936 resultados para Direct-sequence code division multiple access


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Technological developments in biomedical microsystems are opening up new opportunities to improve healthcare procedures. Swallowable diagnostic sensing capsules are an example of these. In none of the diagnostic sensing capsules, is the sensor’s first level packaging achieved via Flip Chip Over Hole (FCOH) method using Anisotropic Conductive Adhesive (ACA). In a capsule application with direct access sensor (DAS), ACA not only provides the electrical interconnection but simultaneously seals the interconnect area and the underlying electronics. The development showed that the ACA FCOH was a viable option for the DAS interconnection. Adequate adhesive formed a strong joint that withstood a shear stress of 120N/mm2 and a compressive stress of 6N required to secure the final sensor assembly in place before encapsulation. Electrical characterization of the ACA joint in a fluid environment showed that the ACA was saturated with moisture and that the ions in the solution actively contributed to the leakage current, characterized by the varying rate of change of conductance. Long term hygrothermal aging of the ACA joint showed that a thermal strain of 0.004 and a hygroscopic strain of 0.0052 were present and resulted in a fatigue like process. In-vitro tests showed that high temperature and acidity had a deleterious effect of the ACA and its joint. It also showed that the ACA contact joints positioned at around or over 1mm would survive the gastrointestinal (GI) fluids and would be able to provide a reliable contact during the entire 72hr of the GI transit time. A final capsule demonstrator was achieved by successfully integrating the DAS, the battery and the final foldable circuitry into a glycerine capsule. Final capsule soak tests suggested that the silicone encapsulated system could survive the 72hr gut transition.

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Dynamically reconfigurable time-division multiplexing (TDM) dense wavelength division multiplexing (DWDM) long-reach passive optical networks (PONs) can support the reduction of nodes and network interfaces by enabling a fully meshed flat optical core. In this paper we demonstrate the flexibility of the TDM-DWDM PON architecture, which can enable the convergence of multiple service types on a single physical layer. Heterogeneous services and modulation formats, i.e. residential 10G PON channels, business 100G dedicated channel and wireless fronthaul, are demonstrated co-existing on the same long reach TDM-DWDM PON system, with up to 100km reach, 512 users and emulated system load of 40 channels, employing amplifier nodes with either erbium doped fiber amplifiers (EDFAs) or semiconductor optical amplifiers (SOAs). For the first time end-to-end software defined networking (SDN) management of the access and core network elements is also implemented and integrated with the PON physical layer in order to demonstrate two service use cases: a fast protection mechanism with end-to-end service restoration in the case of a primary link failure; and dynamic wavelength allocation (DWA) in response to an increased traffic demand.

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Relative to the past 2,000 years, the Arctic region has warmed significantly over the past few decades. However, the evolution of Arctic temperatures during the rest of the Holocene is less clear. Proxy reconstructions, suggest a long-term cooling trend throughout the mid- to late Holocene, whereas climate model simulations show only minor changes or even warming. Here we present a record of the oxygen isotope composition of permafrost ice wedges from the Lena River Delta in the Siberian Arctic. The isotope values, which reflect winter season temperatures, became progressively more enriched over the past 7,000 years, reaching unprecedented levels in the past five decades. This warming trend during the mid- to late Holocene is in opposition to the cooling seen in other proxy records. However, most of these existing proxy records are biased towards summer temperatures. We argue that the opposing trends are related to the seasonally different orbital forcing over this interval. Furthermore, our reconstructed trend as well as the recent maximum are consistent with the greenhouse gas forcing and climate model simulations, thus reconciling differing estimates of Arctic and northern high-latitude temperature evolution during the Holocene.

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Analysis of the molecular composition of the organic matter (OM) from whole sediment samples can avoid analytical bias that might result from isolation of components from the sediment matrix, but has its own analytical challenges. We evaluated the use of GC * GC-ToFMS to analyze the pyrolysis products of six whole sediment samples obtained from above, within and below a 1 million year old OM-rich Mediterranean sapropel layer. We found differences in pyrolysis products multiple analytical variables, particularly the pyrolysis temperature and the operational features of the GC columns.

