These findings highlight yet another way in which the BICS factors lack specificity in ways that could negatively impact children caught in their parents' conflict. © 2016 American Academy of Forensic Sciences.

SiBIC: a web server for generating gene set networks based on biclusters obtained by maximal frequent itemset mining.

PubMed

Takahashi, Kei-ichiro; Takigawa, Ichigaku; Mamitsuka, Hiroshi

2013-01-01

Detecting biclusters from expression data is useful, since biclusters are coexpressed genes under only part of all given experimental conditions. We present a software called SiBIC, which from a given expression dataset, first exhaustively enumerates biclusters, which are then merged into rather independent biclusters, which finally are used to generate gene set networks, in which a gene set assigned to one node has coexpressed genes. We evaluated each step of this procedure: 1) significance of the generated biclusters biologically and statistically, 2) biological quality of merged biclusters, and 3) biological significance of gene set networks. We emphasize that gene set networks, in which nodes are not genes but gene sets, can be more compact than usual gene networks, meaning that gene set networks are more comprehensible. SiBIC is available at http://utrecht.kuicr.kyoto-u.ac.jp:8080/miami/faces/index.jsp.

Analysis of the influence of the macro- and microstructure of dental zirconium implants on osseointegration: a minipig study.

PubMed

Mueller, Cornelia Katharina; Solcher, Philipp; Peisker, Andrè; Mtsariashvilli, Maia; Schlegel, Karl Andreas; Hildebrand, Gerhard; Rost, Juergen; Liefeith, Klaus; Chen, Jiang; Schultze-Mosgau, Stefan

2013-07-01

It was the aim of this study to analyze the influence of implant design and surface topography on the osseointegration of dental zirconium implants. Six different implant designs were tested in the study. Nine or 10 test implants were inserted in the frontal skull in each of 10 miniature pigs. Biopsies were harvested after 2 and 4 months and subjected to microradiography. No significant differences between titanium and zirconium were found regarding the microradiographically detected bone-implant contact (BIC). Cylindric zirconium implants showed a higher BIC at the 2-month follow-up than conic zirconium implants. Among zirconium implants, those with an intermediate Ra value showed a significantly higher BIC compared with low and high Ra implants 4 months after surgery. Regarding osseointegration, titanium and zirconium showed equal properties. Cylindric implant design and intermediate surface roughness seemed to enhance osseointegration. Copyright © 2013 Elsevier Inc. All rights reserved.

The Late Jurassic Panjeh submarine volcano in the northern Sanandaj-Sirjan Zone, northwest Iran: Mantle plume or active margin?

NASA Astrophysics Data System (ADS)

Azizi, Hossein; Lucci, Federico; Stern, Robert J.; Hasannejad, Shima; Asahara, Yoshihiro

2018-05-01

The tectonic setting in which Jurassic igneous rocks of the Sanandaj-Sirjan Zone (SaSZ) of Iran formed is controversial. SaSZ igneous rocks are mainly intrusive granodiorite to gabbroic bodies, which intrude Early to Middle Jurassic metamorphic basement; Jurassic volcanic rocks are rare. Here, we report the age and petrology of volcanic rocks from the Panjeh basaltic-andesitic rocks complex in the northern SaSZ, southwest of Ghorveh city. The Panjeh magmatic complex consists of pillowed and massive basalts, andesites and microdioritic dykes and is associated with intrusive gabbros; the overall sequence and relations with surrounding sediments indicate that this is an unusually well preserved submarine volcanic complex. Igneous rocks belong to a metaluminous sub-alkaline, medium-K to high-K calc-alkaline mafic suite characterized by moderate Al2O3 (13.7-17.6 wt%) and variable Fe2O3 (6.0-12.6 wt%) and MgO (0.9-11.1 wt%) contents. Zircon U-Pb ages (145-149 Ma) define a Late Jurassic (Tithonian) age for magma crystallization and emplacement. Whole rock compositions are enriched in Th, U and light rare earth elements (LREEs) and are slightly depleted in Nb, Ta and Ti. The initial ratios of 87Sr/86Sr (0.7039-0.7076) and εNd(t) values (-1.8 to +4.3) lie along the mantle array in the field of ocean island basalts and subcontinental metasomatized mantle. Immobile trace element (Ti, V, Zr, Y, Nb, Yb, Th and Co) behavior suggests that the mantle source was enriched by fluids released from a subducting slab (i.e. deep-crustal recycling) with some contribution from continental crust for andesitic rocks. Based the chemical composition of Panjeh mafic and intermediate rocks in combination with data for other gabbroic to dioritic bodies in the Ghorveh area we offer two interpretations for these (and other Jurassic igneous rocks of the SaSZ) as reflecting melts from a) subduction-modified OIB-type source above a Neo-Tethys subduction zone or b) plume or rift tectonics involving upwelling metasomatized mantle (mostly reflecting the 550 Ma Cadomian crust-forming event).

Anticonvulsant Effects of Fractions Isolated from Dinoponera quadriceps (Kempt) Ant Venom (Formicidae: Ponerinae).

PubMed

Nôga, Diana Aline Morais Ferreira; Brandão, Luiz Eduardo Mateus; Cagni, Fernanda Carvalho; Silva, Delano; de Azevedo, Dina Lilia Oliveira; Araújo, Arrilton; Dos Santos, Wagner Ferreira; Miranda, Antonio; da Silva, Regina Helena; Ribeiro, Alessandra Mussi

2016-12-23

Natural products, sources of new pharmacological substances, have large chemical diversity and architectural complexity. In this context, some toxins obtained from invertebrate venoms have anticonvulsant effects. Epilepsy is a neurological disorder that affects about 65 million people worldwide, and approximately 30% of cases are resistant to pharmacological treatment. Previous studies from our group show that the denatured venom of the ant Dinoponera quadriceps (Kempt) protects mice against bicuculline (BIC)-induced seizures and death. The aim of this study was to investigate the anticonvulsant activity of compounds isolated from D. quadriceps venom against seizures induced by BIC in mice. Crude venom was fractionated by high-performance liquid chromatography (HPLC) resulting in six fractions referred to as DqTx1-DqTx6. A liquid chromatography-mass spectrometry (LC/MS) analysis revealed a major 431 Da compound in fractions DqTx1 and DqTx2. Fractions DqTx3 and DqTx4 showed a compound of 2451 Da and DqTx5 revealed a 2436 Da compound. Furthermore, the DqTx6 fraction exhibited a major component with a molecular weight of 13,196 Da. Each fraction (1 mg/mL) was microinjected into the lateral ventricle of mice, and the animals were observed in an open field. We did not observe behavioral alterations when the fractions were given alone. Conversely, when the fractions were microinjected 20 min prior to the administration of BIC (21.6 nM), DqTx1, DqTx4, and DqTx6 fractions increased the latency for onset of tonic-clonic seizures. Moreover, all fractions, except DqTx5, increased latency to death. The more relevant result was obtained with the DqTx6 fraction, which protected 62.5% of the animals against tonic-clonic seizures. Furthermore, this fraction protected 100% of the animals from seizure episodes followed by death. Taken together, these findings indicate that compounds from ant venom might be a potential source of new anticonvulsants molecules.

Influence of two barrier membranes on staged guided bone regeneration and osseointegration of titanium implants in dogs. Part 2: augmentation using bone graft substitutes.

PubMed

Mihatovic, Ilja; Becker, Jürgen; Golubovic, Vladimir; Hegewald, Andrea; Schwarz, Frank

2012-03-01

To assess the influence of two barrier membranes and two bone graft substitutes on staged guided bone regeneration and osseointegration of titanium implants in dogs. Saddle-type defects were prepared in the lower jaws of 6 fox hounds and randomly filled with a natural bone mineral (NBM) and a biphasic calcium phosphate (SBC) and allocated to either an in situ gelling polyethylene glycol (PEG) or a collagen membrane (CM). At 8 weeks, modSLA titanium implants were inserted and left to heal in a submerged position. At 8+2 weeks, respectively, dissected blocks were processed for histomorphometrical analysis (e.g., mineralized tissue [MT], bone-to-implant contact [BIC]). The mean MT values (mm2) and BIC values (%) tended to be higher in the PEG groups (MT: NBM [3.4±1.7]; SBC [4.2±2]/BIC: NBM [67.7±16.9]; SBC [66.9±17.8]) when compared with the corresponding CM groups (MT: NBM [2.5±0.8]; SBC [2.3±1.6]/BIC: NBM [54.1±22.6]; SBC [61±8.7]). These differences, however, did not reach statistical significance. It was concluded that all augmentation procedures investigated supported bone regeneration and staged osseointegration of modSLA titanium implants. © 2011 John Wiley & Sons A/S.

Aging effects on the Binaural Interaction Component of the Auditory Brainstem Response in the Mongolian Gerbil: Effects of Interaural Time and Level Differences

PubMed Central

Laumen, Geneviève; Tollin, Daniel J.; Beutelmann, Rainer; Klump, Georg M.

2016-01-01

The effect of interaural time difference (ITD) and interaural level difference (ILD) on wave 4 of the binaural and summed monaural auditory brainstem responses (ABRs) as well as on the DN1 component of the binaural interaction component (BIC) of the ABR in young and old Mongolian gerbils (Meriones unguiculatus) was investigated. Measurements were made at a fixed sound pressure level (SPL) and a fixed level above visually detected ABR threshold to compensate for individual hearing threshold differences. In both stimulation modes (fixed SPL and fixed level above visually detected ABR threshold) an effect of ITD on the latency and the amplitude of wave 4 as well as of the BIC was observed. With increasing absolute ITD values BIC latencies were increased and amplitudes were decreased. ILD had a much smaller effect on these measures. Old animals showed a reduced amplitude of the DN1 component. This difference was due to a smaller wave 4 in the summed monaural ABRs of old animals compared to young animals whereas wave 4 in the binaural-evoked ABR showed no age-related difference. In old animals the small amplitude of the DN1 component was correlated with small binaural-evoked wave 1 and wave 3 amplitudes. This suggests that the reduced peripheral input affects central binaural processing which is reflected in the BIC. PMID:27173973

An outline of tectonic, igneous, and metamorphic events in the Goshute-Toano Range between Silver Zone Pass and White Horse Pass, Elko County, Nevada; a history of superposed contractional and extensional deformation

USGS Publications Warehouse

Ketner, Keith Brindley; Day, Warren C.; Elrick, Maya; Vaag, Myra K.; Zimmerman, Robert A.; Snee, Lawrence W.; Saltus, Richard W.; Repetski, John E.; Wardlaw, Bruce R.; Taylor, Michael E.; Harris, Anita G.

1998-01-01

Seven kinds of fault-bounded tracts are described. One of the tracts provides a good example of Mesozoic contractional folding and faulting; six exemplify various aspects of Miocene extensional faulting. Massive landslide deposits resulting from Tertiary faulting are described. Mesozoic intrusive rocks and extensive exposures of Miocene volcanic rocks are described and dated. The age ranges of stratigraphic units were based on numerous conodont collections, and ages of igneous rocks were determined by argon/argon and fission-track methods. The geologic complexity of the Goshute-Toano Range provides opportunities for many additional productive structural studies.

Comparative histomorphometry and resonance frequency analysis of implants with moderately rough surfaces in a loaded animal model.

PubMed

Al-Nawas, B; Groetz, K A; Goetz, H; Duschner, H; Wagner, W

2008-01-01

Test of favourable conditions for osseointegration with respect to optimum bone-implant contact (BIC) in a loaded animal model. The varied parameters were surface roughness and surface topography of commercially available dental implants. Thirty-two implants of six types of macro and microstructure were included in the study (total 196). The different types were: minimally rough control: Branemark machined Mk III; oxidized surface: TiUnite MkIII and MkIV; ZL Ticer; blasted and etched surface: Straumann SLA; rough control: titanium plasma sprayed (TPS). Sixteen beagle dogs were implanted with the whole set of the above implants. After a healing period of 8 weeks, implants were loaded for 3 months. For the evaluation of the BIC areas, adequately sectioned biopsies were visualized by subsurface scans with confocal laser scanning microscopy (CLSM). The primary statistical analysis testing BIC of the moderately rough implants (mean 56.1+/-13.0%) vs. the minimally rough and the rough controls (mean 53.9+/-11.2%) does not reveal a significant difference (P=0.57). Mean values of 50-70% BIC were found for all implant types. Moderately rough oxidized implants show a median BIC, which is 8% higher than their minimally rough turned counterpart. The intraindividual difference between the TPS and the blasted and etched counterparts revealed no significant difference. The turned and the oxidized implants show median values of the resonance frequency [implant stability quotients (ISQ)] over 60; the nonself-tapping blasted and etched and TPS implants show median values below 60. In conclusion, the benefit of rough surfaces relative to minimally rough ones in this loaded animal model was confirmed histologically. The comparison of different surface treatment modalities revealed no significant differences between the modern moderately rough surfaces. Resonance frequency analysis seems to be influenced in a major part by the transducer used, thus prohibiting the comparison of different implant systems.

Effects of Local and Systemic Zoledronic Acid Application on Titanium Implant Osseointegration: An Experimental Study Conducted on Two Surface Types.

PubMed

Dundar, Serkan; Yaman, Ferhan; Gecor, Orhan; Cakmak, Omer; Kirtay, Mustafa; Yildirim, Tuba Talo; Karaman, Tahir; Benlidayi, Mehmet Emre

2017-06-01

The aim of this study was to evaluate the effects of local and systemic zoledronic acid (ZA) applications on titaniumoksit ceramic blasted (TiO-CB)- and sandblasted large acid-grit (SLA)-surfaced titanium implant osseointegration. Twelve New Zealand White rabbits were used in the study, divided into 6 groups: the TiO-CB (TiO-CB-CNT) (n = 2) and SLA (SLA-CNT) (n = 2) control groups in which TiO-CB- and SLA-surfaced titanium implants were surgically inserted into rabbit tibias but no treatment was applied; the TiO-CB (TiO-CB-LZA) (n = 2) and SLA (SLA-LZA) (n = 2) local ZA groups in which 1 mL of normal saline solution containing 2 mg of ZA was injected into sockets and after this the implants were integrated; and the TiO-CB (TiO-CB-SZA) (n = 2) and SLA (SLA-SZA) (n = 2) systemic ZA groups in which a single infusion of 0.1 mg/kg of ZA was administered during surgical implant insertion. Following a period of osseointegration, bone implant contact (BIC) was recorded as a proportion of the total implant surface length in direct contact with the bone. Results of this study indicate that BIC was greater in the systemic ZA application groups than in the local ZA application groups, and BIC was greater in the local ZA groups than in the controls. Statistically significant differences in BIC were not detected between the TiO-CB- and SLA-surfaced implants in all the groups. Furthermore, this study did not reveal significant differences between the 2 types of surfaces due to similar average roughness values. Overall, systemic ZA application was found to be more effective in increasing BIC than local ZA application based on the results obtained by testing 2 implant surfaces.

Suitability of the Binaural Interaction Component for Interaural Electrode Pairing of Bilateral Cochlear Implants.

PubMed

Hu, Hongmei; Kollmeier, Birger; Dietz, Mathias

2016-01-01

Although bilateral cochlear implants (BiCIs) have succeeded in improving the spatial hearing performance of bilateral CI users, the overall performance is still not comparable with normal hearing listeners. Limited success can be partially caused by an interaural mismatch of the place-of-stimulation in each cochlea. Pairing matched interaural CI electrodes and stimulating them with the same frequency band is expected to facilitate binaural functions such as binaural fusion, localization, or spatial release from masking. It has been shown in animal experiments that the magnitude of the binaural interaction component (BIC) derived from the wave-eV decreases for increasing interaural place of stimulation mismatch. This motivated the investigation of the suitability of an electroencephalography-based objective electrode-frequency fitting procedure based on the BIC for BiCI users. A 61 channel monaural and binaural electrically evoked auditory brainstem response (eABR) recording was performed in 7 MED-EL BiCI subjects so far. These BiCI subjects were directly stimulated at 60% dynamic range with 19.9 pulses per second via a research platform provided by the University of Innsbruck (RIB II). The BIC was derived for several interaural electrode pairs by subtracting the response from binaural stimulation from their summed monaural responses. The BIC based pairing results are compared with two psychoacoustic pairing methods: interaural pulse time difference sensitivity and interaural pitch matching. The results for all three methods analyzed as a function of probe electrode allow for determining a matched pair in more than half of the subjects, with a typical accuracy of ± 1 electrode. This includes evidence for statistically significant tuning of the BIC as a function of probe electrode in human subjects. However, results across the three conditions were sometimes not consistent. These discrepancies will be discussed in the light of pitch plasticity versus less plastic brainstem processing.

Measurement of H2O and other trace gases in the stratosphere using a high resolution far-infrared spectrometer at 28 KM

NASA Technical Reports Server (NTRS)

Traub, W. A.; Chance, K. V.

1986-01-01

The highlights of the stratospheric program were reviewed for the past 2.5 years. The major efforts were analysis of the data from the BIC-2 campaign, and the building or new instrumentation to replace that lost at the end of BIC-2. For clarity, the review will be done by topic, rather than chronologically: construction of the initial far-infrared spectrometer, balloon slight program, laboratory measurement, data analysis, and duplicate stabilized platform.

Influence of stretching and density contrasts on the chemical evolution of continental magmas: An example from the Ivrea-Verbano Zone

USGS Publications Warehouse

Sinigoi, S.; Quick, J.E.; Mayer, A.; Budahn, J.

1996-01-01

The southern Ivrea-Verbano Zone of the Italian Western Alps contains a huge mafic complex that intruded high-grade metamorphic rocks while they were resident in the lower crust. Geologic mapping and chemical variations of the igneous body were used to study the evolution of underplated crust. Slivers of crustal rocks (septa) interlayered with igneous mafic rocks are concentrated in a narrow zone deep in the complex (Paragneiss-bearing Belt) and show evidence of advanced degrees of partial melting. Variations of rare-earth-element patterns and Sr isotope composition of the igneous rocks across the sequence are consistent with increasing crustal contamination approaching the septa. Therefore, the Paragneiss-bearing Belt is considered representative of an "assimilation region" where in-situ interaction between mantle- and crust-derived magmas resulted in production of hybrid melts. Buoyancy caused upwards migration of the hybrid melts that incorporated the last septa and were stored at higher levels, feeding the Upper Mafic Complex. Synmagmatic stretching of the assimilation region facilitated mixing and homogenization of melts. Chemical variations of granitoids extracted from the septa show that deep septa are more depleted than shallow ones. This suggests that the first incorporated septa were denser than the later ones, as required by the high density of the first-injected mafic magmas. It is inferred that density contrasts between mafic melts and crustal rocks play a crucial role for the processes of contamination of continental magmas. In thick under- plated crust, the extraction of early felsic/hybrid melts from the lower crust may be required to increase the density of the lower crust and to allow the later mafic magmas to penetrate higher crustal levels.

GEANT4 benchmark with MCNPX and PHITS for activation of concrete

NASA Astrophysics Data System (ADS)

Tesse, Robin; Stichelbaut, Frédéric; Pauly, Nicolas; Dubus, Alain; Derrien, Jonathan

2018-02-01

The activation of concrete is a real problem from the point of view of waste management. Because of the complexity of the issue, Monte Carlo (MC) codes have become an essential tool to its study. But various codes or even nuclear models exist in MC. MCNPX and PHITS have already been validated for shielding studies but GEANT4 is also a suitable solution. In these codes, different models can be considered for a concrete activation study. The Bertini model is not the best model for spallation while BIC and INCL model agrees well with previous results in literature.

Hawai'i and Gale Crater: A Mars Analogue Study of Igneous, Sedimentary, Weathering, and Alteration Trends in Geochemistry

NASA Technical Reports Server (NTRS)

Berger, J. A.; Flemming, R. L.; Schmidt, M. E.; Gellert, R.; Morris, R. V.; Ming, D. W.

2017-01-01

Sedimentary rocks in Gale Crater on Mars indicate a varied provenance with a range of alteration and weathering [1, 2]. Geochemical trends identified in basaltic and alkalic sedimentary rocks by the Alpha Particle X-ray Spectrometer (APXS) on the Mars rover Curiosity represent a complex interplay of igneous, sedimentary, weathering, and alteration processes. Assessing the relative importance of these processes is challenging with unknown compositions for parent sediment sources and with the constraints provided by Curiosity's instruments. We therefore look to Mars analogues on Earth where higher-resolution analyses and geologic context can constrain interpretations of Gale Crater geochemical observations. We selected Maunakea (AKA Mauna Kea) and Kohala volcanoes, Hawai'i, for an analogue study because they are capped by post-shield transitional basalts and alkalic lavas (hawaiites, mugearites) with compositions similar to Gale Crater [1, 3]. Our aim was to characterize Hawaiian geochemical trends associated with igneous processes, sediment transport, weathering, and alteration. Here, we present initial results and discuss implications for selected trends observed by APXS in Gale Crater.

Sulfide mineralization: Its role in chemical weathering of Mars

NASA Technical Reports Server (NTRS)

Burns, Roger G.

1988-01-01

Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produced degradation products in the Martian regolith. By analogy with terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato- and hydroxo-complex ions and sols formed gossans above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite) and silica (opal). Underlying groundwater, now permafrost, contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, etc., which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates and phyllosilicates during dust storms on Mars.

Weathering of sulfides on Mars

NASA Technical Reports Server (NTRS)

Burns, Roger G.; Fisher, Duncan S.

1987-01-01

Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produce degradation products in the Martian regolith. By analogy and terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni, and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato-and hydroxo-complex ions and sols formed gossan above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite), and silica (opal). Underlying groundwater, now permafrost contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates, and phyllosilicates during dust storms on Mars.

Advanced interstitial chemotherapy combined with targeted treatment of malignant glioma in rats by using drug-loaded nanofibrous membranes.

PubMed

Tseng, Yuan-Yun; Su, Chen-Hsing; Yang, Shun-Tai; Huang, Yin-Chen; Lee, Wei-Hwa; Wang, Yi-Chuan; Liu, Shou-Cheng; Liu, Shih-Jung

2016-09-13

Glioblastoma multiforme (GBM), the most prevalent and malignant form of a primary brain tumour, is resistant to chemotherapy. In this study, we concurrently loaded three chemotherapeutic agents [bis-chloroethylnitrosourea, irinotecan, and cisplatin; BIC] into 50:50 poly[(d,l)-lactide-co-glycolide] (PLGA) nanofibres and an antiangiogenic agent (combretastatin) into 75:25 PLGA nanofibres [BIC and combretastatin (BICC)/PLGA]. The BICC/PLGA nanofibrous membranes were surgically implanted onto the brain surfaces of healthy rats for conducting pharmacodynamic studies and onto C6 glioma-bearing rats for estimating the therapeutic efficacy.The chemotherapeutic agents were rapidly released from the 50:50 PLGA nanofibres after implantation, followed by the release of combretastatin (approximately 2 weeks later) from the 75:25 PLGA nanofibres. All drug concentrations remained higher in brain tissues than in the blood for more than 8 weeks. The experimental results, including attenuated malignancy, retarded tumour growth, and prolonged survival in tumour-bearing rats, demonstrated the efficacy of the BICC/PLGA nanofibrous membranes. Furthermore, the efficacy of BIC/PLGA and BICC/PLGA nanofibrous membranes was compared. The BICC/PLGA nanofibrous membranes more efficiently retarded the tumour growth and attenuated the malignancy of C6 glioma-bearing rats. Moreover, the addition of combretastatin did not significantly change the drug release behaviour of the BIC/PLGA nanofibrous membranes. The present advanced and novel interstitial chemotherapy and targeted treatment provide a potential strategy and regimen for treating GBM.

Effects of the 3D bone-to-implant contact and bone stiffness on the initial stability of a dental implant: micro-CT and resonance frequency analyses.

PubMed

Hsu, J T; Huang, H L; Tsai, M T; Wu, A Y J; Tu, M G; Fuh, L J

2013-02-01

This study investigated the effects of bone stiffness (elastic modulus) and three-dimensional (3D) bone-to-implant contact ratio (BIC%) on the primary stabilities of dental implants using micro-computed tomography (micro-CT) and resonance frequency analyses. Artificial sawbone models with five values of elastic modulus (137, 123, 47.5, 22, and 12.4 MPa) comprising two types of trabecular structure (solid-rigid and cellular-rigid) were investigated for initial implant stability quotient (ISQ), measured using the wireless Osstell resonance frequency analyzer. Bone specimens were attached to 2 mm fibre-filled epoxy sheets mimicking the cortical shell. ISQ was measured after placing a dental implant into the bone specimen. Each bone specimen with an implant was subjected to micro-CT scanning to calculate the 3D BIC% values. The similarity of the cellular type of artificial bone to the trabecular structure might make it more appropriate for obtaining accurate values of primary implant stability than solid-bone blocks. For the cellular-rigid bone models, the ISQ increased with the elastic modulus of cancellous bone. The regression correlation coefficient was 0.96 for correlations of the ISQ with the elasticity of cancellous bone and with the 3D BIC%. The initial implant stability was moderately positively correlated with the elasticity of cancellous bone and with the 3D BIC%. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Evaluation of Guided Bone Regeneration around Oral Implants over Different Healing Times Using Two Different Bovine Bone Materials: A Randomized, Controlled Clinical and Histological Investigation.

PubMed

Kohal, Ralf Joachim; Straub, Lisa Marie; Wolkewitz, Martin; Bächle, Maria; Patzelt, Sebastian Berthold Maximilian

2015-10-01

To evaluate the potential of two bone substitute materials and the influence of different healing periods in guided bone regeneration therapy of osseous defects around implants. Twenty-four edentulous patients received implants in the region of the lost lower incisors. Around two standardized osseous defects were created, treated either with a 50:50 mixture of PepGen P-15® and OsteoGraf®/N-700 (test group) or with BioOss® (control group), and covered with titanium membranes. After healing periods of 2, 4, 6, or 9 months, the implants were removed together with the surrounding bone and subsequently prepared for histological evaluations. Defect depths in both groups showed a clinical reduction after intervention. The histologically measured distance from the implant shoulder to the first point of bone-implant contact (BIC) after treatment did not differ between the two groups. The healing time influenced the level of the first point of BIC, with a longer healing period producing a more coronal first point of BIC. A greater percentage BIC and a higher fraction of mineralized bone were found in the pristine bone area compared with the augmented defect area. It can be concluded that in the treatment of osseous defects around oral implants, both materials were equally effective bone substitute materials when used in combination with guided bone regeneration. © 2014 Wiley Periodicals, Inc.

One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study.

PubMed

Siddiqi, A; Duncan, W J; De Silva, R K; Zafar, S

2016-01-01

Reports have documented titanium (Ti) hypersensitivity after dental implant treatment. Alternative materials have been suggested including zirconia (Zr) ceramics, which have shown predictable osseointegration in animal studies and appear free of immune responses. The aim of the research was to investigate the bone-to-implant contact (BIC) of one-piece Zr, compared with one-piece Ti implants, placed in the jaws and femurs of domestic sheep. Ten New Zealand mixed breed sheep were used. A One-piece prototype Ti (control) and one Zr (test) implant were placed in the mandible, and one of each implant (Ti and Zr) was placed into the femoral epicondyle of each animal. The femur implants were submerged and unloaded; the mandibular implants were placed using a one-stage transgingival protocol and were nonsubmerged. After a healing period of 12 weeks, %BIC was measured. The overall survival rate for mandibular and femur implants combined was 87.5%. %BIC was higher for Zr implants versus Ti implants in the femur (85.5%, versus 78.9%) ( p = 0.002). Zirconia implants in the mandible showed comparable %BIC to titanium implants (72.2%, versus 60.3%) ( p = 0.087). High failure rate of both Zr and Ti one-piece implants in the jaw could be attributed to the one-piece design and surface characteristics of the implant that could have influenced osseointegration. Further clinical trials are recommended to evaluate the performance of zirconia implants under loading conditions.

Aging effects on the binaural interaction component of the auditory brainstem response in the Mongolian gerbil: Effects of interaural time and level differences.

PubMed

Laumen, Geneviève; Tollin, Daniel J; Beutelmann, Rainer; Klump, Georg M

2016-07-01

The effect of interaural time difference (ITD) and interaural level difference (ILD) on wave 4 of the binaural and summed monaural auditory brainstem responses (ABRs) as well as on the DN1 component of the binaural interaction component (BIC) of the ABR in young and old Mongolian gerbils (Meriones unguiculatus) was investigated. Measurements were made at a fixed sound pressure level (SPL) and a fixed level above visually detected ABR threshold to compensate for individual hearing threshold differences. In both stimulation modes (fixed SPL and fixed level above visually detected ABR threshold) an effect of ITD on the latency and the amplitude of wave 4 as well as of the BIC was observed. With increasing absolute ITD values BIC latencies were increased and amplitudes were decreased. ILD had a much smaller effect on these measures. Old animals showed a reduced amplitude of the DN1 component. This difference was due to a smaller wave 4 in the summed monaural ABRs of old animals compared to young animals whereas wave 4 in the binaural-evoked ABR showed no age-related difference. In old animals the small amplitude of the DN1 component was correlated with small binaural-evoked wave 1 and wave 3 amplitudes. This suggests that the reduced peripheral input affects central binaural processing which is reflected in the BIC. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect on Bone Architecture of Marginal Grooves in Dental Implants Under Occlusal Loaded Conditions in Beagle Dogs.

PubMed

Kato, Hatsumi; Kuroshima, Shinichiro; Inaba, Nao; Uto, Yusuke; Sawase, Takashi

2018-02-01

The aim of this study was to clarify whether marginal grooves on dental implants affect osseointegration, bone structure, and the alignment of collagen fibers to determine bone quality under loaded conditions. Anodized Ti-6Al-4V alloy dental implants, with and without marginal grooves (test and control implants, respectively), were used (3.7 × 8.0 mm). Fourth premolars and first molars of 6 beagle mandibles were extracted. Two control and test implants were placed in randomly selected healed sites at 12 weeks after tooth extraction. Screw-retained single crowns for first molars were fabricated. Euthanasia was performed at 8 weeks after the application of occlusal forces. Implant marginal bone level, bone to implant contact (BIC), bone structure around dental implants, and the alignment of collagen fibers determining bone quality were analyzed. The marginal bone level in test implants was significantly higher than that in control implants. Occlusal forces significantly increased BIC in test implants ( P = .007), whereas BIC did not change in control implants, irrespective of occlusal forces ( P = .303). Moreover, occlusal forces significantly increased BIC in test implants compared with control implants ( P = .032). Additionally, occlusal forces preferentially aligned collagen fibers in test implants, but not control implants. Hence, marginal grooves on dental implants have positive effects on increased osseointegration and adapted bone quality based on the preferential alignment of collagen fibers around dental implants under loaded conditions.

One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study

PubMed Central

De Silva, R. K.; Zafar, S.

2016-01-01

Reports have documented titanium (Ti) hypersensitivity after dental implant treatment. Alternative materials have been suggested including zirconia (Zr) ceramics, which have shown predictable osseointegration in animal studies and appear free of immune responses. The aim of the research was to investigate the bone-to-implant contact (BIC) of one-piece Zr, compared with one-piece Ti implants, placed in the jaws and femurs of domestic sheep. Ten New Zealand mixed breed sheep were used. A One-piece prototype Ti (control) and one Zr (test) implant were placed in the mandible, and one of each implant (Ti and Zr) was placed into the femoral epicondyle of each animal. The femur implants were submerged and unloaded; the mandibular implants were placed using a one-stage transgingival protocol and were nonsubmerged. After a healing period of 12 weeks, %BIC was measured. The overall survival rate for mandibular and femur implants combined was 87.5%. %BIC was higher for Zr implants versus Ti implants in the femur (85.5%, versus 78.9%) (p = 0.002). Zirconia implants in the mandible showed comparable %BIC to titanium implants (72.2%, versus 60.3%) (p = 0.087). High failure rate of both Zr and Ti one-piece implants in the jaw could be attributed to the one-piece design and surface characteristics of the implant that could have influenced osseointegration. Further clinical trials are recommended to evaluate the performance of zirconia implants under loading conditions. PMID:28058261

Geometry and controls on the development of igneous sill-related forced folds: 2D seismic reflection case study from offshore Southern Australia

NASA Astrophysics Data System (ADS)

Jackson, Christopher; Schofield, Nick; Magee, Craig; Golenkov, Bogdan

2017-04-01

Emplacement of magma in the shallow subsurface can result in the development of dome-shaped folds at the Earth's surface. These so-called 'forced folds' have been described in the field and in subsurface datasets, although the exact geometry of the folds and the nature of their relationship to underlying sills remains unclear and, in some cases, controversial. As a result, the utility of these features in tracking the subsurface movement of magma, and predicting the potential size and location of potentially hazardous volcanic eruptions, is uncertain. Here we use high-quality, 2D seismic reflection and borehole data from the Ceduna sub-basin, offshore southern Australia to describe the structure and infer the evolution of igneous sill-related forced folds in the Bight Basin Igneous Complex (BBIC). We mapped 33 igneous sills, which were emplaced 200-1500 m below the palaeo-seabed in an Upper Cretaceous, coal-bearing, predominantly coastal-plain succession. The intrusions, which are expressed as packages of high-amplitude reflections, are 32-250 m thick and 7-19 km in diameter. They are overlain by dome-shaped folds, which are up to 17 km wide and display up to 210 m of relief. The edges of these folds coincide with the margins of the underlying sills and the folds display the greatest relief where the underlying sills are thickest; the folds are therefore interpreted as forced folds that formed in response to emplacement of magma in the shallow subsurface. The folds are onlapped by Lutetian (middle Eocene) strata, indicating they formed and the intrusions were emplaced during the latest Ypresian (c. 48 Ma). We demonstrate that fold amplitude is typically less than sill thickness even for sills with very large diameter-to-depth ratios, suggesting that pure elastic bending (forced folding) of the overburden is not the only process accommodating magma emplacement, and that supra-sill compaction may be important even at relatively shallow depths. Based on the observation that the sills intruded a shallowly-buried succession, the discrepancy between fold amplitude and sill thickness may reflect loss of host rock volume by fluidisation and pore fluid expulsion from poorly-lithified, water-rich beds. This study indicates that host rock composition, emplacement depth and deformation mechanisms are important controls on the style of deformation that occurs during intrusive igneous activity, and that forced fold amplitude may not always reflect the thickness of an underlying igneous intrusion. In addition, the results of this study suggest that physical and numerical models need to model more complex host rock stratigraphies and rheologies if they wish to capture the full range of deformation mechanisms that occur during magma emplacement in the Earth's shallow subsurface.

Tectono-Magmatic Cycles and Geodynamic Settings of Ore-Bearing System Formation in the Southern Cis-Argun Region

NASA Astrophysics Data System (ADS)

Petrov, V. A.; Andreeva, O. V.; Poluektov, V. V.; Kovalenko, D. V.

2017-11-01

The ore-bearing geological structural units of the southern Cis-Argun region are considered in the context of varying geodynamic regimes related to the Proterozoic, Caledonian, and Hercynian tectono-magmatic cycles, as well as during the Late Mesozoic within-plate tectono-magmatic activity, which give rise to the formation of subalkaline igneous rocks of the Shakhtama Complex with Au, Cu-Mo, Pb-Zn-Ag metallogenic specialization; volcano-plutonic complexes of calderas with Mo-U, Pb-Zn, and fluorite ores; and rare-metal granite of the Kukulbei Complex with a Sn-W-Li-Ta spectrum of mineralization. The comparative geochemical characteristics inherent to Mesozoic ore-bearing felsic igneous rocks are considered, as well as geodynamic settings of ore-bearing fluido-magmatic systems, taking into consideration new data on geochemistry of bimodal trachybasalt-trachydacite series and rhyolite of the Turga Series, which fill the Strel'tsovka Caldera, whose trend of evolution is defined as a reference for geological history of the studied territory. The geodynamic conditions, phase composition, and geochemistry of rocks along with metallogenic specialization of Mesozoic volcano-plutonic complexes of southern Cis-Argun region are close to those of the Great Khingan Belt in northeastern China and eastern Mongolia.

Vehicle antenna development for mobile satellite applications

NASA Technical Reports Server (NTRS)

Woo, K.

1988-01-01

The paper summarizes results of a vehicle antenna program at JPL in support of a developing U.S. mobile satellite services (MSS) designed to provide telephone and data services for the continental United States. Two classes of circularly polarized vehicle antennas have been considered for the MSS: medium-gain, satellite-tracking antennas with 10-12-dBic gain; and low-gain, azimuthally omnidirectional antennas with 3-5-dBic gain. The design and performance of these antennas are described, and the two antennas are shown to have peculiar advantages and disadvantages.

Effect of alternative peritoneal dialysis solutions on cell viability, apoptosis/necrosis and cytokine expression in human monocytes.

PubMed

Plum, J; Lordnejad, M R; Grabensee, B

1998-07-01

Cellular function, cell viability and the cytokine network of human monocytes are influenced by the specific composition of peritoneal dialysis (PD) fluids. In an in vitro study using isolated human blood monocytes, we investigated the effect of peritoneal dialysates containing amino acids (Amino) or glucose polymer (Glu-poly) instead of glucose (Glu) as the osmotic agent, and bicarbonate (Bic) or PBS instead of lactate (Lac) as a buffer. The following parameters were studied: mitochondrial dehydrogenase activity (using the MTT assay), interleukin (IL)-6 and IL-8 release (ELISA) and cellular IL-6 mRNA expression after lipopolysaccharide (LPS) stimulation (using RT-PCR). FACS flow cytometry with annexin V and propidium iodide as markers and fluorescence microscopic methods were used to study the effects of the test fluids on cell necrosis and apoptosis. Glu/Lac pH 5.5 and Glu-poly/PBS pH 7.4 both significantly reduced mitochondrial dehydrogenase activity by more than 50% after 60 minutes of incubation (30.5 +/- 7.6%, 42.5 +/- 6.5%, referred to RPMI 1640 as 100%). Amino/Bic and Glu/Bic were both superior (Mtt assay > 63%). The rate of necrotic cells after 15 minutes of incubation measured by FACS was mostly increased with Glu/Lac pH 5.5 (29.9 +/- 4.0%). The rate of apoptotic cells, however, was not significantly different between the test solutions. The concentration of IL-6 in the supernatant of stimulated monocytes was highest with Glu/Bic (1023 +/- 278 pg/ml) and Amino/Bic (776 +/- 296 pg/ml) an lowest with Glu/lac pH 5.5 (46 +/- 22 pg/ml) and Glu-poly/PBS (32 +/- 13 pg/ml). IL-8 release from stimulated monocytes showed a similar pattern. Glu-poly/PBS showed a suppressive effect on IL-6 mRNA expression (ratio IL-6/beta-Actin, 0.4 +/- 0.25 vs. RPMI 1.5 +/- 3.6). Bicarbonate buffered solutions both with glucose or amino acids as osmotic agents were superior when regarding cell metabolism, viability and cytokine release, while lactate buffered solutions and Glu-poly/PBS showed some reduced biocompatibility pattern for monocytes in vitro.

The best interest of the child-questionnaire, reliability and validity: preliminary data on the question 'where to live after detention or secure treatment?'.

PubMed

Kalverboer, Margrite; Ten Brummelaar, Mijntje; Post, Wendy; Zijlstra, Elianne; Harder, Annemiek; Knorth, Erik

2012-02-01

The Best Interest of the Child-Questionnaire (BIC-Q) has been designed as an instrument for screening the quality of the rearing situation of children with behavioural problems or delinquency. It is intended to aid legal decisions in juvenile and family law. The aim of the study was to establish the reliability and validation of the BIC-Q. Records of 83 children in detention or secure treatment centres and 58 children with no delinquent behaviours were rated by trained researchers. Interrater reliability was tested with a sub-sample of 31 of the former. Content validity was evaluated across the whole group, using Cronbach's alpha to check internal consistency, Spearman's rho to examine correlations and explorative principal component analysis (PCA) to test the extent to which variance in the 14 underlying conditions could be accounted for by a single factor 'quality of rearing'. Interrater reliability was good (r = 0.89). The PCA lent support to the content validity of the questionnaire with four factors, which together explained 66% of the variance in child rearing: (1) attachment and bonding; (2) rules and provisions; (3) health care and physical care in the family context; and (4) care and models provided for in the societal environment. The BIC-Q is a reliable and valid measure of the overall quality of child rearing. Preliminary results indicate that the BIC-Q may be applied to support court decisions on where the child should live after detention or secure treatment. Copyright © 2011 John Wiley & Sons, Ltd.

Using Evoked Potentials to Match Interaural Electrode Pairs with Bilateral Cochlear Implants

PubMed Central

Delgutte, Bertrand

2007-01-01

Bilateral cochlear implantation seeks to restore the advantages of binaural hearing to the profoundly deaf by providing binaural cues normally important for accurate sound localization and speech reception in noise. Psychophysical observations suggest that a key issue for the implementation of a successful binaural prosthesis is the ability to match the cochlear positions of stimulation channels in each ear. We used a cat model of bilateral cochlear implants with eight-electrode arrays implanted in each cochlea to develop and test a noninvasive method based on evoked potentials for matching interaural electrodes. The arrays allowed the cochlear location of stimulation to be independently varied in each ear. The binaural interaction component (BIC) of the electrically evoked auditory brainstem response (EABR) was used as an assay of binaural processing. BIC amplitude peaked for interaural electrode pairs at the same relative cochlear position and dropped with increasing cochlear separation in either direction. To test the hypothesis that BIC amplitude peaks when electrodes from the two sides activate maximally overlapping neural populations, we measured multiunit neural activity along the tonotopic gradient of the inferior colliculus (IC) with 16-channel recording probes and determined the spatial pattern of IC activation for each stimulating electrode. We found that the interaural electrode pairings that produced the best aligned IC activation patterns were also those that yielded maximum BIC amplitude. These results suggest that EABR measurements may provide a method for assigning frequency–channel mappings in bilateral implant recipients, such as pediatric patients, for which psychophysical measures of pitch ranking or binaural fusion are unavailable. PMID:17225976

Using evoked potentials to match interaural electrode pairs with bilateral cochlear implants.

PubMed

Smith, Zachary M; Delgutte, Bertrand

2007-03-01

Bilateral cochlear implantation seeks to restore the advantages of binaural hearing to the profoundly deaf by providing binaural cues normally important for accurate sound localization and speech reception in noise. Psychophysical observations suggest that a key issue for the implementation of a successful binaural prosthesis is the ability to match the cochlear positions of stimulation channels in each ear. We used a cat model of bilateral cochlear implants with eight-electrode arrays implanted in each cochlea to develop and test a noninvasive method based on evoked potentials for matching interaural electrodes. The arrays allowed the cochlear location of stimulation to be independently varied in each ear. The binaural interaction component (BIC) of the electrically evoked auditory brainstem response (EABR) was used as an assay of binaural processing. BIC amplitude peaked for interaural electrode pairs at the same relative cochlear position and dropped with increasing cochlear separation in either direction. To test the hypothesis that BIC amplitude peaks when electrodes from the two sides activate maximally overlapping neural populations, we measured multiunit neural activity along the tonotopic gradient of the inferior colliculus (IC) with 16-channel recording probes and determined the spatial pattern of IC activation for each stimulating electrode. We found that the interaural electrode pairings that produced the best aligned IC activation patterns were also those that yielded maximum BIC amplitude. These results suggest that EABR measurements may provide a method for assigning frequency-channel mappings in bilateral implant recipients, such as pediatric patients, for which psychophysical measures of pitch ranking or binaural fusion are unavailable.

Thymus-Derived Regulatory T Cell Development Is Regulated by C-Type Lectin-Mediated BIC/MicroRNA 155 Expression

PubMed Central

Sánchez-Díaz, Raquel; Blanco-Dominguez, Rafael; Lasarte, Sandra; Tsilingiri, Katerina; Martín-Gayo, Enrique; Linillos-Pradillo, Beatriz; de la Fuente, Hortensia; Sánchez-Madrid, Francisco; Nakagawa, Rinako; Toribio, María L.

2017-01-01

ABSTRACT Thymus-derived regulatory T (tTreg) cells are key to preventing autoimmune diseases, but the mechanisms involved in their development remain unsolved. Here, we show that the C-type lectin receptor CD69 controls tTreg cell development and peripheral Treg cell homeostasis through the regulation of BIC/microRNA 155 (miR-155) and its target, suppressor of cytokine signaling 1 (SOCS-1). Using Foxp3-mRFP/cd69+/− or Foxp3-mRFP/cd69−/− reporter mice and short hairpin RNA (shRNA)-mediated silencing and miR-155 transfection approaches, we found that CD69 deficiency impaired the signal transducer and activator of transcription 5 (STAT5) pathway in Foxp3+ cells. This results in BIC/miR-155 inhibition, increased SOCS-1 expression, and severely impaired tTreg cell development in embryos, adults, and Rag2−/− γc−/− hematopoietic chimeras reconstituted with cd69−/− stem cells. Accordingly, mirn155−/− mice have an impaired development of CD69+ tTreg cells and overexpression of the miR-155-induced CD69 pathway, suggesting that both molecules might be concomitantly activated in a positive-feedback loop. Moreover, in vitro-inducible CD25+ Treg (iTreg) cell development is inhibited in Il2rγ−/−/cd69−/− mice. Our data highlight the contribution of CD69 as a nonredundant key regulator of BIC/miR-155-dependent Treg cell development and homeostasis. PMID:28167605

High-frequency stimulation of the medial prefrontal cortex decreases cellular firing in the dorsal raphe

PubMed Central

Srejic, Luka R.; Hamani, Clement; Hutchison, William D.

2017-01-01

High-frequency deep brain stimulation (HFS-DBS) of the subcallosal cingulate (SCC) region has been investigated as a treatment for refractory forms of depression with a ~50% remission rate in open label studies. However, the therapeutic mechanisms of DBS are still largely unknown. Using anaesthetized Sprague Dawley rats, we recorded neuronal spiking activity in 102 neurons of the dorsal raphe (DR) before, during and after the induction of a 5-min HFS train in the infralimbic region (IL) of the medial pre-frontal cortex (mPFC), the rodent homologue of the human SCC. The majority of DR cells (82%) significantly decreased firing rate during HFS (P < 0.01, 55.7 ± 4.5% of baseline, 35 rats). To assess whether mPFC-HFS mediates inhibition of DR cellular firing by stimulating local GABAergic interneurons, the GABAA antagonist bicuculline (Bic, 100 μM) was injected directly into the DR during HFS. Neurons inhibited by HFS recovered their firing rate during Bic+HFS (P < 0.01, n = 15, seven rats) to levels not different from baseline. Cells that were not affected by HFS did not change firing rate during Bic+HFS (P = 0.968, n = 7, three rats). These results indicate that blocking GABAA reverses HFS-mediated inhibition of DR neurons. As the cells that were not inhibited by HFS were also unaffected by HFS+Bic, they are probably not innervated by local GABA. Taken together, our results suggest that mPFC-HFS may exert a preferential effect on DR neurons with GABAA receptors. PMID:25712703

Objective Model Selection for Identifying the Human Feedforward Response in Manual Control.

PubMed

Drop, Frank M; Pool, Daan M; van Paassen, Marinus Rene M; Mulder, Max; Bulthoff, Heinrich H

2018-01-01

Realistic manual control tasks typically involve predictable target signals and random disturbances. The human controller (HC) is hypothesized to use a feedforward control strategy for target-following, in addition to feedback control for disturbance-rejection. Little is known about human feedforward control, partly because common system identification methods have difficulty in identifying whether, and (if so) how, the HC applies a feedforward strategy. In this paper, an identification procedure is presented that aims at an objective model selection for identifying the human feedforward response, using linear time-invariant autoregressive with exogenous input models. A new model selection criterion is proposed to decide on the model order (number of parameters) and the presence of feedforward in addition to feedback. For a range of typical control tasks, it is shown by means of Monte Carlo computer simulations that the classical Bayesian information criterion (BIC) leads to selecting models that contain a feedforward path from data generated by a pure feedback model: "false-positive" feedforward detection. To eliminate these false-positives, the modified BIC includes an additional penalty on model complexity. The appropriate weighting is found through computer simulations with a hypothesized HC model prior to performing a tracking experiment. Experimental human-in-the-loop data will be considered in future work. With appropriate weighting, the method correctly identifies the HC dynamics in a wide range of control tasks, without false-positive results.

Cell surface domain specific postsynaptic currents evoked by identified GABAergic neurones in rat hippocampus in vitro

PubMed Central

Maccaferri, Gianmaria; David, J; Roberts, B; Szucs, Peter; Cottingham, Carol A; Somogyi, Peter

2000-01-01

Inhibitory postsynaptic currents (IPSCs) evoked in CA1 pyramidal cells (n = 46) by identified interneurones (n = 43) located in str. oriens were recorded in order to compare their functional properties and to determine the effect of synapse location on the apparent IPSC kinetics as recorded using somatic voltage clamp at −70 mV and nearly symmetrical [Cl−]. Five types of visualised presynaptic interneurone, oriens-lacunosum moleculare (O-LMC), basket (BC), axo-axonic (AAC), bistratified (BiC) and oriens-bistratified (O-BiC) cells, were distinguished by immunocytochemistry and/or synapse location using light and electron microscopy. Somatostatin immunoreactive O-LMCs, innervating the most distal dendritic shafts and spines, evoked the smallest amplitude (26 ± 10 pA, s.e.m., n = 8) and slowest IPSCs (10–90 % rise time, 6.2 ± 0.6 ms; decay, 20.8 ± 1.7 ms, n = 8), with no paired-pulse modulation of the second IPSC (93 ± 4 %) at 100 ms interspike interval. In contrast, parvalbumin-positive AACs evoked larger amplitude (308 ± 103 pA, n = 7) and kinetically faster (rise time, 0.8 ± 0.1 ms; decay 11.2 ± 0.9 ms, n = 7) IPSCs showing paired-pulse depression (to 68 ± 5 %, n = 6). Parvalbumin- or CCK-positive BCs (n = 9) terminating on soma/dendrites, BiCs (n = 4) and O-BiCs (n = 7) innervating dendrites evoked IPSCs with intermediate kinetic parameters. The properties of IPSCs and sensitivity to bicuculline indicated that they were mediated by GABAA receptors. In three cases, kinetically complex, multiphasic IPSCs, evoked by an action potential in the recorded basket cells, suggested that coupled interneurones, possibly through electrotonic junctions, converged on the same postsynaptic neurone. The population of O-BiCs (4 of 4 somatostatin positive) characterised in this study had horizontal dendrites restricted to str. oriens/alveus and innervated stratum radiatum and oriens. Other BiCs had radial dendrites as described earlier. The parameters of IPSCs evoked by BiCs and O-BiCs showed the largest cell to cell variation, and a single interneurone could evoke both small and slow as well as large and relatively fast IPSCs. The kinetic properties of the somatically recorded postsynaptic current are correlated with the innervated cell surface domain. A significant correlation of rise and decay times for the overall population of unitary IPSCs suggests that electrotonic filtering of distal responses is a major factor for the location and cell type specific differences of unitary IPSCs, but molecular heterogeneity of postsynaptic GABAA receptors may also contribute to the observed kinetic differences. Furthermore, domain specific differences in the short-term plasticity of the postsynaptic response indicate a differentiation of interneurones in activity-dependent responses. PMID:10747186

Distribution pattern of public transport passenger in Yogyakarta, Indonesia

NASA Astrophysics Data System (ADS)

Narendra, Alfa; Malkhamah, Siti; Sopha, Bertha Maya

2018-03-01

The arrival and departure distribution pattern of Trans Jogja bus passenger is one of the fundamental model for simulation. The purpose of this paper is to build models of passengers flows. This research used passengers data from January to May 2014. There is no policy that change the operation system affecting the nature of this pattern nowadays. The roads, buses, land uses, schedule, and people are relatively still the same. The data then categorized based on the direction, days, and location. Moreover, each category was fitted into some well-known discrete distributions. Those distributions are compared based on its AIC value and BIC. The chosen distribution model has the smallest AIC and BIC value and the negative binomial distribution found has the smallest AIC and BIC value. Probability mass function (PMF) plots of those models were compared to draw generic model from each categorical negative binomial distribution models. The value of accepted generic negative binomial distribution is 0.7064 and 1.4504 of mu. The minimum and maximum passenger vector value of distribution are is 0 and 41.

Comparison of Penalty Functions for Sparse Canonical Correlation Analysis

PubMed Central

Chalise, Prabhakar; Fridley, Brooke L.

2011-01-01

Canonical correlation analysis (CCA) is a widely used multivariate method for assessing the association between two sets of variables. However, when the number of variables far exceeds the number of subjects, such in the case of large-scale genomic studies, the traditional CCA method is not appropriate. In addition, when the variables are highly correlated the sample covariance matrices become unstable or undefined. To overcome these two issues, sparse canonical correlation analysis (SCCA) for multiple data sets has been proposed using a Lasso type of penalty. However, these methods do not have direct control over sparsity of solution. An additional step that uses Bayesian Information Criterion (BIC) has also been suggested to further filter out unimportant features. In this paper, a comparison of four penalty functions (Lasso, Elastic-net, SCAD and Hard-threshold) for SCCA with and without the BIC filtering step have been carried out using both real and simulated genotypic and mRNA expression data. This study indicates that the SCAD penalty with BIC filter would be a preferable penalty function for application of SCCA to genomic data. PMID:21984855

Comparison of surface modified zirconia implants with commercially available zirconium and titanium implants: a histological study in pigs.

PubMed

Gredes, Tomasz; Kubasiewicz-Ross, Pawel; Gedrange, Tomasz; Dominiak, Marzena; Kunert-Keil, Christiane

2014-08-01

New biomaterials and their various surface modifications should undergo in vitro and in vivo evaluation before clinical trials. The objective of our in vivo study was to evaluate the biocompatibility of newly created zirconium implant surfaces after implantation in the lower jaw of pigs and compare the osseointegration of these dental implants with commercially available zirconium and titanium implants. After a healing period of 12 weeks, a histological analysis of the soft and hard tissues and a histomorphometric analysis of the bone-implant contact (BIC) were performed. The implant surfaces showed an intimate connection to the adjacent bone for all tested implants. The 3 newly created zirconium implant surfaces achieved a BIC of 45% on average in comparison with a BIC of 56% from the reference zirconium implants and 35% from titanium implants. Furthermore, the new zirconium implants had a better attachment to gingival and bone tissues in the range of implant necks as compared with the reference implants. The results suggest that the new implants comparably osseointegrate within the healing period, and they have a good in vivo biocompatibility.

Effect of phosphate treatment of Acid-etched implants on mineral apposition rates near implants in a dog model.

PubMed

Foley, Christine Hyon; Kerns, David G; Hallmon, William W; Rivera-Hidalgo, Francisco; Nelson, Carl J; Spears, Robert; Dechow, Paul C; Opperman, Lynne A

2010-01-01

This study evaluated the effects of phosphate coating of acid-etched titanium on the mineral apposition rate (MAR) and new bone-to-implant contact (BIC) in a canine model. Titanium implants (2.2 3 4 mm) with acid-etched surfaces that were electrolytically phosphated or not were placed in 48 mandibular sites in six foxhounds. Tetracycline and calcein dyes were administered 1 week after implant placement and 1 week before sacrifice. At 12 weeks after implant placement, the animals were sacrificed. MAR and BIC were evaluated using fluorescence microscopy. Light microscopic and histologic evaluations were performed on undecalcified sections. Microscopic evaluation showed the presence of healthy osteoblasts lining bone surfaces near implants. Similar BIC was observed in phosphated and nonphosphated titanium implant sites. MAR was significantly higher around the nonphosphated titanium implant surfaces than around the phosphated titanium samples. No significant differences were found between dogs or implant sites. Acid-etched implants showed significantly higher MARs compared to acid-etched, phosphate-coated implants. Int J Maxillofac Implants 2010;25:278-286.

Response of zircon to melting and metamorphism in deep arc crust, Fiordland (New Zealand): implications for zircon inheritance in cordilleran granites

NASA Astrophysics Data System (ADS)

Bhattacharya, Shrema; Kemp, A. I. S.; Collins, W. J.

2018-04-01

The Cretaceous Mount Daniel Complex (MDC) in northern Fiordland, New Zealand was emplaced as a 50 m-thick dyke and sheet complex into an active shear zone at the base of a Cordilleran magmatic arc. It was emplaced below the 20-25 km-thick, 125.3 ± 1.3 Ma old Western Fiordland Orthogneiss (WFO) and is characterized by metre-scale sheets of sodic, low and high Sr/Y diorites and granites. 119.3 ± 1.2 Ma old, pre-MDC lattice dykes and 117.4 ± 3.1 Ma late-MDC lattice dykes constrain the age of the MDC itself. Most dykes were isoclinally folded as they intruded, but crystallised within this deep-crustal, magma-transfer zone as the terrain cooled and was buried from 25 to 50 km (9-14 kbar), based on published P-T estimated from the surrounding country rocks. Zircon grains formed under these magmatic/granulite facies metamorphic conditions were initially characterized by conservatively assigning zircons with oscillatory zoning as igneous and featureless rims as metamorphic, representing 54% of the analysed grains. Further petrological assignment involved additional parameters such as age, morphology, Th/U ratios, REE patterns and Ti-in-zircon temperature estimates. Using this integrative approach, assignment of analysed grains to metamorphic or igneous groupings improved to 98%. A striking feature of the MDC is that only 2% of all igneous zircon grains reflect emplacement, so that the zircon cargo was almost entirely inherited, even in dioritic magmas. Metamorphic zircons of MDC show a cooler temperature range of 740-640 °C, reflects the moderate ambient temperature of the lower crust during MDC emplacement. The MDC also provides a cautionary tale: in the absence of robust field and microstructural relations, the igneous-zoned zircon population at 122.1 ± 1.3 Ma, derived mostly from inherited zircons of the WFO, would be meaningless in terms of actual magmatic emplacement age of MDC, where the latter is further obscured by younger (ca. 114 Ma) metamorphic overgrowths. Thus, our integrative approach provides the opportunity to discriminate between igneous and metamorphic zircon within deep-crustal complexes. Also, without the tight field relations at Mt Daniel, the scatter beyond a statistically coherent group might be ascribed to the presence of "antecrysts", but it is clear that the WFO solidified before the MDC was emplaced, and these older "igneous" grains are inherited. The bimodal age range of inherited igneous grains, dominated by 125 Ma and 350-320 Ma age clusters, indicate that the adjacent WFO and a Carboniferous metaigneous basement were the main sources of the MDC magmas. Mafic lenses, stretched and highly attenuated into wisps within the MDC and dominated by 124 Ma inherited zircons, are considered to be entrained restitic material from the WFO. A comparison with lower- and upper-crustal, high Sr/Y metaluminous granites elsewhere in Fiordland shows that zircon inheritance is common in the deep crust, near the source region, but generally much less so in coeval, shallow magma chambers (plutons). This is consistent with previous modelling on rapid zircon dissolution rates and high Zr saturation concentrations in metaluminous magmas. Accordingly, unless unusual circumstances exist, such as MDC preservation in the deep crust, low temperatures of magma generation, or rapid emplacement and crystallization at higher structural levels, information on zircon inheritance in upper crustal, Cordilleran plutons is lost during zircon dissolution, along with information on the age, nature and variety of the source material. The observation that dioritic magmas can form at these low temperatures (< 750 °C) also suggests that the petrogenesis of mafic rocks in the arc root might need to be re-assessed.

The Ultramafic Complex of Reinfjord: from the Magnetic Petrology to the Interpretation of the Magnetic Anomalies

NASA Astrophysics Data System (ADS)

Pastore, Zeudia; McEnroe, Suzanne; Church, Nathan; Fichler, Christine; ter Maat, Geertje W.; Fumagalli, Patrizia; Oda, Hirokuni; Larsen, Rune B.

2017-04-01

A 3D model of the geometry of the Reinfjord complex integrating geological and petrophysical data with high resolution aeromagnetic, ground magnetic and gravity data is developed. The Reinfjord ultramafic complex in northern Norway is one of the major ultramafic complexes of the Neoproterozoic Seiland Igneous Province (SIP). This province, now embedded in the Caledonian orogen, was emplaced deep in the crust (30 km of depth) and is believed to represent a section of the deep plumbing system of a large igneous province. The Reinfjord complex consists of three magmatic series formed during multiple recharging events resulting in the formation of a cylindrically zoned complex with a slightly younger dunite core surrounded by wehrlite and lherzolite units. Gabbros and gneiss form the host rock. The ultramafic complex has several distinct magnetic anomalies which do not match the mapped lithological boundaries, but are correlated with changes in magnetic susceptibilities. In particular, the deviating densities and magnetic susceptibilities at the northern side of the complex are interpreted to be due to serpentinization. Detailed studies of magnetic anomalies and magnetic properties of samples can provide a powerful tool for mapping petrological changes. Samples can have wide range of magnetic properties depending on composition, amount of ferromagnetic minerals, grain sizes and microstructures. Later geological processes such as serpentinization can alter this signal. Therefore a micro-scale study of magnetic anomalies at the thin section scale was carried out to understand better the link between the magnetic petrology and the magnetic anomalies. Serpentinization can significantly enhance the magnetic properties and therefore change the nature of the magnetic anomaly. The detailed gravity and magnetic model here presented shows the subsurface structure of the ultramafic complex refining the geological interpretation of the magnetic sources within it, and the local effects of serpentinization.

Rock- and Paleomagnetic Properties and Modeling of a Deep Crustal Volcanic System, the Reinfjord Ultramafic Complex, Seiland Igneous Province, Northern Norway

NASA Astrophysics Data System (ADS)

ter Maat, G. W.; Pastore, Z.; Michels, A.; Church, N. S.; McEnroe, S. A.; Larsen, R. B.

2017-12-01

The Reinfjord Ultramafic Complex is part of the 5000 km2 Seiland Igneous Province (SIP) in Northern Norway. The SIP is argued to be the deep-seated conduit system of a Large Igneous Province and was emplaced at 25-35 km depth in less than 10 Ma (570-560 Ma). The Reinfjord Ultramafic Complex was emplaced during three major successive events at 22-28km depth at pressures of 6-8kb, with associated temperatures 1450-1500°C (Roberts, 2006). The rocks are divided into three formations: the central series (CS) consisting of mainly dunites, upper layered series (ULS) consisting of dunites and wehrlites, a lower layered series (LLS) containing most pyroxene-rich rocks and a marginal zone (MZ) which formed where the ultramafic melts intruded the gabbro-norite and metasedimentary gneisses. Deep exposures such as the Reinfjord Ultramafic Complex are rare, therefore this study gives a unique insight in the rock magnetic properties of a deep ultramafic system. Localised serpentinised zones provide an opportunity to observe the effect of this alteration process on the magnetic properties of deep-seated rocks. Here, we present the results from the rock magnetic properties, a paleomagnetic study and combined potential-fields modeling. The study of the rock magnetic properties provides insight in primary processes associated with the intrusion, and later serpentinization. The paleomagnetic data yields two distinct directions. One direction corresponds to a Laurentia pole at ≈ 532 Ma while the other, though younger, is not yet fully understood. Rock magnetic properties were measured on > 700 specimens and used to constrain the modelling of gravity, high-resolution helicopter, and ground magnetic data. The intrusion is modelled as a cylindrically shaped complex with a dunite core surrounded by wehrlite and gabbro. The ultramafic part of the complex dips to the NE and its maximum vertical extent is modelled to 1400m. Furthermore, modelling allows estimation of relative volumes of ultramafic and mafic rocks below the surface. By integrating different methods this study contributes to the understanding of the magnetization of deep ultramafic rocks in the lithosphere, and to the refinement of the geological interpretation of the Reinfjord ultramafic intrusion.