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Scientists planning to use underwater stereoscopic image technologies are often faced with numerous problems during the methodological implementations: commercial equipment is too expensive; the setup or calibration is too complex; or the imaging processing (i.e. measuring objects in the stereo-images) is too complicated to be performed without a time-consuming phase of training and evaluation. The present paper addresses some of these problems and describes a workflow for stereoscopic measurements for marine biologists. It also provides instructions on how to assemble an underwater stereo-photographic system with two digital consumer cameras and gives step-by-step guidelines for setting up the hardware. The second part details a software procedure to correct stereo-image pairs for lens distortions, which is especially important when using cameras with non-calibrated optical units. The final part presents a guide to the process of measuring the lengths (or distances) of objects in stereoscopic image pairs. To reveal the applicability and the restrictions of the described systems and to test the effects of different types of camera (a compact camera and an SLR type), experiments were performed to determine the precision and accuracy of two generic stereo-imaging units: a diver-operated system based on two Olympus Mju 1030SW compact cameras and a cable-connected observatory system based on two Canon 1100D SLR cameras. In the simplest setup without any correction for lens distortion, the low-budget Olympus Mju 1030SW system achieved mean accuracy errors (percentage deviation of a measurement from the object's real size) between 10.2 and -7.6% (overall mean value: -0.6%), depending on the size, orientation and distance of the measured object from the camera. With the single lens reflex (SLR) system, very similar values between 10.1% and -3.4% (overall mean value: -1.2%) were observed. Correction of the lens distortion significantly improved the mean accuracy errors of either system. Even more, system precision (spread of the accuracy) improved significantly in both systems. Neither the use of a wide-angle converter nor multiple reassembly of the system had a significant negative effect on the results. The study shows that underwater stereophotography, independent of the system, has a high potential for robust and non-destructive in situ sampling and can be used without prior specialist training.

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Oceanic dimethyl sulfide (DMS) is the enzymatic cleavage product of the algal metabolite dimethylsulfoniopropionate (DMSP) and is the most abundant form of sulfur released into the atmosphere. To investigate the effects of two emerging environmental threats (ocean acidification and warming) on marine DMS production, we performed a large-scale perturbation experiment in a coastal environment. At both ambient temperature and 2 °C warmer, an increase in partial pressure of carbon dioxide (pCO2) in seawater (160-830 ppmv pCO2) favored the growth of large diatoms, which outcompeted other phytoplankton species in a natural phytoplankton assemblage and reduced the growth rate of smaller, DMSP-rich phototrophic dinoflagellates. This decreased the grazing rate of heterotrophic dinoflagellates (ubiquitous micrograzers), resulting in reduced DMS production via grazing activity. Both the magnitude and sign of the effect of pCO2 on possible future oceanic DMS production were strongly linked to pCO2-induced alterations to the phytoplankton community and the cellular DMSP content of the dominant species and its association with micrograzers.