A Petrographic History of Martian Meteorite ALH84001: Two Shocks and an Ancient Age

NASA Technical Reports Server (NTRS)

Treiman, Allan H.

1995-01-01

ALH84001 is an igneous meteorite, an orthopyroxenite of martian origin. It contains petrographic evidence of two shock metamorphic events, separated by thermal and chemical events. The evidence for two shock events suggests that ALH84001 is ancient and perhaps a sample of the martian highlands. From petrography and mineral chemistry, the history of ALH84001 must include: crystallization from magma, a first shock (impact) metamorphism, thermal metamorphism, low-temperature chemical alteration, and a second shock (impact) metamorphism. Originally, ALH84001 was igneous, an orthopyroxene-chromite cumulate. In the first shock event, the igneous rock was cut by melt-breccia or cataclastic veinlets, now bands of equigranular fine-grained pyroxene and other minerals (crush zones). Intact fragments of the cumulate were fractured and strained (now converted to polygonized zones). The subsequent thermal metamorphism (possibly related to the first shock) annealed the melt-breccia or cataclastic veinlets to their present granoblastic texture and permitted chemical homogenization of all mineral species present. The temperature of metamorphism was at least 875 C, based on mineral thermometers. Next, Mg-Fe-Ca carbonates and pyrite replaced plagioclase in both clasts and granular bands, producing ellipsoidal carbonate globules with sub-micron scale compositional stratigraphy, repeated identically in all globules, The second shock event produced microfault offsets of carbonate stratigraphy and other mineral contacts, radial fractures around chromite and maskelynite, and strain birefringence in pyroxene. Maskelynite could not have been preserved from the first shock event, because it would have crystallized back to plagioclase. The martian source area for ALH84001 must permit this complex, multiple impact history. Very few craters on young igneous surfaces are on or near earlier impact features. It is more likely that ALH84001 was ejected from an old igneous unit (Hesperian or Noachian age), pocked by numerous impact craters over its long exposure at the martian surface.

Auditory evoked responses to binaural beat illusion: stimulus generation and the derivation of the Binaural Interaction Component (BIC).

PubMed

Ozdamar, Ozcan; Bohorquez, Jorge; Mihajloski, Todor; Yavuz, Erdem; Lachowska, Magdalena

2011-01-01

Electrophysiological indices of auditory binaural beats illusions are studied using late latency evoked responses. Binaural beats are generated by continuous monaural FM tones with slightly different ascending and descending frequencies lasting about 25 ms presented at 1 sec intervals. Frequency changes are carefully adjusted to avoid any creation of abrupt waveform changes. Binaural Interaction Component (BIC) analysis is used to separate the neural responses due to binaural involvement. The results show that the transient auditory evoked responses can be obtained from the auditory illusion of binaural beats.

K-Ar geochronology of the Survey Pass, Ambler River and Eastern Baird Mountains quadrangles, southwestern Brooks Range, Alaska

USGS Publications Warehouse

Turner, Donald L.; Forbes, R.B.; Mayfield, C.F.

1978-01-01

We report 76 previously unpublished K-Ar mineral ages from 47 metamorphic and igneous rocks in the southwestern Brooks Range. The pattern of radiometric ages is complex, reflecting the complex geologic history of this area. Local and regional radiometric evidence suggests that the southern Brooks Range schist belt has, at least in part, undergone a late Precambrian metamorphism and that the parent sedimentary and igneous rocks for the metamorphic rocks dated as late Precambrian are at least this old (Precambrian Z). This schist terrane experienced a major thermal event in mid-Cretaceous time, causing widespread resetting of nearly all K-Ar mica ages. A series of apparent ages intermediate between late Precambrian and mid-Cretaceous are interpreted as indicating varying amounts of partial argon loss from older rocks during the Cretaceous event. The schist belt is characterized by dominant metasediments and subordinate metabasites and metafelsites. Blueschists occur within the schist belt from the Chandalar quadrangle westward to the Baird Mountains quadrangle, but geologic evidence does not support the existence of a fossil subduction zone.

Geologic structures related to New Madrid earthquakes near Memphis, Tennessee, based on gravity and magnetic interpretations

USGS Publications Warehouse

Hildenbrand, T.G.; Stuart, W.D.; Talwani, P.

2001-01-01

New inversions of gravity and magnetic data in the region north of memphis. Tennessee, and south of latitude 36?? define boundaries of regional structures and igneous complexes in the upper crust. Microseismicity patterns near interpreted boundaries suggest that igneous complexes influence the locations of microseismicity. A weak seismicity cluster occurs near one intrusion (Covington pluton), at the intersection of the southwest margin of the Missouri batholith and the southeast margin of the Reelfoot rift. A narrow seismicity trend along the Reelfoot rift axis becomes diffuse near a second intrusion (Osceola intrusive complex) and changes direction to an area along the northwest flank of the intrusion. The axial seismicity trend also contains a tight cluster of earthquakes located just outside the Osceola intrusive complex. The mechanical explanation of the two seismicity patterns is uncertain, but the first cluster may be caused by stress concentration due to the high elastic stiffness and strength of the Covington intrusion. The spatially changing seismicity pattern near the Osceola complex may be caused by the preceding factors plus interaction with faulting along the rift axis. The axial seismicity strand itself is one of several connected and interacting active strands that may produce stress concentrations at strand ends and junctions. The microseismicity clusters at the peripheries of the two intrusions lead us to conclude that these stress concentrations or stressed volumes may be locations of future moderate to large earthquakes near Memphis. Published by Elsevier Science B.V.

The Zhamanshin impact feature: A new class of complex crater?

NASA Technical Reports Server (NTRS)

Garvin, J. B.; Schnetzler, C. C.

1992-01-01

The record of 10-km-scale impact events of Quaternary age includes only two 'proven' impact structures: the Zhamanshin Impact Feature (ZIF) and the Bosumtwi Impact Crater (BIC). What makes these impact landforms interesting from the standpoint of recent Earth history is their almost total lack of morphologic similarity, in spite of similar absolute ages and dimensions. The BIC resembles pristine complex craters on the Moon to first order (i.e., 'U'-shaped topographic cross section with preserved rim), while the ZIF displays virtually none of the typical morphologic elements of a 13- to 14-km-diameter complex crater. Indeed, this apparent lack of a craterlike surficial topographic expression initially led Soviet geologists to conclude that the structure was only 5.5 to 6 km in diameter and at least 4.5 Ma in age. However, more recent drilling and geophysical observations at the ZIF have indicated that its pre-erosional diameter is at least 13.5 km, and that its age is most probably 0.87 Ma. Why the present topographic expression of a 13.5-km complex impact crater less than 1 m.y. old most closely resembles heavily degraded Mesozoic shield craters such as Lappajarvi is a question of considerable debate. Hypotheses for the lack of a clearly defined craterlike form at the ZIF include a highly oblique impact, a low-strength 'cometary' projectile, weak or water-saturated target materials, and anomalous erosion patterns. The problem remains unresolved because typical erosion rates within the arid sedimentary platform environment of central Kazakhstan in which the ZIF is located are typically low; it would require at least a factor of 10 greater erosion at the ZIF in order to degrade the near-rim ejecta typical of a 13.5-km complex crater by hundreds of meters in only 0.87 Ma, and to partially infill an inner cavity with 27 cu km (an equivalent uniform thickness of infill of 166 m). Our analysis of the degree of erosion and infill at the ZIF calls for rates in the 0.19 to 0.38 mm/yr range over the lifetime of the landform, which are a factor of 10 to 20 in excess of typical rates for the Kazakhstan semidesert.

Evaluation of Four Diagnostic Tests for Insulin Dysregulation in Adult Light-Breed Horses.

PubMed

Dunbar, L K; Mielnicki, K A; Dembek, K A; Toribio, R E; Burns, T A

2016-05-01

Several tests have been evaluated in horses for quantifying insulin dysregulation to support a diagnosis of equine metabolic syndrome. Comparing the performance of these tests in the same horses will provide clarification of their accuracy in the diagnosis of equine insulin dysregulation. The aim of this study was to evaluate the agreement between basal serum insulin concentrations (BIC), the oral sugar test (OST), the combined glucose-insulin test (CGIT), and the frequently sampled insulin-modified intravenous glucose tolerance test (FSIGTT). Twelve healthy, light-breed horses. Randomized, prospective study. Each of the above tests was performed on 12 horses. Minimal model analysis of the FSIGTT was considered the reference standard and classified 7 horses as insulin resistant (IR) and 5 as insulin sensitive (IS). In contrast, BIC and OST assessment using conventional cut-off values classified all horses as IS. Kappa coefficients, measuring agreement among BIC, OST, CGIT, and FSIGTT were poor to fair. Sensitivity of the CGIT (positive phase duration of the glucose curve >45 minutes) was 85.7% and specificity was 40%, whereas CGIT ([insulin]45 >100 μIU/mL) sensitivity and specificity were 28.5% and 100%, respectively. Area under the glucose curve (AUCg0-120 ) was significantly correlated among the OST, CGIT, and FSIGTT, but Bland-Altman method and Lin's concordance coefficient showed a lack of agreement. Current criteria for diagnosis of insulin resistance using BIC and the OST are highly specific but lack sensitivity. The CGIT displayed better sensitivity and specificity, but modifications may be necessary to improve agreement with minimal model analysis. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Influence of two barrier membranes on staged guided bone regeneration and osseointegration of titanium implants in dogs: part 1. Augmentation using bone graft substitutes and autogenous bone.

PubMed

Schwarz, Frank; Mihatovic, Ilja; Golubovic, Vladimir; Hegewald, Andrea; Becker, Jürgen

2012-01-01

To assess the influence of two barrier membranes and two bone graft substitutes mixed with autogenous bone (AB) on staged guided bone regeneration and osseointegration of titanium implants in dogs. Four saddle-type defects each were prepared in the upper jaw of six fox hounds and randomly filled with a natural bone mineral (NBM)+AB and a biphasic calcium phosphate (SBC)+AB and allocated to either an in situ gelling polyethylene glycol (PEG) or a collagen membrane (CM). At 8 weeks, modSLA titanium implants were inserted and left to heal in a submerged position. At 8+2 weeks, dissected blocks were processed for histomorphometrical analysis (e.g., treated area [TA], bone-to-implant contact [BIC]). The mean TA values (mm(2) ) and BIC values (%) tended to be higher in the PEG groups(TA: NBM+AB [10.4 ± 2.5]; SBC+AB [10.4 ± 5.8]/BIC: NBM+AB [86.4 ± 20.1]; SBC+AB [80.1 ± 21.5]) when compared with the corresponding CM groups (TA: NBM+AB [9.7 ± 4.8]; SBC+AB [7.8 ± 4.3]/BIC: NBM+AB [71.3 ± 20.8]; SBC+AB [72.4 ± 20.3]). A significant difference was observed for the mean TA values in the SBC+AB groups. It was concluded that all augmentation procedures investigated supported bone regeneration and staged osseointegration of modSLA titanium implants. However, the application of PEG may be associated with increased TA values. © 2011 John Wiley & Sons A/S.

Stigmatellin Y - An anti-biofilm compound from Bacillus subtilis BR4 possibly interferes in PQS-PqsR mediated quorum sensing system in Pseudomonas aeruginosa.

PubMed

Boopathi, Seenivasan; Vashisth, Rajesh; Manoharan, Prabu; Kandasamy, Ruckmani; Sivakumar, Natesan

2017-05-15

Hitherto this is the first report pertaining to production of biofilm inhibitory compound(s) (BIC) from Bacillus subtilis BR4 against Pseudomonas aeruginosa (ATCC 27853) coupled with production optimization. In order to achieve this, combinations of media components were formulated by employing statistical tools such as Plackett-Burman analysis and central composite rotatable design (CCRD). It was evident that at 35mlL -1 glycerol and 3.8gL -1 casamino acid, anti-biofilm activity and production of extracellular protein significantly increased by 1.5-fold and 1.2-fold, respectively. These results corroborate that the combination of glycerol and casamino acid plays a key role in the production of BIC. Further, metabolic profiling of BIC was carried out using liquid chromatography/tandem mass spectrometry (LC-MS/MS) based on m/z value. The presence of Stigmatellin Y was predicted with monoisotopic neutral mass of 484.2825Da. In support of optimization study, higher production of BIC was confirmed in the optimized-media-grown BR4 (OPT-BR4) than in the ideal-media-grown BR4 (ID-BR4) by LC-MS/MS analysis. PqsR in P. aeruginosa is a potential target for anti-virulent therapy. Molecular docking study has revealed that Stigmatellin Y interacts with PqsR in the similar orientation like a cognate signal (PQS) and synthetic inhibitor. In addition, Stigmatellin Y was found to exhibit interaction with four more amino acid residues of PqsR to establish strong affinity. Stigmatellin Y thus might play a role of competitor for PQS to distract PQS-PqsR mediated communication in P. aeruginosa. The present investigation thus paves new avenues to develop anti-Pseudomonas virulent therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Redirecting the Cyanobacterial Bicarbonate Transporters BicA and SbtA to the Chloroplast Envelope: Soluble and Membrane Cargos Need Different Chloroplast Targeting Signals in Plants

PubMed Central

Rolland, Vivien; Badger, Murray R.; Price, G. Dean

2016-01-01

Most major crops used for human consumption are C3 plants, which yields are limited by photosynthetic inefficiency. To circumvent this, it has been proposed to implement the cyanobacterial CO2-concentrating mechanism (CCM), principally consisting of bicarbonate transporters and carboxysomes, into plant chloroplasts. As it is currently not possible to recover homoplasmic transplastomic monocots, foreign genes must be introduced in these plants via nuclear transformation. Consequently, it is paramount to ensure that resulting proteins reach the appropriate sub-cellular compartment, which for cyanobacterial transporters BicA and SbtA, is the chloroplast inner-envelope membrane (IEM). At present, targeting signals to redirect large transmembrane proteins from non-chloroplastic organisms to plant chloroplast envelopes are unknown. The goal of this study was to identify such signals, using agrobacteria-mediated transient expression and confocal microscopy to determine the sub-cellular localization of ∼37 GFP-tagged chimeras. Initially, fragments of chloroplast proteins known to target soluble cargos to the stroma were tested for their ability to redirect BicA, but they proved ineffective. Next, different N-terminal regions from Arabidopsis IEM transporters were tested. We demonstrated that the N-terminus of AtHP59, AtPLGG1 or AtNTT1 (92–115 amino acids), containing a cleavable chloroplast transit peptide (cTP) and a membrane protein leader (MPL), was sufficient to redirect BicA or SbtA to the chloroplast envelope. This constitutes the first evidence that nuclear-encoded transmembrane proteins from non-chloroplastic organisms can be targeted to the envelope of plant chloroplasts; a finding which represents an important advance in chloroplast engineering by opening up the door to further manipulation of the chloroplastic envelope. PMID:26973659

Perturbations in reward-related decision-making induced by reduced prefrontal cortical GABA transmission: Relevance for psychiatric disorders.

PubMed

Piantadosi, Patrick T; Khayambashi, Shahin; Schluter, Magdalen G; Kutarna, Agnes; Floresco, Stan B

2016-02-01

The prefrontal cortex (PFC) is critical for higher-order cognitive functions, including decision-making. In psychiatric conditions such as schizophrenia, prefrontal dysfunction co-occurs with pronounced alterations in decision-making ability. These alterations include a diminished ability to utilize probabilistic reinforcement in guiding future choice, and a reduced willingness to expend effort to receive reward. Among the neurochemical abnormalities observed in the PFC of individuals with schizophrenia are alterations in the production and function of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). To probe how PFC GABA hypofunction may contribute to alterations in cost/benefit decision-making, we assessed the effects GABAA-receptor antagonist bicuculline (BIC; 50 ng in 0.5 μl saline/hemisphere) infusion in the medial PFC of rats during performance on a series of well-validated cost/benefit decision-making tasks. Intra-PFC BIC reduced risky choice and reward sensitivity during probabilistic discounting and decreased the preference for larger rewards associated with a greater effort cost, similar to the behavioral sequelae observed in schizophrenia. Additional experiments revealed that these treatments did not alter instrumental responding on a progressive ratio schedule, nor did they impair the ability to discriminate between reward and no reward. However, BIC induced a subtle but consistent impairment in preference for larger vs. smaller rewards of equal cost. BIC infusion also increased decision latencies and impaired the ability to "stay on task" as indexed by reduced rates of instrumental responding. Collectively, these results implicate prefrontal GABAergic dysfunction as a key contributing factor to abnormal decision-making observed in schizophrenia and other neuropsychiatric conditions with similar neurobiological and behavioral alterations. Copyright © 2015 Elsevier Ltd. All rights reserved.

GABAergic influences on ORX receptor-dependent abnormal motor behaviors and neurodegenerative events in fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Facciolo, Rosa Maria, E-mail: rm.facciolo@unical.i; Crudo, Michele; Giusi, Giuseppina

2010-02-15

At date the major neuroreceptors i.e. gamma-aminobutyric acid{sub A} (GABA{sub A}R) and orexin (ORXR) systems are beginning to be linked to homeostasis, neuroendocrine and emotional states. In this study, intraperitoneal treatment of the marine teleost Thalassoma pavo with the highly selective GABA{sub A}R agonist (muscimol, MUS; 0,1 mug/g body weight) and/or its antagonist bicuculline (BIC; 1 mug/g body weight) have corroborated a GABA{sub A}ergic role on motor behaviors. In particular, MUS induced moderate (p < 0.05) and great (p < 0.01) increases of swimming towards food sources and resting states after 24 (1 dose) and 96 (4 doses) h treatmentmore » sessions, respectively, when compared to controls. Conversely, BIC caused a very strong (p < 0.001) reduction of the former behavior and in some cases convulsive swimming. From the correlation of BIC-dependent behavioral changes to neuronal morphological and ORXR transcriptional variations, it appeared that the disinhibitory action of GABA{sub A}R was very likely responsible for very strong and strong ORXR mRNA reductions in cerebellum valvula and torus longitudinalis, respectively. Moreover these effects were linked to evident ultra-structural changes such as shrunken cell membranes and loss of cytoplasmic architecture. In contrast, MUS supplied a very low, if any, argyrophilic reaction in hypothalamic and mesencephalic regions plus a scarce level of ultra-structural damages. Interestingly, combined administrations of MUS + BIC were not related to consistent damages, aside mild neuronal alterations in motor-related areas such as optic tectum. Overall it is tempting to suggest, for the first time, a neuroprotective role of GABA{sub A}R inhibitory actions against the overexcitatory ORXR-dependent neurodegeneration and consequently abnormal swimming events in fish.« less

An oxidized implant surface may improve bone-to-implant contact in pristine bone and bone defects treated with guided bone regeneration: an experimental study in dogs.

PubMed

Gurgel, Bruno César de Vasconcelos; Gonçalves, Patrícia Furtado; Pimentel, Suzana Peres; Nociti, Francisco Humberto; Sallum, Enilson Antonio; Sallum, Antonio Wilson; Casati, Marcio Zaffalon

2008-07-01

The aim of the present study was to histometrically evaluate bone healing in the absence of bone defects and in the presence of surgically created bone defects treated by guided bone regeneration at oxidized and turned implant surfaces. Three months after dental extractions, standardized buccal dehiscence defects (height: 5 mm; width: 4 mm) were surgically created following implant site preparation in the mandible of 10 dogs. Oxidized-surface implants (OSI) and turned-surface implants (TSI) were inserted bilaterally, and the bone defects were treated by guided bone regeneration. After 3 months of healing, the animals were sacrificed, blocks were dissected, and undecalcified sections were obtained and processed for histometric analysis. The percentage of bone-to-implant contact (BIC) and bone density (BD) was evaluated inside the threads on the buccal (regenerated bone) and lingual sides (pristine bone) of the implants. Data were evaluated using two-way analysis of variance (P <0.05). New bone formation could be observed in OSI and TSI in the region of the defect creation. The BIC values observed in OSI for pristine and regenerated bone were 57.03% +/- 21.86% and 40.86% +/- 22.73%, respectively. TSI showed lower values of BIC in pristine bone (37.39% +/- 23.33%) and regenerated bone (3.52% +/- 4.87%). The differences between OSI and TSI were statistically significant. BD evaluation showed no statistically significant differences between OSI and TSI in pristine and regenerated bone. The oxidized implant surface promoted a higher level of BIC than the turned implant surface at pristine and regenerated bone.

Breakup magmatism on the Vøring Margin, mid-Norway: New insight from interpretation of high-quality 2D and 3D seismic reflection data

NASA Astrophysics Data System (ADS)

Abdelmalak, M. M.; Planke, S.; Millett, J.; Jerram, D. A.; Maharjan, D.; Zastrozhnov, D.; Schmid, D. W.; Faleide, J. I.; Svensen, H.; Myklebust, R.

2017-12-01

The Vøring Margin offshore mid-Norway is a classic volcanic rifted margin, characterized by voluminous Paleogene igneous rocks present on both sides of the continent-ocean boundary. The margin displays (1) thickened transitional crust with a well-defined lower crustal high-velocity body and prominent deep crustal reflections, the so-called T-Reflection, (2) seaward dipping reflector (SDR) wedges and a prominent northeast-trending escarpment on the Vøring Marginal High, and (3) extensive sill complexes in the adjacent Cretaceous Vøring Basin. During the last decade, new 2D and 3D industry seismic data along with improved processing techniques, such as broadband processing and noise reduction processing sequences, have made it possible to image and map the breakup igneous complex in much greater detail than previously possible. Our interpretation includes a combination of (1) seismic horizon picking, (2) integrated seismic-gravity-magnetic (SGM) interpretation, (3) seismic volcanostratigraphy, and (4) igneous seismic geomorphology. The results are integrated with published wide-angle seismic data, re-analyzed borehole data including new geochronology, and new geodynamic modeling of the effects of magmatism on the thermal history and subsidence of the margin. The extensive sill complexes and associated hydrothermal vent complexes in the Vøring Basin have a Paleocene-Eocene boundary age based on high-precision U/Pb dating combined with seismic mapping constraints. On the marginal high, our results show a highly variable crustal structure, with a pre-breakup configuration consisting of large-scale structural highs and sedimentary basins. These structures were in-filled and covered by basalt flows and volcanogenic sediments during the early stages of continental breakup in the earliest Eocene. Subsequently, rift basins developed along the continent-ocean boundary and where infilled by up to ca. 6 km thick basalt sequences, currently imaged as SDRs fed by a dike swarm imaged on seismic data. The addition of magma within the crust had a prominent effect on the thermal history and hydrocarbon maturation of the sedimentary basin, causing uplift, delayed subsidence, and possibly contributing to the triggering of global warming during the Paleocene-Eocene Thermal Maximum (PETM).

Apparent Brecciation Gradient, Mount Desert Island, Maine

NASA Astrophysics Data System (ADS)

Hawkins, A. T.; Johnson, S. E.

2004-05-01

Mount Desert Island, Maine, comprises a shallow level, Siluro-Devonian igneous complex surrounded by a distinctive breccia zone ("shatter zone" of Gilman and Chapman, 1988). The zone is very well exposed on the southern and eastern shores of the island and provides a unique opportunity to examine subvolcanic processes. The breccia of the Shatter Zone shows wide variation in percent matrix and clast, and may represent a spatial and temporal gradient in breccia formation due to a single eruptive or other catastrophic volcanic event. The shatter zone was divided into five developmental stages based on the extent of brecciation: Bar Harbor Formation, Sols Cliffs breccia, Seeley Road breccia, Dubois breccia, and Great Head breccia. A digital camera was employed to capture scale images of representative outcrops using a 0.5 m square Plexiglas frame. Individual images were joined in Adobe Photoshop to create a composite image of each outcrop. The composite photo was then exported to Adobe Illustrator, which was used to outline the clasts and produce a digital map of the outcrop for analysis. The fractal dimension (Fd) of each clast was calculated using NIH Image and a Euclidean distance mapping method described by Bérubé and Jébrak (1999) to quantify the morphology of the fragments, or the complexity of the outline. The more complex the fragment outline, the higher the fractal dimension, indicating that the fragment is less "mature" or has had less exposure to erosional processes, such as the injection of an igneous matrix. Sols Cliffs breccia has an average Fd of 1.125, whereas Great Head breccia has an average Fd of 1.040, with the stages between having intermediate values. The more complex clasts of the Sols Cliffs breccia with a small amount (26.38%) of matrix material suggests that it is the first stage in a sequence of brecciation ending at the more mature, matrix-supported (71.37%) breccia of Great Head. The results of this study will be used to guide isotopic and geochemical analysis of the matrix igneous material in the attempt to better understand the dynamic processes that occur in subvolcanic environments and the mechanisms involved in breccia formation.

Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites - East Fork Valley Range Complex, Former Camp Hale

DTIC Science & Technology

2016-04-01

with cores of igneous and metamorphic rocks flanked by steeply dipping sedimentary rocks . The valley floors range in elevation from about 9,310 to...Camp Hale, East Fork Valley Range Complex Munitions Response Site. This project is one in a series of projects funded by ESTCP to use advanced...Technology Certification Program ft Feet FUDS Formerly Used Defense Site GPS Global Positioning System ID Identification IMU Inertial Measurement Unit

Igneous intrusion models for floor fracturing in lunar craters

NASA Technical Reports Server (NTRS)

Wichman, R. W.; Schultz, P. H.

1991-01-01

Lunar floor-fractured craters are primarily located near the maria and frequently contain ponded mare units and dark mantling deposits. Fracturing is confined to the crater interior, often producing a moat-like feature near the floor edge, and crater depth is commonly reduced by uplift of the crater floor. Although viscous relaxation of crater topography can produce such uplift, the close association of modification with surface volcanism supports a model linking floor fracture to crater-centered igneous intrusions. The consequences of two intrusion models for the lunar interior are quantitatively explored. The first model is based on terrestrial laccoliths and describes a shallow intrusion beneath the crater. The second model is based on cone sheet complexes where surface deformation results from a deeper magma chamber. Both models, their fit to observed crater modifications and possible implications for local volcanism are described.

Effects of Strategy Instruction on the Learning, Use, and Vertical Transfer of Strategies.

ERIC Educational Resources Information Center

Finley, Fred N.; Smith, Edward L.

1980-01-01

Compares group differences in strategy learning, use, and transfer to a more complex task for two groups of elementary students (N=48). Asked to perform three tasks in classifying igneous rocks, the groups differed in whether they received advice on the use of a specific strategy for performing each task. (CS)

Coping with naturally high levels of soil salinity and boron in the westside of central California

USDA-ARS?s Scientific Manuscript database

In the Westside of central California, over 200,000 ha exhibit naturally high levels of salinity and boron (B). The Coast Ranges of the west central California evolved from complex folding and faulting of sedimentary and igneous rocks of Mesozoic and Tertiary age. Cretaceous and Tertiary marine sedi...

Latent Class Analysis of Incomplete Data via an Entropy-Based Criterion

PubMed Central

Larose, Chantal; Harel, Ofer; Kordas, Katarzyna; Dey, Dipak K.

2016-01-01

Latent class analysis is used to group categorical data into classes via a probability model. Model selection criteria then judge how well the model fits the data. When addressing incomplete data, the current methodology restricts the imputation to a single, pre-specified number of classes. We seek to develop an entropy-based model selection criterion that does not restrict the imputation to one number of clusters. Simulations show the new criterion performing well against the current standards of AIC and BIC, while a family studies application demonstrates how the criterion provides more detailed and useful results than AIC and BIC. PMID:27695391

Increased GABA(A) inhibition of the RVLM after hindlimb unloading in rats

NASA Technical Reports Server (NTRS)

Moffitt, Julia A.; Heesch, Cheryl M.; Hasser, Eileen M.

2002-01-01

Attenuated baroreflex-mediated increases in renal sympathetic nerve activity (RSNA) in hindlimb unloaded (HU) rats apparently are due to changes within the central nervous system. We hypothesized that GABA(A) receptor-mediated inhibition of the rostral ventrolateral medulla (RVLM) is increased after hindlimb unloading. Responses to bilateral microinjection of the GABA(A) antagonist (-)-bicuculline methiodide (BIC) into the RVLM were examined before and during caudal ventrolateral medulla (CVLM) inhibition in Inactin-anesthetized control and HU rats. Increases in mean arterial pressure (MAP), heart rate (HR), and RSNA in response to BIC in the RVLM were significantly enhanced in HU rats. Responses to bilateral CVLM blockade were not different. When remaining GABA(A) inhibition in the RVLM was blocked by BIC during CVLM inhibition, the additional increases in MAP and RSNA were significantly greater in HU rats. These data indicate that GABA(A) receptor-mediated inhibition of RVLM neurons is augmented after hindlimb unloading. Effects of input from the CVLM were unaltered. Thus, after cardiovascular deconditioning in rodents, the attenuated increase in sympathetic nerve activity in response to hypotension is associated with greater GABA(A) receptor-mediated inhibition of RVLM neurons originating at least in part from sources other than the CVLM.

Cdk1 Activates Pre-mitotic Nuclear Envelope Dynein Recruitment and Apical Nuclear Migration in Neural Stem Cells.

PubMed

Baffet, Alexandre D; Hu, Daniel J; Vallee, Richard B

2015-06-22

Dynein recruitment to the nuclear envelope is required for pre-mitotic nucleus-centrosome interactions in nonneuronal cells and for apical nuclear migration in neural stem cells. In each case, dynein is recruited to the nuclear envelope (NE) specifically during G2 via two nuclear pore-mediated mechanisms involving RanBP2-BicD2 and Nup133-CENP-F. The mechanisms responsible for cell-cycle control of this behavior are unknown. We now find that Cdk1 serves as a direct master controller for NE dynein recruitment in neural stem cells and HeLa cells. Cdk1 phosphorylates conserved sites within RanBP2 and activates BicD2 binding and early dynein recruitment. Late recruitment is triggered by a Cdk1-induced export of CENP-F from the nucleus. Forced NE targeting of BicD2 overrides Cdk1 inhibition, fully rescuing dynein recruitment and nuclear migration in neural stem cells. These results reveal how NE dynein recruitment is cell-cycle regulated and identify the trigger mechanism for apical nuclear migration in the brain. Copyright © 2015 Elsevier Inc. All rights reserved.

The combined effects of forward masking by noise and high click rate on monaural and binaural human auditory nerve and brainstem potentials.

PubMed

Pratt, Hillel; Polyakov, Andrey; Bleich, Naomi; Mittelman, Naomi

2004-07-01

To study effects of forward masking and rapid stimulation on human monaurally- and binaurally-evoked brainstem potentials and suggest their relation to synaptic fatigue and recovery and to neuronal action potential refractoriness. Auditory brainstem evoked potentials (ABEPs) were recorded from 12 normally- and symmetrically hearing adults, in response to each click (50 dB nHL, condensation and rarefaction) in a train of nine, with an inter-click interval of 11 ms, that followed a white noise burst of 100 ms duration (50 dB nHL). Sequences of white noise and click train were repeated at a rate of 2.89 s(-1). The interval between noise and first click in the train was 2, 11, 22, 44, 66 or 88 ms in different runs. ABEPs were averaged (8000 repetitions) using a dwell time of 25 micros/address/channel. The binaural interaction components (BICs) of ABEPs were derived and the single, centrally located equivalent dipoles of ABEP waves I and V and of the BIC major wave were estimated. The latencies of dipoles I and V of ABEP, their inter-dipole interval and the dipole magnitude of component V were significantly affected by the interval between noise and clicks and by the serial position of the click in the train. The latency and dipole magnitude of the major BIC component were significantly affected by the interval between noise and clicks. Interval from noise and the click's serial position in the train interacted to affect dipole V latency, dipole V magnitude, BIC latencies and the V-I inter-dipole latency difference. Most of the effects were fully apparent by the first few clicks in the train, and the trend (increase or decrease) was affected by the interval between noise and clicks. The changes in latency and magnitude of ABEP and BIC components with advancing position in the click train and the interactions of click position in the train with the intervals from noise indicate an interaction of fatigue and recovery, compatible with synaptic depletion and replenishing, respectively. With the 2 ms interval between noise and the first click in the train, neuronal action potential refractoriness may also be involved.

Origin of the Sudbury Complex by meteoritic impact: Neodymium isotopic evidence

USGS Publications Warehouse

Faggart, B.E.; Basu, A.R.; Tatsumoto, M.

1985-01-01

Samarium-neodymium isotopic data on whole rocks and minerals of the Sudbury Complex in Canada gave an igneous crystallization age of 1840 ?? 21 ?? 106 years. The initial epsilon neodymium values for 15 whole rocks are similar to those for average upper continental crust, falling on the crustal trend of neodymium isotopic evolution as defined by shales. The rare earth element concentration patterns of Sudbury rocks are also similar to upper crustal averages. These data suggest that the Sudbury Complex formed from melts generated in the upper crust and are consistent with a meteoritic impact.

A novel tree-based procedure for deciphering the genomic spectrum of clinical disease entities.

PubMed

Mbogning, Cyprien; Perdry, Hervé; Toussile, Wilson; Broët, Philippe

2014-01-01

Dissecting the genomic spectrum of clinical disease entities is a challenging task. Recursive partitioning (or classification trees) methods provide powerful tools for exploring complex interplay among genomic factors, with respect to a main factor, that can reveal hidden genomic patterns. To take confounding variables into account, the partially linear tree-based regression (PLTR) model has been recently published. It combines regression models and tree-based methodology. It is however computationally burdensome and not well suited for situations for which a large number of exploratory variables is expected. We developed a novel procedure that represents an alternative to the original PLTR procedure, and considered different selection criteria. A simulation study with different scenarios has been performed to compare the performances of the proposed procedure to the original PLTR strategy. The proposed procedure with a Bayesian Information Criterion (BIC) achieved good performances to detect the hidden structure as compared to the original procedure. The novel procedure was used for analyzing patterns of copy-number alterations in lung adenocarcinomas, with respect to Kirsten Rat Sarcoma Viral Oncogene Homolog gene (KRAS) mutation status, while controlling for a cohort effect. Results highlight two subgroups of pure or nearly pure wild-type KRAS tumors with particular copy-number alteration patterns. The proposed procedure with a BIC criterion represents a powerful and practical alternative to the original procedure. Our procedure performs well in a general framework and is simple to implement.

Closed system oxygen isotope redistribution in igneous CAIs upon spinel dissolution

NASA Astrophysics Data System (ADS)

Aléon, Jérôme

2018-01-01

In several Calcium-Aluminum-rich Inclusions (CAIs) from the CV3 chondrites Allende and Efremovka, representative of the most common igneous CAI types (type A, type B and Fractionated with Unknown Nuclear isotopic anomalies, FUN), the relationship between 16O-excesses and TiO2 content in pyroxene indicates that the latter commonly begins to crystallize with a near-terrestrial 16O-poor composition and becomes 16O-enriched during crystallization, reaching a near-solar composition. Mass balance calculations were performed to investigate the contribution of spinel to this 16O-enrichment. It is found that a back-reaction of early-crystallized 16O-rich spinel with a silicate partial melt having undergone a 16O-depletion is consistent with the O isotopic evolution of CAI minerals during magmatic crystallization. Dissolution of spinel explains the O isotopic composition (16O-excess and extent of mass fractionation) of pyroxene as well as that of primary anorthite/dmisteinbergite and possibly that of the last melilite crystallizing immediately before pyroxene. It requires that igneous CAIs behaved as closed-systems relative to oxygen from nebular gas during a significant fraction of their cooling history, contrary to the common assumption that CAI partial melts constantly equilibrated with gas. The mineralogical control on O isotopes in igneous CAIs is thus simply explained by a single 16O-depletion during magmatic crystallization. This 16O-depletion occurred in an early stage of the thermal history, after the crystallization of spinel, i.e. in the temperature range for melilite crystallization/partial melting and did not require multiple, complex or late isotope exchange. More experimental work is however required to deduce the protoplanetary disk conditions associated with this 16O-depletion.

Classification of igneous rocks analyzed by ChemCam at Gale crater, Mars

DOE PAGES

Cousin, Agnes; Sautter, Violaine; Payré, Valérie; ...

2017-02-09

Several recent studies have revealed that Mars is not a simple basalt-covered planet, but has a more complex geological history. In Gale crater on Mars, the Curiosity rover discovered 59 igneous rocks. This article focuses on their textures (acquired from the cameras such as MAHLI and MastCam) and their geochemical compositions that have been obtained using the ChemCam instrument. Light-toned crystals have been observed in most of the rocks. They correspond to feldspars ranging from andesines/oligoclases to anorthoclases and sanidines in the leucocratic vesiculated rocks. Darker crystals observed in all igneous rocks (except the leucocratic vesiculated ones) were analyzed bymore » LIBS and mainly identified as Fe-rich pigeonites and Fe-augites. Iron oxides have been observed in all groups whereas F-bearing minerals have been detected only in few of them. From their textural analysis and their whole-rock compositions, all these 59 igneous rocks have been classified in five different groups; from primitive rocks i.e. dark aphanitic basalts/basanites, trachybasalts, tephrites and fine/coarse-grained gabbros/norites to more evolved materials i.e. porphyritic trachyandesites, leucocratic trachytes and quartz-diorites. The basalts and gabbros are found all along the traverse of the rover, whereas the felsic rocks are located before the Kimberley formation, i.e. close to the Peace Vallis alluvial fan deposits. This suggests that these alkali rocks have been transported by fluvial activity and could come from the Northern rim of the crater, and may correspond to deeper strata buried under basaltic regolith (Sautter et al., 2015). Some of the basaltic igneous rocks are surprisingly enriched in iron, presenting low Mg# similar to the nakhlite parental melt that cannot be produced by direct melting of the Dreibus and Wanke (1986) martian primitive mantle. The basaltic rocks at Gale are thus different from Gusev basalts. They could originate from different mantle reservoirs, or they could have undergone a more extensive fractional crystallization. Lastly, Gale basaltic rocks could have been the parental magma of residual liquid extending into alkali field towards trachyte composition as magma fractionated under anhydrous condition on its way to the surface before sub adiabatic ascent.« less

An 40Ar/39Ar geochronology on a mid-Eocene igneous event on the Barton and Weaver peninsulas: Implications for the dynamic setting of the Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Wang, Fei; Zheng, Xiang-Shen; Lee, Jong I. K.; Choe, Won Hie; Evans, Noreen; Zhu, Ri-Xiang

2009-12-01

The genesis of basaltic to andesitic lavas, mafic dikes, and granitoid plutons composing the subaerial cover on the Barton and Weaver peninsulas, Antarctica, is related to arc formation and subduction processes. Precise dating of these polar rocks using conventional 40Ar/39Ar techniques is compromised by the high degree of alteration (with loss on ignition as high as 8%). In order to minimize the alteration effects we have followed a sample preparation process that includes repeated acid leaching, acetone washing, and hand picking, followed by an overnight bake at 250°C. After this procedure, groundmass samples can yield accurate age plateaus consisting of 70%-100% of the total 39Ark released using high-resolution heating schedules. The different rock types studied on the Barton and Weaver peninsulas yielded almost coeval ages, suggesting a giant igneous event in the Weaver and Barton peninsulas at 44.5 Ma. A compilation of newly published ages indicate that this event took place throughout the whole South Shetland Islands, suggesting a dynamic incident occurred at this stage during the arc evolution history. We related this igneous event to a mantle delamination mechanism during Eocene times. The delamination process began at ˜52 Ma, and the resultant upwelling of asthenosphere baffled the subduction of Phoenix plate, causing an abrupt decrease in convergence rate. Then multiple magmatic sources were triggered, resulting in a culminating igneous activity during 50-40 Ma with a peak at ˜45 Ma along the archipelago. The delamination also caused the extension regime indicated by the dike swarm, plugs and sills all over the archipelago, and the uplift of Smith metamorphic complex and Livingston Island. Delamination process may have finished at some time during 40-30 Ma, leaving a weak igneous activity at that stage and thereafter. The convergence rate then recovered gradually, as indicated by the magnetic anomaly identifications. This model is supported by seismic observation of deep velocity anomalies beneath the Antarctic Peninsula.

Classification of igneous rocks analyzed by ChemCam at Gale crater, Mars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cousin, Agnes; Sautter, Violaine; Payré, Valérie

Several recent studies have revealed that Mars is not a simple basalt-covered planet, but has a more complex geological history. In Gale crater on Mars, the Curiosity rover discovered 59 igneous rocks. This article focuses on their textures (acquired from the cameras such as MAHLI and MastCam) and their geochemical compositions that have been obtained using the ChemCam instrument. Light-toned crystals have been observed in most of the rocks. They correspond to feldspars ranging from andesines/oligoclases to anorthoclases and sanidines in the leucocratic vesiculated rocks. Darker crystals observed in all igneous rocks (except the leucocratic vesiculated ones) were analyzed bymore » LIBS and mainly identified as Fe-rich pigeonites and Fe-augites. Iron oxides have been observed in all groups whereas F-bearing minerals have been detected only in few of them. From their textural analysis and their whole-rock compositions, all these 59 igneous rocks have been classified in five different groups; from primitive rocks i.e. dark aphanitic basalts/basanites, trachybasalts, tephrites and fine/coarse-grained gabbros/norites to more evolved materials i.e. porphyritic trachyandesites, leucocratic trachytes and quartz-diorites. The basalts and gabbros are found all along the traverse of the rover, whereas the felsic rocks are located before the Kimberley formation, i.e. close to the Peace Vallis alluvial fan deposits. This suggests that these alkali rocks have been transported by fluvial activity and could come from the Northern rim of the crater, and may correspond to deeper strata buried under basaltic regolith (Sautter et al., 2015). Some of the basaltic igneous rocks are surprisingly enriched in iron, presenting low Mg# similar to the nakhlite parental melt that cannot be produced by direct melting of the Dreibus and Wanke (1986) martian primitive mantle. The basaltic rocks at Gale are thus different from Gusev basalts. They could originate from different mantle reservoirs, or they could have undergone a more extensive fractional crystallization. Lastly, Gale basaltic rocks could have been the parental magma of residual liquid extending into alkali field towards trachyte composition as magma fractionated under anhydrous condition on its way to the surface before sub adiabatic ascent.« less

Land vehicle antennas for satellite mobile communications

NASA Technical Reports Server (NTRS)

Haddad, H. A.; Paschen, D.; Pieper, B. V.

1985-01-01

Antenna designs applicable to future satellite mobile vehicle communications are examined. Microstrip disk, quadrifilar helix, cylindrical microstrip, and inverted V and U crossed-dipole low gain antennas (3-5 dBic) that provide omnidirectional coverage are described. Diagrams of medium gain antenna (9-12 dBic) concepts are presented; the antennas are classified into three types: (1) electronically steered with digital phase shifters; (2) electronically switched with switchable power divider/combiner; and (3) mechanically steered with motor. The operating characteristics of a conformal antenna with electronic beam steering and a nonconformal design with mechanical steering are evaluated with respect to isolation levels in a multiple satellite system. Vehicle antenna pointing systems and antenna system costs are investigated.

Igneous rocks formed by hypervelocity impact

NASA Astrophysics Data System (ADS)

Osinski, Gordon R.; Grieve, Richard A. F.; Bleacher, Jacob E.; Neish, Catherine D.; Pilles, Eric A.; Tornabene, Livio L.

2018-03-01

Igneous rocks are the primary building blocks of planetary crusts. Most igneous rocks originate via decompression melting and/or wet melting of protolith lithologies within planetary interiors and their classification and compositional, petrographic, and textural characteristics, are well-studied. As our exploration of the Solar System continues, so too does the inventory of intrusive and extrusive igneous rocks, settings, and processes. The results of planetary exploration have also clearly demonstrated that impact cratering is a ubiquitous geological process that has affected, and will continue to affect, all planetary objects with a solid surface, whether that be rock or ice. It is now recognized that the production of igneous rocks is a fundamental outcome of hypervelocity impact. The goal of this review is to provide an up-to-date synthesis of our knowledge and understanding of igneous rocks formed by hypervelocity impact. Following a brief overview of the basics of the impact process, we describe how and why melts are generated during impact events and how impact melting differs from endogenic igneous processes. While the process may differ, we show that the products of hypervelocity impact can share close similarities with volcanic and shallow intrusive igneous rocks of endogenic origin. Such impact melt rocks, as they are termed, can display lobate margins and cooling cracks, columnar joints and at the hand specimen and microscopic scale, such rocks can display mineral textures that are typical of volcanic rocks, such as quench crystallites, ophitic, porphyritic, as well as features such as vesicles, flow textures, and so on. Historically, these similarities led to the misidentification of some igneous rocks now known to be impact melt rocks as being of endogenic origin. This raises the question as to how to distinguish between an impact versus an endogenic origin for igneous-like rocks on other planetary bodies where fieldwork and sample analysis may not be possible and all that may be available is remote sensing data. While the interpretation of some impact melt rocks may be relatively straightforward (e.g., for clast-rich varieties and those with clear projectile contamination) we conclude that distinguishing between impact and endogenic igneous rocks is a non-trivial task that ultimately may require sample investigation and analysis to be conducted. Caution is, therefore, urged in the interpretation of igneous rocks on planetary surfaces.

The Effect of Simplifying Dental Implant Drilling Sequence on Osseointegration: An Experimental Study in Dogs

PubMed Central

Giro, Gabriela; Tovar, Nick; Marin, Charles; Bonfante, Estevam A.; Jimbo, Ryo; Suzuki, Marcelo; Janal, Malvin N.; Coelho, Paulo G.

2013-01-01

Objectives. To test the hypothesis that there would be no differences in osseointegration by reducing the number of drills for site preparation relative to conventional drilling sequence. Methods. Seventy-two implants were bilaterally placed in the tibia of 18 beagle dogs and remained for 1, 3, and 5 weeks. Thirty-six implants were 3.75 mm in diameter and the other 36 were 4.2 mm. Half of the implants of each diameter were placed under a simplified technique (pilot drill + final diameter drill) and the other half were placed under conventional drilling where multiple drills of increasing diameter were utilized. After euthanisation, the bone-implant samples were processed and referred to histological analysis. Bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO) were assessed. Statistical analyses were performed by GLM ANOVA at 95% level of significance considering implant diameter, time in vivo, and drilling procedure as independent variables and BIC and BAFO as the dependent variables. Results. Both techniques led to implant integration. No differences in BIC and BAFO were observed between drilling procedures as time elapsed in vivo. Conclusions. The simplified drilling protocol presented comparable osseointegration outcomes to the conventional protocol, which proved the initial hypothesis. PMID:23431303

A second ortho-rhom-bic polymorph of (Z)-3-(9-anthr-yl)-1-(2-thien-yl)prop-2-en-1-one.

PubMed

Chantrapromma, Suchada; Suwunwong, Thitipone; Boonnak, Nawong; Fun, Hoong-Kun

2010-01-09

The title heteroaryl chalcone, C(21)H(14)OS, is a second ortho-rhom-bic polymorph which crystallizes in the space group P2(1)2(1)2(1). The structure was previously reported [Fun et al. (2009 ▶). Acta Cryst. E65, o2168-o2169] in the space group Pna2(1). The bond distances and angles are similar in both structures. In contrast, the overall crystal packing is different from that in the first ortho-rhom-bic Pna2(1) polymorph in which mol-ecules were stacked into columns along the b axis and the thio-phene units of two adjacent columns were stacked in a head to tail fashion. In the present polymorph, mol-ecules are found to dimerize through a weak S⋯S inter-action [3.6513 (7) Å] and these dimers are arranged into sheets parallel to the bc plane. There are no classical hydrogen bonds in the packing which features short C⋯O [3.2832 (2)-3.6251 (9) Å], C⋯S [3.4879 (17)-3.6251 (19) Å] and S⋯O [2.9948 (16) Å] contacts, together with C-H⋯π inter-actions. Similar contacts were found in the other polymorph.

Repeated High Intensity Bouts with Long Recovery: Are Bicarbonate or Carbohydrate Supplements an Option?

PubMed Central

Stöggl, Thomas; Torres-Peralta, Rafael; Cetin, Ebru

2014-01-01

The effects of varying recovery modes and the influence of preexercise sodium bicarbonate and carbohydrate ingestion on repeated high intensity performance, acid-base response, and recovery were analyzed in 12 well-trained males. They completed three repeated high intensity running bouts to exhaustion with intervening recovery periods of 25 min under the following conditions: sodium bicarbonate, active recovery (BIC); carbohydrate ingestion, active recovery (CHO); placebo ingestion, active recovery (ACTIVE); placebo ingestion, passive recovery (PASSIVE). Blood lactate (BLa), blood gases, heart rate, and time to exhaustion were collected. The three high intensity bouts had a duration of 138 ± 9, 124 ± 6, and 121 ± 6 s demonstrating a decrease from bout 1 to bout 3. Supplementation strategy had no effect on performance in the first bout, even with differences in pH and bicarbonate (HCO3 −). Repeated sprint performance was not affected by supplementation strategy when compared to ACTIVE, while PASSIVE resulted in a more pronounced decrease in performance compared with all other interventions. BIC led to greater BLa, pH, and HCO3 − values compared with all other interventions, while for PASSIVE the opposite was found. BLa recovery was lowest in PASSIVE; recovery in pH, and HCO3 − was lower in PASSIVE and higher in BIC. PMID:25431775

The cross-validated AUC for MCP-logistic regression with high-dimensional data.

PubMed

Jiang, Dingfeng; Huang, Jian; Zhang, Ying

2013-10-01

We propose a cross-validated area under the receiving operator characteristic (ROC) curve (CV-AUC) criterion for tuning parameter selection for penalized methods in sparse, high-dimensional logistic regression models. We use this criterion in combination with the minimax concave penalty (MCP) method for variable selection. The CV-AUC criterion is specifically designed for optimizing the classification performance for binary outcome data. To implement the proposed approach, we derive an efficient coordinate descent algorithm to compute the MCP-logistic regression solution surface. Simulation studies are conducted to evaluate the finite sample performance of the proposed method and its comparison with the existing methods including the Akaike information criterion (AIC), Bayesian information criterion (BIC) or Extended BIC (EBIC). The model selected based on the CV-AUC criterion tends to have a larger predictive AUC and smaller classification error than those with tuning parameters selected using the AIC, BIC or EBIC. We illustrate the application of the MCP-logistic regression with the CV-AUC criterion on three microarray datasets from the studies that attempt to identify genes related to cancers. Our simulation studies and data examples demonstrate that the CV-AUC is an attractive method for tuning parameter selection for penalized methods in high-dimensional logistic regression models.

Impact of monaural frequency compression on binaural fusion at the brainstem level.

PubMed

Klauke, Isabelle; Kohl, Manuel C; Hannemann, Ronny; Kornagel, Ulrich; Strauss, Daniel J; Corona-Strauss, Farah I

2015-08-01

A classical objective measure for binaural fusion at the brainstem level is the so-called β-wave of the binaural interaction component (BIC) in the auditory brainstem response (ABR). However, in some cases it appeared that a reliable detection of this component still remains a challenge. In this study, we investigate the wavelet phase synchronization stability (WPSS) of ABR data for the analysis of binaural fusion and compare it to the BIC. In particular, we examine the impact of monaural nonlinear frequency compression on binaural fusion. As the auditory system is tonotopically organized, an interaural frequency mismatch caused by monaural frequency compression could negatively effect binaural fusion. In this study, only few subjects showed a detectable β-wave and in most cases only for low ITDs. However, we present a novel objective measure for binaural fusion that outperforms the current state-of-the-art technique (BIC): the WPSS analysis showed a significant difference between the phase stability of the sum of the monaurally evoked responses and the phase stability of the binaurally evoked ABR. This difference could be an indicator for binaural fusion in the brainstem. Furthermore, we observed that monaural frequency compression could indeed effect binaural fusion, as the WPSS results for this condition vary strongly from the results obtained without frequency compression.

Comparison of Interaural Electrode Pairing Methods for Bilateral Cochlear Implants

PubMed Central

Dietz, Mathias

2015-01-01

In patients with bilateral cochlear implants (CIs), pairing matched interaural electrodes and stimulating them with the same frequency band is expected to facilitate binaural functions such as binaural fusion, localization, and spatial release from masking. Because clinical procedures typically do not include patient-specific interaural electrode pairing, it remains the case that each electrode is allocated to a generic frequency range, based simply on the electrode number. Two psychoacoustic techniques for determining interaurally paired electrodes have been demonstrated in several studies: interaural pitch comparison and interaural time difference (ITD) sensitivity. However, these two methods are rarely, if ever, compared directly. A third, more objective method is to assess the amplitude of the binaural interaction component (BIC) derived from electrically evoked auditory brainstem responses for different electrode pairings; a method has been demonstrated to be a potential candidate for bilateral CI users. Here, we tested all three measures in the same eight CI users. We found good correspondence between the electrode pair producing the largest BIC and the electrode pair producing the maximum ITD sensitivity. The correspondence between the pairs producing the largest BIC and the pitch-matched electrode pairs was considerably weaker, supporting the previously proposed hypothesis that whilst place pitch might adapt over time to accommodate mismatched inputs, sensitivity to ITDs does not adapt to the same degree. PMID:26631108

The "Key" Method of Identifying Igneous and Metamorphic Rocks in Introductory Laboratory.

ERIC Educational Resources Information Center

Eves, Robert Leo; Davis, Larry Eugene

1987-01-01

Proposes that identification keys provide an orderly strategy for the identification of igneous and metamorphic rocks in an introductory geology course. Explains the format employed in the system and includes the actual key guides for both igneous and metamorphic rocks. (ML)

Neoproterozoic magmatic flare-up along the N. margin of Gondwana: The Taknar complex, NE Iran

NASA Astrophysics Data System (ADS)

Moghadam, Hadi Shafaii; Li, Xian-Hua; Santos, Jose F.; Stern, Robert J.; Griffin, William L.; Ghorbani, Ghasem; Sarebani, Nazila

2017-09-01

Magmatic ;flare-ups; are common in continental arcs. The best-studied examples of such flare-ups are from Cretaceous and younger continental arcs, but a more ancient example is preserved in Late Ediacaran-Cambrian or Cadomian arcs that formed along the northern margin of Gondwana. In this paper, we report new trace-element, isotopic and geochronological data on ∼550 Ma magmatic rocks from the Taknar complex, NE Iran, and use this information to better understand episodes of flare-up, crustal thickening and magmatic periodicity in the Cadomian arcs of Iran and Anatolia. Igneous rocks in the Taknar complex include gabbros, diorites, and granitoids, which grade upward into a sequence of metamorphosed volcano-sedimentary rocks with interlayered rhyolites. Granodioritic dikes crosscut the Taknar gabbros and diorites. Gabbros are the oldest units and have zircon U-Pb ages of ca 556 Ma. Granites are younger and have U-Pb zircon ages of ca 552-547 Ma. Rhyolites are coeval with the granites, with U-Pb zircon ages of ∼551 Ma. Granodioritic dikes show two U-Pb zircon ages; ca 531 and 548 Ma. Geochemically, the Taknar igneous rocks have calc-alkaline signatures typical of continental arcs. Whole-rock Nd and zircon O-Hf isotopic data show that from Taknar igneous rocks were generated via mixing of juvenile magmas with older continental crust components at an active continental margin. Compiled geochronological and geochemical data from Iran and Anatolia allow identification of a Cadomian flare-up along northern Gondwana. The compiled U-Pb results from both magmatic and detrital zircons indicate the flare-up started ∼572 Ma and ended ∼528 Ma. The Cadomian flare-up was linked to strong crustal extension above a S-dipping subduction zone beneath northern Gondwana. The Iran-Anatolian Cadomian arc represents a site of crustal differentiation and stratification and involved older (Archean?) continental lower-middle crust, which has yet to be identified in situ, to form the continental nuclei of Anatolia and Iran. The Cadomian crust of Anatolia and Iran formed a single block ;Cimmeria; that rifted away from northern Gondwana and was accreted to southern Eurasia in late Paleozoic time.

Geochemical characteristics of igneous rocks associated with epithermal mineral deposits—A review

USGS Publications Warehouse

du Bray, Edward A.

2017-01-01

Newly synthesized data indicate that the geochemistry of igneous rocks associated with epithermal mineral deposits varies extensively and continuously from subalkaline basaltic to rhyolitic compositions. Trace element and isotopic data for these rocks are consistent with subduction-related magmatism and suggest that the primary source magmas were generated by partial melting of the mantle-wedge above subducting oceanic slabs. Broad geochemical and petrographic diversity of individual igneous rock units associated with epithermal deposits indicate that the associated magmas evolved by open-system processes. Following migration to shallow crustal reservoirs, these magmas evolved by assimilation, recharge, and partial homogenization; these processes contribute to arc magmatism worldwide.Although epithermal deposits with the largest Au and Ag production are associated with felsic to intermediate composition igneous rocks, demonstrable relationships between magmas having any particular composition and epithermal deposit genesis are completely absent because the composition of igneous rock units associated with epithermal deposits ranges from basalt to rhyolite. Consequently, igneous rock compositions do not constitute effective exploration criteria with respect to identification of terranes prospective for epithermal deposit formation. However, the close spatial and temporal association of igneous rocks and epithermal deposits does suggest a mutual genetic relationship. Igneous systems likely contribute heat and some of the fluids and metals involved in epithermal deposit formation. Accordingly, deposit formation requires optimization of source metal contents, appropriate fluid compositions and characteristics, structural features conducive to hydrothermal fluid flow and confinement, and receptive host rocks, but not magmas with special compositional characteristics.

Lithologic analysis from multispectral thermal infrared data of the alkalic rock complex at Iron Hill, Colorado

USGS Publications Warehouse

Watson, K.; Rowan, L.C.; Bowers, T.L.; Anton-Pacheco, C.; Gumiel, P.; Miller, S.H.

1996-01-01

Airborne thermal-infrared multispectral scanner (TIMS) data of the Iron Hill carbonatite-alkalic igneous rock complex in south-central Colorado are analyzed using a new spectral emissivity ratio algorithm and confirmed by field examination using existing 1:24 000-scale geologic maps and petrographic studies. Color composite images show that the alkalic rocks could be clearly identified and that differences existed among alkalic rocks in several parts of the complex. An unsupervised classification algorithm defines four alkalic rock classes within the complex: biotitic pyroxenite, uncompahgrite, augitic pyroxenite, and fenite + nepheline syenite. Felsic rock classes defined in the surrounding country rock are an extensive class consisting of tuff, granite, and felsite, a less extensive class of granite and felsite, and quartzite. The general composition of the classes can be determined from comparisons of the TIMS spectra with laboratory spectra. Carbonatite rocks are not classified, and we attribute that to the fact that dolomite, the predominant carbonate mineral in the complex, has a spectral feature that falls between TIMS channels 5 and 6. Mineralogical variability in the fenitized granite contributed to the nonuniform pattern of the fenite-nepheline syenite class. The biotitic pyroxenite, which resulted from alteration of the pyroxenite, is spatially associated and appears to be related to narrow carbonatite dikes and sills. Results from a linear unmixing algorithm suggest that the detected spatial extent of the two mixed felsic rock classes was sensitive to the amount of vegetation cover. These results illustrate that spectral thermal infrared data can be processed to yield compositional information that can be a cost-effective tool to target mineral exploration, particularly in igneous terranes.

Extensional tectonics during the igneous emplacement of the mafic-ultramafic rocks of the Barberton greenstone belt

NASA Technical Reports Server (NTRS)

Dewit, M. J.

1986-01-01

The simatic rocks (Onverwacht Group) of the Barberton greenstone belt are part of the Jamestown ophiolite complex. This ophiolite, together with its thick sedimentary cover occupies a complex thrust belt. Field studies have identified two types of early faults which are entirely confined to the simatic rocks and are deformed by the later thrusts and associated folds. The first type of fault (F1a) is regional and always occurs in the simatic rocks along and parallel to the lower contacts of the ophiolite-related cherts (Middle Marker and equivalent layers). These fault zones have previously been referred to both as flaser-banded gneisses and as weathering horizons. In general the zones range between 1-30m in thickness. Displacements along these zones are difficult to estimate, but may be in the order of 1-100 km. The structures indicate that the faults formed close to horizontal, during extensional shear and were therefore low angle normal faults. F1a zones overlap in age with the formation of the ophiolite complex. The second type of faults (F1b) are vertical brittle-ductile shear zones, which crosscut the complex at variable angles and cannot always be traced from plutonic to overlying extrusive (pillowed) simatic rocks. F1b zones are also apparently of penecontemporaneous origin with the intrusive-extrusive igneous processs. F1b zones may either represent transform fault-type activity or represent root zones (steepened extensions) of F1a zones. Both fault types indicate extensive deformation in the rocks of the greenstone belt prior to compressional overthrust tectonics.

Dynamics of Intense Pulsed Proton Beam in the Nagaoka ETIGO-I

NASA Astrophysics Data System (ADS)

Tanaka, Hajime; Konno, Kohji; Masugata, Katsumi; Yatsui, Kiyoshi; Matsui, Masao

1982-10-01

Dynamics of an intense pulsed proton beam have been studied by measuring nuclear reactions as well as by a biased ion-collector (BIC). When the ion-current density (Ji) is small such that Ji<30 A/cm2, the proton number measured by BIC is in good agreement with that by nuclear activation. Good linearity exists between time integrated γ-ray signal and proton number measured by the activation. Hence, it would be possible to obtain the proton number quantitatively even when a target “blow-off” takes place at Ji>1 kA/cm2. Prompt γ-ray is also measured by the time-of-flight method to yield reasonable agreement with the applied peak potential.

Phosphate determination in seawater: toward an autonomous electrochemical method.

PubMed

Jońca, Justyna; León Fernández, Violeta; Thouron, Danièle; Paulmier, Aurélien; Graco, Michelle; Garçon, Véronique

2011-12-15

Initial steps to create an autonomous in situ electrochemical sensor for orthophosphate determination in seawater are presented. First, the optimal conditions to form the molybdophosphate complex in artificial seawater medium were determined by addition of sulphuric acid and sodium molybdate to the solution containing orthophosphate. Secondly, the anodic oxidation of molybdenum to form molybdate ions and protons was used to create the molybdophosphate complex without addition of any liquid reagents. The molybdophosphate complex is detectable by amperometry with an average precision of 2.2% for the concentration range found in the open ocean and the detection limit is 0.12 μM. Three solutions are proposed to address the silicate interferences issue and one of these methods is used for the natural samples collected in the coastal waters offshore Peru during the Pelagico 1011-12-BIC OLAYA cruise in November-December 2010. Results showed a good precision with an average of 2.5% and a reasonable deviation of the amperometric analysis as compared with colorimetric measurements (4.9%). Copyright © 2011 Elsevier B.V. All rights reserved.

[High Precision Identification of Igneous Rock Lithology by Laser Induced Breakdown Spectroscopy].

PubMed

Wang, Chao; Zhang, Wei-gang; Yan, Zhi-quan

2015-09-01

In the field of petroleum exploration, lithology identification of finely cuttings sample, especially high precision identification of igneous rock with similar property, has become one of the geological problems. In order to solve this problem, a new method is proposed based on element analysis of Laser-Induced Breakdown Spectroscopy (LIBS) and Total Alkali versus Silica (TAS) diagram. Using independent LIBS system, factors influencing spectral signal, such as pulse energy, acquisition time delay, spectrum acquisition method and pre-ablation are researched through contrast experiments systematically. The best analysis conditions of igneous rock are determined: pulse energy is 50 mJ, acquisition time delay is 2 μs, the analysis result is integral average of 20 different points of sample's surface, and pre-ablation has been proved not suitable for igneous rock sample by experiment. The repeatability of spectral data is improved effectively. Characteristic lines of 7 elements (Na, Mg, Al, Si, K, Ca, Fe) commonly used for lithology identification of igneous rock are determined, and igneous rock samples of different lithology are analyzed and compared. Calibration curves of Na, K, Si are generated by using national standard series of rock samples, and all the linearly dependent coefficients are greater than 0.9. The accuracy of quantitative analysis is investigated by national standard samples. Element content of igneous rock is analyzed quantitatively by calibration curve, and its lithology is identified accurately by the method of TAS diagram, whose accuracy rate is 90.7%. The study indicates that LIBS can effectively achieve the high precision identification of the lithology of igneous rock.

The Central-Western Mediterranean: Anomalous igneous activity in an anomalous collisional tectonic setting

NASA Astrophysics Data System (ADS)

Lustrino, Michele; Duggen, Svend; Rosenberg, Claudio L.

2011-01-01

The central-western Mediterranean area is a key region for understanding the complex interaction between igneous activity and tectonics. In this review, the specific geochemical character of several 'subduction-related' Cenozoic igneous provinces are described with a view to identifying the processes responsible for the modifications of their sources. Different petrogenetic models are reviewed in the light of competing geological and geodynamic scenarios proposed in the literature. Plutonic rocks occur almost exclusively in the Eocene-Oligocene Periadriatic Province of the Alps while relatively minor plutonic bodies (mostly Miocene in age) crop out in N Morocco, S Spain and N Algeria. Igneous activity is otherwise confined to lava flows and dykes accompanied by relatively greater volumes of pyroclastic (often ignimbritic) products. Overall, the igneous activity spanned a wide temporal range, from middle Eocene (such as the Periadriatic Province) to the present (as in the Neapolitan of southern Italy). The magmatic products are mostly SiO 2-oversaturated, showing calcalkaline to high-K calcalcaline affinity, except in some areas (as in peninsular Italy) where potassic to ultrapotassic compositions prevail. The ultrapotassic magmas (which include leucitites to leucite-phonolites) are dominantly SiO 2-undersaturated, although rare, SiO 2-saturated (i.e., leucite-free lamproites) appear over much of this region, examples being in the Betics (southeast Spain), the northwest Alps, northeast Corsica (France), Tuscany (northwest Italy), southeast Tyrrhenian Sea (Cornacya Seamount) and possibly in the Tell region (northeast Algeria). Excepted for the Alpine case, subduction-related igneous activity is strictly linked to the formation of the Mediterranean Sea. This Sea, at least in its central and western sectors, is made up of several young (< 30 Ma) V-shaped back-arc basins plus several dispersed continental fragments, originally in crustal continuity with the European plate (Sardinia, Corsica, Balearic Islands, Kabylies, Calabria, Peloritani Mountains). The bulk of igneous activity in the central-western Mediterranean is believed to have tapped mantle 'wedge' regions, metasomatized by pressure-related dehydration of the subducting slabs. The presence of subduction-related igneous rocks with a wide range of chemical composition has been related to the interplay of several factors among which the pre-metasomatic composition of the mantle wedges (i.e., fertile vs. refractory mineralogy), the composition of the subducting plate (i.e., the type and amount of sediment cover and the alteration state of the crust), the variable thermo-baric conditions of magma formation, coupled with variable molar concentrations of CO 2 and H 2O in the fluid phase released by the subducting plates are the most important. Compared to classic collisional settings (e.g., Himalayas), the central-western Mediterranean area shows a range of unusual geological and magmatological features. These include: a) the rapid formation of extensional basins in an overall compressional setting related to Africa-Europe convergence; b) centrifugal wave of both compressive and extensional tectonics starting from a 'pivotal' region around the Gulf of Lyon; c) the development of concomitant Cenozoic subduction zones with different subduction and tectonic transport directions; d) subduction 'inversion' events (e.g., currently along the Maghrebian coast and in northern Sicily, previously at the southern paleo-European margin); e) a repeated temporal pattern whereby subduction-related magmatic activity gives way to magmas of intraplate geochemical type; f) the late-stage appearance of magmas with collision-related 'exotic' (potassic to ultrapotassic) compositions, generally absent from simple subduction settings; g) the relative scarcity of typical calcalkaline magmas along the Italian peninsula; h) the absence of igneous activity where it might well be expected (e.g., above the hanging-wall of the Late Cretaceous-Eocene Adria-Europe subduction system in the Alps); i) voluminous production of subduction-related magmas coeval with extensional tectonic régimes (e.g., during Oligo-Miocene Sardinian Trough formation). To summarize, these salient central-western Mediterranean features, characterizing a late-stage of the classic 'Wilson Cycle' offer a 'template' for interpreting magmatic compositions in analogous settings elsewhere.

Development of the Philippine Mobile Belt in northern Luzon from Eocene to Pliocene

NASA Astrophysics Data System (ADS)

Suzuki, Shigeyuki; Peña, Rolando E.; Tam, Tomas A.; Yumul, Graciano P.; Dimalanta, Carla B.; Usui, Mayumi; Ishida, Keisuke

2017-07-01

The origin of the Philippine Archipelago is characterized by the combination of the oceanic Philippine Mobile Belt (PMB) and the Palawan Continental Block (PCB). This paper is focused on the geologic evolution of the PMB in northern Luzon from Eocene to Pliocene. The study areas (northern Luzon) are situated in the central part of the PMB which is occupied by its typical components made up of a pre-Paleocene ophiolitic complex, Eocene successions, Eocene to Oligocene igneous complex and late Oligocene to Pliocene successions. Facies analysis of the middle Eocene and late Oligocene to early Pliocene successions was carried out to understand the depositional environment of their basins. Modal sandstone compositions, which reflect the basement geology of the source area, were analyzed. Major element geochemistry of sediments was considered to reconstruct the tectonic settings. The following brief history of the PMB is deduced. During the middle Eocene, the PMB was covered by mafic volcanic rocks and was a primitive island arc. In late Eocene to late Oligocene time, the intermediate igneous complex was added to the mafic PMB crust. By late Oligocene to early Miocene time, the PMB had evolved into a volcanic island arc setting. Contributions from alkalic rocks are detected from the rock fragments in the sandstones and chemical composition of the Zigzag Formation. During the middle Miocene to Pliocene, the tectonic setting of the PMB remained as a mafic volcanic island arc.

Peri-implant bone formation and implant integration strength of peptide-modified p(AAM-co-EG/AAC) interpenetrating polymer network-coated titanium implants.

PubMed

Barber, Thomas A; Ho, James E; De Ranieri, Aladino; Virdi, Amarjit S; Sumner, Dale R; Healy, Kevin E

2007-02-01

Interpenetrating polymer networks (IPNs) of poly (acrylamide-co-ethylene glycol/acrylic acid) functionalized with an -Arg-Gly-Asp- (RGD) containing 15 amino acid peptides, derived from rat bone sialoprotein (bsp-RGD(15), were grafted to titanium implants in an effort to modulate bone formation in the peri-implant region in the rat femoral ablation model. Bone-implant contact (BIC) and bone formation within the medullary canal were determined using microcomputed tomography at 2 and 4 weeks postimplantation. BIC for bsp-RGD(15)-IPN implants was enhanced relative to hydroxyapatite tricalcium phosphate (HA-TCP) coated implants, but was similar to all other groups. Aggregate bone formation neither indicated a dose-dependent effect of bsp-RGD(15) nor a meaningful trend. Mechanical testing of implant fixation revealed that only the HA-TCP coated implants supported significant (>1 MPa) interfacial shear strength, despite exhibiting lower overall BIC, an indication that bone ingrowth into the rougher coating was the primary mode of implant fixation. While no evidence was found to support the hypothesis that bsp-RGD(15)-modified IPN coated implants significantly impacted bone-implant bonding, these results point to the lack of correlation between in vitro studies employing primary osteoblasts and in vivo wound healing in the peri-implant region. Copyright 2006 Wiley Periodicals, Inc.

Combining Mixture Components for Clustering*

PubMed Central

Baudry, Jean-Patrick; Raftery, Adrian E.; Celeux, Gilles; Lo, Kenneth; Gottardo, Raphaël

2010-01-01

Model-based clustering consists of fitting a mixture model to data and identifying each cluster with one of its components. Multivariate normal distributions are typically used. The number of clusters is usually determined from the data, often using BIC. In practice, however, individual clusters can be poorly fitted by Gaussian distributions, and in that case model-based clustering tends to represent one non-Gaussian cluster by a mixture of two or more Gaussian distributions. If the number of mixture components is interpreted as the number of clusters, this can lead to overestimation of the number of clusters. This is because BIC selects the number of mixture components needed to provide a good approximation to the density, rather than the number of clusters as such. We propose first selecting the total number of Gaussian mixture components, K, using BIC and then combining them hierarchically according to an entropy criterion. This yields a unique soft clustering for each number of clusters less than or equal to K. These clusterings can be compared on substantive grounds, and we also describe an automatic way of selecting the number of clusters via a piecewise linear regression fit to the rescaled entropy plot. We illustrate the method with simulated data and a flow cytometry dataset. Supplemental Materials are available on the journal Web site and described at the end of the paper. PMID:20953302

A second ortho­rhom­bic polymorph of (Z)-3-(9-anthr­yl)-1-(2-thien­yl)prop-2-en-1-one1

PubMed Central

Chantrapromma, Suchada; Suwunwong, Thitipone; Boonnak, Nawong; Fun, Hoong-Kun

2010-01-01

The title heteroaryl chalcone, C21H14OS, is a second ortho­rhom­bic polymorph which crystallizes in the space group P212121. The structure was previously reported [Fun et al. (2009 ▶). Acta Cryst. E65, o2168-o2169] in the space group Pna21. The bond distances and angles are similar in both structures. In contrast, the overall crystal packing is different from that in the first ortho­rhom­bic Pna21 polymorph in which mol­ecules were stacked into columns along the b axis and the thio­phene units of two adjacent columns were stacked in a head to tail fashion. In the present polymorph, mol­ecules are found to dimerize through a weak S⋯S inter­action [3.6513 (7) Å] and these dimers are arranged into sheets parallel to the bc plane. There are no classical hydrogen bonds in the packing which features short C⋯O [3.2832 (2)–3.6251 (9) Å], C⋯S [3.4879 (17)–3.6251 (19) Å] and S⋯O [2.9948 (16) Å] contacts, together with C—H⋯π inter­actions. Similar contacts were found in the other polymorph. PMID:21579743

Effect of healing time on bone-implant contact of orthodontic micro-implants: a histologic study.

PubMed

Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

2014-01-01

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability.

Finite element analysis of dental implant loading on atrophic and non-atrophic cancellous and cortical mandibular bone - a feasibility study.

PubMed

Marcián, Petr; Borák, Libor; Valášek, Jiří; Kaiser, Jozef; Florian, Zdeněk; Wolff, Jan

2014-12-18

The first aim of this study was to assess displacements and micro-strain induced on different grades of atrophic cortical and trabecular mandibular bone by axially loaded dental implants using finite element analysis (FEA). The second aim was to assess the micro-strain induced by different implant geometries and the levels of bone-to-implant contact (BIC) on the surrounding bone. Six mandibular bone segments demonstrating different grades of mandibular bone atrophy and various bone volume fractions (from 0.149 to 0.471) were imaged using a micro-CT device. The acquired bone STL models and implant (Brånemark, Straumann, Ankylos) were merged into a three-dimensional finite elements structure. The mean displacement value for all implants was 3.1 ±1.2 µm. Displacements were lower in the group with a strong BIC. The results indicated that the maximum strain values of cortical and cancellous bone increased with lower bone density. Strain distribution is the first and foremost dependent on the shape of bone and architecture of cancellous bone. The geometry of the implant, thread patterns, grade of bone atrophy and BIC all affect the displacement and micro-strain on the mandible bone. Preoperative finite element analysis could offer improved predictability in the long-term outlook of dental implant restorations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Healing Time on Bone-Implant Contact of Orthodontic Micro-Implants: A Histologic Study

PubMed Central

Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

2014-01-01

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability. PMID:25006463

Evaluation of fixation of expandable implants in the mandibles of ovariectomized sheep.

PubMed

Xiao, Jian-Rui; Li, De-Hua; Chen, Yu-Xuan; Chen, Shu-Jun; Guan, Su-Min; Kong, Liang

2013-04-01

This study aimed to investigate the effects of an expandable implant (EI) in ovariectomized sheep. The EI and taper implant (control group) were produced and placed in mandibles of ovariectomized sheep. Twelve weeks after implantation, resonance frequency analysis, biomechanical tests, histomorphometry, and micro-computed tomography were applied to detect the osseointegration in the 2 groups. The implant stability quotient values, maximal pullout forces, and bone-implant contact (BIC) were 60.3 ± 7.9, 511.0 ± 18.7 N, and 53.14% ± 4.56%, respectively, in the EI group and 58.3 ± 8.9, 394.5 ± 54.5 N, and 46.85% ± 5.04%, respectively, in the control group. There was no significant difference between the 2 groups in implant stability quotient values (P > .05); however, in the EI group the maximal pullout force and BIC were increased significantly (P < .05 and P < .01, respectively). Micro-computed tomography analysis showed that the bone volume/total volume ratio and trabecular number increased significantly (P < .01) and trabecular separation decreased significantly (P < .05) in the EI group. EI could improve osseointegration in osteoporosis after 12 weeks of implantation by increasing BIC around the implant and by supplying an extra osseointegration surface. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

A brief history of the Bioengineering Institute of California and the UC System-wide Symposia.

PubMed

Chien, Shu

2011-04-01

The plan to establish a Multicampus Research Unit (MRU) on Bioengineering in the University of California (UC) System started in August 1999. The cooperative efforts of the UC campuses led to the formal establishment of the Bioengineering Institute of California (BIC) in October 2003. Three years prior to the BIC establishment, the System-wide Annual Bioengineering Symposium was started at UC Davis. The Symposia were then hosted sequentially by UC Santa Barbara, UC Berkeley, UCSD, UC Santa Cruz, UC Irvine, UCSF, UCLA, and UC Riverside, with the completion of the first cycle of a decade in the newest campus of UC Merced in 2009. The second cycle began in 2010 with the Symposium returning again to UC Davis. Each campus hosted a wonderful Symposium, with the active participation of students and faculty from all campuses, with the motto of "Ten campuses united as one, learning and growing together." These Symposia have contributed significantly to the collaborative research and training of students and young scientists in bioengineering, as well as fruitful interactions with industry and government agencies, which have provided strong support for these valuable meetings. The BIC will endeavor to further enhance these efforts by fostering research collaborations and joint education and training activities, with the ultimate goal of advancing bioengineering for the improvement of human health and wellbeing.

Are insertion torque and early osseointegration proportional? A histologic evaluation.

PubMed

Campos, Felipe E B; Jimbo, Ryo; Bonfante, Estevam A; Barbosa, Darceny Z; Oliveira, Maiolino T F; Janal, Malvin N; Coelho, Paulo G

2015-11-01

The objective of this histologic study was to determine the effect of three drilling protocols (oversized, intermediate, and undersized) on biologic responses to a single implant type at early healing periods (2 weeks in vivo) in a beagle dog model. Ten beagle dogs were acquired and subjected to surgeries in the tibia 2 weeks before euthanasia. During surgery, each dog received three Unitite implants, 4 mm in diameter by 10 mm in length, in bone sites drilled to 3.5, 3.75, and 4.0 mm in final diameter. The insertion torque was recorded during surgery, and bone-to-implant contact (BIC), and bone area fraction occupied (BAFO) measured from the histology. Each outcome measure was compared between treatment conditions with the Wilcoxon signed-rank test. Bonferroni-corrected statistical significance was set to 95%. Insertion torque increased as an inverse function of drilling diameter, as indicated by significant differences in torque levels between each pair of conditions (P = 0.005). BIC and BAFO levels were highest and statistically similar in the recommended and undersized conditions and significantly reduced in the oversized condition (P < 0.01). Reduced drilling dimensions resulted in increased insertion torque (primary stability). While BIC and BAFO were maximized when drilling the recommended diameter hole, only the oversized hole resulted in evidence of statistically reduced integration. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Igneous Complexes of the Orochenka Caldera of the East Sikhote-Alin Belt: U-Pb (SHRIMP) Age, Trace and Rare Earth Element Composition, and Au-Ag Mineralization

NASA Astrophysics Data System (ADS)

Sakhno, V. G.; Kovalenko, S. V.

2018-04-01

New data are presented on the geology and composition of volcanic and intrusive rocks of the Orochenka caldera, which is located in the western part of the East Sikhote Alin volcanic belt. The SHRIMP and ICP MS age of zircons of volcanic and intrusive rocks, respectively, and the composition of the volcanic rocks allow comparison of these complexes with volcanic rocks of the eastern part of the volcanic structure. New data indicate the period of transition between subduction to transform regimes.

Structure of the RZZ complex and molecular basis of its interaction with Spindly

PubMed Central

Mosalaganti, Shyamal; Keller, Jenny; Altenfeld, Anika; Rombaut, Pascaline; Petrovic, Arsen; Wohlgemuth, Sabine; Müller, Franziska; Herzog, Franz; Waldmann, Herbert

2017-01-01

Kinetochores are macromolecular assemblies that connect chromosomes to spindle microtubules (MTs) during mitosis. The metazoan-specific ≈800-kD ROD–Zwilch–ZW10 (RZZ) complex builds a fibrous corona that assembles on mitotic kinetochores before MT attachment to promote chromosome alignment and robust spindle assembly checkpoint signaling. In this study, we combine biochemical reconstitutions, single-particle electron cryomicroscopy, cross-linking mass spectrometry, and structural modeling to build a complete model of human RZZ. We find that RZZ is structurally related to self-assembling cytosolic coat scaffolds that mediate membrane cargo trafficking, including Clathrin, Sec13–Sec31, and αβ’ε-COP. We show that Spindly, a dynein adaptor, is related to BicD2 and binds RZZ directly in a farnesylation-dependent but membrane-independent manner. Through a targeted chemical biology approach, we identify ROD as the Spindly farnesyl receptor. Our results suggest that RZZ is dynein’s cargo at human kinetochores. PMID:28320825

Application of air hammer drilling technology in igneous rocks of Junggar basin

NASA Astrophysics Data System (ADS)

Zhao, Hongshan; Feng, Guangtong; Yu, Haiye

2018-03-01

There were many technical problems such as serious well deviation, low penetration rate and long drilling cycle in igneous rocks because of its hardness, strong abrasive and poor drillability, which severely influenced the exploration and development process of Junggar basin. Through analyzing the difficulties of gas drilling with roller bits in Well HS 2, conducting the mechanics experiments about igneous rock, and deeply describing the rock-breaking mechanism of air hammer drilling and its adaptability in igneous rocks, air hammer drilling can realize deviation control and fast drilling in igneous rocks of piedmont zone and avoid the wear and fatigue fracture of drilling strings due to its characteristics of low WOB, low RPM and high frequency impact. Through firstly used in igneous rocks of Well HS 201, compared with gas drilling with cone bit, the average penetration rate and one-trip footage of air hammer drilling respectively increased by more than 2.45 times and 6.42 times while the well deviation was always controlled less than 2 degrees. Two records for Block HS were set up such as the fastest penetration rate of 14.29m/h in Φ444.5mm well hole and the highest one-trip footage of 470.62m in Φ311.2mm well hole. So air hammer drilling was an effective way to realize optimal and fast drilling in the igneous rock formation of Junggar basin.

Primary Igneous Anhydrite: Progress Since the 1982 El Chichón Eruption (Mexico)

NASA Astrophysics Data System (ADS)

Luhr, J. F.

2006-05-01

Anhydrite (CaSO4) was confirmed as a stable primary igneous mineral, capable of precipitating from a silicate melt, through petrographic observations of fresh trachyandesitic pumices erupted in the spring of 1982 from El Chichón, a little known, isolated tuff and lava-dome complex in eastern Mexico. The 1982 eruption was also notable for the associated release of an estimated 5-9 megatons of SO2 to the stratosphere and troposphere, as measured by the Total Ozone Mapping Spectrometer. Subsequent years saw confirmation of primary igneous anhydrite in laboratory phase-equilibrium experiments, and anhydrite was also observed in the products of several subsequent explosive eruptions, most importantly dacitic pumices from the massive 15 June 1991 eruption of Mount Pinatubo, in the Philippines. That eruption involved ~5X the mass of magma and ~3X the mass of SO2 release compared to El Chichón's eruption. For both the Pinatubo and El Chichón eruptions, it has been concluded that the sulfur released to the atmosphere was too great in mass to have been dissolved in the erupted melt volume just prior to eruption. In both cases workers advocated the existence of a separate gas phase prior to eruption, where much of the subsequently released sulfur was present. Thus, primary igneous anhydrite has been linked with another important phenomenon: excess sulfur release during volcanic eruptions. This presentation will review other developments concerning primary igneous anhydrite since 1982. These include: (1) other examples of primary anhydrite from volcanic samples (Nevado del Ruiz, Colombia; Lascar, Chile; Sutter Buttes, USA; Eagle Mountain, USA; Shiveluch, Russia; (2) examples of primary anhydrite from plutonic samples (Julcani, Peru; Santa Rita, USA; Cajon Pass Scientific Drillhole, USA); (3) laboratory experiments that have expanded our understanding of the T-P-fO2 conditions of anhydrite stability, melt/vapor partition coefficients for sulfur as a function of these conditions, and the solubility of anhydrite in NaCl-H2O solutions at high P and T; and (4) ion-microprobe studies of sulfur isotopic compositions for anhydrite crystals in both El Chichón and Pinatubo pumices, which have revealed individually homogeneous crystals, but large inter-crystalline isotopic variations among neighboring grains.

Late Precambrian (740 Ma) charnockite, enderbite, and granite from Jebel Moya, Sudan: A link between the Mozambique Belt and the Arabian-Nubian Shield

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stern, R.J.; Dawoud, A.S.

1991-09-01

New Rb-Sr and whole rock and U-Pb zircon data are reported for deep-seated igneous rocks from Jebel Moya in east-central Sudan. This exposure is important because it may link the high-grade metamorphic and deep-seated igneous rocks of the Mozambique Belt with the greenschist-facies and ophiolitic assemblages of the Arabian-Nubian Shield, both of Pan-African (ca. 900-550 Ma) age. The rocks of Jebel Moya consist of pink granite, green charnockite, and dark enderbite. A twelve-point Rb-Sr whole rock isochron for all three lithologies yields an age of 730 {plus minus} 31 Ma and an initial {sup 87}Sr/{sup 86}Sr of 0.7031 {plus minus}more » 1. Nearly concordant zircon ages for granite, charnockite, and enderbite are 744 {plus minus} 2,742 {plus minus} 2, and 739 {plus minus} 2 Ma, respectively. Initial {epsilon}-Nd for these rocks are indistinguishable at 3.0 {plus minus} 0.4. The data suggest that the charnockite, enderbite, and granite are all part of a deep-seated igneous complex. The initial isotopic compositions of Sr and Nd indicate that Jebel Moya melts were derived from a mantle source that experienced significantly less time-integrated depletion of LRE and LIL elements than the source of Arabian-Nubian Shield melts. The ages for Jebel Moya deep-seated igneous rocks are in accord with data from elsewhere in the Mozambique Belt indicating that peak metamorphism occurred about 700-750 Ma. The northward extension of the Mozambique Belt to the Arabian-Nubian Shield defines a single east Pan-African orogen. The principal difference between the northern and southern sectors of this orogen may be the greater degree of thickening and subsequent erosion experienced in the south during the late Precambrian, perhaps a result of continental collision between East (Australia-India) and West Gondwanaland (S. America-Africa) about 750 Ma.« less

Hydrothermal reequilibration of igneous magnetite in altered granitic plutons and its implications for magnetite classification schemes: Insights from the Handan-Xingtai iron district, North China Craton

NASA Astrophysics Data System (ADS)

Wen, Guang; Li, Jian-Wei; Hofstra, Albert H.; Koenig, Alan E.; Lowers, Heather A.; Adams, David

2017-09-01

Magnetite is a common mineral in igneous rocks and has been used as an important petrogenetic indicator as its compositions and textures reflect changing physiochemical parameters such as temperature, oxygen fugacity and melt compositions. In upper crustal settings, igneous rocks are often altered by hydrothermal fluids such that the original textures and compositions of igneous magnetite may be partly or completely obliterated, posing interpretive problems in petrological and geochemical studies. In this paper, we present textural and compositional data of magnetite from variably albitized granitoid rocks in the Handan-Xingtai district, North China Craton to characterize the hydrothermal reequilibration of igneous magnetite. Four types of magnetite have been identified in the samples studied: pristine igneous magnetite (type 1), reequilibrated porous magnetite (type 2), reequilibrated nonporous magnetite (type 3), and hydrothermal magnetite (type 4). Pristine igneous magnetite contains abundant well-developed ilmenite exsolution lamellae that are largely replaced by titanite during subsequent hydrothermal alteration. The titanite has a larger molar volume than its precursor ilmenite and thus causes micro-fractures in the host magnetite grains, facilitating dissolution and reprecipitation of magnetite. During sodic alteration, the igneous magnetite is extensively replaced by type 2 and type 3 magnetite via fluid-induced dissolution and reprecipitation. Porous type 2 magnetite is the initial replacement product of igneous magnetite and is subsequently replaced by the nonoporous type 3 variety as its surface area is reduced and compositional equilibrium with the altering fluid is achieved. Hydrothermal type 4 magnetite is generally euhedral and lacks exsolution lamellae and porosity, and is interpreted to precipitate directly from the ore-forming fluids. Hydrothermal reequilibration of igneous magnetite has led to progressive chemical purification, during which trace elements such as Ti, Al, Mg, Zn, and Cr contents decrease dramatically (up to 2-3 orders of magnitude different), coupled with significant increase in iron concentrations from less than 64 wt.% to higher than 70 wt.%. Results presented here show that magnetite is much more susceptible to textural and compositional reequilibration than previously thought. The reequilibrated magnetite has geochemical patterns that may be distinctively different from its precursor, making existing discrimination plots questionable when applied to genetic interpretation. Based on textural characterization and high-resolution in situ compositional analyses, we propose that the Fe versus V/Ti diagram can be more confidently used to discriminate between pristine igneous magnetite, reequilibrated magnetite, and hydrothermal magnetite.

Limitations of using micro-computed tomography to predict bone-implant contact and mechanical fixation.

PubMed

Liu, S; Broucek, J; Virdi, A S; Sumner, D R

2012-01-01

Fixation of metallic implants to bone through osseointegration is important in orthopaedics and dentistry. Model systems for studying this phenomenon would benefit from a non-destructive imaging modality so that mechanical and morphological endpoints can more readily be examined in the same specimens. The purpose of this study was to assess the utility of an automated microcomputed tomography (μCT) program for predicting bone-implant contact (BIC) and mechanical fixation strength in a rat model. Femurs in which 1.5-mm-diameter titanium implants had been in place for 4 weeks were either embedded in polymethylmethacrylate (PMMA) for preparation of 1-mm-thick cross-sectional slabs (16 femurs: 32 slabs) or were used for mechanical implant pull-out testing (n= 18 femurs). All samples were scanned by μCT at 70 kVp with 16 μm voxels and assessed by the manufacturer's software for assessing 'osseointegration volume per total volume' (OV/TV). OV/TV measures bone volume per total volume (BV/TV) in a 3-voxel-thick ring that by default excludes the 3 voxels immediately adjacent to the implant to avoid metal-induced artefacts. The plastic-embedded samples were also analysed by backscatter scanning electron microscopy (bSEM) to provide a direct comparison of OV/TV with a well-accepted technique for BIC. In μCT images in which the implant was directly embedded within PMMA, there was a zone of elevated attenuation (>50% of the attenuation value used to segment bone from marrow) which extended 48 μm away from the implant surface. Comparison of the bSEM and μCT images showed high correlations for BV/TV measurements in areas not affected by metal-induced artefacts. In addition for bSEM images, we found that there were high correlations between peri-implant BV/TV within 12 μm of the implant surface and BIC (correlation coefficients ≥0.8, p < 0.05). OV/TV as measured on μCT images was not significantly correlated with BIC as measured on the corresponding bSEM images. However, OV/TV was significantly, but weakly, correlated with implant pull-out strength (r= 0.401, p= 0.049) and energy to failure (r= 0.435, p= 0.035). Thus, the need for the 48-μm-thick exclusion zone in the OV/TV program to avoid metal-induced artefacts with the scanner used in this study means that it is not possible to make bone measurements sufficiently close to the implant surface to obtain an accurate assessment of BIC. Current generation laboratory-based μCT scanners typically have voxel sizes of 6-8 μm or larger which will still not overcome this limitation. Thus, peri-implant bone measurements at these resolutions should only be used as a guide to predict implant fixation and should not be over-interpreted as a measurement of BIC. Newer generation laboratory-based μCT scanners have several improvements including better spatial resolution and X-ray sources and appear to have less severe metal-induced artefacts, but will need appropriate validation as they become available to researchers. Regardless of the μCT scanner being used, we recommend that detailed validation studies be performed for any study using metal implants because variation in the composition and geometry of the particular implants used may lead to different artefact patterns. © 2011 The Authors Journal of Microscopy © 2011 Royal Microscopical Society.

Igneous Rocks

NASA Astrophysics Data System (ADS)

Doe, Bruce R.

“Igneous Rocks was written for undergraduate geology majors who have had a year of college-level chemistry and a course in mineralogy … and for beginning graduate students. Geologists working in industry, government, or academia should find this text useful as a guide to the technical literature up to 1981 and as an overview of topics with which they have not worked but which may have unanticipated pertinence to their own projects.” So starts the preface to this textbook.As one who works part time in research on igneous rocks, especially as they relate to mineral deposits, I have been looking for such a book with this avowed purpose in a field that has a choking richness of evolving terminology and a bewildering volume of interdisciplinary literature. In addition to the standard topics of igneous petrology, the book contains a chapter on the role of igneous activity in the genesis of mineral deposits, its value to geothermal energy, and the potential of igneous rocks as an environment for nuclear waste disposal. These topics are presented rather apologetically in the preface, but the author is to be applauded for including this chapter. The apology shows just how new these interests are to petrology. Recognition is finally coming that, for example, mineral deposits are not “sports of nature,” a view held even by many economic geologists as recently as the early 1960's; instead they are perfectly ordinary geochemical features formed by perfectly ordinary geologic processes. In fact, the mineral deposits and their attendant alteration zones probably have as much to tell us about igneous rocks as the igneous rocks have to tell us about mineral deposits.

Kilbuck terrane: oldest known rocks in Alaska

USGS Publications Warehouse

Box, S.E.; Moll-Stalcup, E. J.; Wooden, J.L.; Bradshaw, J.Y.

1990-01-01

The Kilbuck terrane in southwestern Alaska is a narrow, thin crustal sliver or flake of amphibolite facies orthogneiss. The igneous protolith of this gneiss was a suite of subduction-related plutonic rocks. U-Pb data on zircons from trondhjemitic and granitic samples yield upper-intercept (igneous) ages of 2070 ?? 16 and 2040 ?? 74 Ma, respectively. Nd isotope data from these rocks suggest that a diorite-tonalite-trondhjemite suite (??Nd[T] = +2.1 to +2.7; T is time of crystallization) evolved from partial melts of depleted mantle with no discernible contamination by older crust, whereas a coeval granitic pluton (??Nd[T] = -5.7) contains a significant component derived from Archean crust. Orthogneisses with similar age and Nd isotope characteristics are found in the Idono complex 250 km to the north. Early Proterozoic rocks are unknown elsewhere in Alaska. The possibility that the Kilbuck terrane was displaced from provinces of similar age in other cratons (e.g., Australian, Baltic, Guiana, and west African shields), or from the poorly dated Siberian craton, cannot be excluded. -from Authors

CUMULATE ROCKS ASSOCIATED WITH CARBONATE ASSIMILATION, HORTAVÆR COMPLEX, NORTH-CENTRAL NORWAY

NASA Astrophysics Data System (ADS)

Barnes, C. G.; Prestvik, T.; Li, Y.

2009-12-01

The Hortavær igneous complex intruded high-grade metamorphic rocks of the Caledonian Helgeland Nappe Complex at ca. 466 Ma. The complex is an unusual mafic-silicic layered intrusion (MASLI) because the principal felsic rock type is syenite and because the syenite formed in situ rather than by deep-seated partial melting of crustal rocks. Magma differentiation in the complex was by assimilation, primarily of calc-silicate rocks and melts with contributions from marble and semi-pelites, plus fractional crystallization. The effect of assimilation of calcite-rich rocks was to enhance stability of fassaitic clinopyroxene at the expense of olivine, which resulted in alkali-rich residual melts and lowering of silica activity. This combination of MASLI-style emplacement and carbonate assimilation produced three types of cumulate rocks: (1) Syenitic cumulates formed by liquid-crystal separation. As sheets of mafic magma were loaded on crystal-rich syenitic magma, residual liquid was expelled, penetrating the overlying mafic sheets in flame structures, and leaving a cumulate syenite. (2) Reaction cumulates. Carbonate assimilation, illustrated by a simple assimilation reaction: olivine + calcite + melt = clinopyroxene + CO2 resulted in cpx-rich cumulates such as clinopyroxenite, gabbro, and mela-monzodiorite, many of which contain igneous calcite. (3) Magmatic skarns. Calc-silicate host rocks underwent partial melting during assimilation, yielding a Ca-rich melt as the principal assimilated material and permitting extensive reaction with surrounding magma to form Kspar + cpx + garnet-rich ‘cumulate’ rocks. Cumulate types (2) and (3) do not reflect traditional views of cumulate rocks but instead result from a series of melt-present discontinuous (peritectic) reactions and partial melting of calc-silicate xenoliths. In the Hortavær complex, such cumulates are evident because of the distinctive peritectic cumulate assemblages. It is unclear whether assimilation of ‘normal’ silicate rocks results in peritectic assemblages, or whether they could be identified as such if they exist.

Introduction to the Apollo collections. Part 1: Lunar igneous rocks

NASA Technical Reports Server (NTRS)

Mcgee, P. E.; Warner, J. L.; Simonds, C. H.

1977-01-01

The basic petrographic, chemical, and age data is presented for a representative suite of igneous rocks gathered during the six Apollo missions. Tables are given for 69 samples: 32 igneous rocks and 37 impactites (breccias). A description is given of 26 basalts, four plutonic rocks, and two pyroclastic samples. The textural-mineralogic name assigned each sample is included.

The ammonium content in the Malayer igneous and metamorphic rocks (Sanandaj-Sirjan Zone, Western Iran)

NASA Astrophysics Data System (ADS)

Ahadnejad, Vahid; Hirt, Ann Marie; Valizadeh, Mohammad-Vali; Bokani, Saeed Jabbari

2011-04-01

The ammonium (NH4+) contents of the Malayer area (Western Iran) have been determined by using the colorimetric method on 26 samples from igneous and metamorphic rocks. This is the first analysis of the ammonium contents of Iranian metamorphic and igneous rocks. The average ammonium content of metamorphic rocks decreases from low-grade to high-grade metamorphic rocks (in ppm): slate 580, phyllite 515, andalusite schist 242. In the case of igneous rocks, it decreases from felsic to mafic igneous types (in ppm): granites 39, monzonite 20, diorite 17, gabbro 10. Altered granitic rocks show enrichment in NH4+ (mean 61 ppm). The high concentration of ammonium in Malayer granites may indicate metasedimentary rocks as protoliths rather than meta-igneous rocks. These granitic rocks (S-types) have high K-bearing rock-forming minerals such as biotite, muscovite and K-feldspar which their potassium could substitute with ammonium. In addition, the high ammonium content of metasediments is probably due to inheritance of nitrogen from organic matter in the original sediments. The hydrothermally altered samples of granitic rocks show highly enrichment of ammonium suggesting external sources which intruded additional content by either interaction with metasedimentary country rocks or meteoritic solutions.

Geochemistry of Rock Samples Collected from the Iron Hill Carbonatite Complex, Gunnison County, Colorado

USGS Publications Warehouse

Van Gosen, Bradley S.

2008-01-01

A study conducted in 2006 by the U.S. Geological Survey collected 57 surface rock samples from nine types of intrusive rock in the Iron Hill carbonatite complex. This intrusive complex, located in Gunnison County of southwestern Colorado, is known for its classic carbonatite-alkaline igneous geology and petrology. The Iron Hill complex is also noteworthy for its diverse mineral resources, including enrichments in titanium, rare earth elements, thorium, niobium (columbium), and vanadium. This study was performed to reexamine the chemistry and metallic content of the major rock units of the Iron Hill complex by using modern analytical techniques, while providing a broader suite of elements than the earlier published studies. The report contains the geochemical analyses of the samples in tabular and digital spreadsheet format, providing the analytical results for 55 major and trace elements.

FDA-Approved HIV Medicines

MedlinePlus

... bictegravir sodium / emtricitabine / tenofovir alafenamide fumarate, BIC / FTC / TAF) Biktarvy February 7, 2018 darunavir and cobicistat (darunavir ... elvitegravir / cobicistat / emtricitabine / tenofovir alafenamide, EVG / COBI / FTC / TAF) Genvoya November 5, 2015 elvitegravir, cobicistat, emtricitabine, and ...

Bone Tissue Response to Porous and Functionalized Titanium and Silica Based Coatings

PubMed Central

Chaudhari, Amol; Braem, Annabel; Vleugels, Jozef; Martens, Johan A.; Naert, Ignace; Cardoso, Marcio Vivan; Duyck, Joke

2011-01-01

Background Topography and presence of bio-mimetic coatings are known to improve osseointegration. The objective of this study was to evaluate the bone regeneration potential of porous and osteogenic coatings. Methodology Six-implants [Control (CTR); porous titanium coatings (T1, T2); thickened titanium (Ti) dioxide layer (TiO2); Amorphous Microporous Silica (AMS) and Bio-active Glass (BAG)] were implanted randomly in tibiae of 20-New Zealand white rabbits. The animals were sacrificed after 2 or 4 weeks. The samples were analyzed histologically and histomorphometrically. In the initial bone-free areas (bone regeneration areas (BRAs)), the bone area fraction (BAF) was evaluated in the whole cavity (500 µm, BAF-500), in the implant vicinity (100 µm, BAF-100) and further away (100–500 µm, BAF-400) from the implant. Bone-to-implant contact (BIC-BAA) was measured in the areas where the implants were installed in contact to the host bone (bone adaptation areas (BAAs)) to understand and compare the bone adaptation. Mixed models were used for statistical analysis. Principal Findings After 2 weeks, the differences in BAF-500 for different surfaces were not significant (p>0.05). After 4 weeks, a higher BAF-500 was observed for BAG than CTR. BAF-100 for AMS was higher than BAG and BAF-400 for BAG was higher than CTR and AMS. For T1 and AMS, the bone regeneration was faster in the 100-µm compared to the 400-µm zone. BIC-BAA for AMS and BAG was lower after 4 than 2 weeks. After 4 weeks, BIC-BAA for BAG was lower than AMS and CTR. Conclusions BAG is highly osteogenic at a distance from the implant. The porous titanium coatings didn't stimulate bone regeneration but allowed bone growth into the pores. Although AMS didn't stimulate higher bone response, it has a potential of faster bone growth in the vicinity compared to further away from the surface. BIC-BAA data were inconclusive to understand the bone adaptation. PMID:21935382

The Use of Light/Chemically Hardened Polymethylmethacrylate, Polyhydroxylethylmethacrylate, and Calcium Hydroxide Graft Material in Combination With Polyanhydride Around Implants and Extraction Sockets in Minipigs: Part II: Histologic and Micro-CT Evaluations

PubMed Central

Hasturk, Hatice; Kantarci, Alpdogan; Ghattas, Mazen; Dangaria, Smit J.; Abdallah, Rima; Morgan, Elise F.; Diekwisch, Thomas G.H.; Ashman, Arthur; Van Dyke, Thomas

2015-01-01

Background This report is the second part of the previously published study on the impact of light/chemical hardening technology and a newly formulated composite graft material for crestal augmentation during immediate implant placement. Methods A total of 48 implants were placed into the sockets of the mesial roots of freshly extracted mandibular premolar teeth in three minipigs. Crestal areas and intrabony spaces were randomly augmented with light-hardened graft materials including a composite graft consisting of polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA); PPCH graft; and PA graft, or left untreated. Distal sockets not receiving implants and the sockets of first molars (n = 60) were randomly treated with one of the graft materials or left empty. In addition, two molar sockets were treated with the original PPCH graft material. Quantitative microcomputed tomography (micro-CT) was used to assess alveolar bone structure and tissue compositions. Histologic evaluations included descriptive histology to assess the peri-implant wound healing, as well as histomorphometric measurements to determine bone-to-implant contact (BIC). Results Both trabecular and cortical bone measurements by micro-CT did not reveal any significant differences among the groups. Sites augmented with PPCH+PA resulted in significantly greater BIC surface than PPCH alone and no-graft-treated implants (P <0.05) histologically. Stained ground sections showed complete bone formation between bone and implant surface in the PPCH+PA group, whereas sites without augmentation showed large gaps between bone and implant surfaces, indicating a slower bone apposition and less BIC surface compared to all other groups. Similar to implant sections, all materials showed positive outcome on trabecular and cortical bone formation in extraction sockets with an intact crestal cortical bone. Conclusion Histologic evaluations supported the previous findings on implant stability and function and confirmed that PPCH+PA provides a greater BIC with a well-organized implant–bone interface and is useful in crestal augmentation during immediate implant placement. PMID:24502615

The use of light/chemically hardened polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide graft material in combination with polyanhydride around implants and extraction sockets in minipigs: Part II: histologic and micro-CT evaluations.

PubMed

Hasturk, Hatice; Kantarci, Alpdogan; Ghattas, Mazen; Dangaria, Smit J; Abdallah, Rima; Morgan, Elise F; Diekwisch, Thomas G H; Ashman, Arthur; Van Dyke, Thomas

2014-09-01

This report is the second part of the previously published study on the impact of light/chemical hardening technology and a newly formulated composite graft material for crestal augmentation during immediate implant placement. A total of 48 implants were placed into the sockets of the mesial roots of freshly extracted mandibular premolar teeth in three minipigs. Crestal areas and intrabony spaces were randomly augmented with light-hardened graft materials including a composite graft consisting of polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA); PPCH graft; and PA graft, or left untreated. Distal sockets not receiving implants and the sockets of first molars (n = 60) were randomly treated with one of the graft materials or left empty. In addition, two molar sockets were treated with the original PPCH graft material. Quantitative microcomputed tomography (micro-CT) was used to assess alveolar bone structure and tissue compositions. Histologic evaluations included descriptive histology to assess the peri-implant wound healing, as well as histomorphometric measurements to determine bone-to-implant contact (BIC). Both trabecular and cortical bone measurements by micro-CT did not reveal any significant differences among the groups. Sites augmented with PPCH+PA resulted in significantly greater BIC surface than PPCH alone and no-graft-treated implants (P <0.05) histologically. Stained ground sections showed complete bone formation between bone and implant surface in the PPCH+PA group, whereas sites without augmentation showed large gaps between bone and implant surfaces, indicating a slower bone apposition and less BIC surface compared to all other groups. Similar to implant sections, all materials showed positive outcome on trabecular and cortical bone formation in extraction sockets with an intact crestal cortical bone. Histologic evaluations supported the previous findings on implant stability and function and confirmed that PPCH+PA provides a greater BIC with a well-organized implant-bone interface and is useful in crestal augmentation during immediate implant placement.

Classification scheme for sedimentary and igneous rocks in Gale crater, Mars

NASA Astrophysics Data System (ADS)

Mangold, N.; Schmidt, M. E.; Fisk, M. R.; Forni, O.; McLennan, S. M.; Ming, D. W.; Sautter, V.; Sumner, D.; Williams, A. J.; Clegg, S. M.; Cousin, A.; Gasnault, O.; Gellert, R.; Grotzinger, J. P.; Wiens, R. C.

2017-03-01

Rocks analyzed by the Curiosity rover in Gale crater include a variety of clastic sedimentary rocks and igneous float rocks transported by fluvial and impact processes. To facilitate the discussion of the range of lithologies, we present in this article a petrological classification framework adapting terrestrial classification schemes to Mars compositions (such as Fe abundances typically higher than for comparable lithologies on Earth), to specific Curiosity observations (such as common alkali-rich rocks), and to the capabilities of the rover instruments. Mineralogy was acquired only locally for a few drilled rocks, and so it does not suffice as a systematic classification tool, in contrast to classical terrestrial rock classification. The core of this classification involves (1) the characterization of rock texture as sedimentary, igneous or undefined according to grain/crystal sizes and shapes using imaging from the ChemCam Remote Micro-Imager (RMI), Mars Hand Lens Imager (MAHLI) and Mastcam instruments, and (2) the assignment of geochemical modifiers based on the abundances of Fe, Si, alkali, and S determined by the Alpha Particle X-ray Spectrometer (APXS) and ChemCam instruments. The aims are to help understand Gale crater geology by highlighting the various categories of rocks analyzed by the rover. Several implications are proposed from the cross-comparisons of rocks of various texture and composition, for instance between in place outcrops and float rocks. All outcrops analyzed by the rover are sedimentary; no igneous outcrops have been observed. However, some igneous rocks are clasts in conglomerates, suggesting that part of them are derived from the crater rim. The compositions of in-place sedimentary rocks contrast significantly with the compositions of igneous float rocks. While some of the differences between sedimentary rocks and igneous floats may be related to physical sorting and diagenesis of the sediments, some of the sedimentary rocks (e.g., potassic rocks) cannot be paired with any igneous rocks analyzed so far. In contrast, many float rocks, which cannot be classified from their poorly defined texture, plot on chemistry diagrams close to float rocks defined as igneous from their textures, potentially constraining their nature.

Classification scheme for sedimentary and igneous rocks in Gale crater, Mars

DOE PAGES

Mangold, Nicolas; Schmidt, Mariek E.; Fisk, Martin R.; ...

2016-11-05

Rocks analyzed by the Curiosity rover in Gale crater include a variety of clastic sedimentary rocks and igneous float rocks transported by fluvial and impact processes. Here, to facilitate the discussion of the range of lithologies, we present in this article a petrological classification framework adapting terrestrial classification schemes to Mars compositions (such as Fe abundances typically higher than for comparable lithologies on Earth), to specific Curiosity observations (such as common alkali-rich rocks), and to the capabilities of the rover instruments. Mineralogy was acquired only locally for a few drilled rocks, and so it does not suffice as a systematicmore » classification tool, in contrast to classical terrestrial rock classification. The core of this classification involves (1) the characterization of rock texture as sedimentary, igneous or undefined according to grain/crystal sizes and shapes using imaging from the ChemCam Remote Micro-Imager (RMI), Mars Hand Lens Imager (MAHLI) and Mastcam instruments, and (2) the assignment of geochemical modifiers based on the abundances of Fe, Si, alkali, and S determined by the Alpha Particle X-ray Spectrometer (APXS) and ChemCam instruments. The aims are to help understand Gale crater geology by highlighting the various categories of rocks analyzed by the rover. Several implications are proposed from the cross-comparisons of rocks of various texture and composition, for instance between in place outcrops and float rocks. All outcrops analyzed by the rover are sedimentary; no igneous outcrops have been observed. However, some igneous rocks are clasts in conglomerates, suggesting that part of them are derived from the crater rim. The compositions of in-place sedimentary rocks contrast significantly with the compositions of igneous float rocks. While some of the differences between sedimentary rocks and igneous floats may be related to physical sorting and diagenesis of the sediments, some of the sedimentary rocks (e.g., potassic rocks) cannot be paired with any igneous rocks analyzed so far. Finally, in contrast, many float rocks, which cannot be classified from their poorly defined texture, plot on chemistry diagrams close to float rocks defined as igneous from their textures, potentially constraining their nature.« less

Classification scheme for sedimentary and igneous rocks in Gale crater, Mars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mangold, Nicolas; Schmidt, Mariek E.; Fisk, Martin R.

Rocks analyzed by the Curiosity rover in Gale crater include a variety of clastic sedimentary rocks and igneous float rocks transported by fluvial and impact processes. Here, to facilitate the discussion of the range of lithologies, we present in this article a petrological classification framework adapting terrestrial classification schemes to Mars compositions (such as Fe abundances typically higher than for comparable lithologies on Earth), to specific Curiosity observations (such as common alkali-rich rocks), and to the capabilities of the rover instruments. Mineralogy was acquired only locally for a few drilled rocks, and so it does not suffice as a systematicmore » classification tool, in contrast to classical terrestrial rock classification. The core of this classification involves (1) the characterization of rock texture as sedimentary, igneous or undefined according to grain/crystal sizes and shapes using imaging from the ChemCam Remote Micro-Imager (RMI), Mars Hand Lens Imager (MAHLI) and Mastcam instruments, and (2) the assignment of geochemical modifiers based on the abundances of Fe, Si, alkali, and S determined by the Alpha Particle X-ray Spectrometer (APXS) and ChemCam instruments. The aims are to help understand Gale crater geology by highlighting the various categories of rocks analyzed by the rover. Several implications are proposed from the cross-comparisons of rocks of various texture and composition, for instance between in place outcrops and float rocks. All outcrops analyzed by the rover are sedimentary; no igneous outcrops have been observed. However, some igneous rocks are clasts in conglomerates, suggesting that part of them are derived from the crater rim. The compositions of in-place sedimentary rocks contrast significantly with the compositions of igneous float rocks. While some of the differences between sedimentary rocks and igneous floats may be related to physical sorting and diagenesis of the sediments, some of the sedimentary rocks (e.g., potassic rocks) cannot be paired with any igneous rocks analyzed so far. Finally, in contrast, many float rocks, which cannot be classified from their poorly defined texture, plot on chemistry diagrams close to float rocks defined as igneous from their textures, potentially constraining their nature.« less

Cross-frequency coupling in real and virtual brain networks

PubMed Central

Jirsa, Viktor; Müller, Viktor

2013-01-01

Information processing in the brain is thought to rely on the convergence and divergence of oscillatory behaviors of widely distributed brain areas. This information flow is captured in its simplest form via the concepts of synchronization and desynchronization and related metrics. More complex forms of information flow are transient synchronizations and multi-frequency behaviors with metrics related to cross-frequency coupling (CFC). It is supposed that CFC plays a crucial role in the organization of large-scale networks and functional integration across large distances. In this study, we describe different CFC measures and test their applicability in simulated and real electroencephalographic (EEG) data obtained during resting state. For these purposes, we derive generic oscillator equations from full brain network models. We systematically model and simulate the various scenarios of CFC under the influence of noise to obtain biologically realistic oscillator dynamics. We find that (i) specific CFC-measures detect correctly in most cases the nature of CFC under noise conditions, (ii) bispectrum (BIS) and bicoherence (BIC) correctly detect the CFCs in simulated data, (iii) empirical resting state EEG show a prominent delta-alpha CFC as identified by specific CFC measures and the more classic BIS and BIC. This coupling was mostly asymmetric (directed) and generally higher in the eyes closed (EC) than in the eyes open (EO) condition. In conjunction, these two sets of measures provide a powerful toolbox to reveal the nature of couplings from experimental data and as such allow inference on the brain state dependent information processing. Methodological advantages of using CFC measures and theoretical significance of delta and alpha interactions during resting and other brain states are discussed. PMID:23840188

Geochemistry of magnetite from porphyry Cu and skarn deposits in the southwestern United States

USGS Publications Warehouse

Nadoll, Patrick; Mauk, Jeffrey L.; LeVeille, Richard A.; Koenig, Alan E.

2015-01-01

A combination of petrographic observations, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and statistical data exploration was used in this study to determine compositional variations in hydrothermal and igneous magnetite from five porphyry Cu–Mo and skarn deposits in the southwestern United States, and igneous magnetite from the unmineralized, granodioritic Inner Zone Batholith, Japan. The most important overall discriminators for the minor and trace element chemistry of magnetite from the investigated porphyry and skarn deposits are Mg, Al, Ti, V, Mn, Co, Zn, and Ga—of these the elements with the highest variance for (I) igneous magnetite are Mg, Al, Ti, V, Mn, Zn, for (II) hydrothermal porphyry magnetite are Mg, Ti, V, Mn, Co, Zn, and for (III) hydrothermal skarn magnetite are Mg, Ti, Mn, Zn, and Ga. Nickel could only be detected at levels above the limit of reporting (LOR) in two igneous magnetites. Equally, Cr could only be detected in one igneous occurrence. Copper, As, Mo, Ag, Au, and Pb have been reported in magnetite by other authors but could not be detected at levels greater than their respective LORs in our samples. Comparison with the chemical signature of igneous magnetite from the barren Inner Zone Batholith, Japan, suggests that V, Mn, Co, and Ga concentrations are relatively depleted in magnetite from the porphyry and skarn deposits. Higher formation conditions in combination with distinct differences between melt and hydrothermal fluid compositions are reflected in Al, Ti, V, and Ga concentrations that are, on average, higher in igneous magnetite than in hydrothermal magnetite (including porphyry and skarn magnetite). Low Ti and V concentrations in combination with high Mn concentrations are characteristic features of magnetite from skarn deposits. High Mg concentrations (<1,000 ppm) are characteristic for magnetite from magnesian skarn and likely reflect extensive fluid/rock interaction. In porphyry deposits, hydrothermal magnetite from different vein types can be distinguished by varying Ti, V, Mn, and Zn contents. Titanium and V concentrations are highly variable among hydrothermal and igneous magnetites, but Ti concentrations above 3,560 ppm could only be detected in igneous magnetite, and V concentrations are on average lower in hydrothermal magnetite. The highest Ti concentrations are present in igneous magnetite from gabbro and monzonite. The lowest Ti concentrations were recorded in igneous magnetite from granodiorite and granodiorite breccia and largely overlap with Ti concentrations found in hydrothermal porphyry magnetite. Magnesium and Mn concentrations vary between magnetite from different skarn deposits but are generally greater than in hydrothermal magnetite from the porphyry deposits. High Mg, and low Ti and V concentrations characterize hydrothermal magnetite from magnesian skarn deposits and follow a trend that indicates that magnetite from skarn (calcic and magnesian) commonly has low Ti and V concentrations.

Charge disproportionation of mixed-valent Cr triggered by Bi lone-pair effect in the A -site-ordered perovskite BiC u3C r4O12

NASA Astrophysics Data System (ADS)

Etter, Martin; Isobe, Masahiko; Sakurai, Hiroya; Yaresko, Alexander; Dinnebier, Robert E.; Takagi, Hidenori

2018-05-01

A new A -site-ordered perovskite BiC u3C r4O12 is synthesized under a high pressure of 7.7 GPa. A phase transition from a paramagnetic metal to a ferrimagnetic metal is observed at Tc=190 K accompanied with a structural change from cubic to monoclinic. Structural analysis of the low-temperature monoclinic phase reveals that this transition represents a charge disproportionation of C r3.75 + into C r4 + and C r3.5 + . We argue that the asymmetric displacement of Bi caused by a lone-pair effect triggers the formation of a dimeric Cr4+2O5 unit and leads to an ordering of C r4 + and C r3.5 + below the transition.

Latent class profile of psychiatric symptoms and treatment utilization in a sample of patients with co-occurring disorders.

PubMed

Villalobos-Gallegos, Luis; Marín-Navarrete, Rodrigo; Roncero, Calos; González-Cantú, Hugo

2017-01-01

To identify symptom-based subgroups within a sample of patients with co-occurring disorders (CODs) and to analyze intersubgroup differences in mental health services utilization. Two hundred and fifteen patients with COD from an addiction clinic completed the Symptom Checklist 90-Revised. Subgroups were determined using latent class profile analysis. Services utilization data were collected from electronic records during a 3-year span. The five-class model obtained the best fit (Bayesian information criteria [BIC] = 3,546.95; adjusted BIC = 3,363.14; bootstrapped likelihood ratio test p < 0.0001). Differences between classes were quantitative, and groups were labeled according to severity: mild (26%), mild-moderate (28.8%), moderate (18.6%), moderate-severe (17.2%), and severe (9.3%). A significant time by class interaction was obtained (chi-square [χ2[15

Measurement of stratospheric trace constituent distributions from balloon-borne far infrared observations

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Guo, J.; Carli, B.; Mencaraglia, F.; Bonetti, A.

1987-01-01

FIR limb thermal emission spectra obtained from balloon-borne measurements made as a part of the Balloon Intercomparison Campaign (BIC) have been analyzed for retrieval of stratospheric trace-constituent distributions. The measurements were made with a high-resolution Michelson interferometer and covered the 15-180/cm spectral range with an unapodized spectral resolution of 0.0033/cm. The retrieved vertical profiles of O3, H2O, HDO, HCN, CO, and isotopes of O3 are presented. The results are compared with the BIC measurements for O3 and H2O made from the same balloon gondola and with other published data. A comparison of the simultaneously retrieved profiles for several gases with the published data shows good agreement and indicates the validity of the FIR data and retrieval techniques and the accuracy of the inferred profiles.

Bone Healing Around Dental Implants: Simplified vs Conventional Drilling Protocols at Speed of 400 rpm.

PubMed

Gil, Luiz Fernando; Sarendranath, Alvin; Neiva, Rodrigo; Marão, Heloisa F; Tovar, Nick; Bonfante, Estevam A; Janal, Malvin N; Castellano, Arthur; Coelho, Paulo G

This study evaluated whether simplified drilling protocols would provide comparable histologic and histomorphometric results to conventional drilling protocols at a low rotational speed. A total of 48 alumina-blasted and acid-etched Ti-6Al-4V implants with two diameters (3.75 and 4.2 mm, n = 24 per group) were bilaterally placed in the tibiae of 12 dogs, under a low-speed protocol (400 rpm). Within the same diameter group, half of the implants were inserted after a simplified drilling procedure (pilot drill + final diameter drill), and the other half were placed using the conventional drilling procedure. After 3 and 5 weeks, the animals were euthanized, and the retrieved bone-implant samples were subjected to nondecalcified histologic sectioning. Histomorphology, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) analysis were performed. Histology showed that new bone was formed around implants, and inflammation or bone resorption was not evident for both groups. Histomorphometrically, when all independent variables were collapsed over drilling technique, no differences were detected for BIC and BAFO; when drilling technique was analyzed as a function of time, the conventional groups reached statistically higher BIC and BAFO at 3 weeks, but comparable values between techniques were observed at 5 weeks; 4.2-mm implants obtained statistically higher BAFO relative to 3.75-mm implants. Based on the present methodology, the conventional technique improved bone formation at 3 weeks, and narrower implants were associated with less bone formation.

Can Time of Implant Placement influence Bone Remodeling?

PubMed

Rafael, Caroline F; Passoni, Bernardo; Araúio, Carlos; de Araúio, Maria A; Benfatti, César; Volpato, Claudia

2016-04-01

Since the alveolar process is tissue "dental dependent," after the extraction of the dental element, this process suffers some degree of atrophy during the healing process, which can be reduced with the installation of immediate implants, aiming to maintain the original bone architecture. The aim of this study was to investigate the influence of the time of implant placement on bone formation around them. Seven dogs were selected and randomly divided into two groups: Group 1, where implants were placed immediately after extraction of two lower premolars without flap elevation, and group 2, where implants were delayed by 4 months after extractions. Each group received 14 implants, and 4 months after the second surgery, the samples were processed and analyzed histomorphometrically. A mean average analysis and the Kruskal-Wallis test (p < 0.05) were performed. The buccal bone-implant contact (BIC) mean average was found larger in immediate implants (42.61%) compared with delayed implants (37.69%). Group 1 had statistically higher outcomes in bone formation and BIC on the buccal bone wall. It was concluded that performing immediate implants with the palatal approach technique and leaving a buccal GAP enables a higher or at least equal rate to BIC and bone area around them, when compared with delayed implants. Actually, the patients and dentists want to do a shorter treatment with satisfactory results, but it is necessary to understand whether different times of implant placement can influence the results and longevity of the treatment.

Improved osseointegration with as-built electron beam melted textured implants and improved peri‑implant bone volume with whole body vibration.

PubMed

Ruppert, David S; Harrysson, Ola L A; Marcellin-Little, Denis J; Dahners, Laurence E; Weinhold, Paul S

2018-06-11

Transcutaneous osseointegrated prostheses provide stable connections to the skeleton while eliminating skin lesions experienced with socket prosthetics. Additive manufacturing can create custom textured implants capable of interfacing with amputees' residual bones. Our objective was to compare osseointegration of textured surface implants made by electron beam melting (EBM), an additive manufacturing process, to machine threaded implants. Whole body vibration was investigated to accelerate osseointegration. Two cohorts of Sprague-Dawley rats received bilateral, titanium implants (EBM vs. threaded) in their tibiae. One cohort comprising five groups vibrated at 45 Hz: 0.0 (control), 0.15, 0.3, 0.6 or 1.2 g was followed for six weeks. Osseointegration was evaluated through torsional testing and bone volume fraction (BV/TV). A second cohort, divided into two groups (control and 0.6 g), was followed for 24 days and evaluated for resonant frequency, bone-implant contact (BIC) and fluorochrome labeling. The EBM textured implants exhibited significantly improved mechanical stability independent of vibration, highlighting the benefits of using EBM to produce custom textured surfaces. Bone formation on and around the EBM textured implants increased compared to machined implants, as seen by BIC and fluorescence. No difference in torque, BIC or fluorescence among vibration levels was detected. BV/TV significantly increased at 0.6 g compared to control for both implant types. Copyright © 2018 IPEM. Published by Elsevier Ltd. All rights reserved.