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The compositions of natural glasses and phenocrysts in basalts from Deep Sea Drilling Project Sites 501, 504, and 505, near the Costa Rica Rift, constitute evidence for the existence of a periodically replenished axial magma chamber that repeatedly erupted lavas of remarkably uniform composition. Magma compositions were affected by three general components: (1) injected magmas carrying (in decreasing order of abundance) Plagioclase, olivine, and chrome-spinel phenocrysts (spinel assemblage); (2) injected magmas carrying Plagioclase, clinopyroxene, and olivine phenocrysts, but no spinel (clinopyroxene assemblage); and (3) moderately evolved hybrids in the magma chamber itself. The compositions of the injected phenocrysts and minerals in glomerocrysts are as follows: Plagioclase - An85-94; olivine - Fo87-89; clinopyroxene - high Cr2O3 (0.7-1.1%), endiopside (Wo42En51Fs7), and aluminous chromian spinel (Cr/Cr + Al = 0.3). These minerals resemble those thought to occur in upper mantle sources (9 kbars and less) of ocean-ridge basalts and to crystallize in magmas near those sources. In the magma chamber, more sodic Plagioclase (An79-85), less magnesian olivine (Fo81-86) and low-Cr2O3 (0.1-0.4%) clinopyroxene formed rims on these crystals, grew as other phenocrysts, and formed cumulus segregations on the walls and floors of the magma chamber. In the spinel-assemblage magmas, magnesiochromite (Cr/Cr + Al = 0.4-0.5) also formed. Some cumulus segregations were later entrained in lavas as xenoliths. The glass compositions define 16 internally homogeneous eruptive units, 13 of which are in stratigraphic order in a single hole, Hole 504B, which was drilled 561.5 meters into the ocean crust. These units are defined as differing from each other by more than analytical uncertainty in one or more oxides. However, many of the glass groups in Hole 504B show virtually no differences in TiO2 contents, Mg/Mg + Fe2+, or normative An/An + Ab, all of which are sensitive indicators of crystallization differentiation. The differences are so small that they are only apparent in the glass compositions; they are almost completely obscured in whole-rock samples by the presence of phenocrysts and the effects of alteration. Moreover, several of the glass units at different depths in Hole 504B are compositionally identical, with all oxides falling within the range of analytical uncertainty, with only small variations in the rest of the suite. The repetition of identical chemical types requires (1) very regular injection of magmas into the magma chamber, (2) extreme similarity of injected magmas, and (3) displacement of very nearly the same proportion of the magmas in the chamber at each injection. Numerical modeling and thermal considerations have led some workers to propose the existence of such conditions at certain types of spreading centers, but the lava and glass compositions at Hole 504B represent the first direct evidence revealed by drilling of the existence of a compositionally nearly steady-state magma chamber, and this chapter examines the processes acting in it in some detail. The glass groups that are most similar are from clinopyroxene-assemblage lavas, which have a range of Mg/Mg + Fe2"1" of 0.59 to 0.65. Spinel-assemblage basalts are less evolved, with Mg/Mg + Fe2+ of 0.65 to 0.69, but both types have nearly identical normative An/An + Ab (0.65-0.66). However, the two lava types contain megacrysts (olivine, Plagioclase, clinopyroxene) that crystallized from melts with Mg/Mg + Fe2+ values of 0.70 to 0.72. Projection of glass compositions into ternary normative systems suggests that spinel-assemblage magmas originated deeper in the mantle than clinopyroxene-assemblage magmas, and mineral data indicate that the two types followed different fractionation paths before reaching the magma chamber. The two magma types therefore represent neither a low- nor a high-pressure fractionation sequence. Some of the spinel-assemblage magmas may have had picritic parents, but were coprecipitating all of the spinel-assemblage phenocrysts before reaching the magma chamber. Clinopyroxene-assemblage magmas did not have picritic parents, but the compositions of phenocrysts suggest that they originated at about 9 kbars, near the transition between plagioclase peridotite and spinel peridotite in the mantle. Two glass groups have higher contents of alkalis, TiO2, and P2O5 than the others, evidently as a result of the compositions of mantle sources. Eruption of these lavas implies that conduits and chambers containing magmas from dissimilar sources were not completely interconnected on the Costa Rica Rift. The data are used to draw comparisons with the East Pacific Rise and to consider the mechanisms that may have prevented the eruption of ferrobasalts at these sites.

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IODP Site U1309 was drilled at Atlantis Massif, an oceanic core complex, at 30°N on the Mid-Atlantic Ridge (MAR). We present the results of a bulk rock geochemical study (major and trace elements) carried out on 228 samples representative of the different lithologies sampled at this location. Over 96% of Hole U1309D is made up of gabbroic rocks. Diabases and basalts cross-cut the upper part of the section; they have depleted MORB compositions similar to basalts sampled at MAR 30°N. Relics of mantle were recovered at shallow depth. Mantle peridotites show petrographic and geochemical evidence of extensive melt-rock interactions. Gabbroic rocks comprise: olivine-rich troctolites (> 70% modal olivine) and troctolites having high Mg# (82-89), high Ni (up to 2300 ppm) and depleted trace element compositions (Yb 0.06-0.8 ppm); olivine gabbros and gabbros (including gabbronorites) with Mg# of 60-86 and low trace element contents (Yb 0.125-2.5 ppm); and oxide gabbros and leucocratic dykes with low Mg# (< 50), low Ni (~65 ppm) and high trace element contents (Yb up to 26 ppm). Troctolites and gabbros are amongst the most primitive and depleted oceanic gabbroic rocks. The main geochemical characteristics of Site U1309 gabbroic rocks are consistent with a formation as a cumulate sequence after a common parental MORB melt, although (lack of systematic) downhole variations indicate that the gabbroic series were built by multiple magma injections. In detail, textural and geochemical variations in olivine-rich troctolites and gabbronorites suggest chemical interaction (assimilation?) between the parental melt and the intruded lithosphere. Site U1309 gabbroic rocks do not represent the complementary magmatic product of 30°N volcanics, although they sample the same mantle source. The bulk trace element composition of Site U1309 gabbroic rocks is similar to primitive MORB melt compositions; this implies that there was no large scale removal of melts from this gabbro section. The occurrence of such a large magmatic sequence implies that a high magmatic activity is associated with the formation of Atlantis Massif. Our results suggest that almost all melts feeding this magmatic system stays trapped into the intruded lithosphere.