Performance profiling for brachytherapy applications

NASA Astrophysics Data System (ADS)

Choi, Wonqook; Cho, Kihyeon; Yeo, Insung

2018-05-01

In many physics applications, a significant amount of software (e.g. R, ROOT and Geant4) is developed on novel computing architectures, and much effort is expended to ensure the software is efficient in terms of central processing unit (CPU) time and memory usage. Profiling tools are used during the evaluation process to evaluate the efficiency; however, few such tools are able to accommodate low-energy physics regions. To address this limitation, we developed a low-energy physics profiling system in Geant4 to profile the CPU time and memory of software applications in brachytherapy applications. This paper describes and evaluates specific models that are applied to brachytherapy applications in Geant4, such as QGSP_BIC_LIV, QGSP_BIC_EMZ, and QGSP_BIC_EMY. The physics range in this tool allows it to be used to generate low energy profiles in brachytherapy applications. This was a limitation in previous studies, which caused us to develop a new profiling tool that supports profiling in the MeV range, in contrast to the TeV range that is supported by existing high-energy profiling tools. In order to easily compare the profiling results between low-energy and high-energy modes, we employed the same software architecture as that in the SimpliCarlo tool developed at the Fermilab National Accelerator Laboratory (FNAL) for the Large Hadron Collider (LHC). The results show that the newly developed profiling system for low-energy physics (less than MeV) complements the current profiling system used for high-energy physics (greater than TeV) applications.

Effects of Thread Depth in the Neck Area on Peri-Implant Hard and Soft Tissues: An Animal Study.

PubMed

Sun, Shan-Pao; Lee, Dong-Won; Yun, Jeong-Ho; Park, Kwang-Ho; Park, Kwang-Bum; Moon, Ik-Sang

2016-11-01

Implants with deep thread depth have been developed for the purpose of increasing total implant surface area. However, effects of implant thread depth remain controversial. The aim of this study is to examine effects of thread depth on peri-implant tissues in terms of bone-implant contact (BIC), bone-implant volume (BIV), and hard and soft tissue dimensions using comprehensive analyses, including microcomputed tomography (micro-CT). Five beagle dogs received experimental intramandibular implants 3 months after removal of their premolars and first molars (P 2 , P 3 , P 4 , and M 1 ). Two different types of implants were installed in each animal: deep threaded (DT) and shallow threaded (ST). Resonance frequency testing was performed on the day of implantation as well as 4 and 8 weeks after implantation. Intraoral radiography, micro-CT, and histomorphometry were used to evaluate peri-implant tissues 4 and 8 weeks after implantation. There were no significant differences in resonance frequency test results between the two groups. Although radiographic analysis showed no group differences, micro-CT (P = 0.01) and histomorphometry (P = 0.003) revealed the DT group had significantly lower BIC values than the ST group at 4 weeks. However, by 8 weeks, BIC values of the two groups did not differ significantly. No significant differences in BIV or soft tissue height were observed between the two groups at either time point. DT implants showed no benefits over ST implants when inserted in dog mandibles.

Effects of thread size in the implant neck area on peri-implant hard and soft tissues: an animal study.

PubMed

Choi, Jay-Yong; Moon, Ik-Sang; Yun, Jeong-Ho; Park, Kwang-Ho; Huh, Jong-Ki; Lee, Dong-Won

2016-09-01

The aim of this animal study was to examine the effects of thread size in the implant neck area on peri-implant tissues in terms of BIC and hard- and soft-tissue dimensions. Six Beagle dogs received experimental implants in the mandible 3 month after the removal of premolars and first molars (P2, P3, P4, and M1). Two different types of implants were installed in each animal: Anyone microthread(®) as Group 1 and Anyone(®) as Group 2. Resonance frequency test, intraoral radiography, micro-CT, and histomorphometry were used to evaluate peri-implant tissue after implantation periods of 4 and 8 weeks. No remarkable complication was observed during the healing period in either group. Resonance frequency testing revealed no significant difference between groups. In radiographic evaluation, Group 2 showed more bone loss than Group 1. However, this difference was not statistically significant. In the micro-CT analysis, BIC and BIV values and soft-tissue height were not significant in both groups. Histological analysis revealed no significant difference in BIC ratio, bone density, or bone loss between groups. However, soft-tissue height was significantly greater in Group 2 than in Group 1 (P = 0.0004). No difference in peri-implant hard or soft tissues was observed according to thread size in the implant neck area. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

High-K granites of the Rum Jungle Complex, N-Australia: Insights into the Late Archean crustal evolution of the North Australian Craton

NASA Astrophysics Data System (ADS)

Drüppel, K.; McCready, A. J.; Stumpfl, E. F.

2009-08-01

The Late Archean (c. 2.54-2.52 Ga) high-K granitoids of the Rum Jungle Complex, Northern Australia, display the igneous mineral assemblage of K-feldspar, quartz, plagioclase, biotite, and magnetite, and accessories such as zircon, monazite, titanite, allanite, apatite, and ilmenite. The granites underwent a variably severe greenschist facies alteration and associated deformation during the Barramundi Orogeny (1.88-1.85 Ga). The K-rich granitoids have variable compositions, mainly comprising syenogranite and quartz-monzonite. They can be subdivided into two major groups, (1) felsic granites and (2) intermediate to felsic granites, quartz-monzonites, and diorite. The felsic group (69-76 wt.% SiO 2) shares many features with typical Late Archean potassic granites. They are K- and LILE-rich and show marked depletion in Sr and Eu and the high field strength elements (HFSE), particularly Nb and Ti, relative to LILE and LREE. Compared to the average upper crust they have anomalously high Th (up to 123 ppm) and U (up to 40 ppm). The intermediate to felsic group (56-69 wt.% SiO 2) differs from the felsic group in having weakly lower Th and U but higher Mg#, Ti, Ba, Sr, Ni, Cr and REE, with a less pronounced negative Eu anomaly. This group displays well-defined trends in Harker diagrams, involving a negative correlation of Si with Sr, Ca, Na, and P whereas K, Rb, and Ba increase in the same direction, suggesting fractional crystallization of feldspar was more prominent than in the felsic suite. The mineralogical and geochemical characteristics of the felsic group are consistent with granite formation by intracrustal melting of plagioclase-rich igneous protoliths, probably of tonaltic to granodioritic composition, at moderate crustal levels. The intermediate to felsic granites, on the other hand, appear to be the products of mantle-crust interaction, possibly by melting of or mixing with more mafic igneous rocks. As evidenced by the presence of older inherited zircons crustal recycling of a pre-greenstone crust of the North Australian Craton of > 3.5 Ga played an important role in the formation of the Late Archean granites of the Rum Jungle Complex.

Igneous stratigraphy and rock-types from a deep transect of the gabbroic lower crust of the Atlantis Bank core complex (SW Indian Ridge): preliminary results from IODP Expedition 360

NASA Astrophysics Data System (ADS)

Sanfilippo, A.; France, L.; Ghosh, B.; Liu, C. Z.; Morishita, T.; Natland, J. H.; Dick, H. J.; MacLeod, C. J.; Expedition 360 Scientists, I.

2016-12-01

International Ocean Discovery Program (IODP) Expedition 360 represents the first leg of a multi-phase drilling programme ('SloMo' project) aimed at investigating the nature of the lower crust and Moho at slow spreading ridges. As an initial phase of the SloMo project, IODP Exp. 360 intended to recover a representative transect of the lower oceanic crust formed at Atlantis Bank, an oceanic core complex on the SW Indian Ridge. During this expedition, 89 cores of gabbroic rocks were recovered at Hole U1473A, drilled to 789.7 m below seafloor. This hole was subsequently deepened to 809.4 mbsf during transit Expedition 362T, which recovered additional 7 cores. The gabbroic section recovered at Hole U1473A consists of several types of gabbro, diabase, and felsic veins. The main lithology is dominated by olivine gabbro (76.5% in abundance), followed by gabbro containing 1-2% oxide (9.5%), gabbro with >2% oxide (7.4%), gabbro sensu stricto (5.1%), felsic veins (1.5%) and diabase (<0.5%). The different lithologies appear randomly distributed throughout the section, although oxide abundance seems to decrease slightly downhole, except for the lowermost intervals where oxide gabbros are more abundant. Based on changes in rock types, grain size, texture, and the occurrence of felsic material, we identified eight lithologic units, which locally define separate geochemical trends. Each unit is characterized by meter-scale heterogeneity which classically characterizes gabbros formed at slow spreading ridges. Reaction textures in olivine gabbros, crosscutting relationships between oxide gabbros and host rocks, the presence of intrusive to sutured contacts, igneous layering and the widespread occurrence of felsic veins and segregations indicate that the evolution of this section was controlled by complicated interactions of magmatic processes, e.g., fractional crystallization, melt-rock reaction, late-stage melt migration, which were active in a crystal mush formed by multiple injections of magma. This contribution describes the main features of these rocks and discusses the complexity of the igneous processes producing this 800 m-long transect of oceanic crust that was formed in a robust magmatic segment of an ultraslow spreading ridge.

Possible petrogenetic associations among igneous components in North Massif soils: Evidence in 2-4 mm soil particles from 76503

NASA Technical Reports Server (NTRS)

Jolliff, Bradley L.; Bishop, Kaylynn M.; Haskin, Larry A.

1992-01-01

Studies of Apollo 17 highland igneous rocks and clasts in breccias from the North and South Massifs have described magnesian troctolite, norite, anorthositic gabbro, dunite, spinel cataclasites, and granulitic lithologies that may have noritic anothosite or anorthositic norite/gabbro as igneous precursors, and have speculated on possible petrogenetic relationships among these rock types. Mineral compositions and relative proportions of plagioclase and plagioclase-olivine particles in samples 76503 indicate that the precursor lithology of those particles were troctolitic anorthosite, not troctolite. Mineral and chemical compositions of more pyroxene-rich, magnesian breccias and granulites in 76503 indicate that their precursor lithology was anorthositic norite/gabbro. The combination of mineral compositions and whole-rock trace-element compositional trends supports a genetic relationship among these two groups as would result from differentiation of a single pluton. Although highland igneous lithologies in Apollo 17 materials have been described previously, the proportions of different igneous lithologies present in the massifs, their frequency of association, and how they are related are not well known. We consider the proportions of, and associations among, the igneous lithologies found in a North Massif soil, which may represent those of the North Massif or a major part of it.

Influence of crystallised igneous intrusions on fault nucleation and reactivation during continental extension

NASA Astrophysics Data System (ADS)

Magee, Craig; McDermott, Kenneth G.; Stevenson, Carl T. E.; Jackson, Christopher A.-L.

2014-05-01

Continental rifting is commonly accommodated by the nucleation of normal faults, slip on pre-existing fault surfaces and/or magmatic intrusion. Because crystallised igneous intrusions are pervasive in many rift basins and are commonly more competent (i.e. higher shear strengths and Young's moduli) than the host rock, it is theoretically plausible that they locally intersect and modify the mechanical properties of pre-existing normal faults. We illustrate the influence that crystallised igneous intrusions may have on fault reactivation using a conceptual model and observations from field and subsurface datasets. Our results show that igneous rocks may initially resist failure, and promote the preferential reactivation of favourably-oriented, pre-existing faults that are not spatially-associated with solidified intrusions. Fault segments situated along strike from laterally restricted fault-intrusion intersections may similarly be reactivated. This spatial and temporal control on strain distribution may generate: (1) supra-intrusion folds in the hanging wall; (2) new dip-slip faults adjacent to the igneous body; or (3) sub-vertical, oblique-slip faults oriented parallel to the extension direction. Importantly, stress accumulation within igneous intrusions may eventually initiate failure and further localise strain. The results of our study have important implications for the structural of sedimentary basins and the subsurface migration of hydrocarbons and mineral-bearing fluids.

A major light rare-earth element (LREE) resource in the Khanneshin carbonatite complex, southern Afghanistan

USGS Publications Warehouse

Tucker, Robert D.; Belkin, Harvey E.; Schulz, Klaus J.; Peters, Stephen G.; Horton, Forrest; Buttleman, Kim; Scott, Emily R.

2012-01-01

The rapid rise in world demand for the rare-earth elements (REEs) has expanded the search for new REE resources. We document two types of light rare-earth element (LREE)-enriched rocks in the Khanneshin carbonatite complex of southern Afghanistan: type 1 concordant seams of khanneshite-(Ce), synchysite-(Ce), and parisite-(Ce) within banded barite-strontianite alvikite, and type 2 igneous dikes of coarse-grained carbonatite, enriched in fluorine or phosphorus, containing idiomorphic crystals of khanneshite-(Ce) or carbocernaite. Type 1 mineralized barite-strontianite alvikite averages 22.25 wt % BaO, 4.27 wt % SrO, and 3.25 wt % ∑ LREE2O3 (sum of La, Ce, Pr, and Nd oxides). Type 2 igneous dikes average 14.51 wt % BaO, 5.96 wt % SrO, and 3.77 wt % ∑ LREE2O3. A magmatic origin is clearly indicated for the type 2 LREE-enriched dikes, and type 1 LREE mineralization probably formed in the presence of LREE-rich hydrothermal fluid. Both types of LREE mineralization may be penecontemporaneous, having formed in a carbonate-rich magma in the marginal zone of the central vent, highly charged with volatile constituents (i.e., CO2, F, P2O5), and strongly enriched in Ba, Sr, and the LREE. Based on several assumptions, and employing simple geometry for the zone of LREE enrichment, we estimate that at least 1.29 Mt (million metric tonnes) of LREE2O3 is present in this part of the Khanneshin carbonatite complex.

Alkaline igneous rocks of Magnet Cove, Arkansas: Mineralogy and geochemistry of syenites

USGS Publications Warehouse

Flohr, M.J.K.; Ross, M.

1990-01-01

Syenites from the Magnet Cove alkaline igneous complex form a diverse mineralogical and geochemical suite. Compositional zoning in primary and late-stage minerals indicates complex, multi-stage crystallization and replacement histories. Residual magmatic fluids, rich in F, Cl, CO2 and H2O, reacted with primary minerals to form complex intergrowths of minerals such as rinkite, fluorite, V-bearing magnetite, F-bearing garnet and aegirine. Abundant sodalite and natrolite formed in pegmatitic segregations within nepheline syenite where Cl- and Na-rich fluids were trapped. During autometasomatism compatible elements such as Mn, Ti, V and Zr were redistributed on a local scale and concentrated in late-stage minerals. Early crystallization of apatite and perovskite controlled the compatible behavior of P and Ti, respectively. The formation of melanite garnet also affected the behaviour of Ti, as well as Zr, Hf and the heavy rare-earth elements. Pseudoleucite syenite and garnet-nepheline syenite differentiated along separate trends, but the two groups are related to the same parental magma by early fractionation of leucite, the presumed precursor of intergrowths of K-feldspar and nepheline. The Diamond Jo nepheline syenite group defines a different differentiation trend. Sphene-nepheline syenite, alkali syenite and several miscellaneous nepheline syenites do not consistently plot with the other syenite groups or each other on element and oxide variation diagrams, indicating that they were derived from still other parental syenite magmas. Mineral assemblages indicate that relatively high f{hook};O2, at or above the fayalite-magnetite-quartz buffer, prevailed throughout the crystallization history of the syenites. ?? 1990.

Gravimetric and magnetic fabric study of the Sintra Igneous complex: laccolith-plug emplacement in the Western Iberian passive margin

NASA Astrophysics Data System (ADS)

Terrinha, Pedro; Pueyo, Emilio L.; Aranguren, Aitor; Kullberg, José Carlos; Kullberg, Maria Carla; Casas-Sainz, Antonio; Azevedo, Maria do Rosário

2017-12-01

The geometry and emplacement of the 96 km2, Late Cretaceous Sintra Igneous complex (SIC, ca. 80 Ma) into the West Iberian passive margin is presented, based on structural data, gravimetric modeling, and magnetic fabrics. A granite laccolith ( 76 km2, < 1 km thick, according to gravimetric modeling) surrounds a suite of gabbro-diorite-syenite plugs ( 20 km2, 4 km deep) and is encircled by cone sheets and radial dykes. Anisotropy of Magnetic Susceptibility was interpreted from 54 sites showing fabrics of para- and ferro-magnetic origin. Most fabrics can be interpreted to have a magmatic origin, according to the scarcity of solid-state deformation in most part of the massif. Magnetic foliations are shallowly dipping in the granite laccolith and contain a sub-horizontal ENE-WSW lineation. The gabbro-syenite body displays concentric magnetic foliations having variable dips and steeply-plunging lineations. The SIC can be interpreted to be intruded along an NNW-SSE, 200 km-long fault, perpendicular to the magnetic lineation within the laccolith, and was preceded by the intrusion of basic sills and plugs. The SIC intruded the Mesozoic series of the Lusitanian Basin during the post-rift, passive margin stage, and its geometry was only slightly modified during the Paleogene inversion that resulted in thrusting of the northern border of the intrusion over the country rocks.

A Review of Land and Stream Classifications in Support of Developing a National Ordinary High Water Mark (OHWM) Classification

DTIC Science & Technology

2014-08-01

northern Minnesota, Wisconsin, and Michigan. This region is dominated by igneous and metamorphic rock , with some sedimentary units and a generally...faulted igneous and metamorphic rocks and folded sediments in the Appalachians and flat-lying sedimentary rocks in the Plateau and Catskills. Streams...mixture of igneous, metamorphic , and sedimentary rocks . High relief and coarse materials are typical. Riffle and pool development is largely

The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Thermal histories of Mercury and the Moon. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Leake, M. A.

1982-01-01

To determine a planet's thermal history, a wide range of data is necessary. These data include remote sensing results, photogeologic evidence, magnetic field and remanent magnetization data, composition and ages of samples, and physical parameters of the planet and its orbit. Few of these data form unambiguous constraints for thermal models of Mercury. Igneous Chronology as the time history of the differentiation and igneous activity, is defined. Igneous Chronology is used here in the sense of the apparent igneous or relative chronology of geologic events, such as plains formation (through whatever mechanism) relative to the crater production and tectonic history (lineament and scarp formation).

Under the sea: microbial life in volcanic oceanic crust.

PubMed

Edwards, Katrina J; Wheat, C Geoffrey; Sylvan, Jason B

2011-09-06

Exploration of the microbiology in igneous, 'hard rock' oceanic crust represents a major scientific frontier. The igneous crust harbours the largest aquifer system on Earth, most of which is hydrologically active, resulting in a substantial exchange of fluids, chemicals and microorganisms between oceanic basins and crustal reservoirs. Study of the deep-subsurface biosphere in the igneous crust is technically challenging. However, technologies have improved over the past decade, providing exciting new opportunities for the study of deep-seated marine life, including in situ and cross-disciplinary experimentation in microbiology, geochemistry and hydrogeology. In this Progress article, we describe the recent advances, available technology and remaining challenges in the study of the marine intraterrestrial microbial life that is harboured in igneous oceanic crust.

Age and tectonomagmatic setting of the Eocene Çöpler-Kabataş magmatic complex and porphyry-epithermal Au deposit, East Central Anatolia, Turkey

NASA Astrophysics Data System (ADS)

İmer, Ali; Richards, Jeremy P.; Creaser, Robert A.

2013-06-01

The Çöpler epithermal Au deposit and related subeconomic porphyry Cu-Au deposit is hosted by the middle Eocene Çöpler-Kabataş magmatic complex in central eastern Anatolia. The intrusive rocks of the complex were emplaced into Late Paleozoic-Mesozoic metamorphosed sedimentary basement rocks near the northeastern margin of the Tauride-Anatolide Block. Igneous biotite from two samples of the magmatic complex yielded 40Ar/39Ar plateau ages of 43.75 ± 0.26 Ma and 44.19 ± 0.23, whereas igneous hornblende from a third sample yielded a plateau age of 44.13 ± 0.38. These ages closely overlap with 40Ar/39Ar ages of hydrothermal sericite (44.44 ± 0.28 Ma) and biotite (43.84 ± 0.26 Ma), and Re-Os ages from two molybdenite samples (44.6 ± 0.2 and 43.9 ± 0.2 Ma) suggesting a short-lived (<1 my) magmatic and hydrothermal history at Çöpler. No suitable minerals were found that could be used to date the epithermal system, but it is inferred to be close in age to the precursor porphyry system. The Çöpler-Kabataş intrusive rocks show I-type calc-alkaline affinities. Their normalized trace element patterns show enrichments in large ion lithophile and light rare earth elements and relative depletions in middle and heavy rare earth elements, resembling magmas generated in convergent margins. However, given its distance from the coeval Eocene Maden-Helete volcanic arc, the complex is interpreted to be formed in a back-arc setting, in response to Paleocene slab roll-back and upper-plate extension. The tectonomagmatic environment of porphyry-epithermal mineralization at Çöpler is comparable to some other isolated back-arc porphyry systems such as Bajo de la Alumbrera (Argentina) or Bingham Canyon (USA).

Re-examining the doming uplift model of Emeishan Large Igneous Province (SW China): evidence from high-resolution conodont biostratigraphy and sedimentology

NASA Astrophysics Data System (ADS)

Yadong, S.; Wignall, P. B.; Ali, J. R.; Widdowson, M.; Bond, D. P.; Lai, X.

2010-12-01

The Middle Permian Emeishan large igneous province of SW China is regard by many as providing the quintessential example of kilometre-scale pre-eruption domal uplift associated with mantle plume impingement on the base of the lithosphere. The key line of evidence for this has been the purported deep erosion profile of the Maokou Formation platform carbonates that lie directly beneath the central and inner parts of the volcanic pile. We have tested this interpretation by carrying out conodont age dating and facies analysis on the uppermost beds of the Maokou Formation across these central regions, together with the limestones that are intercalated within the basal lava flows. The investigated sections (from Yunnan, Sichuan, Guizhou and Guangxi provinces) span locations from directly below the centre of the igneous province, to several hundred kilometres beyond its margins. The results show that eruptions began in the Jinogondolella altudaensis Zone (~263 Ma) of the Middle Capitanian Stage, and subsequently greatly increased in extent and volume in the J. xuanhanensis Zone (~262 Ma) (Sun et al., 2010). Most importantly, at most locations within the terrain, and many locations beyond its margins, there appears to have been platform subsidence (not uplift) with deep-water facies (radiolarian cherts, submarine fans) developing immediately prior to the initial volcanism (J. altudaensis Zone). Accordingly, pre-eruption uplift must have been muted because over large areas of the terrain the basal flows rest conformably on a variety of Maokou sedimentary facies. By contrast, the clearest evidence for an emergence surface occurs around the flanks of the province in the J. xuanhanensis Zone. This is after the initial onset of eruptions, and coincides with the regional eustatic fall (Sun et al., 2010). Furthermore, pillow lavas, hydromagmatic deposits and interflow limestone/reef packages are commonly seen around the terrain indicating a strong marine influence at the early stages of volcanism, which is itself further evidence against kilometre-scale up-doming (Wignall et al., 2009, Ali et al., 2010, Sun et al., 2010). We argue that the mantle plume which generated the Emeishan large igneous province 260-odd million years ago, resulted in a complex interaction between plume and overlying lithosphere, and was characterized by localized minor uplift and subsidence. References: Ali et al., 2010. Emeishan Large igneous Province (SW China) and the mantle plume up-doming hypothesis. J. Geol. Soc. Lond. 167, 953-959. Sun et al., 2010. Dating the onset and nature of the Middle Permian Emeishan large igneous province eruptions in SW China using conodont biostratigraphy and its bearing on mantle plume uplift models. Lithos doi: 10.1016/j.lithos.2010.05.012. Wignall et al., 2009. Volcanism, Mass Extinction, and Carbon Isotope Fluctuations in the Middle Permian of China. Science 324, 1179-1182.

Sources of metals in the Porgera gold deposit, Papua New Guinea: Evidence from alteration, isotope, and noble metal geochemistry

NASA Astrophysics Data System (ADS)

Richards, Jeremy P.; McCulloch, Malcolm T.; Chappell, Bruce W.; Kerrich, Robert

1991-02-01

The Porgera gold deposit is spatially and temporally associated with the Late Miocene, mafic, alkalic, epizonal Porgera Intrusive Complex (PIC), located in the highlands of Papua New Guinea (PNG). The highlands region marks the site of a Tertiary age continent-island-arc collision zone, located on the northeastern edge of the Australasian craton. The PIC was emplaced within continental crust near the Lagaip Fault Zone, which represents an Oligocene suture between the craton and volcano-sedimentary rocks of the Sepik terrane. Magmatism at Porgera probably occurred in response to the Late Miocene elimination of an oceanic microplate, and subsequent Early Pliocene collision between the craton margin and an arc system located on the Bismarck Sea plate. Gold mineralization occurred within 1 Ma of the time of magmatism. Metasomatism accompanying early disseminated Au mineralization in igneous host rocks resulted in additions of K, Rb, Mn, S, and CO 2, and depletions of Fe, Mg, Ca, Na, Ba, and Sr; rare-earth and high-field-strength elements remained largely immobile. Pervasive development of illite-K-feldspar-quartz-carbonate alteration assemblages suggests alteration by mildly acidic, 200 to 350°C fluids, at high water/ rock ratios. Strontium and lead isotopic compositions of minerals from early base-metal sulphide veins associated with K-metasomatism, and later quartz-roscoelite veins carrying abundant free gold and tellurides, are remarkably uniform (e.g., 87Sr /86Sr = 0.70745 ± 0.00044 [n = 10] , 207Pb /204Pb = 15.603 ± 0.004 [n = 15] ). These compositions fall between those of unaltered igneous and sedimentary host rocks, and specifically sedimentary rocks from the Jurassic Om Formation which underlies the deposit (igneous rocks: 87Sr /86Sr ≈ 0.7035 , 207Pb /204Pb ≈ 15.560 ; Om Formation: 87Sr /86Sr |t~ 0.7153 , 207Pb /204Pb ≈ 15.636 ). It is therefore suggested that the hydrothermal fluids acquired their Sr and Pb isotopic signatures by interaction with, or direct derivation from, a plutonic root of the PIC and host sedimentary rocks of the Om Formation. It is likely that Au was also derived from one or both of these two sources. Concentrations of Au in unaltered igneous and sedimentary rocks from Porgera (≤10 ppb Au) do not indicate that either lithology represents a significantly enriched protore, although Au and platinum-group element (PGE) abundances in the igneous rocks suggest a mild primary magmatic enrichment of Au relative to the PGE (average [ Au/( Pt + Pd)] mantlenormalized = 14.0 ± 6.5 [ n = 8]). Evidence that the Porgera magmas were rich in volatiles permits speculation that Au may have been concentrated in a magmatic fluid phase, but alternative possibilities such as derivation of Au by hydrothermal leaching of solidified igneous materials or sedimentary rocks cannot be excluded at this time.

P-T-t conditions, Nd and Pb isotopic compositions and detrital zircon geochronology of the Massabesic Gneiss Complex, New Hampshire: isotopic and metamorphic evidence for the identification of Gander basement, central New England

USGS Publications Warehouse

Dorais, Michael J.; Wintsch, Robert P.; Kunk, Michael J.; Aleinikoff, John; Burton, William; Underdown, Christine; Kerwin, Charles M.

2012-01-01

We present new evidence for the assignment of the Neoproterozoic Massabesic Gneiss Complex of New Hampshire to the Gander terrane rather than the Avalon terrane. The majority of Avalonian (sensu stricto) igneous and meta-igneous rocks as defined in Maritime Canada have positive whole-rock ɛNd compared to more negative values for Gander rocks, although there is a region of overlap in ɛNd between the two terranes. Our samples from areas in Connecticut previously thought to be Avalonian and samples from the Willimantic dome have the same isotopic signatures as Maritime Canada Avalon. In contrast, samples from the Clinton dome of southern Connecticut plots exclusively in the Gander field. The majority of the orthogneiss samples from Lyme dome (coastal Connecticut), Pelham dome (central Massachusetts) and Massabesic Gneiss Complex also plot in the Gander field, with a few samples plotting in the overlap zone between Gander and Avalon. U-Pb age distributions of detrital zircon populations from quartzites from the Massabesic Gneiss Complex more closely approximate the data from the Lyme Dome rather than Avalon. Additionally, the similarity of the P-T-t path for the rocks of the Massabesic Gneiss Complex (established by thermobarometry and 40Ar/39Ar dating of amphibole, muscovite, biotite and K-feldspar) with that established in the Ganderian Lyme dome of southern Connecticut strengthens the assignment of these rocks to a single Gander block that docked to Laurentia during the Salinic Orogeny. The identification of Ganderian isotopic signatures for these rocks all of which show evidence for Alleghanian metamorphism, supports the hypothesis that Neoproterozoic Gander lower crustal rocks underlie southern New Hampshire, Massachusetts, and Connecticut, and that all rocks of the overlying Central Maine trough that largely escaped high-grade Alleghanian metamorphism are allochthonous. We suggest that during the Alleghanian, the docking of Gondwana caused Avalon to wedge into Gander, metamorphosing and partially melting the Massabesic Gneiss Complex to the observed P-T-t conditions, with the complex forming an uplifted sheet that was back-thrusted over the Avalonian wedge.

Redetermination of 2-methyl-4-nitro­pyridine N-oxide

PubMed Central

Peukert, Max; Seichter, Wilhelm; Weber, Edwin

2014-01-01

An improved crystal structure of the title compound, C6H6N2O3, is reported. The structure, previously solved [Li et al. (1987 ▶). Jiegou Huaxue (Chin. J. Struct. Chem.), 6, 20–24] in the ortho­rhom­bic space group Pca21 and refined to R = 0.067, has been solved in the ortho­rhom­bic space group Pbcm with data of enhanced quality, giving an improved structure (R = 0.0485). The mol­ecule adopts a planar conformation with all atoms lying on a mirror plane. The crystal structure is composed of mol­ecular sheets extending parallel to the ab plane and connected via C—H⋯O contacts involving ring H atoms and O atoms of the N-oxide and nitro groups, while van der Waals forces consolidate the stacking of the layers. PMID:24826136

RSQRT: AN HEURISTIC FOR ESTIMATING THE NUMBER OF CLUSTERS TO REPORT.

PubMed

Carlis, John; Bruso, Kelsey

2012-03-01

Clustering can be a valuable tool for analyzing large datasets, such as in e-commerce applications. Anyone who clusters must choose how many item clusters, K, to report. Unfortunately, one must guess at K or some related parameter. Elsewhere we introduced a strongly-supported heuristic, RSQRT, which predicts K as a function of the attribute or item count, depending on attribute scales. We conducted a second analysis where we sought confirmation of the heuristic, analyzing data sets from theUCImachine learning benchmark repository. For the 25 studies where sufficient detail was available, we again found strong support. Also, in a side-by-side comparison of 28 studies, RSQRT best-predicted K and the Bayesian information criterion (BIC) predicted K are the same. RSQRT has a lower cost of O(log log n) versus O(n(2)) for BIC, and is more widely applicable. Using RSQRT prospectively could be much better than merely guessing.

RSQRT: AN HEURISTIC FOR ESTIMATING THE NUMBER OF CLUSTERS TO REPORT

PubMed Central

Bruso, Kelsey

2012-01-01

Clustering can be a valuable tool for analyzing large datasets, such as in e-commerce applications. Anyone who clusters must choose how many item clusters, K, to report. Unfortunately, one must guess at K or some related parameter. Elsewhere we introduced a strongly-supported heuristic, RSQRT, which predicts K as a function of the attribute or item count, depending on attribute scales. We conducted a second analysis where we sought confirmation of the heuristic, analyzing data sets from theUCImachine learning benchmark repository. For the 25 studies where sufficient detail was available, we again found strong support. Also, in a side-by-side comparison of 28 studies, RSQRT best-predicted K and the Bayesian information criterion (BIC) predicted K are the same. RSQRT has a lower cost of O(log log n) versus O(n2) for BIC, and is more widely applicable. Using RSQRT prospectively could be much better than merely guessing. PMID:22773923

B-spline parameterization of the dielectric function and information criteria: the craft of non-overfitting

NASA Astrophysics Data System (ADS)

Likhachev, Dmitriy V.

2017-06-01

Johs and Hale developed the Kramers-Kronig consistent B-spline formulation for the dielectric function modeling in spectroscopic ellipsometry data analysis. In this article we use popular Akaike, corrected Akaike and Bayesian Information Criteria (AIC, AICc and BIC, respectively) to determine an optimal number of knots for B-spline model. These criteria allow finding a compromise between under- and overfitting of experimental data since they penalize for increasing number of knots and select representation which achieves the best fit with minimal number of knots. Proposed approach provides objective and practical guidance, as opposite to empirically driven or "gut feeling" decisions, for selecting the right number of knots for B-spline models in spectroscopic ellipsometry. AIC, AICc and BIC selection criteria work remarkably well as we demonstrated in several real-data applications. This approach formalizes selection of the optimal knot number and may be useful in practical perspective of spectroscopic ellipsometry data analysis.

Consistent model identification of varying coefficient quantile regression with BIC tuning parameter selection

PubMed Central

Zheng, Qi; Peng, Limin

2016-01-01

Quantile regression provides a flexible platform for evaluating covariate effects on different segments of the conditional distribution of response. As the effects of covariates may change with quantile level, contemporaneously examining a spectrum of quantiles is expected to have a better capacity to identify variables with either partial or full effects on the response distribution, as compared to focusing on a single quantile. Under this motivation, we study a general adaptively weighted LASSO penalization strategy in the quantile regression setting, where a continuum of quantile index is considered and coefficients are allowed to vary with quantile index. We establish the oracle properties of the resulting estimator of coefficient function. Furthermore, we formally investigate a BIC-type uniform tuning parameter selector and show that it can ensure consistent model selection. Our numerical studies confirm the theoretical findings and illustrate an application of the new variable selection procedure. PMID:28008212

Barberton greenstone belt volcanism: Succession, style and petrogenesis

NASA Technical Reports Server (NTRS)

Byerly, G. R.; Lowe, D. R.

1986-01-01

The Barberton Mountain Land is an early Archean greenstone belt along the eastern margin of the Kaapvaal Craton of southern Africa. Detailed mapping in the southern portion of the belt leads to the conclusion that a substantial thickness is due to original deposition of volcanics and sediments. In the area mapped, a minimum thickness of 12km of predominantly mafic and ultramafic volcanics comprise the Komati, Hooggenoeg, and Kromberg Formations of the Onverwacht Group, and at least one km of predominantly pyroclastic and epiclastic sediments derived from dacitic volcanics comprise the Fig Tree Group. The Barberton greenstone belt formed primarily by ultramafic to mafic volcanism on a shallow marine platform which underwent little or no concurrent extension. Vents for this igneous activity were probably of the non-constructional fissure type. Dacitic volcanism occurred throughout the sequence in minor amounts. Large, constructional vent complexes were formed, and explosive eruptions widely dispersed pyroclastic debris. Only in the final stages of evolution of the belt did significant thrust-faulting occur, generally after, though perhaps overlapping with, the final stage of dacitic igneous activity. A discussion follows.

Summary of the geology and resources of uranium in the San Juan Basin and adjacent region, New Mexico, Arizona, Utah, and Colorado

USGS Publications Warehouse

Ridgley, Jennie L.; Green, M.W.; Pierson, C.T.; Finch, W.I.; Lupe, R.D.

1978-01-01

The San Juan Basin and adjacent region lie predominantly in the southeastern part of the uranium-rich Colorado Plateau of New Mexico, Arizona, Utah, and Colorado. Underlying the province are rocks of the Precambrian basement complex composed mainly of igneous and metamorphic rocks; a thickness of about 3,600 meters of generally horizontal Paleozoic, Mesozoic, and Cenozoic sedimentary rocks; and a variety of Upper Cretaceous and Cenozoic igneous rocks. Sedimentary rocks of the sequence are commonly eroded and well exposed near the present basin margins where Tertiary tectonic activity has uplifted, folded, and faulted the sequence into its present geologic configuration of basins, platforms, monoclines, and other related structural features. Sedimentary rocks of Jurassic age in the southern part of the San Juan Basin contain the largest uranium deposits in the United States, and offer the promise of additional uranium deposits. Elsewhere in the basin and the adjacent Colorado Plateau, reserves and resources of uranium are known primarily in Triassic, Jurassic, and Cretaceous strata. Only scattered occurrences of uranium are known in Paleozoic

Chemical data and variation diagrams of igneous rocks from the Timber Mountain-Oasis Valley Caldera Complex, southern Nevada

USGS Publications Warehouse

Quinlivan, W.D.; Byers, F.M.

1977-01-01

Silica variation diagrams presented here are based on 162 chemical analyses of tuffs, lavas, and intrusives, representative of volcanic centers of the Timber Mountain-Oasis Valley caldera complex and cogenetic rocks of the Silent Canyon ca1dera. Most of the volcanic units sampled are shown on the U.S. Geological Survey geologic map of the Timber Mountain caldera area (I-891) and are described in U.S. Geological Survey Professional Paper 919. Early effusives of the complex, although slightly altered, are probably chemically, and petrographically, more like the calc-alkalic Fraction Tuff (Miocene) of the northern Nellis Air Force Base Bombing and Gunnery Range to the north, whereas effusives of later Miocene age, such as the Paintbrush and Timber Mountain Tuffs, are alkali-calcic.

Photogeologic maps of the Iris SE and Doyleville SW quadrangles, Saguache County, Colorado

USGS Publications Warehouse

McQueen, Kathleen

1957-01-01

The Iris SE and Doyleville SW quadrangles, Saguache County, Colorado include part ot the Cochetopa mining district. Photogeologic maps of these quadrangles show the distribution of sedimentary rocks of Jurassic and Cretaceous age; precambrian granite, schist, and gneiss; and igneous rocks of Tertiary age. Sedimentary rocks lie on an essentially flat erosion surface on Precambrian rocks. Folds appear to be absent but faults present an extremely complex structural terrane. Uraniferous deposits occur at fault intersections in Precambriam and Mesozoic rocks.

Insights into Igneous Geochemistry from Trace Element Partitioning

NASA Technical Reports Server (NTRS)

Jones, J. H.; Hanson, B. Z.

2001-01-01

Partitioning of trivalent elements into olivine are used to explore basic issues relevant to igneous geochemistry, such as Henry's law. Additional information is contained in the original extended abstract.

Correlation analysis of air pollutant index levels and dengue cases across five different zones in Selangor, Malaysia.

PubMed

Thiruchelvam, Loshini; Dass, Sarat C; Zaki, Rafdzah; Yahya, Abqariyah; Asirvadam, Vijanth S

2018-05-07

This study investigated the potential relationship between dengue cases and air quality - as measured by the Air Pollution Index (API) for five zones in the state of Selangor, Malaysia. Dengue case patterns can be learned using prediction models based on feedback (lagged terms). However, the question whether air quality affects dengue cases is still not thoroughly investigated based on such feedback models. This work developed dengue prediction models using the autoregressive integrated moving average (ARIMA) and ARIMA with an exogeneous variable (ARIMAX) time series methodologies with API as the exogeneous variable. The Box Jenkins approach based on maximum likelihood was used for analysis as it gives effective model estimates and prediction. Three stages of model comparison were carried out for each zone: first with ARIMA models without API, then ARIMAX models with API data from the API station for that zone and finally, ARIMAX models with API data from the zone and spatially neighbouring zones. Bayesian Information Criterion (BIC) gives goodness-of-fit versus parsimony comparisons between all elicited models. Our study found that ARIMA models, with the lowest BIC value, outperformed the rest in all five zones. The BIC values for the zone of Kuala Selangor were -800.66, -796.22, and -790.5229, respectively, for ARIMA only, ARIMAX with single API component and ARIMAX with API components from its zone and spatially neighbouring zones. Therefore, we concluded that API levels, either temporally for each zone or spatio- temporally based on neighbouring zones, do not have a significant effect on dengue cases.

Characterization of an Sf-rhabdovirus-negative Spodoptera frugiperda cell line as an alternative host for recombinant protein production in the baculovirus-insect cell system.

PubMed

Maghodia, Ajay B; Geisler, Christoph; Jarvis, Donald L

2016-06-01

Cell lines derived from the fall armyworm, Spodoptera frugiperda (Sf), are widely used as hosts for recombinant protein production in the baculovirus-insect cell system (BICS). However, it was recently discovered that these cell lines are contaminated with a virus, now known as Sf-rhabdovirus [1]. The detection of this adventitious agent raised a potential safety issue that could adversely impact the BICS as a commercial recombinant protein production platform. Thus, we examined the properties of Sf-RVN, an Sf-rhabdovirus-negative Sf cell line, as a potential alternative host. Nested RT-PCR assays showed Sf-RVN cells had no detectable Sf-rhabdovirus over the course of 60 passages in continuous culture. The general properties of Sf-RVN cells, including their average growth rates, diameters, morphologies, and viabilities after baculovirus infection, were virtually identical to those of Sf9 cells. Baculovirus-infected Sf-RVN and Sf9 cells produced equivalent levels of three recombinant proteins, including an intracellular prokaryotic protein and two secreted eukaryotic glycoproteins, and provided similar N-glycosylation patterns. In fact, except for the absence of Sf-rhabdovirus, the only difference between Sf-RVN and Sf9 cells was SF-RVN produced higher levels of infectious baculovirus progeny. These results show Sf-RVN cells can be used as improved, alternative hosts to circumvent the potential safety hazard associated with the use of Sf-rhabdovirus-contaminated Sf cells for recombinant protein manufacturing with the BICS. Copyright © 2016 Elsevier Inc. All rights reserved.

Validation of Geant4 fragmentation for Heavy Ion Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolst, David; Cirrone, Giuseppe A. P.; Cuttone, Giacomo

12C ion therapy has had growing interest in recent years for its excellent dose conformity. However at therapeutic energies, which can be as high as 400 MeV/u, carbon ions produce secondary fragments. For an incident 400 MeV/u 12C ion beam, ~70% of the beam will undergo fragmentation before the Bragg Peak. The dosimetric and radiobiological impact of these fragments must be accurately characterised, as it can result in increasing the risk of secondary cancer for the patient as well as altering the relative biological effectiveness. Here, this work investigates the accuracy of three different nuclear fragmentation models available in themore » Monte Carlo Toolkit Geant4, the Binary Intranuclear Cascade (BIC), the Quantum Molecular Dynamics (QMD) and the Liege Intranuclear Cascade (INCL++). The models were benchmarked against experimental data for a pristine 400 MeV/u 12C beam incident upon a water phantom, including fragment yield, angular and energy distribution. For fragment yields the three alternative models agreed between ~5 and ~35% with experimental measurements, the QMD using the “Frag” option gave the best agreement for lighter fragments but had reduced agreement for larger fragments. For angular distributions INCL++ was seen to provide the best agreement among the models for all elements with the exception of Hydrogen, while BIC and QMD was seen to produce broader distributions compared to experiment. BIC and QMD performed similar to one another for kinetic energy distributions while INCL++ suffered from producing lower energy distributions compared to the other models and experiment.« less

Validation of Geant4 fragmentation for Heavy Ion Therapy

DOE PAGES

Bolst, David; Cirrone, Giuseppe A. P.; Cuttone, Giacomo; ...

2017-07-12

12C ion therapy has had growing interest in recent years for its excellent dose conformity. However at therapeutic energies, which can be as high as 400 MeV/u, carbon ions produce secondary fragments. For an incident 400 MeV/u 12C ion beam, ~70% of the beam will undergo fragmentation before the Bragg Peak. The dosimetric and radiobiological impact of these fragments must be accurately characterised, as it can result in increasing the risk of secondary cancer for the patient as well as altering the relative biological effectiveness. Here, this work investigates the accuracy of three different nuclear fragmentation models available in themore » Monte Carlo Toolkit Geant4, the Binary Intranuclear Cascade (BIC), the Quantum Molecular Dynamics (QMD) and the Liege Intranuclear Cascade (INCL++). The models were benchmarked against experimental data for a pristine 400 MeV/u 12C beam incident upon a water phantom, including fragment yield, angular and energy distribution. For fragment yields the three alternative models agreed between ~5 and ~35% with experimental measurements, the QMD using the “Frag” option gave the best agreement for lighter fragments but had reduced agreement for larger fragments. For angular distributions INCL++ was seen to provide the best agreement among the models for all elements with the exception of Hydrogen, while BIC and QMD was seen to produce broader distributions compared to experiment. BIC and QMD performed similar to one another for kinetic energy distributions while INCL++ suffered from producing lower energy distributions compared to the other models and experiment.« less

The histone lysine demethylase Kdm6b is required for activity-dependent preconditioning of hippocampal neuronal survival

PubMed Central

Wijayatunge, Ranjula; Chen, Liang-Fu; Cha, Young May; Zannas, Anthony S.; Frank, Christopher L.; West, Anne E.

2014-01-01

Enzymes that regulate histone lysine methylation play important roles in neuronal differentiation, but little is known about their contributions to activity-regulated gene transcription in differentiated neurons. We characterized activity-regulated expression of lysine demethylases and lysine methyltransferases in the hippocampus of adult male mice following pilocarpine-induced seizure. Pilocarpine drove a 20-fold increase in mRNA encoding the histone H3 lysine27-specific demethylase Kdm6b selectively in granule neurons of the dentate gyrus, and this induction was recapitulated in cultured hippocampal neurons by bicuculline and 4-aminopyridine (Bic+4AP) stimulation of synaptic activity. Because activity-regulated gene expression is highly correlated with neuronal survival, we tested the requirement for Kdm6b expression in Bic+4AP induced preconditioning of neuronal survival. Prior exposure to Bic+4AP promoted neuronal survival in control neurons upon growth factor withdrawal, however this effect was ablated when we knocked down Kdm6b expression. Loss of Kdm6b did not disrupt activity-induced expression of most genes, including that of a gene set previously established to promote neuronal survival in this assay. However using bioinformatic analysis of RNA sequencing data, we discovered that Kdm6b knockdown neurons showed impaired inducibility of a discrete set of genes annotated for their function in inflammation. These data reveal a novel function for Kdm6b in activity-regulated neuronal survival, and they suggest that activity- and Kdm6b-dependent regulation of inflammatory gene pathways may serve as an adaptive pro-survival response to increased neuronal activity. PMID:24983519

Validation of Geant4 fragmentation for Heavy Ion Therapy

NASA Astrophysics Data System (ADS)

Bolst, David; Cirrone, Giuseppe A. P.; Cuttone, Giacomo; Folger, Gunter; Incerti, Sebastien; Ivanchenko, Vladimir; Koi, Tatsumi; Mancusi, Davide; Pandola, Luciano; Romano, Francesco; Rosenfeld, Anatoly B.; Guatelli, Susanna

2017-10-01

12C ion therapy has had growing interest in recent years for its excellent dose conformity. However at therapeutic energies, which can be as high as 400 MeV/u, carbon ions produce secondary fragments. For an incident 400 MeV/u 12C ion beam, ∼ 70 % of the beam will undergo fragmentation before the Bragg Peak. The dosimetric and radiobiological impact of these fragments must be accurately characterised, as it can result in increasing the risk of secondary cancer for the patient as well as altering the relative biological effectiveness. This work investigates the accuracy of three different nuclear fragmentation models available in the Monte Carlo Toolkit Geant4, the Binary Intranuclear Cascade (BIC), the Quantum Molecular Dynamics (QMD) and the Liege Intranuclear Cascade (INCL++). The models were benchmarked against experimental data for a pristine 400 MeV/u 12C beam incident upon a water phantom, including fragment yield, angular and energy distribution. For fragment yields the three alternative models agreed between ∼ 5 and ∼ 35 % with experimental measurements, the QMD using the "Frag" option gave the best agreement for lighter fragments but had reduced agreement for larger fragments. For angular distributions INCL++ was seen to provide the best agreement among the models for all elements with the exception of Hydrogen, while BIC and QMD was seen to produce broader distributions compared to experiment. BIC and QMD performed similar to one another for kinetic energy distributions while INCL++ suffered from producing lower energy distributions compared to the other models and experiment.

Laser-treated stainless steel mini-screw implants: 3D surface roughness, bone-implant contact, and fracture resistance analysis

PubMed Central

Kang, He-Kyong; Chu, Tien-Min; Dechow, Paul; Stewart, Kelton; Kyung, Hee-Moon

2016-01-01

Summary Background/Objectives: This study investigated the biomechanical properties and bone-implant intersurface response of machined and laser surface-treated stainless steel (SS) mini-screw implants (MSIs). Material and Methods: Forty-eight 1.3mm in diameter and 6mm long SS MSIs were divided into two groups. The control (machined surface) group received no surface treatment; the laser-treated group received Nd-YAG laser surface treatment. Half in each group was used for examining surface roughness (Sa and Sq), surface texture, and facture resistance. The remaining MSIs were placed in the maxilla of six skeletally mature male beagle dogs in a randomized split-mouth design. A pair with the same surface treatment was placed on the same side and immediately loaded with 200g nickel–titanium coil springs for 8 weeks. After killing, the bone-implant contact (BIC) for each MSI was calculated using micro computed tomography. Analysis of variance model and two-sample t test were used for statistical analysis with a significance level of P <0.05. Results: The mean values of Sa and Sq were significantly higher in the laser-treated group compared with the machined group (P <0.05). There were no significant differences in fracture resistance and BIC between the two groups. Limitation: animal study Conclusions/Implications: Laser treatment increased surface roughness without compromising fracture resistance. Despite increasing surface roughness, laser treatment did not improve BIC. Overall, it appears that medical grade SS has the potential to be substituted for titanium alloy MSIs. PMID:25908868

Characteristics of contact and distance osteogenesis around modified implant surfaces in rabbit tibiae

PubMed Central

2017-01-01

Purpose Contact and distance osteogenesis occur around all endosseous dental implants. However, the mechanisms underlying these processes have not been fully elucidated. We hypothesized that these processes occur independently of each other. To test this, we used titanium (Ti) tubes to physically separate contact and distance osteogenesis, thus allowing contact osteogenesis to be measured in the absence of possible triggers from distance osteogenesis. Methods Sandblasted and acid-etched (SLA) and modified SLA (modSLA) implants were used. Both types had been sandblasted with large grit and then etched with acid. The modSLA implants then underwent additional treatment to increase hydrophilicity. The implants were implanted into rabbit tibiae, and half were implanted within Ti tubes. The bone-to-implant contact (BIC) ratio was calculated for each implant. Immunohistochemical analyses of bone morphogenetic protein (BMP)-2 expression and new bone formation (Masson trichrome stain) were performed. Results The implants outside of Ti tubes were associated with good bone formation along the implant surface. Implantation within a Ti tube significantly reduced the BIC ratio (P<0.001). Compared with the modSLA implants, the SLA implants were associated with significantly higher BIC ratios, regardless of the presence or absence of Ti tubes (P=0.043). In the absence of Ti tubes, the bone adjacent to the implant had areas of new bone formation that expressed BMP-2 at high levels. Conclusions This study disproved the null hypothesis and suggested that contact osteogenesis is initiated by signals from the old bone that undergoes distance osteogenesis after drilling. This signal may be BMP-2. PMID:28680714

A search for evidence of solar rotation in Super-Kamiokande solar neutrino dataset

NASA Astrophysics Data System (ADS)

Desai, Shantanu; Liu, Dawei W.

2016-09-01

We apply the generalized Lomb-Scargle (LS) periodogram, proposed by Zechmeister and Kurster, to the solar neutrino data from Super-Kamiokande (Super-K) using data from its first five years. For each peak in the LS periodogram, we evaluate the statistical significance in two different ways. The first method involves calculating the False Alarm Probability (FAP) using non-parametric bootstrap resampling, and the second method is by calculating the difference in Bayesian Information Criterion (BIC) between the null hypothesis, viz. the data contains only noise, compared to the hypothesis that the data contains a peak at a given frequency. Using these methods, we scan the frequency range between 7-14 cycles per year to look for any peaks caused by solar rotation, since this is the proposed explanation for the statistically significant peaks found by Sturrock and collaborators in the Super-K dataset. From our analysis, we do confirm that similar to Sturrock et al, the maximum peak occurs at a frequency of 9.42/year, corresponding to a period of 38.75 days. The FAP for this peak is about 1.5% and the difference in BIC (between pure white noise and this peak) is about 4.8. We note that the significance depends on the frequency band used to search for peaks and hence it is important to use a search band appropriate for solar rotation. However, The significance of this peak based on the value of BIC is marginal and more data is needed to confirm if the peak persists and is real.

Subsurface Structure of the Bushveld Igneous Complex, South Africa: An Application of Geophysics

NASA Astrophysics Data System (ADS)

Vallejo, G.; Galindo, B. L.; Carranza, V.; Gomez, C. D.; Ortiz, K.; Castro, J. G.; Falzone, C.; Guandique, J.; Emry, E.; Webb, S. J.; Nyblade, A.

2014-12-01

South Africa is host to the largest single known platinum group metal supply in the world. The Bushveld Igneous Complex, spanning 300x400 kilometers, hosts hundreds of years' worth of platinum, chromite, vanadium, and other ore. Its wealth of these metals is tied directly to the large layered igneous intrusion that formed roughly 2061 million years ago. The extraction of platinum is vital to the industrial world - as these metals are widely used in the automotive industry, dental restorations, computer technology, in addition to many other applications. In collaboration with the Africa Array geophysics field school and the Penn State Summer Research Opportunities Program (SROP), we surveyed the Modikwa mine located along the border of the provinces of Mpumalanga and Limpopo in South Africa. The following techniques were applied to survey the area of interest: seismic refraction and reflection, gravity, magnetics, electrical resistivity, and electromagnetics. The data collected were used to determine the depth to bedrock and to identify potential mining hazards from dykes and faults in the bedrock. Several areas were studied and with the combination of the above-mentioned methods several possible hazards were identified. One broad, major dyke that was located in a prior aeromagnetic survey and several previously undetected, parallel, minor dykes were identified in the region. The overburden thickness was determined to be ̴4-5 meters in some regions, and as thin as several centimeters in others. This section of rock and soil lies above an area where platinum will likely be mined in the future. The removal of overburden can be accomplished by using power shovels or scrapers; while remaining material can be contained with the use of galvanized steel culverts. Additionally, a number of joints were located that may have allowed water to accumulate underground. The models created from the data permit us to estimate which hazards could be present in different parts of the land surveyed. These results are important information that will help determine how deep to mine while also avoiding hazards that could result in serious injuries to personnel or cause costly damages to equipment.

Probablistic Analyses of Waste Package Quantities Impacted by Potential Igneous Disruption at Yucca Mountain

NASA Astrophysics Data System (ADS)

Wallace, M. G.; Iuzzolina, H.

2005-12-01

A probabilistic analysis was conducted to estimate ranges for the numbers of waste packages that could be damaged in a potential future igneous event through a repository at Yucca Mountain. The analysis includes disruption from an intrusive igneous event and from an extrusive volcanic event. This analysis supports the evaluation of the potential consequences of future igneous activity as part of the total system performance assessment for the license application for the Yucca Mountain Project (YMP). The first scenario, igneous intrusion, investigated the case where one or more igneous dikes intersect the repository. A swarm of dikes was characterized by distributions of length, width, azimuth, and number of dikes and the spacings between them. Through the use in part of a latin hypercube simulator and a modified video game engine, mathematical relationships were built between those parameters and the number of waste packages hit. Corresponding cumulative distribution function curves (CDFs) for the number of waste packages hit under several different scenarios were calculated. Variations in dike thickness ranges, as well as in repository magma bulkhead positions were examined through sensitivity studies. It was assumed that all waste packages in an emplacement drift would be impacted if that drift was intersected by a dike. Over 10,000 individual simulations were performed. Based on these calculations, out of a total of over 11,000 planned waste packages distributed over an area of approximately 5.5 km2 , the median number of waste packages impacted was roughly 1/10 of the total. Individual cases ranged from 0 waste packages to the entire inventory being impacted. The igneous intrusion analysis involved an explicit characterization of dike-drift intersections, built upon various distributions that reflect the uncertainties associated with the inputs. The second igneous scenario, volcanic eruption (eruptive conduits), considered the effects of conduits formed in association with a volcanic eruption through the repository. Mathematical relations were built between the resulting conduit areas and the fraction of the repository area occupied by waste packages. This relation was used in conjunction with a joint distribution incorporating variability in eruptive conduit diameters and in the number of eruptive conduits that could intersect the repository.

Osseointegration in osteoporotic-like condition: A systematic review of preclinical studies.

PubMed

Dereka, X; Calciolari, E; Donos, N; Mardas, N

2018-05-30

Osteoporosis is one of the most common skeletal disorders affecting a significant percentage of people worldwide. Research data suggested that systemic diseases such as osteoporosis could act as risk factors for osseointegration, jeopardizing the healing process and thus the predictability of dental implant success on compromised patients. It is well accepted that preclinical studies in animal models reproducing the osteoporotic condition are one of the most important stages in the research of new biomaterials and therapeutic modalities. The aim of this systematic review was to investigate whether osteoporosis compromises dental implant osseointegration in experimental osteoporotic-like conditions. A 3-stage systematic literature research was conducted in MEDLINE via OVID and EMBASE up to and including March 2017. Experimental studies reporting on dental implant osseointegration on different osteoporotic animal models were assessed. The studies had to report on the percentage of bone-to-implant contact (%BIC) as the primary outcome. ARRIVE guidelines for reporting on animal research were applied to evaluate the methodological quality and risk of bias of the studies. Fifty-seven studies met the inclusion criteria and were assessed qualitatively. The most adopted animal model was the rat. A variability of %BIC values was observed, ranging from 30% to 99% and from 26% to 94% for the healthy and osteoporotic group, respectively. The great majority (47) of the included studies concluded that estrogen deficiency significantly affects BIC values, 9 studies stated that it was not possible to observe statistical differences in BIC between ovariectomized and healthy groups and 1 study did not provide a comparison between the healthy and osteoporotic group. Owing to the great heterogeneity in implant surface, study design, observation time-points, site of implant placement and reported outcomes, a meta-analysis could not be performed. An overall high risk of bias was observed, owing to the limited information on animal housing and husbandry, baseline characteristics and health status, ethical statement and allocation to the experimental groups provided. Although the available studies seem to suggest a lower osseointegration in osteoporotic-like conditions, no robust conclusions can be drawn due to the great heterogeneity and overall low quality of the available studies. Future studies with emphasis on minimizing the possible sources of bias and evaluating osseointegration of dental implants placed into jawbones instead of long bones are warranted. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

LA-ICP-MS zircon U-Pb and muscovite K-Ar ages of basement rocks from the south arm of Sulawesi, Indonesia

NASA Astrophysics Data System (ADS)

Jaya, Asri; Nishikawa, Osamu; Hayasaka, Yasutaka

2017-11-01

The zircon U-Pb and muscovite K-Ar age from the Bantimala, Barru and Biru basement complexes in the South Arm of Sulawesi, Indonesia provide new information regarding the timing of magmatism, metamorphism and sedimentation in this region and have implications for the origin and evolution of the study area. The study area is at the juncture between the southeast margin of Sundaland and Bird's Head-Australia. The age of both the zircon U-Pb of detrital materials in the Bantimala Complex and the muscovite K-Ar of amphibolite in the Biru Complex fall in the Late Early Cretaceous (between 109 and 115 Ma), which is a similar age range to previous data for both the sedimentary and metamorphic rocks. The youngest detrital zircon in the schist samples from the Barru Complex fall into the Triassic in age (between 243 and 247 Ma). These age data indicate that the protolith of all three basement complexes were involved in the subduction system and metamorphosed in the late Early Cretaceous, but there are several differences in their deposition environment under and out of the influence of the late Early Cretaceous magmatism in the Bantimala and Barru Complexes, respectively. Felsic igneous activities are confirmed in the Late Cretaceous and the Eocene by the zircon U-Pb age of igneous rocks intruding or included as detrital fragments in three basement complexes. These dates are similar to those reported from the Meratus Complex of South Kalimantan. The detrital zircon age distributions of the basement rocks in the South Arm of Sulawesi display predominant Mesozoic (Cretaceous and Triassic) and Paleozoic populations with a small population of Proterozoic ages supporting the hypothesis that the West Sulawesi block originated from the region of the circum Bird's Head-Australian, namely the Inner Banda block. The absence of Jurassic zircon age population in the South Arm of Sulawesi suggests the division of the South Arm of Sulawesi from the Inner Banda block in early stage of rifting. Western Sulawesi is composed of several blocks separated from Inner Banda block with different histories, which is supported by the varieties of zircon population distribution in the basement rocks in the Western Sulawesi and also difference of general orientations of structural features between the Bantimala and Barru Complexes.

Ordovician volcanic and plutonic complexes of the Sakmara allochthon in the southern Urals

NASA Astrophysics Data System (ADS)

Ryazantsev, A. V.; Tolmacheva, T. Yu.

2016-11-01

The Ordovician terrigenous, volcanic-sedimentary and volcanic sequences that formed in rifts of the active continental margin and igneous complexes of intraoceanic suprasubduction settings structurally related to ophiolites are closely spaced in allochthons of the Sakmara Zone in the southern Urals. The stratigraphic relationships of the Ordovician sequences have been established. Their age and facies features have been specified on the basis of biostratigraphic and geochronological data. The gabbro-tonalite-trondhjemite complex and the basalt-andesite-rhyolite sequence with massive sulfide mineralization make up a volcanic-plutonic association. These rock complexes vary in age from Late Ordovician to Early Silurian in certain structural units of the Sakmara Allochthon and to the east in the southern Urals. The proposed geodynamic model for the Ordovician in Paleozoides of the southern Urals reconstructs the active continental margin, whose complexes formed under extension settings, and the intraoceanic suprasubduction structures. The intraoceanic complexes display the evolution of a volcanic arc, back-, or interarc trough.

P-T Path and Nd-isotopes of Garnet Pyroxenite Xenoliths From Salt Lake Crater, Oahu

NASA Astrophysics Data System (ADS)

Ichitsubo, N.; Takahashi, E.; Clague, D. A.

2001-12-01

Abundant garnet pyroxenite and spinel lherzolite xenoliths are found in Salt Lake Crater (SLC) in Oahu, Hawaii [Jackson and Wright, 1970]. The SLC pyroxenite suite xenoliths (olivine-poor type) have complex exsolution textures that were probably formed during a slow cooling. In this study, we used digital image software to obtain modal data of exsolved phases in the host pyroxene using backscattered electron images (BEIs). The abundances of the exsolved phases were multiplied by the phase compositions determined by electron probe micro-analyzer (EPMA) to reconstruct pyroxene compositions prior to exsolution. In order to evaluate the error in this calculation, we recalculated the reconstructed pyroxene compositions using the different pyroxene pairs. Reconstructed clinopyroxenes in each sample have almost no variations (MgO, CaO +/-1wt %, FeO +/-0.5wt % and the other oxides ~+/-0.1wt %). Reconstructed orthopyroxenes are more variable in MgO, CaO (+/-2wt %) and FeO (+/-1wt %) than reconstructed clinopyroxenes, but the other oxides have only limited variations ( ~+/-0.5wt %). These compositions were used to calculate igneous stage (magmatic) P-T conditions based on the geothermometers and geobarometers of Wells [1977] and Brey and Kohler [1990] Following assumptions are made: (1) the reconstructed pyroxene compositions are the final record in the primary igneous stage, and (2) cores of the largest garnet grains in each sample record the primary igneous stage composition.. The recalculation using the different pairs of reconstructed pyroxenes show the uncertainty to be +/- 30° C and 0.1 GPa. These appear to be small compared to the large intrinsic errors of geothermometer and geobarometers (+/-20° -35° C and +/- 0.3-0.5 GPa). Estimated P-T conditions for garnet pyroxenites are 1.5-2.2 GPa, 1000° -1100° C in the final reequilibration stage and 2.2-2.6 GPa (at maximum), 1150° -1300° C (at minimum) in the igneous stage. The all samples show ca. 200° C cooling and 0.5 GPa decompression. This implies that the garnet pyroxenites cooled ca. 200° C to develop the observed complex exsolution and may have risen from about 70-80 km to 50-65 km depth. Glass pockets and fine minerals (olivine, pyroxene, spinel) occur in the SLC garnet pyroxenite xenoliths. Amphibole and phlogopite, which may have crystallized by metasomatism, are common accessory minerals in them. In order to study the nature of metasomatism as revealed by the glass pockets and fine aggregate of spinel and pyroxene, Nd-isotope study on the SLC xenoliths is under way.

Field guide to the Mesozoic arc and accretionary complex of South-Central Alaska, Indian to Hatcher Pass

USGS Publications Warehouse

Karl, Susan M.; Oswald, P.J.; Hults, Chad P.

2015-01-01

This field trip traverses exposures of a multi-generation Mesozoic magmatic arc and subduction-accretion complex that had a complicated history of magmatic activity and experienced variations in composition and deformational style in response to changes in the tectonic environment. This Mesozoic arc formed at an unknown latitude to the south, was accreted to North America, and was subsequently transported along faults to its present location (Plafker and others, 1989; Hillhouse and Coe, 1994). Some of these faults are still active. Similar tectonic, igneous, and sedimentary processes to those that formed the Mesozoic arc complex persist today in southern Alaska, building on, and deforming the Mesozoic arc. The rocks we will see on this field trip provide insights on the three-dimensional composition of the modern arc, and the processes involved in the evolution of an arc and its companion accretionary complex.

Igneous history of the aubrite parent asteroid - Evidence from the Norton County enstatite achondrite

NASA Technical Reports Server (NTRS)

Okada, Akihiko; Keil, Klaus; Taylor, G. Jeffrey; Newsom, Horton

1988-01-01

Numerous specimens of the Norton County enstatite achondrite (aubrite) were studied by optical microscopy, electron microprobe, and neutron-activation analysis. Norton County is found to be a fragmental impact breccia, consisting of a clastic matrix made mostly of crushed enstatite, into which are embedded a variety of mineral and lithic clasts of both igneous and impact melt origin. The Norton County precursor materials were igneous rocks, mostly plutonic orthopyroxenites, not grains formed by condensation from the solar nebula. The Mg-silicate-rich aubrite parent body experienced extensive melting and igneous differentiation, causing formation of diverse lithologies including dunites, plutonic orthopyroxenites, plutonic pyroxenites, and plagioclase-silica rocks. The presence of impact melt breccias (the microporphyritic clasts and the diopside-plagioclase-silica clast) of still different compositions further attests to the lithologic diversity of the aubrite parent body.

Luna 16 - Some Li, K, Rb, Sr, Ba, rare-earth, Zr, and Hf concentrations.

NASA Technical Reports Server (NTRS)

Philpotts, J. A.; Schnetzler, C. C.; Schuhmann, S.; Thomas , H. H.; Bottino, M. L.

1972-01-01

Concentrations of Li, K, Rb, Sr, Na, rare-earths, Zr and Hf have been determined for some Luna 16 core materials by mass-spectrometric isotope-dilution. Two regolith fines samples from different depths in the core, and four rock-chips, including both igneous rocks and breccias, have similar trace-element concentrations. The Luna 16 materials have general lunar trace-element characteristics but differ from other returned lunar samples in a manner that suggests the presence of excess feldspar. Unless the Luna 16 igneous rocks are fused soils, they appear to represent either partial plagioclase cumulates or the least differentiated igneous material yet returned from the moon. The similarity in trace-element concentrations of the igneous rocks and the fines would then suggest largely local derivation of the Luna 16 regolith.

Melanesian arc far-field response to collision of the Ontong Java Plateau: Geochronology and petrogenesis of the Simuku Igneous Complex, New Britain, Papua New Guinea

NASA Astrophysics Data System (ADS)

Holm, Robert J.; Spandler, Carl; Richards, Simon W.

2013-09-01

Understanding the evolution of the mid-Cenozoic Melanesian arc is critical for our knowledge of the regional tectonic development of the Australian-Pacific plate margin, yet there have been no recent studies to constrain the nature and timing of magmatic activity in this arc segment. In particular, there are currently no robust absolute age constraints at the plate margin related to either the initiation or cessation of subduction and arc magmatism. We present the first combined U-Pb zircon geochronology and geochemical investigation into the evolution of the Melanesian arc utilizing a comprehensive sample suite from the Simuku Igneous Complex of West New Britain, Papua New Guinea. Development of the embryonic island arc from at least 40 Ma and progressive arc growth was punctuated by distant collision of the Ontong Java Plateau and subduction cessation from 26 Ma. This change in subduction dynamics is represented in the Melanesian arc magmatic record by emplacement of the Simuku Porphyry Complex between 24 and 20 Ma. Petrological and geochemical affinities highlight genetic differences between 'normal' arc volcanics and adakite-like signatures of Cu-Mo mineralized porphyritic intrusives. The contemporaneous emplacement of both 'normal' arc volcanics and adakite-like porphyry intrusives may provide avenues for future research into the origin of diverse styles of arc volcanism. Not only is this one of few studies into the geology of the Melanesian arc, it is also among the first to address the distant tectono-magmatic effects of major arc/forearc collision events and subduction cessation on magmatic arcs, and also offers insight into the tectonic context of porphyry formation in island arc settings.

Basalt-trachybasalt samples in Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Edwards, Peter H.; Bridges, John C.; Wiens, Roger; Anderson, Ryan; Dyar, Darby; Fisk, Martin; Thompson, Lucy; Gasda, Patrick; Filiberto, Justin; Schwenzer, Susanne P.; Blaney, Diana; Hutchinson, Ian

2017-11-01

The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single-laser-shot spectra of igneous targets observed by ChemCam shows a strong peak at 55 wt% SiO2 and 6 wt% total alkalis, with a minor secondary maximum at 47-51 wt% SiO2 and lower alkali content. The centers of these distributions, together with the rock textures, indicate that many of the ChemCam igneous targets are trachybasalts, Mg# = 27 but with a secondary concentration of basaltic material, with a focus of compositions around Mg# = 54. We suggest that all of these igneous rocks resulted from low-pressure, olivine-dominated fractionation of Adirondack (MER) class-type basalt compositions. This magmatism has subalkaline, tholeiitic affinities. The similarity of the basalt endmember to much of the Gale sediment compositions in the first 1000 sols of the MSL mission suggests that this type of Fe-rich, relatively low-Mg#, olivine tholeiite is the dominant constituent of the Gale catchment that is the source material for the fine-grained sediments in Gale. The similarity to many Gusev igneous compositions suggests that it is a major constituent of ancient Martian magmas, and distinct from the shergottite parental melts thought to be associated with Tharsis and the Northern Lowlands. The Gale Crater catchment sampled a mixture of this tholeiitic basalt along with alkaline igneous material, together giving some analogies to terrestrial intraplate magmatic provinces.

Evaluating the Relationships Between NTNU/SINTEF Drillability Indices with Index Properties and Petrographic Data of Hard Igneous Rocks

NASA Astrophysics Data System (ADS)

Aligholi, Saeed; Lashkaripour, Gholam Reza; Ghafoori, Mohammad; Azali, Sadegh Tarigh

2017-11-01

Thorough and realistic performance predictions are among the main requisites for estimating excavation costs and time of the tunneling projects. Also, NTNU/SINTEF rock drillability indices, including the Drilling Rate Index™ (DRI), Bit Wear Index™ (BWI), and Cutter Life Index™ (CLI), are among the most effective indices for determining rock drillability. In this study, brittleness value (S20), Sievers' J-Value (SJ), abrasion value (AV), and Abrasion Value Cutter Steel (AVS) tests are conducted to determine these indices for a wide range of Iranian hard igneous rocks. In addition, relationships between such drillability parameters with petrographic features and index properties of the tested rocks are investigated. The results from multiple regression analysis revealed that the multiple regression models prepared using petrographic features provide a better estimation of drillability compared to those prepared using index properties. Also, it was found that the semiautomatic petrography and multiple regression analyses provide a suitable complement to determine drillability properties of igneous rocks. Based on the results of this study, AV has higher correlations with studied mineralogical indices than AVS. The results imply that, in general, rock surface hardness of hard igneous rocks is very high, and the acidic igneous rocks have a lower strength and density and higher S20 than those of basic rocks. Moreover, DRI is higher, while BWI is lower in acidic igneous rocks, suggesting that drill and blast tunneling is more convenient in these rocks than basic rocks.

Formation of Hadean granites by melting of igneous crust

NASA Astrophysics Data System (ADS)

Burnham, A. D.; Berry, A. J.

2017-06-01

The oldest known samples of Earth, with ages of up to 4.4 Gyr, are detrital zircon grains in meta-sedimentary rocks of the Jack Hills in Australia. These zircons offer insights into the magmas from which they crystallized, and, by implication, igneous activity and tectonics in the first 500 million years of Earth’s history, the Hadean eon. However, the compositions of these magmas and the relative contributions of igneous and sedimentary components to their sources have not yet been resolved. Here we compare the trace element concentrations of the Jack Hills zircons to those of zircons from the locality where igneous (I-) and sedimentary (S-) type granites were first distinguished. We show that the Hadean zircons crystallized predominantly from I-type magmas formed by melting of a reduced, garnet-bearing igneous crust. Further, we propose that both the phosphorus content of zircon and the ratio of phosphorus to rare earth elements can be used to distinguish between detrital zircon grains from I- and S-type sources. These elemental discriminants provide a new geochemical tool to assess the relative contributions of primeval magmatism and melting of recycled sediments to the continents over geological time.

Geochemical distinctions between igneous carbonate, calcite cements, and limestone xenoliths (Polino carbonatite, Italy): spatially resolved LAICPMS analyses

NASA Astrophysics Data System (ADS)

Rosatelli, G.; Wall, F.; Stoppa, F.; Brilli, M.

2010-11-01

Petrography-controlled laser ablation inductively coupled plasma mass spectrometry (LAICPMS) analyses of carbonate in fresh shallow level sub-volcanic Polino monticellite calcio-carbonatite tuffisite have been performed to assess the geochemical differences between fresh igneous, epigenetic carbonates and sedimentary accidental fragments. Igneous calcite has consistently high LREE/HREE ratios (La/Yb N , 15-130) due to high LREE (ΣLREE, 425-1,269 ppm). Secondary calcite cements are characterized by progressively lower and more variable trace element contents, with lower LREE/HREE ratios. A distinguishing geochemical feature is progressively increasing negative Ce anomalies observed through coarse secondary calcite that can be related to the surface environment processes. The limestone accidental fragments in the tuffisite have trace element contents almost two orders of magnitude lower than igneous carbonate and low LREE (ΣLREE < 9.5 ppm) with low LREE/HREE fractionation (La/Yb N ratios < 18). The stable isotope composition of different carbonate types is consistent with their formation in different environments. The tuffisitization processes during diatreme formation under high CO2-OH fugacity conditions may account for the differences noted in the igneous carbonates.

Magmatic ore deposits in layered intrusions - Descriptive model for reef-type PGE and contact-type Cu-Ni-PGE deposits

USGS Publications Warehouse

Zientek, Michael L.

2012-01-01

Layered, ultramafic to mafic intrusions are uncommon in the geologic record, but host magmatic ore deposits containing most of the world's economic concentrations of platinum-group elements (PGE) (figs. 1 and 2). These deposits are mined primarily for their platinum, palladium, and rhodium contents (table 1). Magmatic ore deposits are derived from accumulations of crystals of metallic oxides, or immiscible sulfide, or oxide liquids that formed during the cooling and crystallization of magma, typically with mafic to ultramafic compositions. "PGE reefs" are stratabound PGE-enriched lode mineralization in mafic to ultramafic layered intrusions. The term "reef" is derived from Australian and South African literature for this style of mineralization and used to refer to (1) the rock layer that is mineralized and has distinctive texture or mineralogy (Naldrett, 2004), or (2) the PGE-enriched sulfide mineralization that occurs within the rock layer. For example, Viljoen (1999) broadly defined the Merensky Reef as "a mineralized zone within or closely associated with an unconformity surface in the ultramafic cumulate at the base of the Merensky Cyclic Unit." In this report, we will use the term PGE reef to refer to the PGE-enriched mineralization, not the host rock layer. Within a layered igneous intrusion, reef-type mineralization is laterally persistent along strike, extending for the length of the intrusion, typically tens to hundreds of kilometers. However, the mineralized interval is thin, generally centimeters to meters thick, relative to the stratigraphic thickness of layers in an intrusion that vary from hundreds to thousands of meters. PGE-enriched sulfide mineralization is also found near the contacts or margins of layered mafic to ultramafic intrusions (Iljina and Lee, 2005). This contact-type mineralization consists of disseminated to massive concentrations of iron-copper-nickel-PGE-enriched sulfide mineral concentrations in zones that can be tens to hundreds of meters thick. The modes and textures of the igneous rocks hosting the mineralization vary irregularly on the scale of centimeters to meters; autoliths and xenoliths are common. Mineralization occurs in the igneous intrusion and in the surrounding country rocks. Mineralization can be preferentially localized along contact with country rocks that are enriched in sulfur-, iron-, or CO2-bearing lithologies. Reef-type and contact-type deposits, in particular those in the Bushveld Complex, South Africa, are the world's primary source of platinum and rhodium (tables 2 and 3; fig. 2). Reef-type PGE deposits are mined only in the Bushveld Complex (Merensky Reef and UG2), the Stillwater Complex (J-M Reef), and the Great Dyke (Main Sulphide Layer). PGE-enriched contact-type deposits are only mined in the Bushveld Complex. The other deposits in tables 2 and 3 are undeveloped; some are still under exploration.

Petrology of the igneous rocks

NASA Technical Reports Server (NTRS)

Mccallum, I. S.

1987-01-01

Papers published during the 1983-1986 period on the petrology and geochemistry of igneous rocks are discussed, with emphasis on tectonic environment. Consideration is given to oceanic rocks, subdivided into divergent margin suites (mid-ocean ridge basalts, ridge-related seamounts, and back-arc basin basalts) and intraplate suites (oceanic island basalts and nonridge seamounts), and to igneous rocks formed at convergent margins (island arc and continental arc suites), subdivided into volcanic associations and plutonic associations. Other rock groups discussed include continental flood basalts, layered mafic intrusions, continental alkalic associations, komatiites, ophiolites, ash-flow tuffs, anorthosites, and mantle xenoliths.

Impact origin of the Sudbury structure: Evolution of a theory

NASA Technical Reports Server (NTRS)

Lowman, Paul D., Jr.

1992-01-01

This paper reviews the origin, development, and present status of the widely accepted theory, proposed by Robert S. Dietz in 1962, that the Sudbury structure was formed by meteoritic or asteroidal impact. The impact theory for the origin of the Sudbury structure seems supported by a nearly conclusive body of evidence. However, even assuming an impact origin to be correct, at least three major questions require further study: (1) the original size and shape of the crater, before tectonic deformation and erosion; (2) the source of the melt now forming the Sudbury Igneous Complex; and (3) the degree, if any, to which the Ni-Cu-platinum group elements are meteoritic. The history of the impact theory illustrates several under-appreciated aspects of scientific research: (1) the importance of cross-fertilization between space research and terrestrial geology; (2) the role of the outsider in stimulating thinking by insiders; (3) the value of small science, at least in the initial stages of an investigation, Dietz's first field work having been at his own expense; and (4) the value of analogies (here, between the Sudbury Igneous Complex and the maria), which although incorrect in major aspects, may trigger research on totally new lines. Finally, the Sudbury story illustrates the totally unpredictable and, by implication, unplannable nature of basic research, in that insight to the origin of the world's then-greatest Ni deposit came from the study of tektites and the Moon.

Oxygen isotope trajectories of crystallizing melts: Insights from modeling and the plutonic record

NASA Astrophysics Data System (ADS)

Bucholz, Claire E.; Jagoutz, Oliver; VanTongeren, Jill A.; Setera, Jacob; Wang, Zhengrong

2017-06-01

Elevated oxygen isotope values in igneous rocks are often used to fingerprint supracrustal alteration or assimilation of material that once resided near the surface of the earth. The δ18O value of a melt, however, can also increase through closed-system fractional crystallization. In order to quantify the change in melt δ18O due to crystallization, we develop a detailed closed-system fractional crystallization mass balance model and apply it to six experimentally- and naturally-determined liquid lines of descent (LLDs), which cover nearly complete crystallization intervals (melt fractions of 1 to <0.1). The studied LLDs vary from anhydrous tholeiitic basalts to hydrous high-K and calc-alkaline basalts and are characterized by distinct melt temperature-SiO2 trajectories, as well as, crystallizing phase relationships. Our model results demonstrate that melt fraction-temperature-SiO2 relationships of crystallizing melts, which are strongly a function of magmatic water content, will control the specific δ18O path of a crystallizing melt. Hydrous melts, typical of subduction zones, undergo larger increases in δ18O during early stages of crystallization due to their lower magmatic temperatures, greater initial increases in SiO2 content, and high temperature stability of low δ18O phases, such as oxides, amphibole, and anorthitic plagioclase (versus albite). Conversely, relatively dry, tholeiitic melts only experience significant increases in δ18O at degrees of crystallization greater than 80%. Total calculated increases in melt δ18O of 1.0-1.5‰ can be attributed to crystallization from ∼50 to 70 wt.% SiO2 for modeled closed-system crystallizing melt compositions. As an example application, we compare our closed system model results to oxygen isotope mineral data from two natural plutonic sequences, a relatively dry, tholeiitic sequence from the Upper and Upper Main Zones (UUMZ) of the Bushveld Complex (South Africa) and a high-K, hydrous sequence from the arc-related Dariv Igneous Complex (Mongolia). These two sequences were chosen as their major and trace element compositions appear to have been predominantly controlled by closed-system fractional crystallization and their LLDs have been modeled in detail. We calculated equilibrium melt δ18O values using the measured mineral δ18O values and calculated mineral-melt fractionation factors. Increases of 2-3‰ and 1-1.5‰ in the equilibrium melts are observed for the Dariv Igneous Complex and the UUMZ of the Bushveld Complex, respectively. Closed-system fractional crystallization model results reproduce the 1‰ increase observed in the equilibrium melt δ18O for the Bushveld UUMZ, whereas for the Dariv Igneous Complex assimilation of high δ18O material is necessary to account for the increase in melt δ18O values. Assimilation of evolved supracrustal material is also confirmed with Sr and Nd isotope analyses of clinopyroxene from the sequence. Beginning with a range of mantle-derived basalt δ18O values of 5.7‰ ("pristine" mantle) to ∼7.0‰ (heavily subduction-influenced mantle), our model results demonstrated that high-silica melts (i.e. granites) with δ18O of up to 8.5‰ can be produced through fractional crystallization alone. Lastly, we model the zircon-melt δ18O fractionations of different LLDs, emphasizing their dependence on the specific SiO2-T relationships of a given crystallizing melt. Wet, relatively cool granitic melts will have larger zircon-melt fractionations, potentially by ∼1.5‰, compared to hot, dry granites. Therefore, it is critical to constrain zircon-melt fractionations specific to a system of interest when using zircon δ18O values to calculate melt δ18O.

Petrogenesis of Igneous-Textured Clasts in Martian Meteorite Northwest Africa 7034

NASA Technical Reports Server (NTRS)

Santos, A. R.; Agee, C. B.; Humayun, M.; McCubbin, F. M.; Shearer, C. K.

2016-01-01

The martian meteorite Northwest Africa 7034 (and pairings) is a breccia that samples a variety of materials from the martian crust. Several previous studies have identified multiple types of igneous-textured clasts within the breccia [1-3], and these clasts have the potential to provide insight into the igneous evolution of Mars. One challenge presented by studying these small rock fragments is the lack of field context for this breccia (i.e., where on Mars it formed), so we do not know how many sources these small rock fragments are derived from or the exact formation his-tory of these sources (i.e., are the sources mantle de-rived melt or melts contaminated by a meteorite impactor on Mars). Our goal in this study is to examine specific igneous-textured clast groups to determine if they are petrogenetically related (i.e., from the same igneous source) and determine more information about their formation history, then use them to derive new insights about the igneous history of Mars. We will focus on the basalt clasts, FTP clasts (named due to their high concentration of iron, titanium, and phosphorous), and mineral fragments described by [1] (Fig. 1). We will examine these materials for evidence of impactor contamination (as proposed for some materials by [2]) or mantle melt derivation. We will also test the petrogenetic models proposed in [1], which are igneous processes that could have occurred regardless of where the melt parental to the clasts was formed. These models include 1) derivation of the FTP clasts from a basalt clast melt through silicate liquid immiscibility (SLI), 2) derivation of the FTP clasts from a basalt clast melt through fractional crystallization, and 3) a lack of petrogenetic relationship between these clast groups. The relationship between the clast groups and the mineral fragments will also be explored.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jesus, J.F.; Valentim, R.; Andrade-Oliveira, F., E-mail: jfjesus@itapeva.unesp.br, E-mail: valentim.rodolfo@unifesp.br, E-mail: felipe.oliveira@port.ac.uk

Creation of Cold Dark Matter (CCDM), in the context of Einstein Field Equations, produces a negative pressure term which can be used to explain the accelerated expansion of the Universe. In this work we tested six different spatially flat models for matter creation using statistical criteria, in light of SNe Ia data: Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC) and Bayesian Evidence (BE). These criteria allow to compare models considering goodness of fit and number of free parameters, penalizing excess of complexity. We find that JO model is slightly favoured over LJO/ΛCDM model, however, neither of these, nor Γmore » = 3α H {sub 0} model can be discarded from the current analysis. Three other scenarios are discarded either because poor fitting or because of the excess of free parameters. A method of increasing Bayesian evidence through reparameterization in order to reducing parameter degeneracy is also developed.« less

Polymeric micelles with ionic cores containing biodegradable cross-links for delivery of chemotherapeutic agents.

PubMed

Kim, Jong Oh; Sahay, Gaurav; Kabanov, Alexander V; Bronich, Tatiana K

2010-04-12

Novel functional polymeric nanocarriers with ionic cores containing biodegradable cross-links were developed for delivery of chemotherapeutic agents. Block ionomer complexes (BIC) of poly(ethylene oxide)-b-poly(methacylic acid) (PEO-b-PMA) and divalent metal cations (Ca(2+)) were utilized as templates. Disulfide bonds were introduced into the ionic cores by using cystamine as a biodegradable cross-linker. The resulting cross-linked micelles with disulfide bonds represented soft, hydrogel-like nanospheres and demonstrated a time-dependent degradation in the conditions mimicking the intracellular reducing environment. The ionic character of the cores allowed to achieve a very high level of doxorubicin (DOX) loading (50% w/w) into the cross-linked micelles. DOX-loaded degradable cross-linked micelles exhibited more potent cytotoxicity against human A2780 ovarian carcinoma cells as compared to micellar formulations without disulfide linkages. These novel biodegradable cross-linked micelles are expected to be attractive candidates for delivery of anticancer drugs.

Bayesian analysis of CCDM models

NASA Astrophysics Data System (ADS)

Jesus, J. F.; Valentim, R.; Andrade-Oliveira, F.

2017-09-01

Creation of Cold Dark Matter (CCDM), in the context of Einstein Field Equations, produces a negative pressure term which can be used to explain the accelerated expansion of the Universe. In this work we tested six different spatially flat models for matter creation using statistical criteria, in light of SNe Ia data: Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC) and Bayesian Evidence (BE). These criteria allow to compare models considering goodness of fit and number of free parameters, penalizing excess of complexity. We find that JO model is slightly favoured over LJO/ΛCDM model, however, neither of these, nor Γ = 3αH0 model can be discarded from the current analysis. Three other scenarios are discarded either because poor fitting or because of the excess of free parameters. A method of increasing Bayesian evidence through reparameterization in order to reducing parameter degeneracy is also developed.

The Magnet Cove Rutile Company mine, Hot Spring County, Arkansas

USGS Publications Warehouse

Kinney, Douglas M.

1949-01-01

The Magnet Cove Rutile Company mine was mapped by the U.S. Geological Survey in November 1944. The pits are on the northern edge of Magnet Cove and have been excavated in the oxidized zone of highly weathered and altered volcanic agglomerate. The agglomerate is composed of altered mafic igneous rocks in a matrix of white to gray clay, a highly altered tuff. The agglomerate appears layered and is composed of tuffaceous clay material below and igneous blocks above. The agglomerate is cut by aplite and lamprophyre dikes. Alkalic syenite dikes crop out on the ridge north of the pits. At the present stage of mine development the rutile seems to be concentrated in a narrow zone beneath the igneous blocks of the agglomerate. Rutile, associated with calcite and pyrite, occurs as disseminated acicular crystals and discontinuous vein-like masses in the altered tuff. Thin veins of rutile locally penetrate the mafic igneous blocks of the agglomerate.

Kilbuck terrane: Oldest known rocks in Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Box, S.E.; Moll-Stalcup, E.J.; Wooden, J.L.

1990-12-01

The Kilbuck terrane in southwestern Alaska is a narrow, thin crustal sliver or flake of amphibolite facies orthogneiss. The igneous protolith of this gneiss was a suite of subduction-related plutonic rocks. U-Pb data on zircons from trondhjemitic and granitic samples yield upper-intercept (igneous) ages of 2,070 {plus minus}16 and 2,040 {plus minus}74 Ma, respectively. Nd isotope data from these rocks suggest that a diorite-tonalite-trondhjemite suite ({epsilon}{sub Nd}(T) = +2.1 to +2.7; T is time of crystallization) evolved from partial melts of depleted mantle with no discernible contamination by older crust, whereas a coeval granitic pluton ({epsilon}{sub Nd}(T) = {minus}5.7) containsmore » a significant component derived from Archean crust. Orthogneisses with similar age and Nd isotope characteristics are found in the Idono complex 250 km to the north. Early Proterozoic rocks are unknown elsewhere in Alaska. However, Phanerozoic plutons cutting several continental terranes in Alaska (southern Brooks Range and Ruby, Seward, and Yukon-Tanana terranes) have Nd isotope compositions indicative of Early Proterozoic (or older) crustal components that could be correlative with rocks of the Kilbuck terrane. Rocks with similar igneous ages in cratonal North America are rare, and those few that are known have Nd isotope compositions distinct from those of the Kilbuck terrane. Conversely, provinces with Nd model ages of 2.0-2.1 Ga are characterized by extensive 1.8 Ga or younger plutonism, which is unknown in the Kilbuck terrane. At present the case for a North American parentage of the Kilbuck terrane is not compelling. The possibility that the Kilbuck terrane was displaced from provinces of similar age in other cratons (e.g., Australian, Baltic, Guiana, and west African shields), or from the poorly dated Siberian craton, cannot be excluded.« less

Mineralogy, Provenance, and Diagenesis of a Potassic Basaltic Sandstone on Mars: CheMin X-Ray Diffraction of the Windjana Sample (Kimberley Area, Gale Crater)

NASA Technical Reports Server (NTRS)

Treiman, Allan H.; Bish, David L.; Vaniman, David T.; Chipera, Steve J.; Blake, David F.; Ming, Doug W.; Morris, Richard V.; Bristow, Thomas F.; Morrison, Shaunna M.; Baker, Michael B.;

Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X-ray diffraction of the Windjana sample (Kimberley area, Gale Crater)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Treiman, Allan H.; Bish, David L.; Vaniman, David T.

The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X-ray diffraction (XRD) in the MSL Curiosity rover. From Rietveld refinements of its XRD pattern, Windjana contains the following: sanidine (21% weight, ~Or 95); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (~25%); and percent levels of others including ilmenite, fluorapatite, and bassanite. From mass balance on the Alpha Proton X-ray Spectrometer (APXS) chemical analysis, the amorphous material is Fe rich with nearly no other cations—like ferrihydrite. The Windjana sample shows little alteration and was likely cemented bymore » its magnetite and ferrihydrite. From ChemCam Laser-Induced Breakdown Spectrometer (LIBS) chemical analyses, Windjana is representative of the Dillinger and Mount Remarkable members of the Kimberley formation. LIBS data suggest that the Kimberley sediments include at least three chemical components. The most K-rich targets have 5.6% K 2O, ~1.8 times that of Windjana, implying a sediment component with >40% sanidine, e.g., a trachyte. A second component is rich in mafic minerals, with little feldspar (like a shergottite). A third component is richer in plagioclase and in Na 2O, and is likely to be basaltic. The K-rich sediment component is consistent with APXS and ChemCam observations of K-rich rocks elsewhere in Gale Crater. The source of this sediment component was likely volcanic. Finally, the presence of sediment from many igneous sources, in concert with Curiosity's identifications of other igneous materials (e.g., mugearite), implies that the northern rim of Gale Crater exposes a diverse igneous complex, at least as diverse as that found in similar-age terranes on Earth.« less

Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X‐ray diffraction of the Windjana sample (Kimberley area, Gale Crater)

PubMed Central

Bish, David L.; Vaniman, David T.; Chipera, Steve J.; Blake, David F.; Ming, Doug W.; Morris, Richard V.; Bristow, Thomas F.; Morrison, Shaunna M.; Baker, Michael B.; Rampe, Elizabeth B.; Downs, Robert T.; Filiberto, Justin; Glazner, Allen F.; Gellert, Ralf; Thompson, Lucy M.; Schmidt, Mariek E.; Le Deit, Laetitia; Wiens, Roger C.; McAdam, Amy C.; Achilles, Cherie N.; Edgett, Kenneth S.; Farmer, Jack D.; Fendrich, Kim V.; Grotzinger, John P.; Gupta, Sanjeev; Morookian, John Michael; Newcombe, Megan E.; Rice, Melissa S.; Spray, John G.; Stolper, Edward M.; Sumner, Dawn Y.; Vasavada, Ashwin R.; Yen, Albert S.

2016-01-01

Abstract The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X‐ray diffraction (XRD) in the MSL Curiosity rover. From Rietveld refinements of its XRD pattern, Windjana contains the following: sanidine (21% weight, ~Or95); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (~25%); and percent levels of others including ilmenite, fluorapatite, and bassanite. From mass balance on the Alpha Proton X‐ray Spectrometer (APXS) chemical analysis, the amorphous material is Fe rich with nearly no other cations—like ferrihydrite. The Windjana sample shows little alteration and was likely cemented by its magnetite and ferrihydrite. From ChemCam Laser‐Induced Breakdown Spectrometer (LIBS) chemical analyses, Windjana is representative of the Dillinger and Mount Remarkable members of the Kimberley formation. LIBS data suggest that the Kimberley sediments include at least three chemical components. The most K‐rich targets have 5.6% K2O, ~1.8 times that of Windjana, implying a sediment component with >40% sanidine, e.g., a trachyte. A second component is rich in mafic minerals, with little feldspar (like a shergottite). A third component is richer in plagioclase and in Na2O, and is likely to be basaltic. The K‐rich sediment component is consistent with APXS and ChemCam observations of K‐rich rocks elsewhere in Gale Crater. The source of this sediment component was likely volcanic. The presence of sediment from many igneous sources, in concert with Curiosity's identifications of other igneous materials (e.g., mugearite), implies that the northern rim of Gale Crater exposes a diverse igneous complex, at least as diverse as that found in similar‐age terranes on Earth. PMID:27134806

Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X-ray diffraction of the Windjana sample (Kimberley area, Gale Crater)

DOE PAGES

Treiman, Allan H.; Bish, David L.; Vaniman, David T.; ...

2015-12-27

The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X-ray diffraction (XRD) in the MSL Curiosity rover. From Rietveld refinements of its XRD pattern, Windjana contains the following: sanidine (21% weight, ~Or 95); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (~25%); and percent levels of others including ilmenite, fluorapatite, and bassanite. From mass balance on the Alpha Proton X-ray Spectrometer (APXS) chemical analysis, the amorphous material is Fe rich with nearly no other cations—like ferrihydrite. The Windjana sample shows little alteration and was likely cemented bymore » its magnetite and ferrihydrite. From ChemCam Laser-Induced Breakdown Spectrometer (LIBS) chemical analyses, Windjana is representative of the Dillinger and Mount Remarkable members of the Kimberley formation. LIBS data suggest that the Kimberley sediments include at least three chemical components. The most K-rich targets have 5.6% K 2O, ~1.8 times that of Windjana, implying a sediment component with >40% sanidine, e.g., a trachyte. A second component is rich in mafic minerals, with little feldspar (like a shergottite). A third component is richer in plagioclase and in Na 2O, and is likely to be basaltic. The K-rich sediment component is consistent with APXS and ChemCam observations of K-rich rocks elsewhere in Gale Crater. The source of this sediment component was likely volcanic. Finally, the presence of sediment from many igneous sources, in concert with Curiosity's identifications of other igneous materials (e.g., mugearite), implies that the northern rim of Gale Crater exposes a diverse igneous complex, at least as diverse as that found in similar-age terranes on Earth.« less

Atmospheric trace metals measured at a regional background site (Welgegund) in South Africa

NASA Astrophysics Data System (ADS)

Venter, Andrew D.; van Zyl, Pieter G.; Beukes, Johan P.; Josipovic, Micky; Hendriks, Johan; Vakkari, Ville; Laakso, Lauri

2017-03-01

Atmospheric trace metals can cause a variety of health-related and environmental problems. Only a few studies on atmospheric trace metal concentrations have been conducted in South Africa. Therefore the aim of this study was to determine trace metal concentrations in aerosols collected at a regional background site, i.e. Welgegund, South Africa. PM1, PM1-2. 5 and PM2. 5-10 samples were collected for 13 months, and 31 atmospheric trace metal species were detected. Atmospheric iron (Fe) had the highest concentrations in all three size fractions, while calcium (Ca) was the second-most-abundant species. Chromium (Cr) and sodium (Na) concentrations were the third- and fourth-most-abundant species, respectively. The concentrations of the trace metal species in all three size ranges were similar, with the exception of Fe, which had higher concentrations in the PM1 size fraction. With the exception of titanium (Ti), aluminium (Al) and manganese (Mg), 70 % or more of the trace metal species detected were in the smaller size fractions, which indicated the influence of industrial activities. However, the large influence of wind-blown dust was reflected by 30 % or more of trace metals being present in the PM2. 5-10 size fraction. Comparison of trace metals determined at Welgegund to those in the western Bushveld Igneous Complex indicated that at both locations similar species were observed, with Fe being the most abundant. However, concentrations of these trace metal species were significantly higher in the western Bushveld Igneous Complex. Fe concentrations at the Vaal Triangle were similar to levels thereof at Welgegund, while concentrations of species associated with pyrometallurgical smelting were lower. Annual average Ni was 4 times higher, and annual average As was marginally higher than their respective European standard values, which could be attributed to regional influence of pyrometallurgical industries in the western Bushveld Igneous Complex. All three size fractions indicated elevated trace metal concentrations coinciding with the end of the dry season, which could partially be attributed to decreased wet removal and increases in wind generation of particulates. Principal component factor analysis (PCFA) revealed four meaningful factors in the PM1 size fraction, i.e. crustal, pyrometallurgical-related and Au slimes dams. No meaningful factors were determined for the PM1-2. 5 and PM2. 5-10 size fractions, which was attributed to the large influence of wind-blown dust on atmospheric trace metals determined at Welgegund. Pollution roses confirmed the influence of wind-blown dust on trace metal concentrations measured at Welgegund, while the impact of industrial activities was also substantiated.

Submarine hydrothermal metamorphism of the Del Puerto ophiolite, California.

USGS Publications Warehouse

Evarts, R.C.; Schiffman, P.

1983-01-01

Metamorphic zonation overprinted on the volcanic member and overlying volcanogenic sediments of the ophiolite complex increases downward in grade and is characterized by the sequential appearance with depth of zeolites, ferric pumpellyite and pistacitic epidote. Metamorphic assemblages of the plutonic member of the complex are characterized by the presence of calcic amphibole. The overprinting represents the effects of hydrothermal metamorphism resulting from the massive interaction between hot igneous rocks and convecting sea-water in a submarine environment. A thermal gradient of 100oC/km is postulated to account for the zonal recrystallization effects in the volcanic member. The diversity and sporadic distribution of mineral assemblages in the amphibole zone are considered due to the limited availability of H2O in the deeper part of the complex. Details of the zonation and representative microprobe analyses are tabulated.-M.S.

78 FR 13761 - Designation of One Entity Pursuant to Executive Order 13448

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-28

... branches, of the persons listed in the Annex to E.O. 13448, as well as those persons determined by the..., Burma; No. 1 Ywama Curve, Ba Yint Naung Road, Block (2), Hlaing Township, Yangon, Burma; SWIFT/BIC AYAB...

Basalt-trachybasalt samples in Gale Crater, Mars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, Peter H.; Bridges, John C.; Wiens, Roger Craig

The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single-laser-shot spectra of igneous targets observed by ChemCam shows a strong peak at ~55 wt% SiO 2 and 6 wt% total alkalis, with a minor secondary maximum at 47–51 wt% SiO 2 and lower alkali content. The centers of these distributions, together with the rock textures, indicate that many of the ChemCam igneous targets are trachybasalts, Mg# = 27 but with a secondary concentration of basaltic material, with a focus of compositions around Mg#more » = 54. We suggest that all of these igneous rocks resulted from low-pressure, olivine-dominated fractionation of Adirondack (MER) class-type basalt compositions. This magmatism has subalkaline, tholeiitic affinities. The similarity of the basalt endmember to much of the Gale sediment compositions in the first 1000 sols of the MSL mission suggests that this type of Fe-rich, relatively low-Mg#, olivine tholeiite is the dominant constituent of the Gale catchment that is the source material for the fine-grained sediments in Gale. The similarity to many Gusev igneous compositions suggests that it is a major constituent of ancient Martian magmas, and distinct from the shergottite parental melts thought to be associated with Tharsis and the Northern Lowlands. Finally, the Gale Crater catchment sampled a mixture of this tholeiitic basalt along with alkaline igneous material, together giving some analogies to terrestrial intraplate magmatic provinces.« less

Basalt-trachybasalt samples in Gale Crater, Mars

DOE PAGES

Edwards, Peter H.; Bridges, John C.; Wiens, Roger Craig; ...

2017-09-14

The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single-laser-shot spectra of igneous targets observed by ChemCam shows a strong peak at ~55 wt% SiO 2 and 6 wt% total alkalis, with a minor secondary maximum at 47–51 wt% SiO 2 and lower alkali content. The centers of these distributions, together with the rock textures, indicate that many of the ChemCam igneous targets are trachybasalts, Mg# = 27 but with a secondary concentration of basaltic material, with a focus of compositions around Mg#more » = 54. We suggest that all of these igneous rocks resulted from low-pressure, olivine-dominated fractionation of Adirondack (MER) class-type basalt compositions. This magmatism has subalkaline, tholeiitic affinities. The similarity of the basalt endmember to much of the Gale sediment compositions in the first 1000 sols of the MSL mission suggests that this type of Fe-rich, relatively low-Mg#, olivine tholeiite is the dominant constituent of the Gale catchment that is the source material for the fine-grained sediments in Gale. The similarity to many Gusev igneous compositions suggests that it is a major constituent of ancient Martian magmas, and distinct from the shergottite parental melts thought to be associated with Tharsis and the Northern Lowlands. Finally, the Gale Crater catchment sampled a mixture of this tholeiitic basalt along with alkaline igneous material, together giving some analogies to terrestrial intraplate magmatic provinces.« less

Continental igneous rock composition: A major control of past global chemical weathering

PubMed Central

Bataille, Clément P.; Willis, Amy; Yang, Xiao; Liu, Xiao-Ming

2017-01-01

The composition of igneous rocks in the continental crust has changed throughout Earth’s history. However, the impact of these compositional variations on chemical weathering, and by extension on seawater and atmosphere evolution, is largely unknown. We use the strontium isotope ratio in seawater [(87Sr/86Sr)seawater] as a proxy for chemical weathering, and we test the sensitivity of (87Sr/86Sr)seawater variations to the strontium isotopic composition (87Sr/86Sr) in igneous rocks generated through time. We demonstrate that the 87Sr/86Sr ratio in igneous rocks is correlated to the epsilon hafnium (εHf) of their hosted zircon grains, and we use the detrital zircon record to reconstruct the evolution of the 87Sr/86Sr ratio in zircon-bearing igneous rocks. The reconstructed 87Sr/86Sr variations in igneous rocks are strongly correlated with the (87Sr/86Sr)seawater variations over the last 1000 million years, suggesting a direct control of the isotopic composition of silicic magmatism on (87Sr/86Sr)seawater variations. The correlation decreases during several time periods, likely reflecting changes in the chemical weathering rate associated with paleogeographic, climatic, or tectonic events. We argue that for most of the last 1000 million years, the (87Sr/86Sr)seawater variations are responding to changes in the isotopic composition of silicic magmatism rather than to changes in the global chemical weathering rate. We conclude that the (87Sr/86Sr)seawater variations are of limited utility to reconstruct changes in the global chemical weathering rate in deep times. PMID:28345044

Analysis of significant factors for dengue fever incidence prediction.

PubMed

Siriyasatien, Padet; Phumee, Atchara; Ongruk, Phatsavee; Jampachaisri, Katechan; Kesorn, Kraisak

2016-04-16

Many popular dengue forecasting techniques have been used by several researchers to extrapolate dengue incidence rates, including the K-H model, support vector machines (SVM), and artificial neural networks (ANN). The time series analysis methodology, particularly ARIMA and SARIMA, has been increasingly applied to the field of epidemiological research for dengue fever, dengue hemorrhagic fever, and other infectious diseases. The main drawback of these methods is that they do not consider other variables that are associated with the dependent variable. Additionally, new factors correlated to the disease are needed to enhance the prediction accuracy of the model when it is applied to areas of similar climates, where weather factors such as temperature, total rainfall, and humidity are not substantially different. Such drawbacks may consequently lower the predictive power for the outbreak. The predictive power of the forecasting model-assessed by Akaike's information criterion (AIC), Bayesian information criterion (BIC), and the mean absolute percentage error (MAPE)-is improved by including the new parameters for dengue outbreak prediction. This study's selected model outperforms all three other competing models with the lowest AIC, the lowest BIC, and a small MAPE value. The exclusive use of climate factors from similar locations decreases a model's prediction power. The multivariate Poisson regression, however, effectively forecasts even when climate variables are slightly different. Female mosquitoes and seasons were strongly correlated with dengue cases. Therefore, the dengue incidence trends provided by this model will assist the optimization of dengue prevention. The present work demonstrates the important roles of female mosquito infection rates from the previous season and climate factors (represented as seasons) in dengue outbreaks. Incorporating these two factors in the model significantly improves the predictive power of dengue hemorrhagic fever forecasting models, as confirmed by AIC, BIC, and MAPE.

Effect of recombinant human bone morphogenetic protein-2 on bone regeneration and osseointegration of dental implants.

PubMed

Sykaras, N; Triplett, R G; Nunn, M E; Iacopino, A M; Opperman, L A

2001-08-01

Recombinant human bone morphogenetic protein-2 (rhBMP-2) induced bone regeneration and osseointegration was evaluated in bony defects created within the hollow chamber of endosseous dental implants in 14 foxhound dogs. Bilateral extractions of mandibular premolars were performed and surgical implantation of 104 hollow cylinder implants followed after 8 weeks of healing. Experimental implants had their hollow chamber filled with 20 microg of rhBMP-2 delivered with a bovine collagen carrier, whereas the control implants had their apical chamber left empty. Dogs were followed for 2, 4, 8 and 12 weeks. Histomorphometric evaluation and immunohistochemical analysis were performed. Minimal bone was regenerated at 2 weeks for both groups. At 4 weeks, bone fill averaged 23.48% for the rhBMP-2 and 5.98% for the control group (P<0.05). At 8 weeks, mean bone fill was 20.94% and 7.75% for the rhBMP-2 and the controls, respectively (P<0.05). At 12 weeks, mean bone fill was 31.39% and 24.31% for the rhBMP-2 and control implants, respectively (P>0.05). Bone-implant contact (BIC) increased for both groups over time and at 8 weeks the rhBMP-2 BIC value was 18.65% and for the control 7.22% (P<0.05). At 12 weeks, the BIC was 43.78% and 21.05% for the rhBMP-2 and the control group, respectively (P<0.05). Immunohistochemical staining for type II collagen was positive only for parts of the collagen carrier and formation of cartilaginous intermediate was not observed in any of the specimens. The results suggest that, in confined defects adjacent to dental implants, rhBMP-2 can induce bone regeneration in close apposition to the implant surface.

Elder American Indian women's knowledge of pelvic floor disorders and barriers to seeking care.

PubMed

Dunivan, Gena C; Komesu, Yuko M; Cichowski, Sara B; Lowery, Christine; Anger, Jennifer T; Rogers, Rebecca G

2015-01-01

The objectives of this study are to evaluate urinary incontinence and pelvic organ prolapse knowledge among elder southwestern American Indian women and to assess barriers to care for pelvic floor disorders through community-engaged research. Our group was invited to provide an educational talk on urinary incontinence and pelvic organ prolapse at an annual meeting of American Indian elders. Female attendees aged 55 years or older anonymously completed demographic information and 2 validated questionnaires, the Prolapse and Incontinence Knowledge Questionnaire (PIKQ) and Barriers to Incontinence Care Seeking Questionnaire (BICS-Q). Questionnaire results were compared with historical controls from the original PIKQ and BICS-Q validation study. One hundred forty-four women completed the questionnaires. The mean age was 77.7 ± 9.1 years. The mean (SD) for PIKQ of urinary incontinence score was 6.6 (3.0) (similar to historic gynecology controls 6.8 [3.3], P = 0.49), and the mean (SD) for PIKQ on pelvic organ prolapse score was 5.4 (2.9) (better than historic gynecology controls 3.6 [3.2], P < 0.01). Barriers to care seeking reported by the elder women were highest on the BICS-Q subscales of "cost" and "inconvenience." Urinary incontinence knowledge is similar to historic gynecology controls, and pelvic organ prolapse knowledge is higher than historic gynecology controls among elder southwestern American Indian women. American Indian elder women report high levels of barriers to care. The greatest barriers to care seeking for this population were related to cost and inconvenience, reflecting the importance of assessing socioeconomic status when investigating barriers to care. Addressing these barriers may enhance care-seeking southwestern American Indian women.

Different bone regeneration patterns in periimplant circumferential gap defects grafted with two types of osteoconductive biomaterial.

PubMed

Lee, Jung-Seok; Sohn, Joo-Yeon; Lim, Hyun-Chang; Jung, Ui-Won; Choi, Seong-Ho

2016-08-01

This study aimed to determine healing patterns in periimplant gap defect grafted with demineralized bovine bone mineral (DBBM) and porous titanium granules (PTG), which are known to induce a minimal tissue reaction and to undergo minimal biodegradation in healing process. Experiments were performed using a standardized periimplant gap-defect model in dogs with two observational periods: 4 and 8 weeks. Circumferential defects were surgically induced around dental implants on unilateral mandibles in five dogs, and collagen barrier membranes were placed over the DBBM and PTG grafts at two experimental sites and over a nongrafted site. Four weeks later, the same procedures were performed on the contralateral mandible, and the animals allowed to heal for a further 4 weeks, after which they were sacrificed and their mandibles with graft/control sites harvested for histologic evaluation. Both types of grafted biomaterials significantly enhanced the defect fill with newly formed bone, but the bone-to-implant contact (BIC) was significantly increased only at sites that had been grafted with DBBM. The two experimental sites exhibited different healing patterns, with new bone formation being observed on the surface of the DBBM particles throughout the defect, while there was no de novo bone formation on the PTG surface, but rather appositional bone growth from the base and lateral walls of the defect. It has been suggested that gap-defect filling with DBBM around dental implants may enhance both BIC and defect fill; however, the present findings show that defect grafting with PTG enhances only defect fill and not BIC. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1202-1209, 2016. © 2015 Wiley Periodicals, Inc.

Influence of family dynamics on burden among family caregivers in aging Japan

PubMed Central

Kusaba, Tesshu; Sato, Kotaro; Fukuma, Shingo; Yamada, Yukari; Matsui, Yoshinori; Matsuda, Satoshi; Ando, Takashi; Sakushima, Ken; Fukuhara, Shunichi

2016-01-01

Background. Long-term care for the elderly is largely shouldered by their family, representing a serious burden in a hyper-aging society. However, although family dynamics are known to play an important role in such care, the influence of caring for the elderly on burden among caregiving family members is poorly understood. Objective. To examine the influence of family dynamics on burden experienced by family caregivers. Methods. We conducted a cross-sectional study at six primary care clinics, involving 199 caregivers of adult care receivers who need long-term care. Participants were divided into three groups based on tertile of Index of Family Dynamics for Long-term Care (IF-Long score), where higher scores imply poorer relationships between care receivers and caregiving family: best, <2; intermediate, 2 to <5; worst, ≥5. The mean differences in burden index of caregivers (BIC-11) between the three groups were estimated by linear regression model with adjustment for care receiver’s activity of daily living and cognitive function. Results. Mean age of caregivers was 63.2 years (with 40.7% aged ≥ 65 years). BIC-11 scores were higher in the worst IF-Long group (adjusted mean difference: 4.4, 95% confidence interval: 1.2 to 7.5) than in the best IF-Long group. We also detected a positive trend between IF-Long score and BIC-11 score (P-value for trend <0.01). Conclusion. Our findings indicate that family dynamics strongly influences burden experienced by caregiving family members, regardless of the care receiver’s degree of cognitive impairment. These results underscore the importance of evaluating relationships between care receivers and their caregivers when discussing a care regimen for care receivers. PMID:27450988

Incorporating Neutrophil-to-lymphocyte Ratio and Platelet-to-lymphocyte Ratio in Place of Neutrophil Count and Platelet Count Improves Prognostic Accuracy of the International Metastatic Renal Cell Carcinoma Database Consortium Model

PubMed Central

Chrom, Pawel; Stec, Rafal; Bodnar, Lubomir; Szczylik, Cezary

2018-01-01

Purpose The study investigated whether a replacement of neutrophil count and platelet count by neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) within the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model would improve its prognostic accuracy. Materials and Methods This retrospective analysis included consecutive patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors. The IMDC and modified-IMDC models were compared using: concordance index (CI), bias-corrected concordance index (BCCI), calibration plots, the Grønnesby and Borgan test, Bayesian Information Criterion (BIC), generalized R2, Integrated Discrimination Improvement (IDI), and continuous Net Reclassification Index (cNRI) for individual risk factors and the three risk groups. Results Three hundred and twenty-one patients were eligible for analyses. The modified-IMDC model with NLR value of 3.6 and PLR value of 157 was selected for comparison with the IMDC model. Both models were well calibrated. All other measures favoured the modified-IMDC model over the IMDC model (CI, 0.706 vs. 0.677; BCCI, 0.699 vs. 0.671; BIC, 2,176.2 vs. 2,190.7; generalized R2, 0.238 vs. 0.202; IDI, 0.044; cNRI, 0.279 for individual risk factors; and CI, 0.669 vs. 0.641; BCCI, 0.669 vs. 0.641; BIC, 2,183.2 vs. 2,198.1; generalized R2, 0.163 vs. 0.123; IDI, 0.045; cNRI, 0.165 for the three risk groups). Conclusion Incorporation of NLR and PLR in place of neutrophil count and platelet count improved prognostic accuracy of the IMDC model. These findings require external validation before introducing into clinical practice. PMID:28253564

Incorporating Neutrophil-to-lymphocyte Ratio and Platelet-to-lymphocyte Ratio in Place of Neutrophil Count and Platelet Count Improves Prognostic Accuracy of the International Metastatic Renal Cell Carcinoma Database Consortium Model.

PubMed

Chrom, Pawel; Stec, Rafal; Bodnar, Lubomir; Szczylik, Cezary

2018-01-01

The study investigated whether a replacement of neutrophil count and platelet count by neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) within the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model would improve its prognostic accuracy. This retrospective analysis included consecutive patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors. The IMDC and modified-IMDC models were compared using: concordance index (CI), bias-corrected concordance index (BCCI), calibration plots, the Grønnesby and Borgan test, Bayesian Information Criterion (BIC), generalized R 2 , Integrated Discrimination Improvement (IDI), and continuous Net Reclassification Index (cNRI) for individual risk factors and the three risk groups. Three hundred and twenty-one patients were eligible for analyses. The modified-IMDC model with NLR value of 3.6 and PLR value of 157 was selected for comparison with the IMDC model. Both models were well calibrated. All other measures favoured the modified-IMDC model over the IMDC model (CI, 0.706 vs. 0.677; BCCI, 0.699 vs. 0.671; BIC, 2,176.2 vs. 2,190.7; generalized R 2 , 0.238 vs. 0.202; IDI, 0.044; cNRI, 0.279 for individual risk factors; and CI, 0.669 vs. 0.641; BCCI, 0.669 vs. 0.641; BIC, 2,183.2 vs. 2,198.1; generalized R 2 , 0.163 vs. 0.123; IDI, 0.045; cNRI, 0.165 for the three risk groups). Incorporation of NLR and PLR in place of neutrophil count and platelet count improved prognostic accuracy of the IMDC model. These findings require external validation before introducing into clinical practice.

Application of seasonal auto-regressive integrated moving average model in forecasting the incidence of hand-foot-mouth disease in Wuhan, China.

PubMed

Peng, Ying; Yu, Bin; Wang, Peng; Kong, De-Guang; Chen, Bang-Hua; Yang, Xiao-Bing

2017-12-01

Outbreaks of hand-foot-mouth disease (HFMD) have occurred many times and caused serious health burden in China since 2008. Application of modern information technology to prediction and early response can be helpful for efficient HFMD prevention and control. A seasonal auto-regressive integrated moving average (ARIMA) model for time series analysis was designed in this study. Eighty-four-month (from January 2009 to December 2015) retrospective data obtained from the Chinese Information System for Disease Prevention and Control were subjected to ARIMA modeling. The coefficient of determination (R 2 ), normalized Bayesian Information Criterion (BIC) and Q-test P value were used to evaluate the goodness-of-fit of constructed models. Subsequently, the best-fitted ARIMA model was applied to predict the expected incidence of HFMD from January 2016 to December 2016. The best-fitted seasonal ARIMA model was identified as (1,0,1)(0,1,1) 12 , with the largest coefficient of determination (R 2 =0.743) and lowest normalized BIC (BIC=3.645) value. The residuals of the model also showed non-significant autocorrelations (P Box-Ljung (Q) =0.299). The predictions by the optimum ARIMA model adequately captured the pattern in the data and exhibited two peaks of activity over the forecast interval, including a major peak during April to June, and again a light peak for September to November. The ARIMA model proposed in this study can forecast HFMD incidence trend effectively, which could provide useful support for future HFMD prevention and control in the study area. Besides, further observations should be added continually into the modeling data set, and parameters of the models should be adjusted accordingly.

miR expression in MYC-negative DLBCL/BL with partial trisomy 11 is similar to classical Burkitt lymphoma and different from diffuse large B-cell lymphoma.

PubMed

Zajdel, Michalina; Rymkiewicz, Grzegorz; Chechlinska, Magdalena; Blachnio, Katarzyna; Pienkowska-Grela, Barbara; Grygalewicz, Beata; Goryca, Krzysztof; Cieslikowska, Maria; Bystydzienski, Zbigniew; Swoboda, Pawel; Walewski, Jan; Siwicki, Jan Konrad

2015-07-01

Fast and reliable differential diagnosis of Burkitt lymphoma (BL) vs. diffuse large B cell lymphoma (DLBCL) is of major importance for therapeutic decisions and patient outcome. Aggressive B cell non-Hodgkin lymphomas (B-NHLs) that do not belong to the abovementioned entities were categorized by the current WHO lymphoma classification as "B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL" (DLBCL/BL). We have recently described a DLBCL/BL subgroup with recurrent chromosome 11q aberrations, resembling BL (B-NHLs[11q]). Here, we analyzed 102 prospectively collected fine needle aspirates from patients with aggressive B-NHLs in order to investigate the potential of microRNA (miR)-155, its precursor BIC, as well as miR-21 and miR-26a to differentiate BL from DLBCL, and from DLBCL/BL that include B-NHLs[11q]. Both BL and DLBCL/BL cases, including B-NHLs[11q], demonstrated significantly lower expression levels of miR-155/BIC, miR-21, and miR-26a compared to primary DLBCL. In conclusion, the miRs expression in B-NHLs[11q] provides a new suggestion, in addition to pathomorphological and clinical similarities between classical, i.e., MYC translocation-positive BL, and B-NHLs[11q], to recognize the B-NHLs[11q] subgroup of DLBCL/BL category as a MYC translocation-negative variant of BL in most cases, and points to the potential utility of miR-155/BIC/miR-21/miR-26a for the differential diagnosis of a heterogeneous category of DLBCL/BL.

Acute sleep deprivation preconditions the heart against ischemia/ reperfusion injury: the role of central GABA-A receptors

PubMed Central

Parsa, Hoda; Imani, Alireza; Faghihi, Mahdieh; Riahi, Esmail; Badavi, Mohammad; Shakoori, Abbas; Rastegar, Tayebeh; Aghajani, Marjan; Rajani, Sulail Fatima

2017-01-01

Objective(s): Central γ-aminobutyric acid (GABA) neurotransmission modulates cardiovascular functions and sleep. Acute sleep deprivation (ASD) affects functions of various body organs via different mechanisms. Here, we evaluated the effect of ASD on cardiac ischemia/reperfusion injury (IRI), and studied the role of GABA-A receptor inhibition in central nucleus of amygdala (CeA) by assessing nitric oxide (NO) and oxidative stress. Materials and Methods: The CeA in sixty male Wistar rats was cannulated for saline or bicuculline (GABA-A receptor antagonist) administration. All animals underwent 30 min of coronary occlusion (ischemia), followed by 2 hr reperfusion (IR). The five experimental groups (n=12) included are as follows: IR: received saline; BIC+IR: received Bicuculline; MLP+IR: received saline, followed by the placement of animals in an aquarium with multiple large platforms; ASD+IR: underwent ASD in an aquarium with multiple small platforms; and BIC+ASD+IR: received bicuculline prior to ASD. Results: Bicuculline administration increased the malondialdehyde levels and infarct size, and decreased the NO metabolites levels and endothelial nitric oxide synthase (eNOS) gene expression in infarcted and non-infarcted areas in comparison to IR group. ASD reduced malondialdehyde levels and infarct size and increased NO metabolites, corticosterone levels and eNOS expression in infarcted and non-infarcted areas as compared to the IR group. Levels of malondialdehyde were increased while levels of NO metabolites, corticosterone and eNOS expression in infarcted and non-infarcted areas were reduced in the BIC+ASD+IR as compared to the ASD+IR group. Conclusion: Blockade of GABA-A receptors in the CeA abolishes ASD-induced cardioprotection by suppressing oxidative stress and NO production. PMID:29299201

Acute sleep deprivation preconditions the heart against ischemia/ reperfusion injury: the role of central GABA-A receptors.

PubMed

Parsa, Hoda; Imani, Alireza; Faghihi, Mahdieh; Riahi, Esmail; Badavi, Mohammad; Shakoori, Abbas; Rastegar, Tayebeh; Aghajani, Marjan; Rajani, Sulail Fatima

2017-11-01

Central γ-aminobutyric acid (GABA) neurotransmission modulates cardiovascular functions and sleep. Acute sleep deprivation (ASD) affects functions of various body organs via different mechanisms. Here, we evaluated the effect of ASD on cardiac ischemia/reperfusion injury (IRI), and studied the role of GABA-A receptor inhibition in central nucleus of amygdala (CeA) by assessing nitric oxide (NO) and oxidative stress. The CeA in sixty male Wistar rats was cannulated for saline or bicuculline (GABA-A receptor antagonist) administration. All animals underwent 30 min of coronary occlusion (ischemia), followed by 2 hr reperfusion (IR). The five experimental groups (n=12) included are as follows: IR: received saline; BIC+IR: received Bicuculline; MLP+IR: received saline, followed by the placement of animals in an aquarium with multiple large platforms; ASD+IR: underwent ASD in an aquarium with multiple small platforms; and BIC+ASD+IR: received bicuculline prior to ASD. Bicuculline administration increased the malondialdehyde levels and infarct size, and decreased the NO metabolites levels and endothelial nitric oxide synthase (eNOS) gene expression in infarcted and non-infarcted areas in comparison to IR group. ASD reduced malondialdehyde levels and infarct size and increased NO metabolites, corticosterone levels and eNOS expression in infarcted and non-infarcted areas as compared to the IR group. Levels of malondialdehyde were increased while levels of NO metabolites, corticosterone and eNOS expression in infarcted and non-infarcted areas were reduced in the BIC+ASD+IR as compared to the ASD+IR group. Blockade of GABA-A receptors in the CeA abolishes ASD-induced cardioprotection by suppressing oxidative stress and NO production.

Burden and Depression in Caregivers of Blind Patients in New York State.

PubMed

Braich, Puneet S; Jackson, Matthew; Knohl, Stephen J; Bhoiwala, Devang; Gandham, Sai B; Almeida, David

2016-06-01

To describe the degree of burden of care and the proportion at risk of depression among individuals caring for legally blind patients. We performed a cross-sectional study of 486 individuals providing care to their family members who were legally blind. Best-corrected visual acuity of the better-seeing eye in patients determined group placement: Group 1, 20/200-10/200; group 2, 10/200 to light perception (LP); group 3, no light perception (NLP); group VF, visual field loss to <20 central degrees. Burden was evaluated using the Burden Index of Caregivers (BIC-11) and the prevalence at risk of depression was determined by the Center for Epidemiologic Studies Depression (CES-D) scale. Total mean BIC-11 scores ranged from 8.78 ± 4.82 (group 1) to 12.03 ± 5.22 (group 3; p = 0.04). Daily hours spent on close supervision, intensity of caregiving and presence of multiple chronic illnesses in caregivers were the significant covariates affecting BIC-11 scores (p < 0.05). The prevalence of caregivers at risk of depression increased with vision loss from 6.9% (group 1) to 17.9% (group 3; p < 0.05). Female caregivers had an odds ratio (OR) of 2.89 for depression (95% confidence interval, CI, 1.07-3.97; p = 0.04). Caregivers with ≥2 comorbidities had OR 4.24 (95% CI 2.41-6.11) for risk of depression (p < 0.01). Burden of care was highest among caregivers who provided greater hours of supervision. Patients with more limitations in their activities of daily living had caregivers who reported higher burden. Female caregivers and caregivers with multiple chronic illnesses were at higher risk of depression.

In vivo and in vitro investigations of a nanostructured coating material – a preclinical study

PubMed Central

Adam, Martin; Ganz, Cornelia; Xu, Weiguo; Sarajian, Hamid-Reza; Götz, Werner; Gerber, Thomas

2014-01-01

Immediate loading of dental implants is only possible if a firm bone-implant anchorage at early stages is developed. This implies early and high bone apposition onto the implant surface. A nanostructured coating material based on an osseoinductive bone grafting is investigated in relation to the osseointegration at early stages. The goal is to transmit the structure (silica matrix with embedded hydroxyapatite) and the properties of the bone grafting into a coating material. The bone grafting substitute offers an osseoinductive potential caused by an exchange of the silica matrix in vivo accompanied by vascularization. X-ray diffraction and transmission electron microscopy analysis show that the coating material consists of a high porous silica matrix with embedded nanocrystalline hydroxyapatite with the same morphology as human hydroxyapatite. An in vitro investigation shows the early interaction between coating and human blood. Energy-dispersive X-ray analysis showed that the silica matrix was replaced by an organic matrix within a few minutes. Uncoated and coated titanium implants were inserted into the femora of New Zealand White rabbits. The bone-to-implant contact (BIC) was measured after 2, 4, and 6 weeks. The BIC of the coated implants was increased significantly at 2 and 4 weeks. After 6 weeks, the BIC was decreased to the level of the control group. A histological analysis revealed high bone apposition on the coated implant surface after 2 and 4 weeks. Osteoblastic and osteoclastic activities on the coating material indicated that the coating participates in the bone-remodeling process. The nanostructure of the coating material led to an exchange of the silica matrix by an autologous, organic matrix without delamination of the coating. This is the key issue in understanding initial bone formation on a coated surface. PMID:24627631

Influence of Piezosurgery on Bone Healing around Titanium Implants: A Histological Study in Rats.

PubMed

Sirolli, Marcelo; Mafra, Carlos Eduardo Secco; Santos, Rodrigo Albuquerque Basílio Dos; Saraiva, Luciana; Holzhausen, Marinella; César, João Batista

2016-01-01

The aim of this study was to evaluate histomorphometrically the influence of two techniques of dental implant site preparation on bone healing around titanium implants. Fifteen male Wistar rats (±300 g) were used in the study. Each tibia was randomly assigned to receive the implant site preparation either with a conventional drilling technique (control - DRILL group) or with a piezoelectric device (PIEZO group). The animals were sacrificed after 30 days and then the following histomorphometric parameters were evaluated (percentage) separately for cortical and cancellous regions: proportion of mineralized tissue (PMT) adjacent to implant threads (500 μm adjacent); bone area within the threads (BA) and bone-implant contact (BIC). The results demonstrated that there were no statistically significant differences between both groups for cancellous BIC (p>0.05) and cortical PMT (p>0.05). On the other hand, a higher percentage of BA was observed in the PIEZO group in the cortical (71.50±6.91 and 78.28±4.38 for DRILL and PIEZO groups, respectively; p<0.05) and cancellous regions (9.62±4.06 and 19.94±14.18 for DRILL and PIEZO groups, respectively; p<0.05). The piezosurgery also showed higher PMT values in the cancellous zone (9.35±5.54 and 18.72±13.21 for DRILL and PIEZO groups, respectively; p<0.05). However, the DRILL group presented better results for BIC in cortical region (80.42±10.88 and 70.25±16.93 for DRILL and PIEZO groups, respectively; p<0.05). In conclusion, for the implant site preparation, the piezosurgery was beneficial to bone healing rates in the cancellous bone region, while the drill technique produced better results in the cortical bone.

Class Enumeration and Parameter Recovery of Growth Mixture Modeling and Second-Order Growth Mixture Modeling in the Presence of Measurement Noninvariance between Latent Classes

PubMed Central

Kim, Eun Sook; Wang, Yan

2017-01-01

Population heterogeneity in growth trajectories can be detected with growth mixture modeling (GMM). It is common that researchers compute composite scores of repeated measures and use them as multiple indicators of growth factors (baseline performance and growth) assuming measurement invariance between latent classes. Considering that the assumption of measurement invariance does not always hold, we investigate the impact of measurement noninvariance on class enumeration and parameter recovery in GMM through a Monte Carlo simulation study (Study 1). In Study 2, we examine the class enumeration and parameter recovery of the second-order growth mixture modeling (SOGMM) that incorporates measurement models at the first order level. Thus, SOGMM estimates growth trajectory parameters with reliable sources of variance, that is, common factor variance of repeated measures and allows heterogeneity in measurement parameters between latent classes. The class enumeration rates are examined with information criteria such as AIC, BIC, sample-size adjusted BIC, and hierarchical BIC under various simulation conditions. The results of Study 1 showed that the parameter estimates of baseline performance and growth factor means were biased to the degree of measurement noninvariance even when the correct number of latent classes was extracted. In Study 2, the class enumeration accuracy of SOGMM depended on information criteria, class separation, and sample size. The estimates of baseline performance and growth factor mean differences between classes were generally unbiased but the size of measurement noninvariance was underestimated. Overall, SOGMM is advantageous in that it yields unbiased estimates of growth trajectory parameters and more accurate class enumeration compared to GMM by incorporating measurement models. PMID:28928691

Workshop on Evolution of Igneous Asteroids: Focus on Vesta and the HED Meteorites. Pt. 1

NASA Technical Reports Server (NTRS)

Mittlefehldt, David W. (Editor); Papike, James J. (Editor)

1996-01-01

This volume contains abstracts of papers that have been accepted for presentation at the Workshop on Evolution of Igneous Asteroids: Focus on Vesta and the HED Meteorites, October 16-18, 1996, in Houston, Texas.

Elevation and igneous crater modification on Venus: Implications for magmatic volatile content

NASA Technical Reports Server (NTRS)

Wichman, R. W.

1993-01-01

Although most impact craters on Venus preserve nearly pristine crater rim and ejecta features, a small number of craters have been identified showing clear evidence of either igneous intrusion emplacement (floor-fracturing) beneath the crater floor or of volcanically embayed exterior ejecta deposits. Since the volcanically embayed craters consistently occur at higher elevations than the identified floor-fractured craters, this report proposes that igneous crater modification on Venus is elevation dependent. This report describes how regional variations in magmatic neutral buoyancy could produce such elevation dependent crater modification and considers the implications for typical magmatic volatile contents on Venus.

31 CFR 203.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... LOAN PROGRAM General Information § 203.2 Definitions. Advice of credit (AOC) means the paper or electronic form depositaries use to summarize and report Federal Tax Deposit (FTD) coupon deposits to the... in its Treasury Investment Program (TIP) main account. Borrower-In-Custody (BIC) collateral means an...

Measuring Language Dominance and Bilingual Proficiency Development of Tarahumara Children.

ERIC Educational Resources Information Center

Paciotto, Carla

This paper examines the language dominance and oral bilingual proficiency of Tarahumara-Spanish speaking students from Chihuahua, Mexico, within the framework of Cummins' model of bilingual proficiency development. Cummins' model distinguishes between basic interpersonal communicative skills (BICS) and cognitive academic language proficiency…

Model Selection Methods for Mixture Dichotomous IRT Models

ERIC Educational Resources Information Center

Li, Feiming; Cohen, Allan S.; Kim, Seock-Ho; Cho, Sun-Joo

2009-01-01

This study examines model selection indices for use with dichotomous mixture item response theory (IRT) models. Five indices are considered: Akaike's information coefficient (AIC), Bayesian information coefficient (BIC), deviance information coefficient (DIC), pseudo-Bayes factor (PsBF), and posterior predictive model checks (PPMC). The five…

Maximum likelihood-based analysis of single-molecule photon arrival trajectories

NASA Astrophysics Data System (ADS)

Hajdziona, Marta; Molski, Andrzej

2011-02-01

In this work we explore the statistical properties of the maximum likelihood-based analysis of one-color photon arrival trajectories. This approach does not involve binning and, therefore, all of the information contained in an observed photon strajectory is used. We study the accuracy and precision of parameter estimates and the efficiency of the Akaike information criterion and the Bayesian information criterion (BIC) in selecting the true kinetic model. We focus on the low excitation regime where photon trajectories can be modeled as realizations of Markov modulated Poisson processes. The number of observed photons is the key parameter in determining model selection and parameter estimation. For example, the BIC can select the true three-state model from competing two-, three-, and four-state kinetic models even for relatively short trajectories made up of 2 × 103 photons. When the intensity levels are well-separated and 104 photons are observed, the two-state model parameters can be estimated with about 10% precision and those for a three-state model with about 20% precision.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Afzal, Muhammad U., E-mail: muhammad.afzal@mq.edu.au; Esselle, Karu P.

This paper presents a quasi-analytical technique to design a continuous, all-dielectric phase correcting structures (PCSs) for circularly polarized Fabry-Perot resonator antennas (FPRAs). The PCS has been realized by varying the thickness of a rotationally symmetric dielectric block placed above the antenna. A global analytical expression is derived for the PCS thickness profile, which is required to achieve nearly uniform phase distribution at the output of the PCS, despite the non-uniform phase distribution at its input. An alternative piecewise technique based on spline interpolation is also explored to design a PCS. It is shown from both far- and near-field results thatmore » a PCS tremendously improves the radiation performance of the FPRA. These improvements include an increase in peak directivity from 22 to 120 (from 13.4 dBic to 20.8 dBic) and a decrease of 3 dB beamwidth from 41.5° to 15°. The phase-corrected antenna also has a good directivity bandwidth of 1.3 GHz, which is 11% of the center frequency.« less

Stratospheric O3, H2O, and HDO distributions from balloon-based far-infrared observations

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Guo, J.; Carli, B.; Mencaraglia, F.; Bonetti, A.

1987-01-01

Limb thermal emission spectra of the earth's stratosphere in the FIR obtained as part of the Balloon Intercomparison Campaign (BIC), have been analyzed for retrieval of trace constituent distributions. The observations analyzed here were made with a balloon-borne high-resolution Michelson interferometer operating in the 20-100/cm region, with an unapodized spectral resolution of 0.0033/cm. In this paper the vertical profiles of O3, H2O, and HDO retrieved from the observed spectra are presented and compared with the results from other BIC experiments. The retrieved profiles are found to be in good agreement with other measurements. The measurement of the HDO profile provides information about the sources of stratospheric water vapor. The variation of the D/H ratio of water vapor is derived from an analysis of HDO and H2O lines observed in the FIR spectra and is compared with the available measurements in the literature.

Combined 40Ar/39Ar and Fission-Track study of the Freetown Layered Igneous Complex, Freetown, Sierra Leone, West Africa: Implications for the Initial Break-up of Pangea to form the Central Atlantic Ocean and Insight into the Post-rift Evolution of the Sie

NASA Astrophysics Data System (ADS)

Barrie, Ibrahim; Wijbrans, Jan; Andriessen, Paul; Beunk, Frank; Strasser-King, Victor; Fode, Daniel

2010-05-01

Sierra Leone lies within the south-western part of the West African Craton and comprises two major Archaean structural divisions: a low-grade granite-greenstone terrane characterised by N-S striking structures and a NW-SE striking highly metamorphosed belt of strained rocks that form the coastal margin of the craton. Intruded into the belt is the Freetown Layered Igneous Complex (FLIC), a tholeiitic magamtic body emplaced prior to or during the break-up of Pangea to form the Central Atlantic Ocean and, forming today the high ground of the coastal outline of Sierra Leone which is one of the most distinctive features on the West African coast. The break-up of Pangaea to form the Central Atlantic and its passive margins began in the Early Jurassic. Geo-tectonically, the break-up was particularly characterised by the formation of the Central Atlantic Magmatic Province (CAMP), covering once-contiguous parts of North America, Europe, Africa and South America. The FLIC forming part of the heart of CAMP is the largest single layered igneous intrusive yet known on either side of the Central Atlantic, measuring on surface, 65 x 14 x 7 km. Geophysical investigations indicate that the intrusion extends offshore to a depth of about 20 km. Geologically the Complex is a rhythmically layered elongated ultramafic-mafic lopolith divisible into 4 major zones each comprising repeated sequences of troctolitic, gabbroic and anorthositic rocks. An idealised unit of layering is from base upwards: dunite, troctolite, olivine-gabbro, leuco-gabbro, gabbro-norite and anorthosite cumulates. 40Ar-39Ar age spectra and 40Ar/36Ar versus 39Ar/36Ar isochron plots obtained by stepwise-heating experiments on plagioclases, biotites and amphiboles from troctolites, olivine-gabbros, gabbro-norites and anorthosites of the four zones yield plateau and isochron ages that seem to depict the cooling history of the Complex after emplacement. The biotites and some of the plagioclases and amphiboles give very good plateaus that range from 196.3 ± 3 Ma to 232.1 ± 9 Ma with the best-fit isochron plots showing a range from 193.3± 10 Ma to 234.1 ± 11 Ma. Because these dates represent cooling ages, we interpret them as representing a minimum intrusion-age of the Complex implying that its true emplacement age might be somewhat older than 230 Ma. Given that most established CAMP ages revolve around 200 Ma or younger, we hypothesise that FLIC represents a hitherto unknown pre-CAMP magmatic event that might have thermally triggered the initial break-up of Pangaea to form the Central Atlantic. This view is consistent with field-observations that the Complex is cross-cut by predominantly coast-parallel mafic dykes attributed to the CAMP dyke-swarm. To ascertain the hypothesis, we are currently carrying out U-Pb zircon dating to establish, precisely, the true emplacement age of the Complex. The Fission-track ages vary from 91.7 ± 7 Ma to 114.6 ± 9 Ma. This age range shows that after emplacement and crystallisation, the FLIC underwent an extremely slow cooling for a long period of time. This in turn implies that after the break-up of Pangea to form, in part, the Sierra Leone margin, a late and slow uplift (Erosion/denudation) that took place during the Cretaceous was a very important geological process that characterised the post-rift evolution of the margin. References: Barrie, I.J., P.A.M. Andriessen, F.F. Beunk, J.R. Wijbrans, V.E.H. Strasser-King, D.V.A.Fode. (2006). Tectonothermal Evolution of the Sierra Leone Passive Continental Margin, West Africa: Constraints from Thermochronology. Geochemica et Cosmochemica Acta 70 (18): A36- A36 Suppl. S Aug-Sep 2006. Marzoli, A., P.R. Renne, E.M. Piccirillo, M. Ernesto, G. Bellieni, A De Min. (1999). Extensive 200-Million-Year-Old Continental Flood Basalts of the Central Atlantic Magmatic Province. Science284: 616-618. McHone, J.G. (2000). Non-plume magmatism and rifting during the opening of the central Atlantic Ocean. Tectonophysics, 316: 287-296. Umeji, A.C. (1983). Geochemistry and Mineralogy of the Freetown Layered Basic Igneous Complex of Sierra Leone. Chemical Geology, 39: 17-38. Wells, M.K. (1962). Structure and Petrology of the Freetown Layered Basic Complex of Sierra Leone. Overseas Geol. Mineral. Res. Bull. Suppl., 4, 115 pp. Williams, H.R. (1986). The Archaean Kaila Group of Western Sierra Leone: Geology and Relations with adjacent Granite-Greenstone Terrane. Precambrian Research, 38: 201-213.

Episodic Cenozoic volcanism and tectonism in the Andes of Peru

USGS Publications Warehouse

Noble, D.C.; McKee, E.H.; Farrar, E.; Petersen, U.

1974-01-01

Radiometric and geologic information indicate a complex history of Cenozoic volcanism and tectonism in the central Andes. K-Ar ages on silicic pyroclastic rocks demonstrate major volcanic activity in central and southern Peru, northern Chile, and adjacent areas during the Early and Middle Miocene, and provide additional evidence for volcanism during the Late Eocene. A provisional outline of tectonic and volcanic events in the Peruvian Andes during the Cenozoic includes: one or more pulses of igneous activity and intense deformation during the Paleocene and Eocene; a period of quiescence, lasting most of Oligocene time; reinception of tectonism and volcanism at the beginning of the Miocene; and a major pulse of deformation in the Middle Miocene accompanied and followed through the Pliocene by intense volcanism and plutonism. Reinception of igneous activity and tectonism at about the Oligocene-Miocene boundary, a feature recognized in other circum-Pacific regions, may reflect an increase in the rate of rotation of the Pacific plate relative to fixed or quasifixed mantle coordinates. Middle Miocene tectonism and latest Tertiary volcanism correlates with and probably is genetically related to the beginning of very rapid spreading at the East Pacific Rise. ?? 1974.

Lunar Cordierite-Spinel Troctolite: Igneous History, and Volatiles

NASA Astrophysics Data System (ADS)

Treiman, A. H.; Gross, J.

2012-03-01

Apollo sample 15295,101 contains a cordierite spinel troctolite (Marvin et al., 1989). The cordierite is volatile-free, at least by EMP — more precise analyses are in progress. The troctolite may be a partial melt of a spinel-rich igneous cumulate.

Complications with computer-aided designed/computer-assisted manufactured titanium and soldered gold bars for mandibular implant-overdentures: short-term observations.

PubMed

Katsoulis, Joannis; Wälchli, Julia; Kobel, Simone; Gholami, Hadi; Mericske-Stern, Regina

2015-01-01

Implant-overdentures supported by rigid bars provide stability in the edentulous atrophic mandible. However, fractures of solder joints and matrices, and loosening of screws and matrices were observed with soldered gold bars (G-bars). Computer-aided designed/computer-assisted manufactured (CAD/CAM) titanium bars (Ti-bars) may reduce technical complications due to enhanced material quality. To compare prosthetic-technical maintenance service of mandibular implant-overdentures supported by CAD/CAM Ti-bar and soldered G-bar. Edentulous patients were consecutively admitted for implant-prosthodontic treatment with a maxillary complete denture and a mandibular implant-overdenture connected to a rigid G-bar or Ti-bar. Maintenance service and problems with the implant-retention device complex and the prosthesis were recorded during minimally 3-4 years. Annual peri-implant crestal bone level changes (ΔBIC) were radiographically assessed. Data of 213 edentulous patients (mean age 68 ± 10 years), who had received a total of 477 tapered implants, were available. Ti-bar and G-bar comprised 101 and 112 patients with 231 and 246 implants, respectively. Ti-bar mostly exhibited distal bar extensions (96%) compared to 34% of G-bar (p < .001). Fracture rate of bars extensions (4.7% vs 14.8%, p < .001) and matrices (1% vs 13%, p < .001) was lower for Ti-bar. Matrices activation was required 2.4× less often in Ti-bar. ΔBIC remained stable for both groups. Implant overdentures supported by soldered gold bars or milled CAD/CAM Ti-bars are a successful treatment modality but require regular maintenance service. These short-term observations support the hypothesis that CAD/CAM Ti-bars reduce technical complications. Fracture location indicated that the titanium thickness around the screw-access hole should be increased. © 2013 Wiley Periodicals, Inc.

Predictability of Seasonal Rainfall over the Greater Horn of Africa

NASA Astrophysics Data System (ADS)

Ngaina, J. N.

2016-12-01

The El Nino-Southern Oscillation (ENSO) is a primary mode of climate variability in the Greater of Africa (GHA). The expected impacts of climate variability and change on water, agriculture, and food resources in GHA underscore the importance of reliable and accurate seasonal climate predictions. The study evaluated different model selection criteria which included the Coefficient of determination (R2), Akaike's Information Criterion (AIC), Bayesian Information Criterion (BIC), and the Fisher information approximation (FIA). A forecast scheme based on the optimal model was developed to predict the October-November-December (OND) and March-April-May (MAM) rainfall. The predictability of GHA rainfall based on ENSO was quantified based on composite analysis, correlations and contingency tables. A test for field-significance considering the properties of finiteness and interdependence of the spatial grid was applied to avoid correlations by chance. The study identified FIA as the optimal model selection criterion. However, complex model selection criteria (FIA followed by BIC) performed better compared to simple approach (R2 and AIC). Notably, operational seasonal rainfall predictions over the GHA makes of simple model selection procedures e.g. R2. Rainfall is modestly predictable based on ENSO during OND and MAM seasons. El Nino typically leads to wetter conditions during OND and drier conditions during MAM. The correlations of ENSO indices with rainfall are statistically significant for OND and MAM seasons. Analysis based on contingency tables shows higher predictability of OND rainfall with the use of ENSO indices derived from the Pacific and Indian Oceans sea surfaces showing significant improvement during OND season. The predictability based on ENSO for OND rainfall is robust on a decadal scale compared to MAM. An ENSO-based scheme based on an optimal model selection criterion can thus provide skillful rainfall predictions over GHA. This study concludes that the negative phase of ENSO (La Niña) leads to dry conditions while the positive phase of ENSO (El Niño) anticipates enhanced wet conditions

Isotopic ages for alkaline igneous rocks, including a 26 Ma ignimbrite, from the Peshawar plain of northern Pakistan and their tectonic implications

NASA Astrophysics Data System (ADS)

Ahmad, Irshad; Khan, Shuhab; Lapen, Thomas; Burke, Kevin; Jehan, Noor

2013-01-01

New isotopic ages on zircons from rocks of the Peshawar Plain Alkaline Igneous Province (PPAIP) reveal for the first time the occurrence of ignimbritic Cenozoic (Oligocene) volcanism in the Himalaya at 26.7 ± 0.8 Ma. Other new ages confirm that PPAIP rift-related igneous activity was Permian and lasted from ˜290 Ma to ˜250 Ma. Although PPAIP rocks are petrologically and geochemically typical of rifts and have been suggested to be linked to rifting on the Pangea continental margin at the initiation of the Neotethys Ocean, there are no documented rift-related structures mapped in Permian rocks of the Peshawar Plain. We suggest that Permian rift-related structures have been dismembered and/or reactivated during shortening associated with India-Asia collision. Shortening in the area between the Main Mantle Thrust (MMT) and the Main Boundary Thrust (MBT) may be indicative of the subsurface northern extension of the Salt Range evaporites. Late Cenozoic sedimentary rocks of the Peshawar Plain deposited during and after Himalayan thrusting occupy a piggy-back basin on top of the thrust belt. Those sedimentary rocks have buried surviving evidence of Permian rift-related structures. Igneous rocks of the PPAIP have been both metamorphosed and deformed during the Himalayan collision and Cenozoic igneous activity, apart from the newly recognized Gohati volcanism, has involved only the intrusion of small cross-cutting granitic bodies concentrated in areas such as Malakand that are close to the MMT. Measurements on Chingalai Gneiss zircons have confirmed the occurrence of 816 ± 70 Ma aged rocks in the Precambrian basement of the Peshawar Plain that are comparable in age to rocks in the Malani igneous province of the Rajasthan platform ˜1000 km to the south.

Novel hybrid drilling protocol: evaluation for the implant healing--thermal changes, crestal bone loss, and bone-to-implant contact.

PubMed

Calvo-Guirado, José Luis; Delgado-Peña, Jorge; Maté-Sánchez, Jose E; Mareque Bueno, Javier; Delgado-Ruiz, Rafael Arcesio; Romanos, Georgios E

2015-07-01

To evaluate a new hybrid drilling protocol, by the analysis of thermal changes in vitro, and their effects in the crestal bone loss and bone-to-implant contact in vivo. Temperature changes during simulated osteotomies with a hybrid drilling technique (biologic plus simplified) (test) versus an incremental drilling technique (control) were investigated. One hundred and twenty random osteotomies were performed (60 by group) in pig ribs up to 3.75-mm-diameter drill to a depth of 10 mm. Thermal changes and time were recorded by paired thermocouples. In a parallel experiment, bilateral mandibular premolars P2, P3, P4, and first molar M1 were extracted from six dogs. After 2-month healing, implant sites were randomly prepared using either of the drilling techniques. Forty eight implants of 3.75 mm diameter and 10 mm length were inserted. The dogs were euthanized at 30 and 90 days, and crestal bone loss (CBL) and bone-to-implant contact (BIC) were evaluated. The control group showed maximum temperatures of 35.3 °C ± 1.8 °C, ΔT of 10.4 °C, and a mean time of 100 s/procedure; meanwhile, the test group showed maximum temperatures of 36.7 °C ± 1.2 °C, ΔT of 8.1 °C, and a mean time of 240 s/procedure. After 30 days, CBL values for both groups (test: 1.168 ± 0.194 mm; control: 1.181 ± 0.113 mm) and BIC values (test: 43 ± 2.8%; control: 45 ± 1.3%) were similar, without significant differences (P > 0.05). After 90 days, CBL (test: 1.173 ± 0.187 mm; control: 1.205 ± 0.122 mm) and BIC (test: 64 ± 3.3%; control: 64 ± 2.4%) values were similar, without significant differences (P > 0.05). The BIC values were increased at 90 days in both groups compared with the 30-day period (P < 0.05). Within the limitations of this study, the new hybrid protocol for the preparation of the implant bed without irrigation, increase the temperature similarly to the incremental conventional protocol, and requires twice the time for the completion of the drilling procedure in vitro. Crestal bone loss and bone-to-implant contact in the hybrid drilling protocol are comparable with the conventional drilling protocol and do not affect the osseointegration process in vivo. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In vivo evaluation of biofunctionalized implant surfaces with a synthetic peptide (P-15) and its impact on osseointegration. A preclinical animal study.

PubMed

Schmitt, Christian M; Koepple, Markus; Moest, Tobias; Neumann, Konrad; Weisel, Tamara; Schlegel, Karl Andreas

2016-11-01

The overall aim of the study was to investigate a biofunctionalized implant surface with electrochemically deposition of hydroxyapatite and the synthetic peptide (P-15) and its effect on osseointegration. Three modified implant types of ANKYLOS ® C/X implants were used; (1) machined implants used as negative control (M, n = 20), (2) implants with the FRIADENT ® plus surface (grit blasted and acid-etched) used as positive control (P, n = 20), and (3) implants with a biomimetic surface consisting of hydroxyapatite and the synthetic 15 aminoacids containing peptide P-15 (BP, n = 40). The implants were randomly inserted in the mandibles of 10 beagle dogs following 4 months after tooth extraction (P1-P4). Three animals were sacrificed 2 and 7 days after implant insertion, respectively, and four animals were sacrificed 6 months post implant insertion. Bone-to-implant contacts (BICs) were analyzed via histomorphometrical analyses at five different region of interests (ROIs); two at the middle part on either side of the implant (ROI 1/4), two at the apical part of the implant at each side (ROI 2/3), and one at the tip of the implant (ROI 5). All implant surfaces showed a high level of osseointegration and osteoconductivity. The cumulative implant survival rate (CSR) was 93.8%, 100% in the M, 85% in the P, and 95% in the BP group. No statistical difference in BICs at ROI 1/4, 2/3, and 5 could be shown between implant types following 2 and 7 days of healing. BIC values increased in all groups over time. After 6 months of healing the BP group showed superiority in BIC in ROI 2/3 (73.2 ± 15.6%) compared to the P (48.3 ± 10.6%) and M group (66.3 ± 30.2%) with a significant difference between BP and P (P = 0.002). It is hypothesized, that the surface biofunctionalization improves peri-implant bone formation and remodeling, leading to an increased bone-to implant contact. However, within the limitations of the study set-up no benefit in the early phase of osseointegration could be established for dental implants with P-15 containing surface in this study. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Ages of igneous and hydrothermal events in the Round Mountain and Manhattan gold districts, Nye County, Nevada.

USGS Publications Warehouse

Shawe, D.R.; Marvin, R.F.; Andriessen, P.A.M.; Mehnert, H.H.; Merritt, V.M.

1986-01-01

Isotopic age determinations of rocks and minerals separated from them are applied to refining and correlating the geological history of igneous and mineralizing events in a part of the Basin and Range province. -G.J.N.

Rock burst governance of working face under igneous rock

NASA Astrophysics Data System (ADS)

Chang, Zhenxing; Yu, Yue

2017-01-01

As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

Geology and porphyry copper-type alteration-mineralization of igneous rocks at the Christmas Mine, Gila County, Arizona

USGS Publications Warehouse

Koski, Randolph A.

1979-01-01

The Christmas copper deposit, located in southern Gila County, Arizona, is part of the major porphyry copper province of southwestern North America. Although Christmas is known for skarn deposits in Paleozoic carbonate rocks, ore-grade porphyry-type copper mineralization also occurs in a composite granodioritic intrusive complex and adjacent mafic volcanic country rocks. This study considers the nature, distribution, and genesis of alteration-mineralization in the igneous rock environment at Christmas. At the southeast end of the Dripping Spring Mountains, the Pennsylvanian Naco Limestone is unconformably overlain by the Cretaceous Williamson Canyon Volcanics, a westward-thinning sequence of basaltic volcanic breccia and lava flows, and subordinate clastic sedimentary rocks. Paleozoic and Mesozoic strata are intruded by Laramide-age dikes, sills, and small stocks of hornblende andesite porphyry and hornblende rhyodacite porphyry, and the mineralized Christmas intrusive complex. Rocks of the elongate Christmas stock, intruded along an east-northeast-trending fracture zone, are grouped into early, veined quartz diorite (Dark Phase), biotite granodiorite porphyry (Light Phase), and granodiorite; and late, unveined dacite porphyry and granodiorite porphyry. Biotite rhyodacite porphyry dikes extending east and west from the vicinity of the stock are probably coeval with biotite granodiorite porphyry. Accumulated normal displacement of approximately 1 km along the northwest-trending Christmas-Joker fault system has juxtaposed contrasting levels (lower, intrusive-carbonate rock environment and upper, intrusive-volcanic rock environment) within the porphyry copper system. K-Ar age determinations and whole-rock chemical analyses of the major intrusive rock types indicate that Laramide calc-alkaline magmatism and ore deposition at Christmas evolved over an extended period from within the Late Cretaceous (~75-80 m.y. ago) to early Paleocene (~63-61 m.y. ago). The sequence of igneous rocks is progressively more alkaline and silicic from basalt to granodiorite. Early (Stage I) chalcopyrite-bornite (-molybdenite) mineralization and genetically related K-silicate alteration are centered on the Christmas stock. K-silicate alteration is manifested by pervasive hornblende-destructive biotitization in the stock, biotitization of basaltic volcanic wall rocks, and a continuous stockwork of K-feldspar veinlets and quartz-K-feldspar veins in the stock and quartz-sulfide veins in volcanic rocks. Younger (Stage II) pyrite-chalcopyrite mineralization and quartz-sericite-chlorite alteration occur in a zone overlapping with but largely peripheral to the zone of Stage I stockwork veins. Within the Christmas intrusive complex, K-silicate-altered rocks in the central stock are flanked east and west by zones of fracture-controlled quartz-sericite alteration and strong pyritization. In volcanic rocks quartz-chlorite-pyrite-chalcopyrite veins are superimposed on earlier biotitization and crosscut Stage I quartz-sulfide veins. Beyond the zones of quartz-sericite alteration, biotite rhyodacite porphyry dikes contain the propylitic alteration assemblage epidote-chlorite-albite-sphene. Chemical analyses indicate the following changes during pervasive alteration of igneous rocks: (1) addition of Si, K, H, S, and Cu, and loss of Fe 3+ and Ca during intense biotitization of basalt; (2) loss of Na and Ca, increase of Fe3+/Fe2+, and strong H-metasomatism during sericitization of quartz diorite; and (3) increase in Ca, Na, and Fe3+/Fe2+, and loss of K during intense propylitization of biotite rhyodacite porphyry dikes. Thorough biotitization of biotite granodiorite porphyry in the Christmas stock was largely an isochemical process. Fluid-inclusion petrography reveals that Stage I veins are characterized by low to moderate populations of moderate-salinity and gas-rich inclusions, and sparse but ubiquitous halite-bearing inclusions. Moderate-salinity an

Shoshonites and Associated Calc-Alkaline Rocks from the Eastern Sayan, Central Asian Orogenic Belt: Geochemistry and Tectonic Setting

NASA Astrophysics Data System (ADS)

Vernikovskaya, A. E.; Romanov, M. I.; Kadilnikov, P. I.; Matushkin, N. Y.; Romanova, I.

2017-12-01

The Central Asian Orogenic Belt (CAOB) is one of the largest accretionary orogens in the world, which formation started in the Neoproterozoic giving rise to numerous assemblages of island arcs, ophiolites, continental fragments and sedimentary basins. The Eastern Sayan, located at the southwestern margin of the Siberian craton, is the key area in understanding the initiation of orogenic processes in the CAOB. Widely distributed mafic igneous rocks (dolerites, gabbro etc.) in the Eastern Sayan were previously considered as part of the Nersa igneous complex of the Neoproterozoic age, whereas tectonic setting of these rocks remained highly debatable. New geochemical and mineralogical data from igneous mafic rocks within the Eastern Sayan show presence of rocks with shoshonitic and high- and low-K calc-alkaline affinities and allowed us to refine the tectonic context of their formation in the southwestern margin of the Siberian craton.All studied intrusive and volcanic rocks in the Eastern Sayan showing OIB-like geochemical signatures. The high-K rocks contain orthoclase, olivine, diopside, augite, anorthite, various amphiboles, including edenite, cataphorite, Mg-cataphorite, anthophyllite-gedrite, Mg-Fe hornblende, biotites of the siderophyllite-eastonite-annite series, as well as zircon, baddeleyite, apatite, magnetite, ilmenite and Cr-spinel. The high-K rock type is characterised by high K2O contents (up to 9.2 wt. %), K2O/Na2O ratios over 90, lowered TiO2 and MgO and moderate FeO contents and negative P and Sr anomalies. In contrast, low-K rocks, characterised by moderate and increased TiO2 and MgO contents, contain augite, pigeonite, olivine, andesine and accessory minerals, such as rutile, titanite, ilmenite and apatite. Both rock types vary considerably in Nb and Ta concentrations, from OIB-like to E-MORB. Such geochemical signatures of calc-alkaline and shoshonitic igneous rocks are indicative of an active continental margin setting. Presence of the active continental margin setting in the southwestern margin of the Siberian craton during the late Neoproterozoic-early Cambrian time is in agreement with the U-Pb age of 511 Ma of high-K dolerites (Gladkochub et al., 2006) and the development of the coeval island arc assemblages in the northern part of the CAOB.

Light rare earth element systematics as a tool for investigating the petrogenesis of phoscorite-carbonatite associations, as exemplified by the Phalaborwa Complex, South Africa

NASA Astrophysics Data System (ADS)

Milani, Lorenzo; Bolhar, Robert; Frei, Dirk; Harlov, Daniel E.; Samuel, Vinod O.

2017-12-01

In-situ trace element analyses of fluorapatite, calcite, dolomite, olivine, and phlogopite have been undertaken on representative phoscorite and carbonatite rocks of the Palaeoproterozoic Phalaborwa Complex. Textural and compositional characterization reveals uniformity of fluorapatite and calcite among most of the intrusions, and seems to favor a common genetic origin for the phoscorite-carbonatite association. Representing major repositories for rare earth elements (REE), fluorapatite and calcite exhibit tightly correlated light REE (LREE) abundances, suggesting that partitioning of LREE into these rock forming minerals was principally controlled by simple igneous differentiation. However, light rare earth element distribution in apatite and calcite cannot be adequately explained by equilibrium and fractional crystallization and instead favors a complex crystallization history involving mixing of compositionally distinct magma batches, in agreement with previously reported mineral isotope variability that requires open-system behaviour.

Facies, Stratigraphic and Depositional Model of the Sediments in the Abrolhos Archipelago (Bahia, BRAZIL)

NASA Astrophysics Data System (ADS)

Matte, R. R.; Zambonato, E. E.

2012-04-01

Located in the Mucuri Basin on the continental shelf of southern Bahia state, northeast Brazil, about 70 km from the city of Caravelas,the Abrolhos archipelago is made up of five islands; Santa Barbara, Redonda, Siriba, Guarita and Sueste. The exhumed sediments in the Abrolhos archipelago are a rare record of the turbidite systems which fill the Brazilian Atlantic Basin, and are probably an unprecedented example of a plataform turbidite system (Dr. Mutti, personal communication). Despite the limited area, the outcrops display a wide facies variation produced by different depositional processes, and also allow for the observation of the layer geometries. Associated with such sedimentary rocks, the Abrolhos Volcanic Complex belongs stratigraphically to the Abrolhos Formation. These igneous rocks were dated by the Ar / Ar method, with ages ranging from 60 to 40 My, placing such Volcanic Complex between the Paleocene and Eocene. The sedimentary section is best exposed in the Santa Barbara and Redonda islands and altogether it is 70 m thick. The measured vertical sections show a good stratigraphic correlation between the rocks of the western portion of the first island and those of Redonda Island. However, there is no correlation between the eastern and western portions of Santa Barbara Island, since they are very likely interrupted by the igneous intrusion and possibly by faulting. The sedimentary stack consists of deposits with alternated regressive and transgressive episodes interpreted as high frequency sequences. The coarse facies, sandstones and conglomerates, with abrupt or erosive bases record regressive phases. On the other hand, finer sandstones and siltstones facies, which are partly bioturbated, correspond to phases of a little sediment supply. In the central and eastern portions of Santa Barbara Island, there is a trend of progradational stacking, while both in the western portion of Santa Barbara and in Redonda islands an agradational trend is observed. The predominance of layers with tabular geometry, characteristic of turbidite lobes, the presence of hummocky stratification, trace fossils typical of shallow water (Ophiomorphs and Thalassinoides), all associated with the occurrence of the carbonaceous material as well as plant fragments suggest a deltaic/ plataform depositional context. Textural features and sedimentary structures observed in the conglomerates and sandstones show the action of gravitational flows of high and low density. The fine interlaminated sandstones and siltstones later deformed as slumps or slides, and conglomerates with oriented clasts indicate, respectively, mass movements and action of debris flow. Conglomeratic lags levels record a bypass phenomenon. There are no biostratigraphic data in these studied outcrops. However, petrographic analyses revealed the presence of fragments of igneous rocks (basalts and diabases) in both sandstones and conglomerates, suggesting a relative contemporaneity between igneous activity and sediment deposition. Futhermore, petrographic analyses also found poor permo-porous conditions in the reservoirs due to the presence of fragments of volcanic rocks and the abundance of intraclasts / pseudomatrix.

The Formation of Igneous CAIs and Chondrules by Impacts?

NASA Technical Reports Server (NTRS)

Connolly, Harold C., Jr.; Love, Stanley G.

2001-01-01

Numerous challenges exist with forming the igneous spheres found within chondrites via collision events in the early solar nebula. We explore these challenges and discuss potential methods to overcome them. Collision models should be received cautiously. Additional information is contained in the original extended abstract.

Permian-Carboniferous arc magmatism in southern Mexico: U-Pb dating, trace element and Hf isotopic evidence on zircons of earliest subduction beneath the western margin of Gondwana

NASA Astrophysics Data System (ADS)

Ortega-Obregón, C.; Solari, L.; Gómez-Tuena, A.; Elías-Herrera, M.; Ortega-Gutiérrez, F.; Macías-Romo, C.

2014-07-01

Undeformed felsic to mafic igneous rocks, dated by U-Pb zircon geochronology between 311 and 255 Ma, intrude different units of the Oaxacan and Acatlán metamorphic complexes in southwestern Mexico. Rare earth element concentrations on zircons from most of these magmatic rocks have a typical igneous character, with fractionated heavy rare earths and negative Eu anomalies. Only inherited Precambrian zircons are depleted in heavy rare earth elements, which suggest contemporaneous crystallization in equilibrium with metamorphic garnet during granulite facies metamorphism. Hf isotopic signatures are, however, different among these magmatic units. For example, zircons from two of these magmatic units (Cuanana pluton and Honduras batholith) have positive ɛHf values (+3.8-+8.5) and depleted mantle model ages (using a mean crustal value of 176Lu/177Hf = 0.015) ( T DMC) ranging between 756 and 1,057 Ma, whereas zircons from the rest of the magmatic units (Etla granite, Zaniza batholith, Carbonera stock and Sosola rhyolite) have negative ɛHf values (-1 to -14) and model ages between 1,330 and 2,160 Ma. This suggests either recycling of different crustal sources or, more likely, different extents of crustal contamination of arc-related mafic magmas in which the Oaxacan Complex acted as the main contaminant. These plutons thus represent the magmatic expression of the initial stages of eastward subduction of the Pacific plate beneath the western margin of Gondwana, and confirm the existence of a Late Carboniferous-Permian magmatic arc that extended from southern North America to Central America.

A review of scientific literature examining the mining history, geology, mineralogy, and amphibole asbestos health effects of the Rainy Creek igneous complex, Libby, Montana, USA.

PubMed

Bandli, Bryan R; Gunter, Mickey E

2006-11-01

This article reviews the past 90 yr of scientific research directed on multiple aspects of the unique geology and environmental health issues surrounding the vermiculite deposit found at Libby, MT. Hydrothermal alteration and extensive weathering of the ultramafic units resulted in the formation of a rich deposit of vermiculite that was mined for 67 yr and used in numerous consumer products in its expanded form. Later intrusions of alkaline units caused hydrothermal alteration of the pyroxenes, resulting in formation of amphiboles. Some of these amphiboles occur in the asbestiform habit and have been associated with pulmonary disease in former miners and mill workers. Identification of these amphibole asbestos minerals has received little attention in the past, but recent work shows that the majority of the amphibole mineral species present may not be any of the amphibole species currently regulated by government agencies. Epidemiological studies on former miners have, nevertheless, shown that the amphibole asbestos from the Rainy Creek igneous complex is harmful; also, a recent study by the Agency for Toxic Substances and Disease Registry shows that residents of Libby who had not been employed in the vermiculite mining or milling operations also appear to have developed asbestos-related pulmonary diseases at a higher rate than the general public elsewhere. Since November 1999, the U.S. Environmental Protection Agency has been involved in the cleanup of asbestos-contaminated sites in and around Libby associated with the mining and processing of vermiculite.

Platinum group elements in stream sediments of mining zones: The Hex River (Bushveld Igneous Complex, South Africa)

NASA Astrophysics Data System (ADS)

Almécija, Clara; Cobelo-García, Antonio; Wepener, Victor; Prego, Ricardo

2017-05-01

Assessment of the environmental impact of platinum group elements (PGE) and other trace elements from mining activities is essential to prevent potential environmental risks. This study evaluates the concentrations of PGE in stream sediments of the Hex River, which drains the mining area of the Bushveld Igneous Complex (South Africa), at four sampling points. Major, minor and trace elements (Fe, Ca, Al, Mg, Mn, V, Cr, Zn, Cu, As, Co, Ni, Cd, and Pb) were analyzed by FAAS and ETAAS in suspended particulate matter and different sediment fractions (<63, 63-500 and 500-2000 μm), and Pt, Pd, Rh, and Ir were measured by ICP-MS after removal of interfering elements (cation exchange resin 50W-DOWEX-X8). Procedures were blank-corrected and accuracy checked using reference materials. Nickel, Cr, Pt, Pd, Rh and Ir show concentrations 3-, 13- 18-, 28-, 48- and 44- fold the typical upper continental crust levels, respectively, although lower than concentrations reported for the parent rocks. The highest concentrations were observed closer to the mining area, decreasing with distance and in the <63 μm fraction, probably derived from atmospheric deposition and surface runoff of PGE-rich particles released from mining activities. Thus, mining activities are causing some disturbance of the surface PGE geochemical cycle, increasing the presence of PGE in the fine fraction of river sediments. We propose that indicators such as airborne particulate matter, and soil and river sediment quality, should be added to the protocols for evaluating the sustainability of mining activities.

Evolution of Incubation Models: Evidence from the Italian Incubation Industry

ERIC Educational Resources Information Center

Grandi, Alessandro; Grimaldi, Rosa

2004-01-01

This paper addresses the role of incubators in supporting new venture creation. A mapping of four different types of incubator is proposed: corporate private incubators (CPIs), independent private incubators (IPIs), business innovation centres (BICs) and university business incubators (UBIs). This mapping is exemplified through case studies of one…

Winter Ice and Snow as Models of Igneous Rock Formation.

ERIC Educational Resources Information Center

Romey, William D.

1983-01-01

Examines some features of ice and snow that offer teachers and researchers help in understanding many aspects of igneous processes and configurations. Careful observation of such processes as melting, decay, evolution, and snow accumulation provide important clues to understanding processes by which many kinds of rocks form. (Author/JN)

Multiple Mechanisms of Transient Heating Events in the Protoplanetary Disk: Evidence from Precursors of Chondrules and Igneous Ca,Al-Rich Inclusions

NASA Astrophysics Data System (ADS)

Krot, A. N.; Nagashima, K.; Libourel, G.; Miller, K. E.

2017-02-01

Here we review the mineralogy, petrography, O-isotope compositions, and trace element abundances of precursors of chondrules and igneous CAIs which provide important constraints on the mechanisms of transient heating events in the protoplanetary disk.

Oxidative mobilization of cerium and uranium and enhanced release of "immobile" high field strength elements from igneous rocks in the presence of the biogenic siderophore desferrioxamine B

NASA Astrophysics Data System (ADS)

Kraemer, Dennis; Kopf, Sebastian; Bau, Michael

2015-09-01

Polyvalent trace elements such as the high field strength elements (HFSE) are commonly considered rather immobile during low-temperature water-rock interaction. Hence, they have become diagnostic tools that are widely applied in geochemical studies. We present results of batch leaching experiments focused on the mobilization of certain HFSE (Y, Zr, Hf, Th, U and rare earth elements) from mafic, intermediate and felsic igneous rocks in the presence and absence, respectively, of the siderophore desferrioxamine B (DFOB). Our data show that DFOB strongly enhances the mobility of these trace elements during low-temperature water-rock interaction. The presence of DFOB produces two distinct features in the Rare Earths and Yttrium (REY) patterns of leaching solutions, regardless of the mineralogical and chemical composition or the texture of the rock type studied. Bulk rock-normalized REY patterns of leaching solutions with DFOB show (i) a very distinct positive Ce anomaly and (ii) depletion of La and other light REY relative to the middle REY, with a concave downward pattern between La and Sm. These features are not observed in experiments with hydrochloric acid, acetic acid or deionized water. In DFOB-bearing leaching solutions Ce and U are decoupled from and selectively enriched relative to light REY and Th, respectively, due to oxidation to Ce(IV) and U(VI). Oxidation of Ce3+ and U4+ is promoted by the significantly higher stability of the Ce(IV) and U(VI) DFOB complexes as compared to the Ce(III) and U(IV) DFOB complexes. This is similar to the relationship between the Ce(IV)- and Ce(III)-pentacarbonate complexes that cause positive Ce anomalies in alkaline lakes. However, while formation of Ce(IV) carbonate complexes is confined to alkaline environments, Ce(IV) DFOB complexes may produce positive Ce anomalies even in mildly acidic and near-neutral natural waters. Siderophore-promoted dissolution processes also significantly enhance mobility of other 'immobile' HFSE and may not only cause or modify Ce anomalies and Th-U fractionation, but also mobilization of and fractionation between Zr, Hf, Th and redox-insensitive REY during weathering, pedogenesis, diagenesis and incongruent dissolution of particles in seawater and freshwater. Siderophores may significantly affect the use of HFSE as geochemical tools. Concave downward light REY patterns may be used as a biosignature for water-rock interaction in the presence of siderophores. Enhanced and preferential mobilization of U relative to Th in the presence of siderophores may produce Th-U signals comparable to those indicative of weathering under oxidized conditions, which might constrain the use of U concentrations and Th/U ratios as a paleoredox-proxy. The enhanced mobilization of Zr and especially Hf from igneous rocks in the presence of DFOB might have implications for the use of the latter as a tracer for the impact of continental weathering on seawater chemistry. Because siderophore complexes affect the particle-reactivity of Hf and Zr, they may prevent effective removal of terrigenous Hf and Zr during aggregation/coagulation of riverine particles in estuaries. Siderophore-promoted solubilization and stabilization might hence be an additional way to transport continental Hf and Zr to the oceans. Furthermore, siderophore-enhanced mobilization may also have implications for the remediation techniques employed to immobilize HFSE such as U, Th and REY, at nuclear waste and reprocessing sites and at REY ore processing plants, where soils are commonly contaminated with these (sometimes radioactive) heavy metals.

Grains of Nonferrous and Noble Metals in Iron-Manganese Formations and Igneous Rocks of Submarine Elevations of the Sea of Japan

NASA Astrophysics Data System (ADS)

Kolesnik, O. N.; Astakhova, N. V.

2018-01-01

Iron-manganese formations and igneous rocks of submarine elevations in the Sea of Japan contain overlapping mineral phases (grains) with quite identical morphology, localization, and chemical composition. Most of the grains conform to oxides, intermetallic compounds, native elements, sulfides, and sulfates in terms of the set of nonferrous, noble, and certain other metals (Cu, Zn, Sn, Pb, Ni, Mo, Ag, Pd, and Pt). The main conclusion that postvolcanic hydrothermal fluids are the key sources of metals is based upon a comparison of the data of electron microprobe analysis of iron-manganese formations and igneous rocks dredged at the same submarine elevations in the Sea of Japan.

Thorium and rare earth minerals in the Powderhorn district, Gunnison County, Colorado

USGS Publications Warehouse

Olson, Jerry C.; Wallace, Stewart R.

1954-01-01

Thorium has been found since 1949 in at least 33 deposits in an area 6 miles wide and 20 miles long in the Powderhorn district, Gunnison County, Colo. The district is composed largely of pre-Jurassic metamorphic and igneous rocks, which are chiefly if not entirely pre-Cambrian in age. The metamorphic and igneous rocks are overlain by sandstone of the Morrison formation of Jurassic age, and by volcanic rocks of the Alboroto group and Hinsdale formation of Miocene and Pliocene (?) age, respectively. The thorium deposits occur in or near alkalic igneous rocks in which such elements as titanium, rare earths, barium, strontium, and niobium occur in greater-than-average amounts. The greatest mass of the alkalic igneous rocks the Iron Hill composite stoc,- occupies an area of 12 square miles in the southeastern part of the district. The age of the thorium deposits, like that of the alkalic igneous rocks, is not known other than pre-Jurassic. The thorium veins and mineralized shear zones range from a few inches to 18 feet in thickness and from a few feet to 3,500 feet in length. The veins are composed of calcite,.dolomite, siderite, ankerite, quartz, barite, pyrite, sphalerite, galena, goethite,. apatite, alkali feldspar, and many other minerals. The thorium occurs at least partly in thorite or hydrothorite. Sparse xenotime has been tentatively identified in one deposit. Several minerals containing rare earths of the cerium group as major constituents are found in carbonate veins near Iron Hill. Bastnaesite has been identified by X-ray methods, and cerite and synchisite are probably present also.The fluorapatite in some veins and in parts of the carbonate rock mass that occupies 2 square miles in the central part of the Iron Hill complex contains rare earths of the cerium group, generally in amounts of a fraction of a percent of the rock. The radioactivity of the deposits appears to be due almost entirely to thorium and its daughter products The ThO2 content of selected highgrade samples from the Little Johnnie vein is as much as 4 percent. The ThO2 content of the veins is generally less than 1 percent, however, and is only 0.05 to 0.1 percent in many of the veins studied. The little Johnnie vein, which was mapped in detail, can be traced discontinuously for a distance of more than 3,500 feet. The thoriumbearing material occurs as irregular veinlets and thin films introduced into the fault zone. The mineralized shear zone ranges from less than 6 inches to 5 feet in thickness. Near its west end the vein is broken by many faults in a zone that marks the edge of a roughly circular fault block, 11/2.miles in diameter, that has dropped 1,000 feet or more since the deposition of Miocene volcanic-rocks that now floor the Milkranch basin.

IS ISLAND PARK A HOT DRY ROCK SYSTEM?

USGS Publications Warehouse

Hoover, D.B.; Pierce, Herbert A.; Long, C.L.

1985-01-01

The Island Park-Yellowstone National Park region comprises a complex caldera system which has formed over the last 2 m. y. The caldera system has been estimated to contain 50% of the total thermal energy remaining in all young igneous systems in the United States. As the result of a reexamination of the data and recent electrical work in the area, the authors now postulate that much of the area where the first- and second-stage calderas developed is underlain by a solidified but still hot pluton. They postulate that the pluton represents a significant hot-dry-rock resource for the United States.

Peering Through a Martian Veil: ALHA84001 Sm-Nd Age Revisited

NASA Technical Reports Server (NTRS)

Nyquist, Laurence E.; Shih, Chi-Yu

2013-01-01

The ancient Martian orthopyroxenite ALH84001experienced a complex history of impact and aqueous alteration events. Here we summarize Sm-147-Nd-143 and Sm-146-Nd-142 analyses performed at JSC. Further, using REE data, we model the REE abundance pattern of the basaltic magma parental to ALH84001 cumulus orthopyroxene. We find the Sm-146-Nd-142 isotopic data to be consistent with isotopic evolution in material having the modeled Sm/Nd ratio from a time very close to the planet's formation to igneous crystallization of ALH84001 as inferred from the Sm-Nd studies.

Sudbury project (University of Muenster-Ontario Geological Survey): Isotope systematics support the impact origin

NASA Technical Reports Server (NTRS)

Deutsch, A.; Buhl, D.; Brockmeyer, P.; Lakomy, R.; Flucks, M.

1992-01-01

Within the framework of the Sudbury project a considerable number of Sr-Nd isotope analyses were carried out on petrographically well-defined samples of different breccia units. Together with isotope data from the literature these data are reviewed under the aspect of a self-consistent impact model. The crucial point of this model is that the Sudbury Igneous Complex (SIC) is interpreted as a differentiated impact melt sheet without any need for an endogenic 'magmatic' component such as 'impact-triggered' magmatism or 'partial' impact melting of the crust and mixing with a mantle-derived magma.

Rare earths and other trace elements in Apollo 14 samples.

NASA Technical Reports Server (NTRS)

Helmke, P. A.; Haskin, L. A.; Korotev, R. L.; Ziege, K. E.

1972-01-01

REE and other trace elements have been determined in igneous rocks 14053, 14072, and 14310, in breccias 14063 and 14313, and in fines 14163. All materials analyzed have typical depletions of Eu except for feldspar fragments from the breccias and igneous fragments from 14063. Igneous rocks 14072 and 14053 have REE concentrations very similar to Apollo 12 basalts; 14310 has the highest REE concentrations yet observed for a large fragment of lunar basalt. The effects of crystallization of a basaltic liquid as a closed system on the concentrations of Sm and Eu in feldspar are considered. Small anorthositic fragments may have originated by simple crystallization from very highly differentiated basalt (KREEP) or by closed-system crystallization in a less differentiated starting material. Application of independent models of igneous differentiation to Sm and Eu in massive anorthosite 15415 and to Sm and Eu in lunar basalts suggests a common starting material with a ratio of concentrations of Sm and Eu about the same as that in chondrites and with concentrations of those elements about 15 times enriched over chondrites.

Significance of elevated K/Rb ratios in lower crustal rocks

NASA Technical Reports Server (NTRS)

Frost, B. Ronald; Frost, Carol D.

1988-01-01

The granulite uncertainty principle, which states that it is difficult or impossible to determine with certainty the maximum geopressure and geotemperature that a granulite has experienced, is addressed. Also, geochemical fingerprinting cannot always be used reliably in the nebulous region that is transitional between metamorphic and igneous environments. Ion exchange thermometers are typically useful to approximately 800 C in slowly cooled plutonic rocks unless one uses a reintegration technique on unmixed minerals, or unless a metastable mineral assemblage can be observed. It is argued that in most granulites, fossil temperatures are typically obliterated by reequilibration and/or deformation during slow cooling. Granulite metamorphism may be further complicated by the common association with igneous activity. The previously-used geochemical indicators such as high K/Rb ratios and LIL depletion may not be strictly the result of granulite facies metamorphic depletion, but also may result from igneous processes, which depend on bulk and mineral compositions and on the mineralogy of the protolith. Detailed geologic mapping will be the ultimate arbitrator of whether a given geochemical signature is the result of igneous or metamorphic processes.

Multiscale Architecture of a Subduction Complex and Insight into Large-scale Material Movement in Subduction Systems

NASA Astrophysics Data System (ADS)

Wakabayashi, J.

2014-12-01

The >1000 km by >100 km Franciscan complex of California records >100 Ma of subduction history that terminated with conversion to a transform margin. It affords an ideal natural laboratory to study the rock record of subduction-interface and related processes exhumed from 10-70 km. The Franciscan comprises coherent and block-in-matrix (mélange) units forming a nappe stack that youngs structurally downward in accretion age, indicating progressive subduction accretion. Gaps in accretion ages indicate periods of non-accretion or subduction erosion. The Franciscan comprises siliciclastic trench fill rocks, with lesser volcanic and pelagic rocks and serpentinite derived from the downgoing plate, as well as serpentinite and felsic-intermediate igneous blocks derived as detritus from the upper plate. The Franciscan records subduction, accretion, and metamorphism (including HP), spanning an extended period of subduction, rather than a single event superimposed on pre-formed stratigraphy. Melanges (serpentinite and siliciclastic matrix) with exotic blocks, that include high-grade metamorphic blocks, and felsic-intermediate igneous blocks from the upper plate, are mostly/entirely of sedimentary origin, whereas block-in-matrix rocks formed by tectonism lack exotic blocks and comprise disrupted ocean plate stratigraphy. Mélanges with exotic blocks are interbedded with coherent sandstones. Many blocks-in-melange record two HP burial events followed by surface exposure, and some record three. Paleomegathrust horizons, separating nappes accreted at different times, appear restricted to narrow fault zones of <100's of m thickness, and <50 m in best constrained cases; these zones lack exotic blocks. Large-scale displacements, whether paleomegathrust horizons, shortening within accreted nappes, or exhumation structures, are accommodated by discrete faults or narrow shear zones, rather than by significant penetrative strain. Exhumation of Franciscan HP units, both coherent and mélange, was accommodated by significant extension of the overlying plate, and possibly extension within the subduction complex, with cross-sectional extrusion, and like subduction burial, took place at different times.

Provenance of Marine Sediment in the Gulf of Alaska, IODP Expedition 341: Links Between Sediment Derivation, Glacial Systems, and Exhumation of the Coastal Mountain Belts

NASA Astrophysics Data System (ADS)

Allen, W. K.; Dunn, C. A.; Enkelmann, E.; Ridgway, K.; Colliver, L.

2015-12-01

Provenance analysis of Neogene sand and diamict beds from marine boreholes drilled by the IODP Expedition 341 provides a marine sedimentary record of the interactions between tectonics, climate and sediment deposition along a glaciated convergent margin. The 341 boreholes represent a cross-margin transect that sampled the continental shelf, slope, and deep sea Surveyor Fan of the Gulf of Alaska. Our dataset currently consists of ~ 650 detrital zircons selected for double dating method utilizing both detrital zircon fission track (FT) and U-Pb analysis from sand and diamict beds, as well as zircon U-Pb geochronology and apatite FT from igneous and gneissic clasts. Detrital zircon U-Pb geochronology of sand records dominant peak ages of 53, 62, 70, and 98 Ma with minor populations of 117, 154, and 170 Ma. Most of these ages can be correlated to primary igneous sources in the Coast Plutonic Complex, the Chugach Metamorphic Complex, the plutonic rocks of Wrangellia, and the Sanak-Baranoff plutonic belt. All samples analyzed to date, covering a 10 Myr range, share nearly identical detrital zircon populations suggesting similar primary sediment sources and reworking of sediment in thrust belts and accretionary prisms along this convergent margin. Plutonic and gneissic clasts collected from the boreholes on the shelf have already been double dated. These clasts have general U-Pb zircon crystallization ages of 52-54 Ma and apatite fission track cooling ages of 10-12 Ma. These results, along with previous published studies, indicate that these clasts were derived from the Chugach Metamorphic Complex and were eroded and transported by the Bagley Ice Field and Bering Glacier. Future results using this approach should allow us to pinpoint which parts of the exhumed onshore ranges and which glacial systems provided sediment to marine environments in the Gulf of Alaska.

Iron Isotope Systematics of the Bushveld Complex, South Africa: Initial Results

NASA Astrophysics Data System (ADS)

Stausberg, N.; Lesher, C. E.; Hoffmann-Barfod, G.; Glessner, J. J.; Tegner, C.

2014-12-01

Iron isotopes show systematic changes in igneous rocks that have been ascribed to fractional crystallization, partial melting, as well as, diffusion effects. Layered mafic intrusions, such as the Paleoproterozoic Bushveld Igneous Complex, are ideally suited to investigate stable isotope fractionation arising principally by fractional crystallization. The upper 2.1km of the Bushveld Complex (Upper and Upper Main Zone, UUMZ) crystallized from a basaltic magma produced by a major recharge event, building up a sequence of tholeiitic, Fe-rich, gabbroic cumulate rocks that display systematic variations in mineralogy and mineral compositions consistent with fractional crystallization. Within this sequence, magnetite joins the liquidus assemblage at ˜260m, followed by olivine at 460m and apatite at 1000m. Here, we present iron isotope measurements of bulk cumulate rocks from the Bierkraal drill core of UUMZ of the western limb. Iron was chemically separated from its matrix and analyzed for δ56Fe (relative to IRMM- 014) with a Nu plasma MC-ICPMS at the University of California, Davis, using (pseudo-) high resolution and sample-standard bracketing. The δ56Fe values for Bushveld cumulates span a range from 0.04‰ to 0.36‰, and systematically correlate with the relative abundance of pyroxene + olivine, magnetite and plagioclase. Notably, the highest δ56Fe values are found in plagioclase-rich cumulates that formed prior to magnetite crystallization. δ56Fe is also high in magnetite-rich cumulates at the onset of magnetite crystallization, while subsequent cumulates exhibit lower and variable δ56Fe principally reflecting fractionation of and modal variations in magnetite, pyroxene and fayalitic olivine. The overall relationships for δ56Fe are consistent with positive mineral - liquid Fe isotope fractionation factors for magnetite and plagioclase, and negative to near zero values for pyroxene and olivine. These initial results are being integrated into a forward model of the Bushveld liquid line of descent and will be compared to complementary work on the Skaergaard intrusion.

Thermobarometric studies on the Levack Gneisses: Footwall rocks to the Sudbury Igneous Complex

NASA Technical Reports Server (NTRS)

James, R. S.; Peredery, W.; Sweeny, J. M.

1992-01-01

Granulite and amphibolite facies gneisses and migmatites of the Levack Gneiss Complex occupy a zone up to 8 km wide around the northern part of the Sudbury Igneous Complex (SIC). Orthopyroxene- and garnet-bearing tonalitic and semipelitic assemblages of granulite facies grade occur within 3 km of the SIC together with lenses of mafic and pyroxenitic rock compositions normally represented by an amphibole +/- cpx-rich assemblage; amphibolite facies assemblages dominate elsewhere in this terrain. These 2.711-Ga gneisses were introduced by (1) the Cartier Granite Batholith during late Archaean to early Proterozoic time and (2) the SIC, at 1.85 Ga, which produced a contact aureole 1-1.5 km wide in which pyroxene hornfelses are common within 200-300 m of the contact. A suite of 12 samples including both the opx-gt and amphibole-rich rock compositions have been studied. Garnets in the semipelitic gneisses are variably replaced by a plg-bio assemblage. Thermobarometric calculations using a variety of barometers and thermometers reported in the literature suggest that the granulite facies assemblages formed at depths in the 21-28 km range (6-8 kbar). Textures and mineral chemistry in the garnet-bearing semipelitic rocks indicate that this terrain underwent a second metamorphic event during uplift to depth in the 5-11 km range (2-3 kbar) and at temperatures as low as 500-550 C. This latter event is distinct from thermal recrystallization caused by the emplacement of the SIC; it probably represents metamorphism attributable to intrusion of the Cartier Granite Batholith. These data allow two interpretations for the crustal uplift of the Levack Gneisses: (1) The gneisses were tectonically uplifted prior to the Sudbury Event (due to intrusion of the Cartier Batholith); or (2) the gneisses were raised to epizonal levels as a result of meteorite impact at 1.85 Ga.

Igneous fractionation and subsolidus equilibration of diogenite meteorites

NASA Technical Reports Server (NTRS)

Mittlefehldt, David W.

1993-01-01

Diogenites are coarse-grained orthopyroxenite breccias of remarkably uniform major element composition. Most diogenites contain homogeneous pyroxene fragments up to 5 cm across of Wo2En74Fs24 composition. Common minor constituents are chromite, olivine, trolite and metal, while silica, plagioclase, merrillite and diopside are trace phases. Diogenites are generally believed to be cumulates from the eucrite parent body, although their relationship with eucrites remains obscure. It has been suggested that some diogenites are residues after partial melting. I have performed EMPA and INAA for major, minor and trace elements on most diogenites, concentrating on coarse-grained mineral and lithic clasts in order to elucidate their igneous formation and subsequent metamorphic history. Major element compositions of diogenites are decoupled from minor and trace element compositions; the latter record an igneous fractionation sequence that is not preserved in the former. Low equilibration temperatures indicate that major element diffusion continued long after crystallization. Diffusion coefficients for trivalent and tetravalent elements in pyroxene are lower than those of divalent elements. Therefore, major element compositions of diogenites may represent means of unknown portions of a cumulate homogenized by diffusion, while minor and trace elements still yield information on their igneous history. The scale of major element equilibration is unknown, but is likely to be on the order of a few cm. Therefore, the diogenite precursors may have consisted largely of cm-sized, igneously zoned orthopyroxene grains, which were subsequently annealed during slow cooling, obliterating major element zoning but preserving minor and trace incompatible element zoning.

Preliminary reconnaissance survey for thorium, uranium, and rare-earth oxides, Bear Lodge Mountains, Crook County, Wyoming

USGS Publications Warehouse

Wilmarth, V.R.; Johnson, D.H.

1953-01-01

An area about 6 miles north of Sundance, in the Bear Lodge Mountains, in Crook County, Wyo., was examined during August 1950 for thorium, uranium, and rare-earth oxides and samples were collected. Uranium is known to occur in fluorite veins and iron-manganese veins and in the igneous rocks of Tertiary age that compose the core of the Bear Lodge Mountains. The uranium content of the samples ranges from 0.001 to 0.015 percent in those from the fluorite veins, from 0.005 to 0.018 percent in those from the iron-manganese veins, and from 0.001 to 0.017 percent in those from the igneous rocks. The radioactivity of the samples is more than that expected from the uranium content. Thorium accounts for most of this discrepancy. The thorium oxide content of samples ranges from 0.07 to 0.25 percent in those from the iron-manganese veins and from 0.07 to 0.39 percent in those from the sedimentary rocks, and from0.04 to 0.30 in those from the igneous rocks. Rare-earth oxides occur in iron-manganese veins and in zones of altered igneous rocks. The veins contain from 0.16 to 12.99 percent rare-earth oxides, and the igneous rocks, except for two localities, contain from 0.01 to 0.42 percent rare-earth oxides. Inclusions of metamorphosed sedimentary rocks in the intrusive rocks contain from 0.07 to 2.01 percent rare-earth oxides.

76 FR 72502 - Removal From the List of Specially Designated Nationals and Blocked Persons of Certain Entities...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-23

..., Kayseri, Turkey; Incilipinar Mah., Kibris Cad., Zeugma Is Merkezi, No: 13-14, 27090 Sehitkamil, Gaziantep... Address [email protected] ; Email Address [email protected] [LIBYA2] 13. GLAHCO HOTELS AND TOURISM..., SAR Bldg, Beirut, Lebanon; Registration ID 30199 (Lebanon) issued 13 Oct 1973; SWIFT/BIC NACBLBBE...

Everyday Engineering: What Makes a Bic Click?

ERIC Educational Resources Information Center

Moyer, Richard; Everett, Susan

2009-01-01

The ballpoint pen is an ideal example of simple engineering that we use everyday. But is it really so simple? The ballpoint pen is a remarkable combination of technology and science. Its operation uses several scientific principles related to chemistry and physics, such as properties of liquids and simple machines. They represent significant…

31 CFR 26.2 - Availability of project listings.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Availability of project listings. 26.2 Section 26.2 Money and Finance: Treasury Office of the Secretary of the Treasury ENVIRONMENTAL...-8191, not a toll-free call). (2) If a copy is not available from the BIC, members of the public may...

31 CFR 26.2 - Availability of project listings.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Availability of project listings. 26.2 Section 26.2 Money and Finance: Treasury Office of the Secretary of the Treasury ENVIRONMENTAL...-8191, not a toll-free call). (2) If a copy is not available from the BIC, members of the public may...

31 CFR 26.2 - Availability of project listings.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Availability of project listings. 26.2 Section 26.2 Money and Finance: Treasury Office of the Secretary of the Treasury ENVIRONMENTAL...-8191, not a toll-free call). (2) If a copy is not available from the BIC, members of the public may...

31 CFR 26.2 - Availability of project listings.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Availability of project listings. 26.2 Section 26.2 Money and Finance: Treasury Office of the Secretary of the Treasury ENVIRONMENTAL...-8191, not a toll-free call). (2) If a copy is not available from the BIC, members of the public may...

31 CFR 26.2 - Availability of project listings.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Availability of project listings. 26.2 Section 26.2 Money and Finance: Treasury Office of the Secretary of the Treasury ENVIRONMENTAL...-8191, not a toll-free call). (2) If a copy is not available from the BIC, members of the public may...

Magic Termites: Exploring Scientific Inquiry

ERIC Educational Resources Information Center

Callis, Kristine; Henkel, Melissa; Lund, Rachael

2010-01-01

The objective of the termite experiment is to walk students through the process of designing and conducting an experiment while allowing them to use inquiry-based methods to infer why, in this lab, termites follow the line of blue Bic or Paper Mate brand ballpoint pens. This experiment also reinforces the concept of observation versus inference…

An Evaluation of Information Criteria Use for Correct Cross-Classified Random Effects Model Selection

ERIC Educational Resources Information Center

Beretvas, S. Natasha; Murphy, Daniel L.

2013-01-01

The authors assessed correct model identification rates of Akaike's information criterion (AIC), corrected criterion (AICC), consistent AIC (CAIC), Hannon and Quinn's information criterion (HQIC), and Bayesian information criterion (BIC) for selecting among cross-classified random effects models. Performance of default values for the 5…

75 FR 71794 - Blocking of Specially Designated Nationals Pursuant to Executive Order 13551

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-24

... 13551 of August 30, 2010, ``Blocking Property of Certain Persons With Respect to North Korea.'' DATES... President found that the continued actions and policies of the Government of North Korea, manifested most...., Potonggang District, Pyongyang, Korea, North; SWIFT/BIC KDBK KP PY (Korea, North); PHONE 850 2 381 8221...

Evaluation of Model Fit in Cognitive Diagnosis Models

ERIC Educational Resources Information Center

Hu, Jinxiang; Miller, M. David; Huggins-Manley, Anne Corinne; Chen, Yi-Hsin

2016-01-01

Cognitive diagnosis models (CDMs) estimate student ability profiles using latent attributes. Model fit to the data needs to be ascertained in order to determine whether inferences from CDMs are valid. This study investigated the usefulness of some popular model fit statistics to detect CDM fit including relative fit indices (AIC, BIC, and CAIC),…

Histomorphometry and bone mechanical property evolution around different implant systems at early healing stages: an experimental study in dogs.

PubMed

Jimbo, Ryo; Anchieta, Rodolfo; Baldassarri, Marta; Granato, Rodrigo; Marin, Charles; Teixeira, Hellen S; Tovar, Nick; Vandeweghe, Stefan; Janal, Malvin N; Coelho, Paulo G

2013-12-01

Commercial implants differ at macro-, micro-, and nanolevels, which makes it difficult to distinguish their effect on osseointegration. The aim of this study was to evaluate the early integration of 5 commercially available implants (Astra OsseoSpeed, Straumann SLA, Intra-Lock Blossom Ossean, Nobel Active, and OsseoFix) by histomorphometry and nanoindentation. Implants were installed in the tibiae of 18 beagle dogs. Samples were retrieved at 1, 3, and 6 weeks (n = 6 for each time point) and were histologically and nanomechanically evaluated. The results presented that both time (P < 0.01) and implant system and time interaction (P < 0.02) significantly affected the bone-to-implant contact (BIC). At 1 week, the different groups presented statistically different outcomes. No significant changes in BIC were noted thereafter. There were no significant differences in rank elastic modulus (E) or in rank hardness (H) for time (E: P > 0.80; H: P > 0.75) or implant system (E: P > 0.90; H: P > 0.85). The effect of different implant designs on osseointegration was evident especially at early stages of bone healing.

Maximum likelihood-based analysis of single-molecule photon arrival trajectories.

PubMed

Hajdziona, Marta; Molski, Andrzej

2011-02-07

In this work we explore the statistical properties of the maximum likelihood-based analysis of one-color photon arrival trajectories. This approach does not involve binning and, therefore, all of the information contained in an observed photon strajectory is used. We study the accuracy and precision of parameter estimates and the efficiency of the Akaike information criterion and the Bayesian information criterion (BIC) in selecting the true kinetic model. We focus on the low excitation regime where photon trajectories can be modeled as realizations of Markov modulated Poisson processes. The number of observed photons is the key parameter in determining model selection and parameter estimation. For example, the BIC can select the true three-state model from competing two-, three-, and four-state kinetic models even for relatively short trajectories made up of 2 × 10(3) photons. When the intensity levels are well-separated and 10(4) photons are observed, the two-state model parameters can be estimated with about 10% precision and those for a three-state model with about 20% precision.

Use of FEC coding to improve statistical multiplexing performance for video transport over ATM networks

NASA Astrophysics Data System (ADS)

Kurceren, Ragip; Modestino, James W.

1998-12-01

The use of forward error-control (FEC) coding, possibly in conjunction with ARQ techniques, has emerged as a promising approach for video transport over ATM networks for cell-loss recovery and/or bit error correction, such as might be required for wireless links. Although FEC provides cell-loss recovery capabilities it also introduces transmission overhead which can possibly cause additional cell losses. A methodology is described to maximize the number of video sources multiplexed at a given quality of service (QoS), measured in terms of decoded cell loss probability, using interlaced FEC codes. The transport channel is modelled as a block interference channel (BIC) and the multiplexer as single server, deterministic service, finite buffer supporting N users. Based upon an information-theoretic characterization of the BIC and large deviation bounds on the buffer overflow probability, the described methodology provides theoretically achievable upper limits on the number of sources multiplexed. Performance of specific coding techniques using interlaced nonbinary Reed-Solomon (RS) codes and binary rate-compatible punctured convolutional (RCPC) codes is illustrated.

Dimensionality of the 9-item Utrecht Work Engagement Scale revisited: A Bayesian structural equation modeling approach.

PubMed

Fong, Ted C T; Ho, Rainbow T H

2015-01-01

The aim of this study was to reexamine the dimensionality of the widely used 9-item Utrecht Work Engagement Scale using the maximum likelihood (ML) approach and Bayesian structural equation modeling (BSEM) approach. Three measurement models (1-factor, 3-factor, and bi-factor models) were evaluated in two split samples of 1,112 health-care workers using confirmatory factor analysis and BSEM, which specified small-variance informative priors for cross-loadings and residual covariances. Model fit and comparisons were evaluated by posterior predictive p-value (PPP), deviance information criterion, and Bayesian information criterion (BIC). None of the three ML-based models showed an adequate fit to the data. The use of informative priors for cross-loadings did not improve the PPP for the models. The 1-factor BSEM model with approximately zero residual covariances displayed a good fit (PPP>0.10) to both samples and a substantially lower BIC than its 3-factor and bi-factor counterparts. The BSEM results demonstrate empirical support for the 1-factor model as a parsimonious and reasonable representation of work engagement.

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation.

PubMed

Kang, Sung-Won; Lee, Woo-Jin; Choi, Soon-Chul; Lee, Sam-Sun; Heo, Min-Suk; Huh, Kyung-Hoe; Kim, Tae-Il; Yi, Won-Jin

2015-03-01

We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.

A Wideband Circularly Polarized Antenna with a Multiple-Circular-Sector Dielectric Resonator.

PubMed

Trinh-Van, Son; Yang, Youngoo; Lee, Kang-Yoon; Hwang, Keum Cheol

2016-11-03

This paper presents the design of a wideband circularly polarized antenna using a multiple-circular-sector dielectric resonator (DR). The DR is composed of twelve circular-sector DRs with identical central angles of 30 ∘ but with different radii. A genetic algorithm is utilized to optimize the radii of the twelve circular-sector DRs to realize wideband circular polarization. The proposed antenna is excited using an aperture-coupled feeding technique through a narrow rectangular slot etched onto the ground plane. An antenna prototype is experimentally verified. The measured -10 dB reflection and 3 dB axial ratio (AR) bandwidths are 31.39% (1.88-2.58 GHz) and 19.30% (2.06-2.50 GHz), respectively, covering the operating bands of the following systems: UMTS-2100 (2.145 GHz), WiMAX (2.3 GHz), and Wi-Fi (2.445 GHz). A measured peak gain of 7.65 dBic at 2.225 GHz and gain variation of less than 2.70 dBic within the measured 3 dB AR bandwidth are achieved. In addition, the radiation patterns of the proposed antenna are presented and discussed.

Geant4 hadronic physics for space radiation environment.

PubMed

Ivantchenko, Anton V; Ivanchenko, Vladimir N; Molina, Jose-Manuel Quesada; Incerti, Sebastien L

2012-01-01

To test and to develop Geant4 (Geometry And Tracking version 4) Monte Carlo hadronic models with focus on applications in a space radiation environment. The Monte Carlo simulations have been performed using the Geant4 toolkit. Binary (BIC), its extension for incident light ions (BIC-ion) and Bertini (BERT) cascades were used as main Monte Carlo generators. For comparisons purposes, some other models were tested too. The hadronic testing suite has been used as a primary tool for model development and validation against experimental data. The Geant4 pre-compound (PRECO) and de-excitation (DEE) models were revised and improved. Proton, neutron, pion, and ion nuclear interactions were simulated with the recent version of Geant4 9.4 and were compared with experimental data from thin and thick target experiments. The Geant4 toolkit offers a large set of models allowing effective simulation of interactions of particles with matter. We have tested different Monte Carlo generators with our hadronic testing suite and accordingly we can propose an optimal configuration of Geant4 models for the simulation of the space radiation environment.

Evaluation of centrifuged bone marrow on bone regeneration around implants in rabbit tibia.

PubMed

Betoni, Walter; Queiroz, Thallita P; Luvizuto, Eloá R; Valentini-Neto, Rodolpho; Garcia-Júnior, Idelmo R; Bernabé, Pedro F E

2012-12-01

To evaluate the bone regeneration of cervical defects produced around titanium implants filled with blood clot and filled with centrifuged bone marrow (CBM) by means of histomorphometric analysis. Twelve rabbits received 2 titanium implants in each right tibia, with the upper cortical prepared with a 5-mm drill and the lower cortex with a 3-mm-diameter drill. Euthanasia was performed to allow analysis at 7, 21, and 60 days after operation. The samples were embedded in light curing resin, cut and stained with alizarin red and Stevenel blue for a histomorphometric analysis of the bone-to-implant contact (BIC) and the bone area around implant (BA). The values obtained were statistically analyzed using the nonparametric Kruskal-Wallis test (P = 0.05). At 60 days postoperation, the groups had their cervical defects completely filled by neoformed bone tissue. There was no statistically significant difference between the groups regarding BIC and BA during the analyzed periods. There was no difference in the bone repair of periimplant cervical defects with or without the use of CBM.

A triclinic polymorph of tri­cyclo­hexyl­phosphane sulfide: crystal structure and Hirshfeld surface analysis

PubMed Central

Tan, Yi Jiun; Yeo, Chien Ing; Halcovitch, Nathan R.; Jotani, Mukesh M.

2017-01-01

The title compound, (C6H11)3PS (systematic name: tri­cyclo­hexyl-λ5-phosphane­thione), is a triclinic (P-1, Z′ = 1) polymorph of the previously reported ortho­rhom­bic form (Pnma, Z′ = 1/2) [Kerr et al. (1977 ▸). Can. J. Chem. 55, 3081–3085; Reibenspies et al. (1996 ▸). Z. Kristallogr. 211, 400]. While conformational differences exist between the non-symmetric mol­ecule in the triclinic polymorph, cf. the mirror-symmetric mol­ecule in the ortho­rhom­bic form, these differences are not chemically significant. The major feature of the mol­ecular packing in the triclinic polymorph is the formation of linear chains along the a axis sustained by methine-C—H⋯S(thione) inter­actions. The chains pack with no directional inter­actions between them. The analysis of the Hirshfeld surface for both polymorphs indicates a high degree of similarity, being dominated by H⋯H (ca 90%) and S⋯H/H⋯S contacts. PMID:28435705

A Radioelement Analysis of the Northern Black Hills, South Dakota, U.S.A

NASA Astrophysics Data System (ADS)

Young, Dylan Wade

The uranium, thorium, and potassium contents from 736 samples, within a 15-km radius of the Homestake Gold Mine and Sanford Underground Research Facility in the Northern Black Hills indicate the geoneutrino background may be higher than average for the continental crust. The radioactive element contents of igneous, metamorphic, and sedimentary rocks were determined by gamma ray spectrometry. Many rocks show hydrothermal and metamorphic alteration within the last ten Ma of the Tertiary period. Young alkali rich igneous rocks, such as rhyolite, phonolite and other volcanic rocks, have lower than average Th:U ratios. The radioelement content of 215 igneous rocks were determined. The radioelement contents of 143 metamorphic rocks were determined. This study also shows that metamorphic rocks were found to have low variable U:Th content when compared to content in igneous rocks. Sedimentary rocks, in general, have low U, Th, and K content. The radioelement content of 236 sedimentary rocks were determined. Rocks present within the Homestake Gold Mine, are highly altered by hydrothermal and metamorphic activity, enriching U, and in some areas, Th content. The Homestake Gold Mine lies almost entirely within metamorphic rocks. Igneous rocks occur in the mine as veins and dikes. The dominant igneous rock present is rhyolite. Metamorphic rocks present inside the HGM, were divided by formation; Ellison Fm, Poorman Fm, Yates Unit [lower Poorman Fm], Homestake Fm, and Flagrock Fm. The finding of high radioelement content in the rocks suggests that the antineutrinos background at the HGM will need to be considered and calibrated for, in future experiments conducted at the Sanford Underground Research Facility. A geoneutrino luminosity of 1.26x105 (mg-1s -1) was calculated from the samples analyzed within the Homestake Gold Mine. A total geoneutrino luminosity of 4.44x105 (mg -1s=1) was calculated from the sum of all analyses conducted in the Northern Black Hills.

Towards a comprehensive classification of igneous rocks and magmas

NASA Astrophysics Data System (ADS)

Middlemost, Eric A. K.

1991-08-01

The IUGS Subcommission on the Systematics of Igneous Rocks has recently published an excellent book on the classification of these rocks. This event has shifted the vexed question of classification towards the top of the agenda in igneous petrology. Over the years the Subcommission has used many different criteria to establish the positions of the boundaries between the various common igneous rocks. It now has to adopt a holistic approach and develop a comprehensive, coherent classification that is purged of all the minor anomalies that arise between the various classifications that it has approved. It is appreciated that the Subcommission's classification was never intended to have any genetic implications; however, it is suggested that an ideal classification should he presented in such a way that it is able to group rocks into an order that directs attention to petrogenetic relationships between individual rocks and larger groups of rocks. Unfortunately, many of the Subcommission's definitions are Earth chauvinistic; for example, igneous rocks are defined as being those rocks that solidified from a molten state either within or on the surface of the Earth. Nowhere in the book is it acknowledged that during the past 20 years, while the Subcommission has been framing its many recommendations, a whole new science of planetary petrology has subsumed classical petrology. In any new edition of the book, the Subcommission should acknowledge that rocks are essentially the solid materials of which planets, natural satellites and other broadly similar cosmic bodies are made. The Subcommission should also explicitly recognise that igneous rocks can be divided into either a main sequence of essentially common rocks or a number of supplementary clans of special rocks that evolved outside the main sequence. It is hoped that in the near future the Subcommission will rescind its recommendation that the TAS classification should be regarded as an adjunct to its more traditional QAPF modal classification. The QAPF and TAS classifications are regarded as being of equal validity, with the TAS classification being of more practical value in the classification of the common volcanic rocks and the various magmas conjured up in petrogenetic discussions. A new, comprehensive, hierarchical classification of igneous rocks is introduced, and the petrographic character and systematic position of the various rocks and clans that make up this classification are reviewed.

From Carbonatite to Ikaite: How high-T carbonates are transformed into low-T carbonate minerals in SW Greenland

NASA Astrophysics Data System (ADS)

Stockmann, G. J.; Tollefsen, E.; Ranta, E.; Skelton, A.; Sturkell, E.; Lundqvist, L.

2015-12-01

The 1300 Ma Grønnedal-Íka igneous complex in southwest Greenland comprises nepheline syenites and carbonatites. It belongs to a suite of intrusions formed 1300-1100 Ma ago referred to as the Gardar period. In modern time (the last ca. 8000 years), fluid-rock interactions involving the nepheline syenites and carbonatites gives rise to about one thousand submarine columns made of the rare low-T mineral ikaite (CaCO3x6H2O). The columns are found in a shallow, narrow fjord named Ikka Fjord and their distribution clearly follows the outcrop of the Grønnedal-Íka complex. When meteoric water percolates through the highly fractured complex, a sodium carbonate solution of pH 10 is formed through hitherto unknown fluid-rock reactions. This basic solution seeps up through fractures at the bottom of Ikka Fjord and when mixed with seawater, the mineral ikaite is formed. As the seepage water has a lower density than seawater, there is an upwards flow that creates columns. What is peculiar about ikaite is its limited stability making it unstable above +6 °C. Isotopic studies of ikaite reveal a seawater origin for the Ca2+ ions, and the carbonatite being the most likely source for the CO32- ions. The carbonatite is mainly of søvite composition (CaCO3) with high contents of siderite and ankerite in certain areas. The nepheline syenites contain Na,K-rich minerals like nepheline, alkali-feldspar, aegirine-augite, katophorite and biotite. Nepheline is mainly replaced by muscovite, and aegirine-augite partly by chlorite, which could release sodium into solution. A dolerite dyke of unknown age prompted extensive mineralization of magnetite by activating hydrothermal fluid convection. The fluid interacted with the carbonatite, replacing siderite and ankerite by magnetite and later hematite. In a newly launched project at Stockholm University, we are trying to unravel the chemical reactions taking place inside the Grønnedal-Íka igneous complex leading to the formation of the sodium carbonate solution issuing in Ikka Fjord.

Nonexplosive and explosive magma/wet-sediment interaction during emplacement of Eocene intrusions into Cretaceous to Eocene strata, Trans-Pecos igneous province, West Texas

USGS Publications Warehouse

Befus, K.S.; Hanson, R.E.; Miggins, D.P.; Breyer, J.A.; Busbey, A.B.

2009-01-01

Eocene intrusion of alkaline basaltic to trachyandesitic magmas into unlithified, Upper Cretaceous (Maastrichtian) to Eocene fluvial strata in part of the Trans-Pecos igneous province in West Texas produced an array of features recording both nonexplosive and explosive magma/wet-sediment interaction. Intrusive complexes with 40Ar/39Ar dates of ~ 47-46??Ma consist of coherent basalt, peperite, and disrupted sediment. Two of the complexes cutting Cretaceous strata contain masses of conglomerate derived from Eocene fluvial deposits that, at the onset of intrusive activity, would have been > 400-500??m above the present level of exposure. These intrusive complexes are inferred to be remnants of diatremes that fed maar volcanoes during an early stage of magmatism in this part of the Trans-Pecos province. Disrupted Cretaceous strata along diatreme margins record collapse of conduit walls during and after subsurface phreatomagmatic explosions. Eocene conglomerate slumped downward from higher levels during vent excavation. Coherent to pillowed basaltic intrusions emplaced at the close of explosive activity formed peperite within the conglomerate, within disrupted Cretaceous strata in the conduit walls, and within inferred remnants of the phreatomagmatic slurry that filled the vents during explosive volcanism. A younger series of intrusions with 40Ar/39Ar dates of ~ 42??Ma underwent nonexplosive interaction with Upper Cretaceous to Paleocene mud and sand. Dikes and sills show fluidal, billowed, quenched margins against the host strata, recording development of surface instabilities between magma and groundwater-rich sediment. Accentuation of billowed margins resulted in propagation of intrusive pillows into the adjacent sediment. More intense disruption and mingling of quenched magma with sediment locally produced fluidal and blocky peperite, but sufficient volumes of pore fluid were not heated rapidly enough to generate phreatomagmatic explosions. This work suggests that Trans-Pecos Texas may be an important locale for the study of subvolcanic phreatomagmatic processes and associated phenomena. Eocene intrusions in the study area underwent complex interactions with wet sediment at shallow levels beneath the surface in strata as old as Maastrichtian, which must have remained unlithified and rich in pore water for ~ 20-25??Ma. ?? 2009 Elsevier B.V. All rights reserved.

Partial Melting of the Indarch (EH4) Meteorite : A Textural, Chemical and Phase Relations View of Melting and Melt Migration

NASA Technical Reports Server (NTRS)

McCoy, Timothy J.; Dickinson, Tamara L.; Lofgren, Gary E.

2000-01-01

To Test whether Aubrites can be formed by melting of enstatite Chondrites and to understand igneous processes at very low oxygen fugacities, we have conducted partial melting experiments on the Indarch (EH4) chondrite at 1000-1500 C. Silicate melting begins at 1000 C. Substantial melt migration occurs at 1300-1400 C and metal migrates out of the silicate change at 1450 C and approx. 50% silicate partial melting. As a group, our experiments contain three immiscible metallic melts 9Si-, and C-rich), two immiscible sulfide melts(Fe-and FeMgMnCa-rich) and Silicate melt. Our partial melting experiments on the Indarch (EH4) enstatite Chondrite suggest that igneous processes at low fO2 exhibit serveral unique features. The complete melting of sulfides at 1000 C suggest that aubritic sulfides are not relicts. Aubritic oldhamite may have crystallized from Ca and S complexed in the silicate melt. Significant metal-sulfide melt migration might occur at relatively low degrees of silicate partial melting. Substantial elemental exchange occurred between different melts (e.g., between sulfide and silicate, Si between silicate and metal), a feature not observed during experiments at higher fO2. This exchange may help explain the formation of aubrites from known enstatite chondrites.

Paleomagnetism of the Permian-Triassic intrusions from the Tunguska syncline and the Angara-Taseeva depression, Siberian Traps Large Igneous Province: Evidence of contrasting styles of magmatism

NASA Astrophysics Data System (ADS)

Latyshev, A. V.; Veselovskiy, R. V.; Ivanov, A. V.

2018-01-01

Based on the detailed paleomagnetic investigation, we distinguished different styles of intrusive magmatic activity in two regions of the Siberian Traps Large Igneous Province (LIP). The emplacement of intrusions in the Angara-Taseeva depression (the southern periphery of the Siberian Traps LIP) occurred as brief but intense bursts of magmatic activity that led to the emplacement of large and extensive sills. We argue that this pulsating style of intrusive magmatic activity is common for the margins of the Siberian Traps LIP. We also estimated the duration of the main magmatic events as < 104-105 years for the large sills and their area of manifestation (> 200-250 km in diameter and dozens of thousands km2 in square). On the contrary, in the central part of the Siberian Traps LIP (the Tunguska syncline) the intrusive magmatism was more or less continuous without intense peaks of magmatic activity. Furthermore, we obtained the first reliable magnetostratigraphic data from the volcanic section of the Tunguska syncline. Finally, we analyzed the available paleomagnetic and geochronological data from the Siberian platform and suggested the correlation scheme of the studied intrusive complexes with the volcanic sequences of the Siberian Traps LIP.

Sill induced hydrothermal venting: A summary of our current understanding

NASA Astrophysics Data System (ADS)

Jerram, Dougal; Svenesn, Henrik; Planke, Sverre; Millett, John; Reynolds, Pete

2017-04-01

Hydrothermal vent structures which are predominantly related with the emplacement of large (>1000 km3) intrusions into the sub-volcanic basins represent a specific style of piercement structure, where climate-forcing gases can be transferred into the atmosphere and hydrosphere. In this case, the types and volumes of gas produced by intrusions is heavily dependent on the host-rock sediment properties that they intrude through. The distribution of vent structures can be shown to be widespread in Large Igneous Provinces for example on both the Norwegian and the Greenland margins of the North Atlantic Igneous Province (NAIP). In this overview we assess the distribution, types and occurrence of hydrothermal vent structures associated with LIPs. There is particular focus on those within the NAIP using mapped examples from offshore seismic data as well as outcrop analogues, highlighting the variability of these structures and their deposits. As the availability of 3D data from offshore and onshore increases, the full nature of the volcanic stratigraphy from the subvolcanic intrusive complexes, through the main eruption cycles into the piercing vent structures, can be realised along the entirety of volcanic rifted margins and LIPs. This will help greatly in our understanding of the evolving palaeo-environments, and climate contributions during the evolution of these short lived massive volcanic events.

Gaussian processes with optimal kernel construction for neuro-degenerative clinical onset prediction

NASA Astrophysics Data System (ADS)

Canas, Liane S.; Yvernault, Benjamin; Cash, David M.; Molteni, Erika; Veale, Tom; Benzinger, Tammie; Ourselin, Sébastien; Mead, Simon; Modat, Marc

2018-02-01

Gaussian Processes (GP) are a powerful tool to capture the complex time-variations of a dataset. In the context of medical imaging analysis, they allow a robust modelling even in case of highly uncertain or incomplete datasets. Predictions from GP are dependent of the covariance kernel function selected to explain the data variance. To overcome this limitation, we propose a framework to identify the optimal covariance kernel function to model the data.The optimal kernel is defined as a composition of base kernel functions used to identify correlation patterns between data points. Our approach includes a modified version of the Compositional Kernel Learning (CKL) algorithm, in which we score the kernel families using a new energy function that depends both the Bayesian Information Criterion (BIC) and the explained variance score. We applied the proposed framework to model the progression of neurodegenerative diseases over time, in particular the progression of autosomal dominantly-inherited Alzheimer's disease, and use it to predict the time to clinical onset of subjects carrying genetic mutation.

Toxic cocaine- and convulsant-induced modification of forced swimming behaviors and their interaction with ethanol: comparison with immobilization stress

PubMed Central

Hayase, Tamaki; Yamamoto, Yoshiko; Yamamoto, Keiichi

2002-01-01

Background Swimming behaviors in the forced swimming test have been reported to be depressed by stressors. Since toxic convulsion-inducing drugs related to dopamine [cocaine (COC)], benzodiazepine [methyl 6,7-dimethoxy-4-ethyl-β-carboline-carboxylate (DMCM)], γ-aminobutyric acid (GABA) [bicuculline (BIC)], and glutamate [N-methyl-D-aspartate (NMDA)] receptors can function as stressors, the present study compared their effects on the forced swimming behaviors with the effects of immobilization stress (IM) in rats. Their interactions with ethanol (EtOH), the most frequently coabused drug with COC which also induces convulsions as withdrawal symptoms but interferes with the convulsions caused by other drugs, were also investigated. Results Similar to the IM (10 min) group, depressed swimming behaviors (attenuated time until immobility and activity counts) were observed in the BIC (5 mg/kg IP) and DMCM (10 mg/kg IP) groups at the 5 h time point, after which no toxic behavioral symptoms were observed. However, they were normalized to the control levels at the 12 h point, with or without EtOH (1.5 g/kg IP). In the COC (60 mg/kg IP) and NMDA (200 mg/kg IP) groups, the depression occurred late (12 h point), and was normalized by the EtOH cotreatment. At the 5 h point, the COC treatment enhanced the swimming behaviors above the control level. Conclusions Although the physiological stress (IM), BIC, and DMCM also depressed the swimming behaviors, a delayed occurrence and EtOH-induced recovery of depressed swimming were observed only in the COC and NMDA groups. This might be correlated with the previously-reported delayed responses of DA and NMDA neurons rather than direct effects of the drugs, which could be suppressed by EtOH. Furthermore, the characteristic psychostimulant effects of COC seemed to be correlated with an early enhancement of swimming behaviors. PMID:12425723

Peri-implant soft tissue and marginal bone adaptation on implant with non-matching healing abutments: micro-CT analysis.

PubMed

Finelle, Gary; Papadimitriou, Dimitrios E V; Souza, André B; Katebi, Negin; Gallucci, German O; Araújo, Mauricio G

2015-04-01

To assess (i) the outcome of changing the horizontal-offset dimension on the peri-implant soft tissues and the crestal bone and (ii) the effect of different healing abutments (flared vs. straight) on the marginal peri-implant soft tissues and crestal bone. Two-piece dental implants diameters of 3.5 and 4.5 mm were placed at least 1 mm subcrestal in five beagle dogs. Three different investigational groups: (i) 3.5-mm-diameter implant with narrow healing abutment (3.5N), (ii) 4.5-mm-diameter implant with narrow healing abutment (4.5N), and (iii) 3.5-mm-diameter implant with wide healing abutment (3.5W), were assessed. After 4 months of healing, the vertical distance from the marginal crestal bone (MB) to the implant shoulder (IS); the vertical distance from the IS to the first bone-to-implant contact; and the horizontal distance of bone ingrowth on the implant platform were measured with a high-resolution micro-CT (Xradia MicroXCT-200 system). Implants with a narrow healing caps showed an interproximal MB located between 0 and 1 mm above the implant shoulder, while the 3.5W group exhibits a mean value -0.50 mm. As all implants in group 3.5N presented a fBIC located at the level of the IS. For the 4.5N group, the mean fBIC-IS distance was -0.52 mm apically to the IS. For the 3.5WC group, the mean fBIC-IS distance was -1.42 mm. Horizontal bone apposition was only observed for the 3.5N group and the 4.5N group. The dimension of the horizontal offset would play a minimal role in reducing bone remodeling, whereas the configuration of the transmucosal component would directly influence marginal bone remodeling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Topiramate via NMDA, AMPA/kainate, GABAA and Alpha2 receptors and by modulation of CREB/BDNF and Akt/GSK3 signaling pathway exerts neuroprotective effects against methylphenidate-induced neurotoxicity in rats.

PubMed

Motaghinejad, Majid; Motevalian, Manijeh; Fatima, Sulail; Beiranvand, Tabassom; Mozaffari, Shiva

2017-11-01

Chronic abuse of methylphenidate (MPH) often causes neuronal cell death. Topiramate (TPM) carries neuroprotective effects, but its exact mechanism of action remains unclear. In the present study, the role of various doses of TPM and its possible mechanisms, receptors and signaling pathways involved against MPH-induced hippocampal neurodegeneration were evaluated in vivo. Thus, domoic acid (DOM) was used as AMPA/kainate receptor agonist, bicuculline (BIC) as GABA A receptor antagonist, ketamine (KET) as NMDA receptor antagonist, yohimbine (YOH) as α 2 adrenergic receptor antagonist and haloperidol (HAL) was used as dopamine D 2 receptor antagonist. Open field test (OFT) was used to investigate the disturbances in motor activity. Hippocampal neurodegenerative parameters were evaluated. Protein expressions of CREB/BDNF and Akt/GSK3 signaling pathways were also evaluated. Cresyl violet staining was performed to show and confirm the changes in the shape of the cells. TPM (70 and 100 mg/kg) reduced MPH-induced rise in lipid peroxidation, oxidized form of glutathione (GSSG), IL-1β and TNF-α levels, Bax expression and motor activity disturbances. In addition, TPM treatment increased Bcl-2 expression, the level of reduced form of glutathione (GSH) and the levels and activities of superoxide dismutase, glutathione peroxidase and glutathione reductase enzymes. TPM also inhibited MPH-induced hippocampal degeneration. Pretreatment of animals with DOM, BIC, KET and YOH inhibited TPM-induced neuroprotection and increased oxidative stress, neuroinflammation, neuroapoptosis and neurodegeneration while reducing CREB, BDNF and Akt protein expressions. Also pretreatment with DOM, BIC, KET and YOH inhibited TPM-induced decreases in GSK3. It can be concluded that the mentioned receptors by modulation of CREB/BDNF and Akt/GSK3 pathways, are involved in neuroprotection of TPM against MPH-induced neurodegeneration.

Using a Differential Scanning Calorimeter to Teach Phase Equilibria to Students of Igneous and Metamorphic Petrology

ERIC Educational Resources Information Center

Maria, Anton H.; Millam, Evan L.; Wright, Carrie L.

2011-01-01

As an aid for teaching phase equilibria to undergraduate students of igneous and metamorphic petrology, we have designed a laboratory exercise that allows them to create a phase diagram from data produced by differential scanning calorimetry. By preparing and analyzing samples of naphthalene and phenanthrene, students acquire hands-on insight into…

FeO and MgO in plagioclase of lunar anorthosites: Igneous or metamorphic?

NASA Technical Reports Server (NTRS)

Phinney, W. C.

1994-01-01

The combined evidence from terrestrial anorthosites and experimental laboratory studies strongly implies that lunar anorthosites have been subjected to high-grade metamorphic events that have erased the igneous signatures of FeO and MgO in their plagioclases. Arguments to the contrary have, to this point, been more hopeful than rigorous.

Positive Holes Flowing through Stressed Igneous Rocks

NASA Astrophysics Data System (ADS)

Takeuchi, Akihiro

Igneous rocks generally involve positive hole pairs (PHPs), a kind of lattice defects also known as peroxy links: O3X-OO-YO3 with X, Y = Si4+, Al3+ etc. When a portion of such a rock block is stressed or heated, PHPs are deformed and positive holes (p-holes) are activated. They are defect electrons corresponding to the O- electronic state in the O2- sublattice and can spread away into unstressed portion. Currents and positive surface electrifications detected in laboratory stressed igneous rocks can be explained by the p-holes. When the p-holes are activated in the Earth's crust accompanied with seismic or volcanic events, they would lead to anomalous electromagnetic phenomena and could affect our electronic communication.

Martian Igneous Geochemistry: The Nature of the Martian Mantle

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Elkins-Tanton, L. T.; Peng, Z. X.; Herrin, J. S.

2012-01-01

Mafic igneous rocks probe the interiors of their parent objects, reflecting the compositions and mineralogies of their source regions, and the magmatic processes that engendered them. Incompatible trace element contents of mafic igneous rocks are widely used to constrain the petrologic evolution of planets. We focus on incompatible element ratios of martian meteorites to constrain the petrologic evolution of Mars in the context of magma ocean/cumulate overturn models [1]. Most martian meteorites contain some cumulus grains, but regardless, their incompatible element ratios are close to those of their parent magmas. Martian meteorites form two main petrologic/ age groupings; a 1.3 Ga group composed of clinopyroxenites (nakhlites) and dunites (chassignites), and a <1 Ga group composed of basalts and lherzolites (shergottites).

How tectonics controlled post-collisional magmatism within the Dinarides: Inferences based on study of tectono-magmatic events in the Kopaonik Mts. (Southern Serbia)

NASA Astrophysics Data System (ADS)

Mladenović, Ana; Trivić, Branislav; Cvetković, Vladica

2015-04-01

In this study, we report evidence about coupling between tectonic and magmatic processes in a complex orogenic system. The study focuses on the Kopaonik Mts. situated between the Dinarides and the Carpatho-Balkanides (Southern Serbia), and a perfect area for investigating tectono-magmatic evolution. We combine a new data set on tectonic paleostress tensors with the existing information on Cenozoic magmatic rocks in the wider Kopaonik Mts. area. The paleostress study revealed the presence of four brittle deformational phases. The established link between fault mechanism and igneous processes suggests that two large tectono-magmatic events occurred in this area. The Late Eocene-Early Miocene tectono-magmatic event was generally characterized by transpressional tectonics that provided conditions for formation of basaltic underplating and subsequent lower crustal melting and generation of I-type magmas. Due to predominant compression in the first half of this event, these magmas could not reach the upper crustal levels. Later on, limited extensional pulses that occurred before the end of this event opened pathways for newly formed mantle melts to reach shallower crustal levels and mix with the evolving I-type magmas. The second event is Middle-Late Miocene in age. It was first associated with clear extensional conditions that caused advancing of basaltic melts to mid-crustal levels. This, in turn, induced the elevation of geotherms, melting of shallow crust and S-type granite formation. This event terminated with transpression that produced small volumes of basaltic melts and finally closed the igneous scene in this part of the Balkan Peninsula. Although we agree that the growth of igneous bodies is usually internally controlled and can be independent from the ambient structural pattern, we have strong reasons to believe that the integration of regional scale observations of fault kinematics with crucial petrogenetic information can be used for establishing spatial-temporal relationships between brittle tectonics and magmatism.

The geology of the Inconsolable Range, east-central Sierra Nevada, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hathaway, G.M; Reed, W.E.

1993-04-01

Detailed mapping of the Inconsolable Range in the east-central Sierra Nevada reveals a structurally and lithologically complex region of multi-phase intrusions. Some plutons are compositionally-zoned [e.g., Inconsolable (100 Ma) and Lamarck (90 Ma)]; others may be the result of magma mixing. Intrusive borders vary from brittle to ductile and sharp to gradational, and are bounded by contact aureoles of varying metamorphic grade. A shear zone (Long Lake shear zone -- LLSZ) bounds the western margin of the Inconsolable Range for 8 km; this is truncated in the south by the Cretaceous Lamarck intrusive suite, and is tectonically overlain in themore » north by the Bishop Creek Pendant (Ordovician ). The LLSZ is a complex zone of interleaved septa of biotite schists, orthogneisses, aplitic screens, and calc-silicate gneisses approximately 500 to 800 m wide. Preliminary interpretation suggests that the LLSZ is the sheared remnant of a Triassic-Jurassic igneous terrane complete with metasedimentary pendants. Juxtaposition of greenschist facies meta-sedimentary rocks of the Chocolate Peak klippe over highly deformed amphibolite grade meta-igneous rocks of the LLSZ postdates movement along the LLSZ. Metamorphic grades suggest that deeper structural levels are exposed within the LLSZ near its southern terminus. Twenty plutonic lithologies have been mapped and informally named (e.g., Spotted biotite quartz diorite), including 3 compositionally-zoned plutons. Zonation within the Lamarck, Inconsolable, and Spotted intrusions are the result of multiple emplacement events into partially crystallized host plutons. Along the eastern border of the Lamarck intrusive suite field evidence indicates four separate intrusive events. The Inconsolable body is a compositionally-zoned biotite, clinopyroxene, quartz diorite with irregular granodiorite margins. The base of the Spotted intrusion appears to have been magmatically eroded by a pulse of the younger Lamarck intrusion.« less

The Lusi eruption and implications for understanding fossil piercement structures in sedimentary basins

NASA Astrophysics Data System (ADS)

Svensen, Henrik; Mazzini, Adriano; Planke, Sverre; Hadi, Soffian

2016-04-01

The Lusi eruption started in northeast Java, Indonesia, on May 29th 2006, and it has been erupting rocks, mud, water, and gas ever since. We have been doing field work and research on Lusi ever since the eruption commenced. This work was initially motivated from studying the initiation of a mud volcano. However, the longevity of the eruption has made it possible to describe and monitor the lifespan of this unique piercement structure. . One of the first-order questions regarding the eruption is how it should be classified and if there are any other modern or fossil analogues that can place Lusi in a relevant geological context. During the initial stages of eruption, Lusi was classified as a mud volcano, but following geochemical studies the eruption did not show the typical CH4-dominated gas composition of other mud volcanoes and the temperature was also too high. Moreover, mud volcano eruptions normally last a few days, but Lusi never stopped during the past decade. In particular, the crater fluid geochemistry suggests a connection to the neighboring volcanic complex. Lusi represent a sedimentary hosted hydrothermal system. This opens up new possibilities for understanding fossil hydrothermal systems in sedimentary basins, such as hydrothermal vent complexes and breccia-pipes found in sedimentary basins affected by the formation of Large igneous provinces. We will present examples from the Karoo Basin (South Africa) and the Vøring Basin (offshore Norway) and discuss how Lusi can be used to refine existing formation models. Finally, by comparing Lusi to fossil hydrothermal systems we may get insight into the processes operating at depth where the Lusi system interacts with the igneous rocks of the neighbouring volcanic arc.

Neoproterozoic extension in the greater dharwar craton: A reevaluation of the "betsimisaraka suture" in madagascar

USGS Publications Warehouse

Tucker, R.D.; Roig, J.-Y.; Delor, C.; Amlin, Y.; Goncalves, P.; Rabarimanana, M.H.; Ralison, A.V.; Belcher, R.W.

2011-01-01

The Precambrian shield of Madagascar is reevaluated with recently compiled geological data and new U-Pb sensitive high-resolution ion microprobe (SHRIMP) geochronology. Two Archean domains are recognized: the eastern Antongil-Masora domain and the central Antananarivo domain, the latter with distinctive belts of metamafic gneiss and schist (Tsaratanana Complex). In the eastern domain, the period of early crust formation is extended to the Paleo-Mesoarchean (3.32-3.15 Ga) and a supracrustal sequence (Fenerivo Group), deposited at 3.18 Ga and metamorphosed at 2.55 Ga, is identified. In the central domain, a Neoarchean period of high-grade metamorphism and anatexis that affected both felsic (Betsiboka Suite) and mafic gneisses (Tsaratanana Complex) is documented. We propose, therefore, that the Antananarivo domain was amalgamated within the Greater Dharwar Craton (India + Madagascar) by a Neoarchean accretion event (2.55-2.48 Ga), involving emplacement of juvenile igneous rocks, high-grade metamorphism, and the juxtaposition of disparate belts of mafic gneiss and schist (metagreenstones). The concept of the "Betsimisaraka suture" is dispelled and the zone is redefined as a domain of Neoproterozoic metasedimentary (Manampotsy Group) and metaigneous rocks (Itsindro-Imorona Suite) formed during a period of continental extension and intrusive igneous activity between 840 and 760 Ma. Younger orogenic convergence (560-520 Ma) resulted in east-directed overthrusting throughout south Madagascar and steepening with local inversion of the domain in central Madagascar. Along part of its length, the Manampotsy Group covers the boundary between the eastern and central Archean domains and is overprinted by the Angavo-Ifanadiana high-strain zone that served as a zone of crustal weakness throughout Cretaceous to Recent times.

Variable sulfur isotope composition of sulfides provide evidence for multiple sources of contamination in the Rustenburg Layered Suite, Bushveld Complex

NASA Astrophysics Data System (ADS)

Magalhães, Nivea; Penniston-Dorland, Sarah; Farquhar, James; Mathez, Edmond A.

2018-06-01

The Rustenburg Layered Suite (RLS) of the Bushveld Complex (BC) is famous for its platinum group element (PGE) ore, which is hosted in sulfides. The source of sulfur necessary to generate this type of mineralization is inferred to be the host rock of the intrusion. The RLS has a sulfur isotopic signature that indicates the presence of Archean surface-derived material (Δ33 S ≠ 0) in the magma. This signature, with an average value of Δ33 S = 0.112 ± 0.024 ‰, deviates from the expected Δ33 S value of the mantle of 0 ± 0.008 ‰. Previous work suggested that this signature is uniform throughout the RLS, which contrasts with radiogenic isotopes which vary throughout the igneous stratigraphy of the RLS. In this study, samples from key intervals within the igneous stratigraphy were analyzed, showing that Δ33 S values vary in the same stratigraphic levels as Sr and Nd isotopes. However, the variation is not consistent; in some levels there is a positive correlation and in others a negative correlation. This observation suggests that in some cases distinct magma pulses contained assimilated sulfur from different sources. Textural analysis shows no evidence for late addition of sulfur. These results also suggest that it is unlikely that large-scale assimilation and/or efficient mixing of host rock material in a single magma chamber occurred during emplacement. The data do not uniquely identify the source of sulfur in the different layers of the RLS, but the variation in sulfur isotope composition and its relationship to radiogenic isotope data calls for a reevaluation of the models for the formation and evolution of the RLS, which has the potential to impact the knowledge of how PGE deposits form.

Cadomian magmatism and metamorphism at the Ossa Morena/Central Iberian zone boundary, Iberian Massif, Central Portugal: Geochemistry and P-T constraints of the Sardoal Complex

NASA Astrophysics Data System (ADS)

Henriques, S. B. A.; Neiva, A. M. R.; Tajčmanová, L.; Dunning, G. R.

2017-01-01

A well preserved Cadomian basement is exposed in the Iberian Massif, Central Portugal, at the Ossa Morena/Central Iberian zone boundary, which allows the determination of reliable geochemical data. A sequence of Cadomian and Variscan magmatic and tectonometamorphic events has been already described for this area and are documented in other areas of the Avalonian-Cadomian orogen. However, the geochemical information concerning the Cadomian basement for this area is still limited. We present whole rock geochemical and oxygen isotopic information to characterize the igneous protoliths of the Sardoal Complex, located within the Tomar-Badajoz-Córdoba Shear Zone, and identify their tectonic setting. We use detailed petrography, mineral chemistry and P-T data to characterize the final Cadomian tectonometamorphic event. The Sardoal Complex contains orthogneiss and amphibolite units. The protoliths of the orthogneiss are calc-alkaline magmas of acid composition and peraluminous character that were generated in an active continental margin in three different stages (ca. 692 Ma, ca. 569 Ma and ca. 548 Ma). The most significant processes in their petrogenesis are the partial melting of old metasedimentary and meta-igneous crust at different crustal levels and the crystal fractionation of plagioclase, alkali feldspars, apatite, zircon and Fe-Ti oxides. The protoliths of the amphibolite, older than ca. 540 Ma, are tholeiitic and calc-alkaline magmas of basic composition that display N-, T- and E-MORB affinities. They were generated in an active continental margin. Crustal contamination and fractional crystallization of hornblende and diopside were involved in their petrogenesis. However, the fractional crystallization was not significant. The magmatic activity recorded in the Sardoal Complex indicates the existence of a long-lived continental arc (ca. 692-540 Ma) with coeval felsic and mafic magmatism. The final stage of the Cadomian metamorphism is usually represented in other areas of the Cadomian basement as a LP-HT metamorphic event. However, the P-T data obtained by thermodynamic modelling indicates medium pressure/high temperature conditions at ca. 540 Ma. These data suggest that the Sardoal Complex represents a deeper level of the exhumed Cadomian basement where the final stage of the Cadomian metamorphism was recorded.

Transient Auditory Storage of Acoustic Details Is Associated with Release of Speech from Informational Masking in Reverberant Conditions

ERIC Educational Resources Information Center

Huang, Ying; Huang, Qiang; Chen, Xun; Wu, Xihong; Li, Liang

2009-01-01

Perceptual integration of the sound directly emanating from the source with reflections needs both temporal storage and correlation computation of acoustic details. We examined whether the temporal storage is frequency dependent and associated with speech unmasking. In Experiment 1, a break in correlation (BIC) between interaurally correlated…

Microcomputer Interfaces with U.S. Marine Corps Tactical Communications Systems,

DTIC Science & Technology

1991-04-01

Schneider and Mrs. Kirkpatrick at the Communications officer School Quantico, Virginia This document has been approvedf or p,bic Yleaze cncd sae; its...communications systems; however, there is not a comprehensive USMC Command, Control, Communications, and Computers (C4) operational policy that documents these...5-6 COMMUNICATIONS SYSTEMS .... ............. 5-6 ADP SYSTEMS ....... .................. 5-6 OPERATIONAL POLICIES

Screening for Sleep Problems in Early Intervention and Early Childhood Special Education: A Systematic Review of Screening and Assessment Instruments

ERIC Educational Resources Information Center

Bonuck, Karen A.; Hyden, Christel; Ury, Guenn; Barnett, Josephine; Ashkinaze, Hannah; Briggs, Rahil D.

2011-01-01

Behavioral insomnias of childhood (BIC) and sleep disordered breathing (SDB) disorders cause disrupted and/or inefficient sleep. Left untreated in early childhood, both conditions increase the risk of compromised development, particularly in the areas of behavior, cognition, and growth. This systematic review determined whether and how current…

Autonomous omnidirectional spacecraft antenna system

NASA Technical Reports Server (NTRS)

Taylor, T. H.

1983-01-01

The development of a low gain Electronically Switchable Spherical Array Antenna is discussed. This antenna provides roughly 7 dBic gain for receive/transmit operation between user satellites and the Tracking and Data Relay Satellite System. When used as a pair, the antenna provides spherical coverage. The antenna was tested in its primary operating modes: directed beam, retrodirective, and Omnidirectional.

Potassium bicarbonate supplementation lowers bone turnover and calcium excretion in older men and women a randomized dose-finding trial

USDA-ARS?s Scientific Manuscript database

The acid load accompanying modern diets may have adverse effects on bone and muscle metabolism. Treatment with alkaline salts of potassium can neutralize the acid load, but the optimal amount of alkali is not established. Our objective was to determine the effectiveness of two doses of potassium bic...

Database Dictionary for Ethiopian National Ground-Water Database (ENGDA) Data Fields

DTIC Science & Technology

2007-01-01

Coarse Sand Fine Sand Fine-Grained Sandstone Fractured Igneous and Metamorphic Rock Gravel Karst Limestone, Dolomite Medium Sand Medium-Grained...Coarse Sand; Fine Sand; Fine-Grained Sandstone; Fractured Igneous and Metamorphic Rock; Gravel; Karst Limestone/ Dolomite ; Medium Sand; Medium...aquifer lithology (rock type; Babcock and other, 2004). - 20 - Data Type: List, 1-character code C Consolidated porous sedimentary I Fractured

Geochemical and geochronological constraints on the genesis of Au-Te deposits at Cripple Creek, Colorado

USGS Publications Warehouse

Kelley, K.D.; Romberger, S.B.; Beaty, D.W.; Pontius, J.A.; Snee, L.W.; Stein, H.J.; Thompson, T.B.

1998-01-01

The Cripple Creek district (653 metric tons (t) of Au) consists of Au-Te veins and disseminated gold deposits that are spatially related to alkaline igneous rocks in an Oligocene intrusive complex. Vein paragenesis includes quartz-biotite-K feldspar-fluorite-pyrite followed by base metal sulfides and telluride minerals. Disseminated deposits consist of microcrystalline native gold with pyrite that are associated with zones of pervasive adularia. New 40Ar/39Ar dates indicate that there was a complex magmatic and hydrothermal history. Relatively felsic rocks (tephriphonolite, trachyandesite, and phonolite) were emplaced into the complex over about 1 m.y., from 32.5 ?? 0.1 (1??) to 31.5 ?? 0.1 Ma. A younger episode of phonolite emplacement outside of the complex is indicated by an age of 30.9 ?? 0.1 Ma. Field relationships suggest that at least one episode of mafic and ultramafic dike emplacement occurred after relatively more felsic rocks and prior to the main gold mineralizing event. Only a single whole-rock date for mafic phonolite (which indicated a maximum age of 28.7 Ma) was obtained. However, constraints on the timing of mineralization are provided by paragenetically early vein minerals and K feldspar from the disseminated gold pyrite deposits. Early vein minerals (31.3 ?? 0.1-29.6 ?? 0.1 Ma) and K feldspar (29.8 ?? 0.1 Ma) from the Cresson disseminated deposit, together with potassically altered phonolite adjacent to the Pharmacist vein (28.8 and 28.2 ?? 0.1 Ma), suggest there was a protracted history of hydrothermal activity that began during the waning stages of phonolite and early mafic-ultramafic activity and continued, perhaps intermittently, for at least 2 m.y. Estimated whole-rock ??18O values of the alkaline igneous rocks range from 6.4 to 8.2 per mil. K feldspar and albite separates from igneous rocks have lead isotope compositions of 206Pb/204Pb = 17.90 to 18.10, 207Pb/204Pb = 15.51 to 15.53, and 208Pb/204Pb = 38.35 to 38.56. These isotopic compositions, together with major and trace element data, indicate that the phonolitic magmas probably evolved by fractional crystallization of an alkali basalt that assimilated lower crustal material. Upper crustal contamination of the magmas was not significant. The 206Pb/204Pb compositions of vein galenas almost entirely overlap those of phonolites, suggesting a genetic relationship between alkaline magmatism and mineralization. However, a trend toward higher 207Pb/204Pb (15.57-15.60) and 208Pb/204Pb ratios (38.94-39.48) of some galenas suggests a contribution to the ore fluid from surrounding Early Proterozoic rocks, probably through leaching by mineralizing fluids. Limited stable isotope compositions of quartz, K feldspar, and biotite from this and previous studies support a largely magmatic origin for the early vein fluids. It is suggested that three features were collectively responsible for generating alkaline magmas and associated mineral deposits: (1) the timing of magmatism and mineralization, which coincided with the transition between subduction-related compression and extension related to continental rifting; (2) the location of Cripple Creek at the junction of four major Precambrian units and at the intersection of major northeast-trending regional structures with northwest-trending faults, which served as conduits for magmas and subsequent hydrothermal fluids; and (3) the complex magmatic history which included emplacement of relatively felsic magmas followed by successively more mafic magmas with time.

Phanerozoic tectonic evolution of the Circum-North Pacific

USGS Publications Warehouse

Nokleberg, Warren J.; Parfenov, Leonid M.; Monger, James W.H.; Norton, Ian O.; Khanchuk, Alexander I.; Stone, David B.; Scotese, Christopher R.; Scholl, David W.; Fujita, Kazuya

2000-01-01

The Phanerozoic tectonic evolution of the Circum-North Pacific is recorded mainly in the orogenic collages of the Circum-North Pacific mountain belts that separate the North Pacific from the eastern part of the North Asian Craton and the western part of the North American Craton. These collages consist of tectonostratigraphic terranes that are composed of fragments of igneous arcs, accretionary-wedge and subduction-zone complexes, passive continental margins, and cratons; they are overlapped by continental-margin-arc and sedimentary-basin assemblages. The geologic history of the terranes and overlap assemblages is highly complex because of postaccretionary dismemberment and translation during strike-slip faulting that occurred subparallel to continental margins.We analyze the complex tectonics of this region by the following steps. (1) We assign tectonic environments for the orogenic collages from regional compilation and synthesis of stratigraphic and faunal data. The types of tectonic environments include cratonal, passive continental margin, metamorphosed continental margin, continental-margin arc, island arc, oceanic crust, seamount, ophiolite, accretionary wedge, subduction zone, turbidite basin, and metamorphic. (2) We make correlations between terranes. (3) We group coeval terranes into a single tectonic origin, for example, a single island arc or subduction zone. (4) We group igneous-arc and subduction- zone terranes, which are interpreted as being tectonically linked, into coeval, curvilinear arc/subduction-zone complexes. (5) We interpret the original positions of terranes, using geologic, faunal, and paleomagnetic data. (6) We construct the paths of tectonic migration. Six processes overlapping in time were responsible for most of the complexities of the collage of terranes and overlap assemblages around the Circum-North Pacific, as follows. (1) During the Late Proterozoic, Late Devonian, and Early Carboniferous, major periods of rifting occurred along the ancestral margins of present-day Northeast Asia and northwestern North America. The rifting resulted in the fragmentation of each continent and the formation of cratonal and passive continental-margin terranes that eventually migrated and accreted to other sites along the evolving margins of the original or adjacent continents. (2) From about the Late Triassic through the mid-Cretaceous, a succession of island arcs and tectonically paired subduction zones formed near the continental margins. (3) From about mainly the mid-Cretaceous through the present, a succession of igneous arcs and tectonically paired subduction zones formed along the continental margins. (4) From about the Jurassic to the present, oblique convergence and rotations caused orogenparallel sinistral and then dextral displacements within the upper-plate margins of cratons that have become Northeast Asia and North America. The oblique convergences and rotations resulted in the fragmentation, displacement, and duplication of formerly more nearly continuous arcs, subduction zones, and passive continental margins. These fragments were subsequently accreted along the expanding continental margins. (5) From the Early Jurassic through Tertiary, movement of the upper continental plates toward subduction zones resulted in strong plate coupling and accretion of the former island arcs and subduction zones to the continental margins. Accretions were accompanied and followed by crustal thickening, anatexis, metamorphism, and uplift. The accretions resulted in substantial growth of the North Asian and North American Continents. (6) During the middle and late Cenozoic, oblique to orthogonal convergence of the Pacifi c plate with present-day Alaska and Northeast Asia resulted in formation of the modern-day ring of volcanoes around the Circum-North Pacific. Oblique convergence between the Pacific plate and Alaska also resulted in major dextral-slip faulting in interior and southern Alaska and along the western p

Radioactive occurrences in veins and igneous and metamorphic rocks of New Mexico with annotated bibliography. [Over 600 citations

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLemore, V. T.

1982-01-01

From an extensive literature search and field examination of 96 nonsandstone radioactive occurrences, the author compiled an annotated bibliography of over 600 citations and a list of 327 radioactive occurrences in veins and igneous and metamorphic rocks of New Mexico. The citations are indexed by individual radioactive occurrence, geographic area, county, fluorspar deposits and occurrences, geochemical analyses, and geologic maps. In addition, the geology, mineralization, and uranium and thorium potential of 41 geographic areas in New Mexico containing known radioactive occurrences in veins and igneous and metamorphic rocks or that contain host rocks considered favorable for uranium or thorium mineralizationmore » are summarized. A list of aerial-radiometric, magnetic, hydrogeochemical, and stream-sediment survey reports is included.« less

Generation of syntectonic calc-alkaline, magnesian granites through remelting of pre-tectonic igneous sources - U-Pb zircon ages and Sr, Nd and Pb isotope data from the Donkerhoek granite (southern Damara orogen, Namibia)

NASA Astrophysics Data System (ADS)

Schwark, L.; Jung, S.; Hauff, F.; Garbe-Schönberg, D.; Berndt, J.

2018-06-01

The 541 ± 4 Ma-old magnesian, weakly peraluminous, calc-alkalic Donkerhoek Onanis granite is part of the ca. 6000 km2 large Donkerhoek batholith in the Southern Zone of the Damara orogen of Namibia. Linear major and trace element variations and decreasing MgO, FeO, Al2O3, CaO, K2O, Na2O, Ba and Sr concentrations with increasing SiO2 indicate that this part of the batholith represent a coherent mass and underwent fractional crystallization processes. The Donkerhoek Onanis granites are isotopically evolved (initial εNd: -4.7 to -12.3, initial 87Sr/86Sr: 0.7099-0.7157) with moderately radiogenic Pb isotope ratios (206Pb/204Pb: 17.26-18.22; 207Pb/204Pb: 15.59-15.67; 208Pb/204Pb: 37.60-38.06). Beside heterogeneities imparted by the sources, an evaluation of LREE fractionation and Nd isotope data suggests that AFC processes also modified some samples. Based on the chemical and isotope data, the Donkerhoek Onanis granites cannot be derived by partial melting of Al- and Fe-rich metasedimentary rocks of the Kuiseb formation in which they intruded. Instead, melting of meta-igneous crustal sources with Proterozoic crustal residence ages is more likely. Three igneous to meta-igneous rock suites from the area (Matchless amphibolites, Proterozoic mafic to felsic gneisses from the southern Kalahari craton basement, syn-tectonic Salem granodiorites to granites) are potential sources. An evaluation of chemical and isotope data suggests that remelting of early syn-orogenic Salem-type granites is the most likely process which would also explain the existence of ca. 563 ± 4 Ma-old zircon in the Donkerhoek Onanis granites. Comparison of the Donkerhoek Onanis granites with experimentally derived melt compositions from an intermediate igneous parent indicates temperatures between 800 and 850 °C. It is suggested that the Pan-African igneous activity in this part of the Damara Belt was a moderate-temperature intra-crustal event. Although there are some compositional similarities with juvenile granites generated in subduction zones, unradiogenic Pb isotope ratios and moderately radiogenic Sr and unradiogenic Nd isotopes suggest that reprocessed crustal rocks are more likely sources. Previously obtained high δ18O values of the Donkerhoek Onanis granites ranging from 11.8 to 13.6‰, covering the range of δ18O values obtained on Salem-type granites from the area (12.5-13.3‰) confirm this view. In contrast to igneous processes along active continental margins that produce juvenile batholiths with calc-alkaline affinities, this igneous event was not a major crust-forming episode and the Donkerhoek Onanis granites represent reprocessed crustal material.

Link between the granitic and volcanic rocks of the Bushveld Complex, South Africa

NASA Astrophysics Data System (ADS)

Schweitzer, J. K.; Hatton, C. J.; De Waal, S. A.

1997-02-01

Until recently, it was proposed that the Bushveld Complex, consisting of the extrusive Rooiberg Group and the intrusive Rashoop Granophyre, Rustenburg Layered and Lebowa Granite Suites, evolved over a long period of time, possibly exceeding 100 Ma. Most workers therefore considered that the various intrusive and extrusive episodes were unrelated. Recent findings suggest that the intrusive, mafic Rustenburg Layered Suite, siliceous Rashoop Granophyre Suite and the volcanic Rooiberg Group were synchronous, implying that the Bushveld igneous event was short-lived. Accepting the short-lived nature of the complex, the hypothesis that the granites are genetically unrelated to the other events of the Bushveld Complex can be reconsidered. Re-examination of the potential Rooiberg Group/Lebowa Granite Suite relationship suggests that the granites form part of the Bushveld event. Rhyolite lava, granite and granophyre melts originated from a source similar in composition to upper crustal rocks. This source is interpreted to have been melted by a thermal input associated with a mantle plume. Granite intruded after extrusion of the last Rooiberg rhyolite, or possibly overlapped in time with the formation of the youngest volcanic flows.

Relation Between the Molopo Farms and Bushveld Complexes: An Analysis of Pyroxene Exsolution Lamellae

NASA Astrophysics Data System (ADS)

Moore, I.; Feineman, M. D.; Nyblade, A.

2017-12-01

The Molopo Farms Complex (MFC) is a layered igneous intrusion in Botswana, considered to be related to the nearby South African Bushveld Complex (BC) due to their similarities. The BC has been researched in depth for its economic deposits of platinum group elements (PGEs), while the under-researched MFC has no PGEs and is under 200 m of sediment. This study aims to increase knowledge about the MFC regarding the theory that the BC and MFC come from the same parental magma body by showing similar cooling history in the exsolution of pyroxenes. Using optical microscopy and scanning electron microscopy (SEM) paired with an energy-dispersive detector (EDS), thin sections of pyroxenes with exsolution lamellae from both complexes were observed in terms of chemical composition and microtextures. MFC pyroxenes were then compared to literature data of BC pyroxenes. The pyroxenes are closely related, indicating that the MFC and the BC cooled at a similar rate and come from the same parental magma body. Further research can expand on these findings to prove that the MFC and BC are from the same magma.

Apollo 16 exploration of Descartes - A geologic summary.

NASA Technical Reports Server (NTRS)

1973-01-01

The Cayley Plains at the Apollo 16 landing site consist of crudely stratified breccias to a depth of at least 200 meters, overlain by a regolith 10 to 15 meters thick. Samples, photographs, and observations by the astronauts indicate that most of the rocks are impact breccias derived from an anorthosite-gabbro complex. The least brecciated members of the suite include coarse-grained anorthosite and finer-grained, more mafic rocks, some with igneous and some with metamorphic textures. Much of the transverse area is covered by ejecta from North Ray and South Ray craters, but the abundance of rock fragments increases to the south toward the younger South Ray crater.

Experimental geochemistry of Pu and Sm and the thermodynamics of trace element partitioning

NASA Technical Reports Server (NTRS)

Jones, John H.; Burnett, Donald S.

1987-01-01

An experimental study of the partitioning of Pu and Sm between diopside/liquid and whitlockite/liquid supports the hypothesis that Pu behaves as a light rare earth element during igneous processes in reducing environments. D-Pu/D-Sm is found to be about 2 for both diopsidic pyroxene and whitlockite, and the amount of fractionation would be decreased further if Pu were compared to Ce or Nd. Data indicate that temperature, rather than melt composition, is the most important control on elemental partitioning, and that P2O5 in aluminosilicate melts serves as a complexing agent for the actinides and lanthanides.

Vesta Evolution from Surface Mineralogy: Mafic and Ultramafic Mineral Distribution

NASA Technical Reports Server (NTRS)

DeSanctis, M. C.; Ammannito, E.; Palomba, E.; Longobardo, A.; Mittlefehldt, D. W.; McSween, H. Y; Marchi, S.; Capria, M. T.; Capaccioni, F.; Frigeri, A.;

The High Arctic Large Igneous Province Mantle Plume caused uplift of Arctic Canada

NASA Astrophysics Data System (ADS)

Galloway, Jennifer; Ernst, Richard; Hadlari, Thomas

2016-04-01

The Sverdrup Basin is an east-west-trending extensional sedimentary basin underlying the northern Canadian Arctic Archipelago. The tectonic history of the basin began with Carboniferous-Early Permian rifting followed by thermal subsidence with minor tectonism. Tectonic activity rejuvenated in the Hauterivian-Aptian by renewed rifting and extension. Strata were deformed by diapiric structures that developed during episodic flow of Carboniferous evaporites during the Mesozoic and the basin contains igneous components associated with the High Arctic Large Igneous Province (HALIP). HALIP was a widespread event emplaced in multiple pulses spanning ca. 180 to 80 Ma, with igneous rocks on Svalbard, Franz Josef Island, New Siberian Islands, and also in the Sverdrup Basin on Ellef Ringnes, Axel Heiberg, and Ellesmere islands. Broadly contemporaneous igneous activity across this broad Arctic region along with a reconstructed giant radiating dyke swarm suggests that HALIP is a manifestation of large mantle plume activity probably centred near the Alpha Ridge. Significant surface uplift associated with the rise of a mantle plume is predicted to start ~10-20 my prior to the generation of flood basalt magmatism and to vary in shape and size subsequently throughout the LIP event (1,2,3) Initial uplift is due to dynamical support associated with the top of the ascending plume reaching a depth of about 1000 km, and with continued ascent the uplift topography broadens. Additional effects (erosion of the ductile lithosphere and thermal expansion caused by longer-term heating of the mechanical lithosphere) also affect the shape of the uplift. Topographic uplift can be between 1 to 4 km depending on various factors and may be followed by subsidence as the plume head decays or become permanent due to magmatic underplating. In the High Arctic, field and geochronological data from HALIP relevant to the timing of uplift, deformation, and volcanism are few. Here we present new evidence based on stratigraphic correlation that show thinning of strata in the northeastern part of the basin. The Isachsen Formation (Valanginian or Hauterivian to late Aptian) is a sandstone unit with interbeds of mudstone, coal, volcanic, and volcaniclastic/tuffaceous rocks attributed to HALIP. Isachsen Formation has a fairly consistent thickness over most of the Sverdrup Basin, ranging from ~120 m at basin margins to 1370 m on western Axel Heiberg Island but is generally > 400 m thick, even over the large salt domes that rose almost to the surface immediately prior to its deposition. The thickness of the formation decreases from over 400 m thick at Ellef Ringnes Island and southern Axel Heiberg Island to less than 120 m across a broad area of central Ellesmere Island. We interpret NE thinning of these strata to be the result of topographic uplift associated with initial mantle plume activity of HALIP. However, the rejuvenation of Sverdrup Basin formation (nearer the plume centre) in the Hauterivian-Aptian reflects complexities in the uplift pattern. References: 1-Griffiths, R.W. and Campbell, I.H. 1991 JGR 96: 18295-18310. 2-Campbell, I.H. 2007. Chem. Geol., 241: 153-176. 3-Ernst, 2014. LIPs. Cambridge U. Press, 653 p.

Igneous lithologies on asteroid (4) Vesta mapped using gamma-ray and neutron data

NASA Astrophysics Data System (ADS)

Beck, Andrew W.; Lawrence, David J.; Peplowski, Patrick N.; Viviano-Beck, Christina E.; Prettyman, Thomas H.; McCoy, Timothy J.; McSween, Harry Y.; Yamashita, Naoyuki

2017-04-01

We use data collected by the Dawn Gamma-Ray and Neutron Detector (GRaND) at Vesta to map compositions corresponding to nearly pure igneous lithologies in the howardite, eucrite, diogenite (HED) meteorite clan (samples likely from Vesta). At the ∼300-km spatial scale of GRaND measurements, basaltic eucrite occurs on only 3% of the surface, whereas cumulate eucrite and orthopyroxenitic diogenite are not detected. The basaltic eucrite region is generally coincident with an area of the surface with thick regolith, elevated H, and moderate crater density, and may represent the best compositional sample of primordial vestan crust. We observe an absence of pure orthopyroxenitic diogenite terrains in the Rheasilvia basin and its ejecta, an observation corroborated by VIR (0.1%), which suggests the south-polar crust was a polymict mixture of igneous lithologies (howardite) at the time of the Rheasilvia impact, or was a thick basaltic eucrite crust with heterogeneously distributed orthopyroxenitic diogenite plutons. The most dominant igneous composition detected (11% of the surface) corresponds to one of the least-abundant igneous lithologies in the HED meteorite collection, the Yamato Type B diogenites (plagioclase-bearing pyroxenites). The distribution of Type B diogenite is spatially correlated with post-Rheasilvia craters in the north-polar region that are in close proximity to the Rheasilvia basin antipode. This suggests that north-polar Type B plutonism may have been associated with the Rheasilvia impact event. We propose that this was either through 1) uplift of pre-existing plutons at the antipode through focusing of Rheasilvia impact stress, or 2) Rheasilvia impact antipodal crustal melting, creating magmas that underwent fractionation to produce Type B plutons.

31 CFR 26.3 - Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental Impact Assessments (EIAs). 26.3 Section 26.3 Money and...) 466-8191, not a toll-free call). (ii) If a copy of an EIA Summary is not available from the BIC...

31 CFR 26.3 - Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental Impact Assessments (EIAs). 26.3 Section 26.3 Money and...) 466-8191, not a toll-free call). (ii) If a copy of an EIA Summary is not available from the BIC...

31 CFR 26.3 - Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental Impact Assessments (EIAs). 26.3 Section 26.3 Money and...) 466-8191, not a toll-free call). (ii) If a copy of an EIA Summary is not available from the BIC...

31 CFR 26.3 - Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental Impact Assessments (EIAs). 26.3 Section 26.3 Money and...) 466-8191, not a toll-free call). (ii) If a copy of an EIA Summary is not available from the BIC...

31 CFR 26.3 - Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental Impact Assessments (EIAs). 26.3 Section 26.3 Money and...) 466-8191, not a toll-free call). (ii) If a copy of an EIA Summary is not available from the BIC...

Sediment Acoustics: Wideband Model, Reflection Loss and Ambient Noise Inversion

DTIC Science & Technology

2010-01-01

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Sediment acoustics : Wideband model , reflection loss and...Physically sound models of acoustic interaction with the ocean floor including penetration, reflection and scattering in support of MCM and ASW needs...OBJECTIVES (1) Consolidation of the BIC08 model of sediment acoustics , its verification in a variety of sediment types, parameter reduction and

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation

PubMed Central

Kang, Sung-Won; Lee, Woo-Jin; Choi, Soon-Chul; Lee, Sam-Sun; Heo, Min-Suk; Huh, Kyung-Hoe

2015-01-01

Purpose We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). Materials and Methods The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. Results VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). Conclusion It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method. PMID:25793178

A Wideband Circularly Polarized Antenna with a Multiple-Circular-Sector Dielectric Resonator

PubMed Central

Trinh-Van, Son; Yang, Youngoo; Lee, Kang-Yoon; Hwang, Keum Cheol

2016-01-01

This paper presents the design of a wideband circularly polarized antenna using a multiple-circular-sector dielectric resonator (DR). The DR is composed of twelve circular-sector DRs with identical central angles of 30∘ but with different radii. A genetic algorithm is utilized to optimize the radii of the twelve circular-sector DRs to realize wideband circular polarization. The proposed antenna is excited using an aperture-coupled feeding technique through a narrow rectangular slot etched onto the ground plane. An antenna prototype is experimentally verified. The measured −10 dB reflection and 3 dB axial ratio (AR) bandwidths are 31.39% (1.88–2.58 GHz) and 19.30% (2.06–2.50 GHz), respectively, covering the operating bands of the following systems: UMTS-2100 (2.145 GHz), WiMAX (2.3 GHz), and Wi-Fi (2.445 GHz). A measured peak gain of 7.65 dBic at 2.225 GHz and gain variation of less than 2.70 dBic within the measured 3 dB AR bandwidth are achieved. In addition, the radiation patterns of the proposed antenna are presented and discussed. PMID:27827881

Integron- and Carbenicillinase-Mediated Reduced Susceptibility to Amoxicillin-Clavulanic Acid in Isolates of Multidrug-Resistant Salmonella enterica Serotype Typhimurium DT104 from French Patients

PubMed Central

Poirel, Laurent; Guibert, Michele; Bellais, Samuel; Naas, Thierry; Nordmann, Patrice

1999-01-01

Fifty-seven Salmonella enterica serotype Typhimurium (S. typhimurium) isolates were collected from human patients in two French hospitals, Hôpital Antoine Béclère (Clamart, France) and Hôpital Bicêtre (Le Kremlin-Bicêtre, France), between 1996 and 1997. Thirty of them (52 percent) were resistant to amino-, carbeni-, and ureidopenicillins, had reduced susceptibility to amoxicillin-clavulanic acid, were susceptible to cephalothin, and were resistant to sulfonamides, streptomycin, chloramphenicol, and tetracyclines. All these strains possessed a blaPSE-1-like gene and were of phage type DT104. Ten of them were studied in more detail, which revealed that blaPSE-1 is located on the variable region of a class 1 integron. This integron was found to be chromosomally located, as was another class 1 integron containing aadA2, a streptomycin-spectinomycin resistance gene. The reduced susceptibility to amoxicillin-clavulanic acid (and to ticarcillin-clavulanic acid) may result from the high level of hydrolysis of the β-lactam rather than to the clavulanic acid resistance properties of PSE-1 in these clonally related S. typhimurium isolates. PMID:10223920

Metal nanoinks as chemically stable surface enhanced scattering (SERS) probes for the analysis of blue BIC ballpoint pens.

PubMed

Alyami, A; Saviello, D; McAuliffe, M A P; Mirabile, A; Lewis, L; Iacopino, D

2017-06-07

Metal nanoinks constituted by Ag nanoparticles and Au nanorods were employed as probes for the Surface Enhanced Raman Scattering (SERS) analysis of a blue BIC ballpoint pen. The dye components of the pen ink were first separated by thin layer chromatography (TLC) and subsequently analysed by SERS at illumination wavelengths of 514 nm and 785 nm. Compared to normal Raman conditions, enhanced spectra were obtained for all separated spots, allowing easy identification of phthalocyanine Blue 38 and triarylene crystal violet in the ink mixture. A combination of effects such as molecular resonance, electromagnetic and chemical effects were the contributing factors to the generation of spectra enhanced compared to normal Raman conditions. Enhancement factors (EFs) between 5 × 10 3 and 3 × 10 6 were obtained, depending on the combination of SERS probes and laser illumination used. In contrast to previous conflicting reports, the metal nanoinks were chemically stable, allowing the collection of reproducible spectra for days after deposition on TLC plates. In addition and in advance to previously reported SERS probes, no need for additional aggregating agents or correction of electrostatic charge was necessary to induce the generation of enhanced SERS spectra.

Effect of Induced Periimplantitis on Dental Implants With and Without Ultrathin Hydroxyapatite Coating.

PubMed

Madi, Marwa; Zakaria, Osama; Ichinose, Shizuko; Kasugai, Shohei

2016-02-01

The aim of this study was to compare the effect of ligature-induced periimplantitis on dental implants with and without hydroxyapatite (HA) coat. Thirty-two dental implants (3.3 mm wide, 13 mm long) with 4 surface treatments (8 implant/group) (M: machined, SA: sandblasted acid etched, S: sputter HA coat and P: plasma-sprayed HA coat) were inserted into canine mandibles. After 12 weeks, oral hygiene procedures were stopped and silk ligatures were placed around the implant abutments to allow plaque accumulation for the following 16 weeks. Implants with the surrounding tissues were retrieved and prepared for histological examination. Bone-to-implant contact (BIC) and implant surfaces were examined using scanning electron microscopy and energy dispersive x-ray spectroscopy. Histological observation revealed marginal bone loss and large inflammatory cell infiltrates in the periimplant soft tissue. Sputter HA implants showed the largest BIC (98.1%) and machined implant showed the smallest values (70.4%). After 28 weeks, thin sputter HA coat was almost completely dissolved, whereas plasma-sprayed HA coat showed complete thickness preservation. Thin sputter HA-coated implants showed more bone implant contact and less marginal bone loss than thick HA-coated implants under periimplantitis condition.

Lunar igneous rocks and the nature of the lunar interior

NASA Technical Reports Server (NTRS)

Hays, J. F.; Walker, D.

1974-01-01

Lunar igneous rocks are interpreted, which can give useful information about mineral assemblages and mineral chemistry as a function of depth in the lunar interior. Terra rocks, though intensely brecciated, reveal, in their chemistry, evidence for a magmatic history. Partial melting of feldspathic lunar crustal material occurred in the interval 4.6 to 3.9 gy. Melting of ilmenite-bearing cumulates at depths near 100 km produced parent magmas for Apollo 11 and 17 titaniferous mare basalts in the interval 3.8 to 3.6 gy. Melting of ilmenite-free olivine pyroxenites at depths greater than 200 km produced low-titanium mare basalts in the interval 3.4 to 3.1 gy. No younger igneous rocks have yet been recognized among the lunar samples and present-day melting seems to be limited to depths greater than 1000 km.

Lunar igneous rocks and the nature of the lunar interior

NASA Technical Reports Server (NTRS)

Hays, J. F.; Walker, D.

1977-01-01

Lunar igneous rocks, properly interpreted, can give useful information about mineral assemblages and mineral chemistry as a function of depth in the lunar interior. Though intensely brecciated, terra rocks reveal, in their chemistry, evidence for a magmatic history. Partial melting of feldspathic lunar crustal material occurred in the interval 4.6 to 3.9 Gy. Melting of ilmenite-bearing cumulates at depths near 100 km produced parent magmas for Apollo 11 and 17 titaniferous mare basalts in the interval 3.8 to 3.6 Gy. Melting of ilmenite-free olivine pyroxenites (also cumulates?) at depths greater than 200 km produced low-titanium mare basalts in the interval 3.4 to 3.1 Gy. No younger igneous rocks have yet been recognized among the lunar samples and present-day melting seems to be limited to depths greater than 1000 km.

New Ages for Gorgona Island, Colombia: Implications for Previous Petrogenetic and Tectonic Models

NASA Astrophysics Data System (ADS)

Serrano Duran, L.; Lopez Martinez, M.; Ferrari, L.

2007-05-01

The Gorgona Island, located 50 km to the west of the Colombian Pacific coast, is the only known site with Phanerozoic komatiites in the world besides a key element in several reconstruction of the interaction between the Caribbean and the South America Plate. The Gorgona komatiites are part of an igneous complex that also includes picritic basalts and breccias, gabbros and peridotites (dunites and wherlites), and is covered by deformed mid-Eocene and younger underformed marine sediments. Datings of the igneous rocks were only performed on basalts and include an 86 Ma K-Ar age, an 88.9 ± 1.2 Ma weighted mean of four Ar-Ar ages and an 89.2 ± 5.2 Ma Re-Os isochron age from basalts. Gorgona rocks are affected by reverse faulting with a general eastward vergence. The island is the only subaerially exposed part of a NE elongated sliver accreted in a dextral transpressional regime to the South America continental margin between the Late Eocene and the Early Miocene. Petrologic studies found large spread in radiogenic isotopes and incompatible trace element ratios in Gorgona ultramafic rocks, which have been interpreted as requiring at least two different sources of: 1) a depleted mantle responsible for the generation of the komatiites and most basalts, and 2) an enriched mantle responsible for some rarer enriched basalts and picrites. Despite the large compositional and isotopic heterogeneity the most common interpretation is that the Gorgona ultramafic rocks are the product of a single mantle plume, although it has recently proposed that this would be a separate plume from that generating the bulk of the Caribbean plateau at ~90 Ma. Our new study focused on the geochronology of the Gorgona igneous suite as we consider that this tectonically and petrologically complex island is unlike to have such a narrow age range. We attempted to date eight samples of komatiites, basalts and gabbros by Ar-Ar laser step heating. For four of these samples we successfully obtain reliable plateau and/or isochron ages. Only one basaltic sample, located in the western coast, yielded an age comparable with those previously reported in the literature. For two basalts intercalated with komatiites and a gabbro exposed in the north-eastern coast of the island we obtained younger ages, similar to those reported for some mafic and ultramafic rocks along the Pacific coast of Colombia. The two sets of ages for the ultramafic suite of Gorgona also correspond to different petrologic types. The depleted rocks in the eastern coast are younger than the enriched basalts and picrites located in the southern and western part of the island with ages around 90 Ma, suggesting a more complex tectonic evolution with the accretion of at least two different blocks. This eventually questions the "single plume" model for the formation of the Gorgona Island plateau.

Publications - PDF 97-29I | Alaska Division of Geological & Geophysical

Science.gov Websites

igneous rocks of the Tanana B-1 Quadrangle and vicinity Authors: Newberry, R.J., and Haug, S.A , and Sr isotopic data for igneous rocks of the Tanana B-1 Quadrangle and vicinity: Alaska Division of ; Isotopes; Plutonic; STATEMAP Project; Trace Elements; Volcanic Top of Page Department of Natural Resources

Meteoritic basalts. Final report, 1986-1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Treiman, A.H.

1989-10-01

The objectives were to: explain the abundances of siderophile elements in the SNC meteorite suite, of putative Martian origin; discover the magmatic origins and possibly magma compositions behind the Nakhla meteorite, one of the SNC meteorites; and a re-evaluation of the petrology of Angra dos Reis, a unique meteorite linked to the earliest planetary bodies of the solar nebula. A re-evaluation of its petrography showed that the accepted scenario for its origin, as a cumulate igneous rock, was not consistent with the meteorite's textures (Treiman). More likely is that the meteorite represents a prophyritic igneous rock, originally with magma dominant.more » Studies of the Nakhla meteorite, of possible Martian origin, although difficult, were successful. It became necessary to reject the basic categorization of Nakhla: that is was a cumulate igneous rock. Detailed studies of the chemical zoning of Nakhlas' minerals, coupled with the failure of experimental studies to yield expected results, forced the conclusion that Nakhla is not a cumulate rock in the usual sense: a rock composed of igneous crystals and intercrystal magma. Study of the siderophile element abundances in the SNC meteorite groups involved trying to find reasonable core formation processes and parameters that would reproduce the observed abundances. Modelling was successful, and delimited a range of models which overlap with those reasonable from geophysical constraints.« less

Compilation of new and previously published geochemical and modal data for Mesoproterozoic igneous rocks of the St. Francois Mountains, southeast Missouri

USGS Publications Warehouse

du Bray, Edward A.; Day, Warren C.; Meighan, Corey J.

2018-04-16

The purpose of this report is to present recently acquired as well as previously published geochemical and modal petrographic data for igneous rocks in the St. Francois Mountains, southeast Missouri, as part of an ongoing effort to understand the regional geology and ore deposits of the Mesoproterozoic basement rocks of southeast Missouri, USA. The report includes geochemical data that is (1) newly acquired by the U.S. Geological Survey and (2) compiled from numerous sources published during the last fifty-five years. These data are required for ongoing petrogenetic investigations of these rocks. Voluminous Mesoproterozoic igneous rocks in the St. Francois Mountains of southeast Missouri constitute the basement buried beneath Paleozoic sedimentary rock that is over 600 meters thick in places. The Mesoproterozoic rocks of southeast Missouri represent a significant component of approximately 1.4 billion-year-old (Ga) igneous rocks that crop out extensively in North America along the southeast margin of Laurentia and subsequent researchers suggested that iron oxide-copper deposits in the St. Francois Mountains are genetically associated with ca. 1.4 Ga magmatism in this region. The geochemical and modal data sets described herein were compiled to support investigations concerning the tectonic setting and petrologic processes responsible for the associated magmatism.

Meteoritic basalts

NASA Technical Reports Server (NTRS)

Treiman, Allan H.

1989-01-01

The objectives were to: explain the abundances of siderophile elements in the SNC meteorite suite, of putative Martian origin; discover the magmatic origins and possibly magma compositions behind the Nakhla meteorite, one of the SNC meteorites; and a re-evaluation of the petrology of Angra dos Reis, a unique meteorite linked to the earliest planetary bodies of the solar nebula. A re-evaluation of its petrography showed that the accepted scenario for its origin, as a cumulate igneous rock, was not consistent with the meteorite's textures (Treiman). More likely is that the meteorite represents a prophyritic igneous rock, originally with magma dominant. Studies of the Nakhla meteorite, of possible Martian origin, although difficult, were successful. It became necessary to reject the basic categorization of Nakhla: that is was a cumulate igneous rock. Detailed studies of the chemical zoning of Nakhlas' minerals, coupled with the failure of experimental studies to yield expected results, forced the conclusion that Nakhla is not a cumulate rock in the usual sense: a rock composed of igneous crystals and intercrystal magma. Study of the siderophile element abundances in the SNC meteorite groups involved trying to find reasonable core formation processes and parameters that would reproduce the observed abundances. Modelling was successful, and delimited a range of models which overlap with those reasonable from geophysical constraints.

Igpet software for modeling igneous processes: examples of application using the open educational version

NASA Astrophysics Data System (ADS)

Carr, Michael J.; Gazel, Esteban

2017-04-01

We provide here an open version of Igpet software, called t-Igpet to emphasize its application for teaching and research in forward modeling of igneous geochemistry. There are three programs, a norm utility, a petrologic mixing program using least squares and Igpet, a graphics program that includes many forms of numerical modeling. Igpet is a multifaceted tool that provides the following basic capabilities: igneous rock identification using the IUGS (International Union of Geological Sciences) classification and several supplementary diagrams; tectonic discrimination diagrams; pseudo-quaternary projections; least squares fitting of lines, polynomials and hyperbolae; magma mixing using two endmembers, histograms, x-y plots, ternary plots and spider-diagrams. The advanced capabilities of Igpet are multi-element mixing and magma evolution modeling. Mixing models are particularly useful for understanding the isotopic variations in rock suites that evolved by mixing different sources. The important melting models include, batch melting, fractional melting and aggregated fractional melting. Crystallization models include equilibrium and fractional crystallization and AFC (assimilation and fractional crystallization). Theses, reports and proposals concerning igneous petrology are improved by numerical modeling. For reviewed publications some elements of modeling are practically a requirement. Our intention in providing this software is to facilitate improved communication and lower entry barriers to research, especially for students.

DOE Office of Scientific and Technical Information (OSTI.GOV)

P. Persoff

The evaluation of impacts of potential volcanic eruptions on populations and facilities far in the future may involve detailed volcanological studies that differ from traditional hazards analyses. The proximity of Quaternary volcanoes to a proposed repository for disposal of the USA's high-level radioactive waste at Yucca Mountain, Nevada, has required in-depth study of probability and consequences of basaltic igneous activity. Because of the underground nature of the repository, evaluation of the potential effects of dike intrusion and interaction with the waste packages stored in underground tunnels (dnfts) as well as effects of eruption and ash dispersal have been important. Thesemore » studies include analyses of dike propagation, dike-drift intersection, flow of magma into dnfts, heat and volcanic gas migration, atmospheric dispersal of tephra, and redistribution of waste-contaminated tephra by surficial processes. Unlike traditional volcanic hazards studies that focus on impacts on housing, transportation, communications, etc. (to name a small subset), the igneous consequences studies at Yucca Mountain have focused on evaluation of igneous impacts on nuclear waste packages and implications for enhanced radioactive dose on a hypothetical future ({le} 10000 yrs) local population. Potential exposure pathways include groundwater (affected by in-situ degradation of waste packages by igneous heat and corrosion) and inhalation, ingestion, and external exposure due to deposition and redistribution of waste-contaminated tephra.« less

Bermuda and Appalachian-Labrador rises: Common non-hotspot processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogt, P.R.

1991-01-01

Other than the Corner Rise-New England seamounts and associated White Mountains, most postbreakup intraplate igneous activity and topographic uplift in the western North Atlantic and eastern North America do not readily conform to simple hotspot models. For examples, the Bermuda Rise trends normal to its predicted hotspot trace. On continental crust, Cretaceous-Eocene igneous activity is scattered along a northeast-trending belt {approximately}500-1,000 km west of and paralleling the continent-ocean boundary. Corresponding activity in the western Atlantic generated seamounts preferentially clustered in a belt {approximately}1,000 km east of the boundary. The Eocene volcanism on Bermuda is paired with coeval magmatism of themore » Shenandoah igneous province, and both magmatic belts are associated with northeast-trending topographic bulges - the Appalachian-Labrador Rise to the west and the Bermuda Rise (Eocene ) to the east. The above observations suggest the existence of paired asthenosphere upwelling, paralleling and controlled by the deep thermal contrast across the northeast-trending continental margin. Such convection geometry, apparently fixed to the North American plate rather than to hotspots, is consistent with recent convection models by B. Hager. The additional importance of plate-kinematic reorganizations (causing midplate stress enhancement) is suggested by episodic igneous activity ca. 90-100 Ma and 40-45 Ma.« less

Geochronology of the Sleeper deposit, Humboldt County, Nevada: epithermal gold-silver mineralization following emplacement of a silicic flow-dome complex

USGS Publications Warehouse

Conrad, J.E.; McKee, E.H.; Rytuba, J.J.; Nash, J.T.; Utterback, W.C.

1993-01-01

The high-grade gold-silver deposits at the Sleeper mine are low sulfidation, quartz-adularia-type epithermal deposits, formed during the final stages of igneous hydrothermal activity of a small middle Miocene silicic flow-dome complex in north-central Nevada. There were multiple pulses of alteration and mineralization but all occurred within a period of less than 2 m.y. Later supergene alteration formed opal and alunite about 5.4 Ma but produced no Au or Ag mineralization other than some remobilization to produce locally rich pockets of secondary Au and Ag enrichment and is unrelated to the older magmatic hydrothermal system. The Sleeper deposit in the northern part of the Great Basin is genetically related to bimodal volcanism that followed a long period of arc-related andesitic volcanism in the same general region. -from Authors

Variable Melt Production Rate of the Kerguelen HotSpot Due To Long-Term Plume-Ridge Interaction

NASA Astrophysics Data System (ADS)

Bredow, Eva; Steinberger, Bernhard

2018-01-01

For at least 120 Myr, the Kerguelen plume has distributed enormous amounts of magmatic rocks over various igneous provinces between India, Australia, and Antarctica. Previous attempts to reconstruct the complex history of this plume have revealed several characteristics that are inconsistent with properties typically associated with plumes. To explore the geodynamic behavior of the Kerguelen hotspot, and in particular address these inconsistencies, we set up a regional viscous flow model with the mantle convection code ASPECT. Our model features complex time-dependent boundary conditions in order to explicitly simulate the surrounding conditions of the Kerguelen plume. We show that a constant plume influx can result in a variable magma production rate if the plume interacts with nearby spreading ridges and that a dismembered plume, multiple plumes, or solitary waves in the plume conduit are not required to explain the fluctuating magma output and other unusual characteristics attributed to the Kerguelen hotspot.

Bedrock geology of the Mount Carmel and Southington quadrangles, Connecticut

USGS Publications Warehouse

Fritts, Crawford Ellswroth

1962-01-01

New data concerning the geologic structure, stratigraphy, petrography, origin, and ages of bedrock formations in an area of approximately 111 square miles in south-central Connecticut were obtained in the course of detailed geologic mapping from 1957 to 1960. Mapping was done at a scale of 1:24,000 on topographic base maps having a 10-foot contour interval. Bedrock formations are classified in two principal categories. The first includes metasedimentary, meta-igneous, and igneous rocks of Precambrian to Devonian age, which crop out in the western parts of both quadrangles. The second includes sedimentary and igneous rocks of the Newark Group of Late Triassic age, which crop out in the eastern parts of the quadrangles. Diabase dikes, which are Late Triassic or younger in age, intruded rocks in both the western and eastern parts of the map area. Rocks in the western part of the area underwent progressive regional metamorphism in Middle to Late Devonian time. The arrangement of the chlorite, garnet, biotite, staurolite, and kyanite zones here is approximately the mirror-image of metamorphic zones in Dutchess County, New York. However, garnet appeared before biotite in politic rocks in the map area, because the ration MgO/FeO is low. Waterbury Gneiss and the intrusive Woodtick Gneiss are parts of a basement complex of Precambrian age, which forms the core of the Waterbury dome. This structure is near the southern end of a line of similar domes that lie along the crest of a geanticline east of the Green Mountain anticlinorium. The Waterbury Gneiss is believed to have been metamorphosed in Precambrian time as well as in Paleozoic time. The Woodtick Gneiss also may have been metamorphosed more than once. In Paleozoic time, sediments were deposited in geosynclines during two main cycles of sedimentation. The Straits, Southington Mountain, and Derby Hill Schists, which range in age from Cambrian to Ordovician, reflect a transition from relatively clean politic sediments to thinly layered sediments that contained rather high percentages of fine-grained volcanic debris. Metadiabase and metabasalt extrusives above Derby Hill Schist south of the map area represent more intense volcanic activity before or during the early stages of the Taconic disturbance in Late Ordovician time. Impure argillaceous, siliceous, and minor calcareous sediments of the Wepawaug Schist, which is Silurian and Devonian in age, were deposited unconformably on older rocks during renewed subsidence of a geosyncline. The Wepawaug now occupies the trough of a tight syncline, which formed before and during progressive regional metamorphism at the time of the Acadian orogeny in middle to Late Devonian time. Felsic igneous rocks were intruded into the metasedimentary formations of Paleozoic age before the climax of the latest progressive regional metamorphism. Intrusives that gave rise to the Prospect and Ansonia Gneisses were emplaced mainly in the Southington Mountain Schist, and the igneous rocks as well as the host rocks were metamorphosed in the staurolite zone. Although it is possible that these two intrusives were emplaced during the Taconic disturbance, the writer believes it more likely that the igneous rocks from which the Prospect and Ansonia Gneisses formed were emplaced during the Acadian orogeny. Woodbridge Granite, which intruded the Wepawaug Schist, is Devonian in age and undoubtedly was emplaced during the Acadian orogeny. In this area the granite is essentially unmetamorphosed, because it is in the chlorite, garnet, and biotite zones. Southwest of the map area, however, metamorphic equivalents of the Woodbridge are found in Wepawaug Schist in the staurolite zone. The Ansonia Gneiss, therefore, may be a metamorphic equivalent of the Woodbridge Granite. Rocks of Late Triassic age formerly covered the entire map area, but were eroded from the western part after tilting and faulting in Late Triassic time. The New Haven Arkose of the Newark

Geology and geochemistry of samples from Los Alamos National Laboratory HDR Well EE-2, Fenton Hill, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laney, R.; Laughlin, A.W.; Aldrich, M.J. Jr.

1981-07-01

Petrologic, geochemical, and structural analyses of cores and cuttings obtained from 3000 to 4389-m true vertical depth in drill hole EE-2 indicate that this deeper part of the Precambrian section at Fenton Hill, New Mexico is composed primarily of a very heterogeneous and structurally anisotropic metamorphic complex, locally intruded by dikes and sills of granodioritic and monzogranitic composition. In this borehole none of these igneous bodies approach in size the 335-m-thick biotite-granodiorite body encountered at 2591-m depth beneath Fenton Hill in the other two drill holes. Contacts between the igneous and metamorphic rocks range from sharp and discordant to gradational.more » Analysis of cuttings indicates that clay-rich alteration zones are relatively common in the openhole portion of EE-2. These zones average about 20 m in thickness. Fracture sets in the Precambrian basement rock intersected by the EE-2 well bore mostly trend northeast and are steeply dipping to vertical; however, one of the sets dips gently to the northwest. Slickensided fault planes are present in a core (No.5) taken from a true vertical depth of 4195 m. Available core orientation data and geologic inference suggest that the faults dip steeply and trend between N.42/sup 0/ and 59/sup 0/E.« less

Holocene evolution of Dahab coastline - Gulf of Aqaba, Sinai Peninsula, Egypt

NASA Astrophysics Data System (ADS)

Torab, Magdy

2018-03-01

Dahab is a little Bedouin-village in Sinai Peninsula on the east coast of the Gulf of Aqaba and it lies approximately 90 km north of Sharm-el-Sheikh City. Dahab means "gold" in the Arabic language; over the past 20 years it has become one of the most visited tourist sites in Egypt. The basement complex is composed mostly of biotite aplite-granite, mica-aplite granite, granodiorite, quartz diorite, alaskite, and diorite. This composition correlates to similar igneous rocks in the most southern areas of Sinai and the Red Sea. Wadi Dahab is composed of igneous and metamorphic rocks and the coastline is formed of fragments of its rocks mixed with fragments of coral reef. The morphology of Dahab's coastline is characterized by a hooked marine spit composed of fluvial sediments carried by marine currents from the mouth of Wadi Dahab. This spit encloses a shallow lagoon, but the active deposition on the lagoon bottom will turn it into saline marsh. This paper investigates the evolution of the Dahab spit and lagoon during the Holocene and over the last 100 years, as well as the potential impacts of future management of the coastal area. The coastline mapping during the study was dependent on GIS techniques and data were collected by using total station, aerial photographs and satellite image interpretation as well as soil sample dating.

Ring complexes and related rocks in Africa

NASA Astrophysics Data System (ADS)

Vail, J. R.

Over 625 igneous complexes throughout Africa and Arabia have been selected and classified on the basis of petrographic association and chronology into six broad age groups forming 29 provinces. The groups range from Mid-Proterozoic to Tertiary and include gabbro, granite, syenite, foid syenite and carbonatite plutonic rocks, the majority in the form of ring-dykes, cone-sheets, plugs, circular intrusions, and their associated extrusive phases. Pan-African late or post-orogenic complexes (720-490 Ma) are common in the Arabian-Nubian and Tuareg shields of north Africa originating from subduction zone derived magmatism. Anorogenic complexes in Egypt, NE and central Sudan, Niger, Nigeria, Cameroon, Zaïre-Burundi, Malawi, Mozambique, Zimbabwe, Namibia and Angola span 550 to 50 Ma and are dominantly alkali granites and foid syenites. Many groups occur as en-echelon bands within linear arrays, and show migrating centres of intrusion in variable directions. In W. Africa there was a progressive shift of emplacement southwards during early Ordovician to Mid-Cretaceous times. Distribution patterns suggest thatdeep seated features, such as shear zones associated with lithospheric plate movements,controlled melting, and the resultant location of the complexes. Economic mineralization is not widespread in the rocks of the African ring complexes and is mainly restricted to small deposits of Sn, W, F, U and Nb.

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Eastern Mountains and Piedmont Region (Version 2.0)

DTIC Science & Technology

2012-04-01

are the Blue Ridge Province and the Piedmont Plateau, composed mainly of highly eroded Precambrian metamorphic rocks . The Piedmont Plateau extends...older igneous and metamorphic rocks (Atwood 1940; Hunt 1974; USGS 2004). Caverns and karst features are found in marble formations in the Piedmont...colluvium derived from sandstone, shale, limestone, and metamorphic and igneous rocks . Other parent materials include deposits of wind-blown loess

Al-in-olivine thermometry evidence for the mantle plume origin of the Emeishan large igneous province

NASA Astrophysics Data System (ADS)

Xu, Rong; Liu, Yongsheng

2016-12-01

The Emeishan large igneous province (ELIP) is renowned for its world-class Ni-Cu-(PGE) deposits and its link with the Capitanian mass extinction. The ELIP is generally thought to be associated with a deep mantle plume; however, evidence for such a model has been challenged through geology, geophysics and geochemistry. In many large igneous province settings, olivine-melt equilibrium thermometry has been used to argue for or against the existence of plumes. However, this method involves large uncertainties such as assumptions regarding melt compositions and crystallisation pressures. The Al-in-olivine thermometer avoids these uncertainties and is used here to estimate the temperatures of picrites in the ELIP. The calculated maximum temperature (1440 °C) is significantly ( 250 °C) higher than the Al-in-olivine temperature estimated for the average MORB, thus providing compelling evidence for the existence of thermal mantle plumes in the ELIP.

The Manihiki Plateau—a key to missing hotspot tracks?

NASA Astrophysics Data System (ADS)

Pietsch, R.; Uenzelmann-Neben, G.

2016-08-01

A Neogene magmatic reactivation of the Manihiki Plateau, a large igneous province (LIP) in the central Pacific, is studied using seismic reflection data. Igneous diapirs have been identified exclusively within a narrow WNW-ESE striking corridor in the southern High Plateau (HP), which is parallel to the Neogene Pacific Plate motion and overlaps with an extrapolation of the Society Islands Hotspot (SIH) path. The igneous diapirs are characterized by a narrow width (>5 km), penetration of the Neogene sediments, and they become progressively younger towards the East (23-10 Ma). The magmatic source appears to be of small lateral extent, which leads to the conclusion that the diapirs represent Neogene hotspot volcanism within a LIP, and thus may be an older, previously unknown extension of the SIH track (>4.5 Ma). Comparing hotspot volcanism within oceanic and continental lithosphere, we further conclude that hotspot volcanism within LIP crust has similarities to tectonically faulted continental crust.

Geochemical and modal data for igneous rocks associated with epithermal mineral deposits

USGS Publications Warehouse

du Bray, Edward A.

2014-01-01

The purposes of this report are to (1) present available geochemical and modal data for igneous rocks associated with epithermal mineral deposits and (2) to make those data widely and readily available for subsequent, more in-depth consideration and interpretation. Epithermal precious and base-metal deposits are commonly associated with subduction-related calc-alkaline to alkaline arc magmatism as well as back-arc continental rift magmatism. These deposits form in association with compositionally diverse extrusive and intrusive igneous rocks. Temperature and depth regimes prevailing during deposit formation are highly variable. The deposits form from hydrothermal fluids that range from acidic to near-neutral pH, and they occur in a variety of structural settings. The disparate temperature, pressure, fluid chemistry, and structural controls have resulted in deposits with wide ranging characteristics. Economic geologists have employed these characteristics to develop classification schemes for epithermal deposits and to constrain the important genetic processes responsible for their formation.

Magnetic investigation and 2½ D gravity profile modelling across the Beattie magnetic anomaly in the southeastern Karoo Basin, South Africa

NASA Astrophysics Data System (ADS)

Baiyegunhi, Christopher; Gwavava, Oswald

2017-03-01

The southeastern Karoo Basin is considered to be one of the most prospective areas for shale gas exploration in South Africa. An interesting magnetic anomaly, the Beattie magnetic anomaly (BMA), and geologic intrusions are seen on the magnetic map. To date, the source of the BMA and interconnectivity of the igneous intrusions are not well understood. In this study, we investigate the interconnectivity of the igneous intrusions and possible location of the source of the BMA using gravity and magnetic methods. The gravity model results showed that igneous intrusions are interconnected at depth, which probably pose threat by increasing the risk of fracking the Karoo for shale gas exploration. The magnetic results revealed that the BMA becomes stronger with depth. The average depths to the top of the shallow and deep magnetic sources were estimated to be approximately 0.6 and 15 km, respectively.

Paleozoic and Paleoproterozoic Zircon in Igneous Xenoliths Assimilated at Redoubt Volcano, Alaska

NASA Astrophysics Data System (ADS)

Bacon, C. R.; Vazquez, J. A.; Wooden, J. L.

2010-12-01

Historically active Redoubt Volcano is a basalt-to-dacite cone constructed upon the Jurassic-early Tertiary Alaska-Aleutian Range batholith. New SHRIMP-RG U-Pb age and trace-element concentration results for zircons from gabbroic xenoliths and crystal-rich andesitic mush from a late Pleistocene pyroclastic deposit indicate that ~310 Ma and ~1865 Ma igneous rocks underlie Redoubt at depth. Two gabbros have sharply terminated prismatic zircons that yield ages of ~310 Ma. Zircons from a crystal mush sample are overwhelmingly ~1865 Ma and appear rounded due to incomplete dissolution. Binary plots of element concentrations or ratios show clustering of data for ~310-Ma grains and markedly coherent trends for ~1865-Ma grains; e.g., ~310-Ma grains have higher Eu/Eu* than most of the ~1865-Ma grains, the majority of which form a narrow band of decreasing Eu/Eu* with increasing Hf content which suggests that ~1865-Ma zircons come from igneous source rocks. It is very unlikely that detrital zircons from a metasedimentary rock would have this level of homogeneity in age and composition. One gabbro contains abundant ~1865 Ma igneous zircons, ~300-310 Ma fluid-precipitated zircons characterized by very low U and Th concentrations and Th/U ratios, and uncommon ~100 Ma zircons. We propose that (1) ~310 Ma gabbro xenoliths from Redoubt Volcano belong to the same family of plutons dated by Aleinikoff et al. (USGS Circular 1016, 1988) and Gardner et al. (Geology, 1988) located ≥500 km to the northeast in basement rocks of the Wrangellia and Alexander terranes and (2) ~1865 Ma zircons are inherited from igneous rock, potentially from a continental fragment that possibly correlates with the Fort Simpson terrane or Great Bear magmatic zone of the Wopmay Orogen of northwestern Laurentia. Possibly, elements of these Paleoproterozoic terranes intersected the Paleozoic North American continental margin where they may have formed a component of the basement to the Wrangellia-Alexander-Peninsular composite terrane prior to transport to its present location (e.g., Colpron and Nelson, Geological Society, London, Special Publication 318, 2009). Xenocrysts from the ~1865 Ma igneous rocks, and possibly also ~310 Ma gabbros, are contained in relatively low-temperature mush and partially melted gabbro that we interpret to have been derived from the margin of the subvolcanic magma accumulation and storage region defined by seismicity at 4-10 km bsl. The Redoubt crystal mush contains evidence for assimilation of ~1865 Ma igneous rocks that have no equivalent exposed in Alaska. The discovery of Paleoproterozoic grains as the dominant zircon component in crystal mush raises the question of the origin of other crystals in Redoubt magmas.

Early healing of nanothickness bioceramic coatings on dental implants. An experimental study in dogs.

PubMed

Coelho, Paulo G; Cardaropoli, Giuseppe; Suzuki, Marcelo; Lemons, Jack E

2009-02-01

Thick bioceramic coatings like plasma sprayed hydroxyapatite have been shown to increase the overall tissue response and biomechanical fixation of dental implants. However, the presence and potential fracture of a bone-coating-metallic substrate interface at long times after implantation led these implants to fall from favor in clinical practice. The purpose of this study was to evaluate the biomechanical fixation and biological response of Ca- and P-based, 20-50 nm thickness bioceramic deposition on a previously alumina-blasted/acid-etched Ti-6Al-4V implant surface in a dog model. Cylindrical alumina-blasted/acid-etched (AB/AE) (Control, n = 16), and Nanothickness bioceramic coated AB/AE(Nano, n = 16) implant surfaces were surgically placed in dogs proximal tibia and remained for 2 and 4 weeks in vivo. Following euthanization, the implants-in-bone were mounted in epoxy and pullout at a 0.5 mm/min rate. Following mechanical testing, the specimens were decalcified and processed (Hematoxylin and Eosin) for standard transmitted light microscopy evaluation. Percent bone-to-implant contact (BIC) to the pulled out implant surface was determined through computer software. Statistical analyses were performed by one-way ANOVA at 95% level of significance and Tukey's post-hoc multiple comparisons. No significant differences in pullout force were observed (p > 0.88): 2W Control (212.08 +/- 42.96 N), 2W Nano (224.35 +/- 42.97 N), 4W Control (207.07 +/- 42.97 N), and 4W Nano (190.15 +/- 45.94 N). No significant differences in %BIC were observed (p > 0.94): 2W Control (72.66 +/- 8.51), 2W Nano (69.44 +/- 8.51), 4W Control (70.44 +/- 8.51), and 4W Nano (69.11 +/- 9.09). It is shown that 20-50 nm thickness bioceramic depositions onto previously alumina-blasted/acid-etched substrates did not improve the biomechanical fixation and the BIC at early implantation times, and studies concerning shorter and longer implantation times are recommended for confirmation or before a conclusion can be made. Copyright 2008 Wiley Periodicals, Inc.

Antidepressant, anticonvulsant and antinociceptive effects of 3'-methoxy-6-methylflavone and 3'-hydroxy-6-methylflavone may involve GABAergic mechanisms.

PubMed

Karim, Nasiara; Khan, Imran; Ahmad, Naveed; Umar, Muhammad Naveed; Gavande, Navnath

2017-10-01

GABA A receptors have been implicated in the pathophysiology of depression, epilepsy and pain disorders. The purpose of this study was to investigate two novel synthetic flavones, 3'-methoxy-6-methylflavone (3'-MeO6MF) and 3'-hydroxy-6-methylflavone (3'-OH6MF), for their effect on GABA A receptors and subsequently investigate their antidepressant, anticonvulsant and antinociceptive effects. Recombinant GABA A receptor subunits were expressed in Xenopus oocytes and a two electrode voltage clamp technique was used for electrophysiological studies. The antidepressant and anticonvulsant activities were determined using forced swim (FST) and tail suspension tests (TST) and bicuculline (BIC)-induced seizures respectively. Furthermore, the antinociceptive activity was determined using tail immersion and hot plate tests. 3'-MeO6MF and 3'-OH6MF potentiated GABA-induced currents through ternary α1-2β1-3γ2L and binary α1β2 receptors indicating that the positive modulation by these flavonoids is not dependent on the γ subunit. In behavioral studies, 3'-MeO6MF and 3'-OH6MF (10-100mg/kg, ip) exerted significant antidepressant like effects in the FST and TST. 3'-MeO6MF (10-100mg/kg) and 3'-OH6MF (30 and 100mg/kg) also exhibited significant anticonvulsant effects in BIC-induced seizures, and antinociceptive activity in tail immersion and hot plate tests (*p<0.05, **p<0.01, ***p<0.001). Furthermore, the antidepressant and antinociceptive activities of 3'-MeO6MF and 3'-OH6MF were partially ameliorated by co-administration of BIC (3mg/kg) suggesting the involvement of GABAergic mechanisms. The findings of this study suggest that 3'-MeO6MF and 3'-OH6MF exhibited significant antidepressant, anticonvulsant and antinociceptive effects mediated via interactions with GABA A receptors. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Geochemistry and metamorphism of the Mouriscas Complex, Ossa-Morena/Central Iberian zone boundary, Iberian Massif, Central Portugal: Implications for the Cadomian and Variscan orogenies

NASA Astrophysics Data System (ADS)

Henriques, S. B. A.; Neiva, A. M. R.; Tajčmanová, L.; Dunning, G. R.

2018-01-01

The Mouriscas Complex is a deformed and metamorphosed predominantly mafic igneous complex of Ediacaran and Ordovician age and crops out at the Ossa-Morena/Central Iberian zone boundary in the Iberian Massif, Central Portugal. It comprises amphibolite with Neoproterozoic protoliths (ca. 544 Ma), protomylonitic felsic dykes derived from younger trondhjemitic protoliths (ca. 483 Ma) and garnet amphibolite derived of even younger dioritic protoliths (ca. 477 Ma). The protoliths of the Neoproterozoic amphibolites are calc-alkaline magmas of basic to intermediate compositions with intraplate and active continental margin affinities and are considered to represent the final phase of the Cadomian arc magmatism. They are interpreted to have originated as coarse-grained intrusions, likely gabbro or diorite and generated from the partial melting of meta-igneous lower crust and mantle. Their emplacement occurred near the Cadomian metamorphic event dated at ca. 540 Ma (P = 7-8 kbar and T = 640-660 °C) which is interpreted to represent a continental collision. During the Late Cambrian-Early Ordovician an extensional episode occurred in the central-southern Iberian Massif and was also observed in other areas of the Variscan Orogen. It led to mantle upwelling and to the development of an aborted intracratonic rift located at the Ossa-Morena/Central Iberian zone boundary and to the opening of the Rheic Ocean to the south of the area studied in present coordinates (i.e., between the Ossa-Morena and South Portuguese Zones). This event has been dated at ca. 477 Ma and was responsible for the melting of deep ancient mafic crust and mantle with formation of bimodal magmatism in an intra-plate setting, as indicated by the protoliths of the protomylonitic felsic dykes with trondhjemitic composition and of the garnet amphibolite. Subsequent Variscan metamorphism took place under amphibolite facies conditions (P = 4-5.5 kbar; T = 600-625 °C) at lower P-T conditions than the Cadomian metamorphic event. It was followed by greenschist retrogression as suggested by the appearance of actinolite rims and formation of chlorite and epidote.

Southern African Phanerozoic Carbonatites: Perspectives on Their Sources and Petrogeneses

NASA Astrophysics Data System (ADS)

Janney, P. E.; Ogungbuyi, P. I.; Marageni, M.; Harris, C.; Reid, D. L.

2017-12-01

Found worldwide, carbonatites are particularly numerous in southern Africa and reflect one expression of abundant intraplate alkaline magmatism of Proterozoic to Paleogene age in the region. Phanerozoic southern African carbonatites tend to be concentrated near the margins of the continent (especially the western margin), and near the East African Rift, and often occur in discrete magmatic lineations also containing kimberlites, melilitites, nephelinites and differentiated silica-undersaturated rocks such as phonolites and syenites. We present a synthesis of geochemical and radiogenic and stable isotope results for southern African carbonatites, including new trace element and isotope data from four Phanerozoic carbonatite complexes in South Africa and Namibia: Marinkas Quellen (MQ; southernmost Namibia, ≈525 Ma), Saltpeterkop (SPK; near Sutherland, South Africa, 74 Ma), Zandkopsdrift (ZKD; near Garies, South Africa, 55 Ma, a major REE deposit in development), and Dicker Willem (DW; near Aus, southern Namibia, 49 Ma). All are located in the Early-mid Proterozoic Namaqua-Natal mobile belt. These carbonatite complexes are each associated with linear, NE-SW oriented magmatic provinces, i.e., the Kuboos-Bremen Line of felsic alkaline intrusions and ultramafic lamprophyres (MQ); the Western Cape olivine melilitite province (SPK); the Namaqualand-Bushmanland-Warmbad province of olivine melilitites and kimberlites (ZKD) and the Schwarzeberg-Klinghardt-Gibeon swarm of nephelinites, phonolites and kimberlites (DW), the latter three provinces are of Paleogene to Late Cretaceous age and are clearly age progressive. Each of the four carbonatite complexes contain silica-undersaturated igneous rocks such as potassic trachyte (MQ, SPK & DW), alkaline lamprophyre (ZKD), ijolite (MQ & DW) and olivine melilitite (ZKD and SPK). Most also contain hybrid silicate-carbonate igneous rocks with <35 wt.% SiO2 and ≥20 wt.% CO2 such as nepheline sövite (DW), aillikite (ZKD) and other carbonated ultramafic lamprophyre types (SPK) that could represent magmas parental to the carbonatites. Like the magmatic provinces that host them, the carbonatites span a range of isotopic compositions from strong HIMU to EM1. We will present a model of carbonatite origin and source evolution related to lithospheric setting.

Geochemical and isotopic constraints on the role of juvenile crust and magma mixing in the UDMA magmatism, Iran: evidence from mafic microgranular enclaves and cogenetic granitoids in the Zafarghand igneous complex

NASA Astrophysics Data System (ADS)

Sarjoughian, Fatemeh; Lentz, David; Kananian, Ali; Ao, Songjian; Xiao, Wenjiao

2018-04-01

The Zafarghand Igneous Complex is composed of granite, granodiorite, diorite, and gabbro that contain many mafic microgranular enclaves. This complex was emplaced during the late Oligocene (24.6 Ma) to form part of the Urumieh-Dokhtar magmatic arc of Central Iran. The enclaves have spheroidal to elongated/lenticular shapes and are quenched mafic melts in felsic host magma as evidenced by fine-grained sinuous margins and (or) locally transitional and diffuse contacts with the host rocks, as well as having disequilibrium textures. These textures including oscillatory zoning with resorption surfaces on plagioclase, feldspar megacrysts with poikilitic and anti-rapakivi textures, mafic clots, acicular apatites, and small lath-shaped plagioclase in larger plagioclase crystals all indicate that the enclaves crystallized from mafic magma that was injected into and mixing/mingling with the host felsic magma. The studied rocks have calc-alkaline, metaluminous compositions, with an arc affinity. They are enriched in large ion lithophile elements, light rare-earth elements, and depleted in high field strength elements with significant negative Eu anomalies. The Sr-Nd isotopic data for all of the samples are similar and display ISr = 0.705123-0.705950 and ɛNd (24.6 Ma) = - 1.04-1.03 with TDM 0.9-1.1 Ga. The host granites and enclaves are of mixed/mingled origin and most probably formed by the interaction between the juvenile lower crust with a basaltic composition and old lower or middle continental crust as a major component and lithospheric mantle as a minor component; this was followed by fractional crystallization and possibly minor crustal assimilation. The source seems to be comprised of about 90-80% of the basaltic magma and about 10-20% of lower/middle-crust-derived magma. Geochemical characteristics indicate that the intrusion of these rocks from a subduction zone setting below the Central Iran micro-continent was related to an active continental margin, although was transitional to a transtensional setting possibly due oblique convergence to slab rollback or break-off.

Evolution of Palaeoproterozoic mafic intrusions located within the thermal aureole of the Sudbury Igneous Complex, Canada: Isotopic, geochronological and geochemical evidence

NASA Astrophysics Data System (ADS)

Prevec, Stephen A.; Baadsgaard, Halfdan

2005-07-01

Impact cratering and their resultant geological phenomena are recognised as significant factors in the lithological and biologic evolution of the earth. Age-dating of impact events is critical in correlating cause and effects for these catastrophic processes. The Falconbridge and Drury Township (Twp) intrusions were emplaced at the contact between Neoarchaean basement and Palaeoproterozoic volcanosedimentary rocks, and also lie at the southeast and southwest edges of the Sudbury Igneous Complex (SIC), within its thermal contact aureole. The Falconbridge Twp intrusion is dated at 2441 ± 3 Ma by U-Pb zircon, with evidence of Archaean inheritance from its host granitoids. Granitoids from the southernmost Abitibi Subprovince are dated here between 2670 ± 11 Ma for an undeformed Algoman granite, and 2696 ± 18 Ma for a foliated granitoid, consistent with existing data from the Abitibi Greenstone Belt and from the Wawa Subprovince. Major and trace element geochemical evidence, common-Pb isotopic compositions, and ɛNd2440 values between 0 and -1 are all consistent with a Palaeoproterozoic origin for the Falconbridge Twp intrusion, and support inclusion in the East Bull Lake-type suite of leucogabbroic plutons and sills. In contrast, the Drury Twp intrusion gives a U-Pb zircon age of 1859 ± 13 Ma, coincident with the date of SIC-emplacement. While the major and trace element compositions are comparable to the Falconbridge data, the Drury displays significant heterogeneity in ɛNd2440, with values ranging from +3.7 to -0.1, and contains more radiogenic Pb isotopic compositions. Field, geochemical and isotopic evidence clearly distinguishes this intrusion from constituents of the SIC itself, and indicates that the Drury too is a Palaeoproterozoic intrusion. This requires that apparently unshocked, undeformed magmatic-looking zircon has been grown or reset in a postmagmatic setting. This has significant implications for the identification of mantle-derived magmas and crustal remelts associated with large impact craters. A resetting mechanism involving aggressive hydrothermal alteration of zircon facilitated by halogen-complexing is proposed, inducing rapid, postshock lead loss and subsequent annealing.

A Lithospheric Origin for the Elk Creek Carbonatite Complex, SE Nebraska?

NASA Astrophysics Data System (ADS)

Farmer, G. L.

2015-12-01

The Elk Creek carbonatite complex in southeastern Nebraska is part of a widespread Cambrian-Ordovician alkali igneous event that affected much of North America during and after the break-up of the Rodinian supercontinent. We conducted whole rock and mineral Nd, Sr, Pb and Hf isotopic analyses of drill cores obtained from this complex in order to assess the source regions of the parental carbonatite magma. Low precision laser ablation U-Pb age determinations from individual zircon grains separated from carbonate-rich "syenites" range from 480 +/- 20 Ma to 540+/- 14 Ma. Whole rock Nd, Sr and Pb isotopic compositions all plot on Cambrian (~550 Ma) isochrons, implying that the carbonatites crystallized from melts with homogeneous radiogenic isotopic compositions. Initial ɛNd and ɛHf are well defined at ~+2 and ~0, respectively, while initial 87Sr/86Sr values are more variable and range from 0.7028 to 0.7058. The contemporaneously emplaced State Line kimberlites in the Front Range of north central Colorado share the same Nd and Sr isotopic compositions imply that sources of these rocks were similar and geographically widespread. Overall, the isotopic compositions are those expected from "Group 1" alkaline igneous rocks, usually interpreted as derivates from the sublithospheric mantle. Cretaceous-Tertiary alkaline rocks in North America generally belong to "Group 1" and may have originated in this fashion (Genet et al., 2014, Earth Planet. Sci. Lett.). An alternative possibility is that the Cambrian-Ordovician carbonatites and kimberlites were derived from underlying, carbonated portions of the lithospheric mantle that formed after the original stabilization of the latter in the Paleoproterozoic. Nd and Hf depleted mantle model ages for the Elk Creek and State Line alkaline rocks range from ~0.8 Ga to ~1.1 Ga and allow the possibility that both sets of intrusive rocks represent melting of mantle metasomatized either during or after the assembly of Rodinia. Widespread thinning and heating of the metasomatized mantle during the subsequent breakup of Rodinia could have led to the widespread kimberlite and carbonatite magmatism observed in North America during the Cambrian.