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Multiple Sclerosis (MS), an idiopathic progressive immune-mediated neurological disorder of the central nervous system (CNS), is characterized by recurrent episodes of inflammatory demyelination and consequent axonal deterioration. It accounts for functional deterioration and lasting disability among young adults. A body of literature demonstrates that physical activity counteracts fatigue and depression and may improve overall quality of life in MS patients. Furthermore, much data indicates that exercise ameliorates chronic neuroinflammation and its related pathologies by tipping cytokine profiles toward an anti-inflammatory signature. Recent data has focused on the direct impact of exercise training on the innate immune system by targeting toll-like receptors (TLRs), signaling pattern recognition receptors that govern the innate immune response, shedding light on the physiological role of TLRs in health and disease. Indeed, TLRs continue to emerge as players in the neuroinflammatory processes underpinning MS. This review will highlight evidence that physical activity and exercise are potential immunomodulatory therapies, targeting innate signaling mechanism(s) to modulate MS symptom development and progression.

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The scope of this study is to identify the prevalence of access to information about how to prevent oral problems among schoolchildren in the public school network, as well as the factors associated with such access. This is a cross-sectional and analytical study conducted among 12-year-old schoolchildren in a Brazilian municipality with a large population. The examinations were performed by 24 trained dentists and calibrated with the aid of 24 recorders. Data collection occurred in 36 public schools selected from the 89 public schools of the city. Descriptive, univariate and multiple analyses were conducted. Of the 2510 schoolchildren included in the study, 2211 reported having received information about how to prevent oral problems. Access to such information was greater among those who used private dental services; and lower among those who used the service for treatment, who evaluated the service as regular or bad/awful. The latter use toothbrush only or toothbrush and tongue scrubbing as a means of oral hygiene and who reported not being satisfied with the appearance of their teeth. The conclusion drawn is that the majority of schoolchildren had access to information about how to prevent oral problems, though access was associated with the characteristics of health services, health behavior and outcomes.

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ANKHD1 (Ankyrin repeat and KH domain-containing protein 1) is highly expressed and plays an important role in the proliferation and cell cycle progression of multiple myeloma (MM) cells. ANKHD1 downregulation modulates cell cycle gene expression and upregulates p21 irrespective of the TP53 mutational status of MM cell lines. The present study was aimed to investigate the role of ANKHD1 in MM in vitro clonogenicity and in vivo tumourigenicity, as well as the role of ANKHD1 in p21 transcriptional regulation. ANKHD1 silencing in MM cells resulted in significantly low no. of colonies formed and in slow migration as compared to control cells (p < 0.05). Furthermore, in xenograft MM mice models, tumour growth was visibly suppressed in mice injected with ANKHD1 silenced cells compared to the control group. There was a significant decrease in tumour volume (p = 0.006) as well as in weight (p = 0.02) in the group injected with silenced cells compared to those of the control group. Co-immunoprecipitation and chromatin immunoprecipitation (ChIP) assays confirmed the interaction between p21 and ANKHD1. Moreover, overexpression of ANKHD1 downregulated the activity of a p21 promoter in luciferase assays. Decrease in luciferase activity suggests a direct role of ANKHD1 in p21 transcriptional regulation. In addition confocal analysis after U266 cells were treated with Leptomycin B (LMB) for 24 h showed accumulation of ANKHD1 inside the nucleus as compared to untreated cells where ANKHD1 was found to be predominantly in cytoplasm. This suggests ANKHD1 might be shuttling between cytoplasm and nucleus. In conclusion, ANKHD1 promotes MM growth by repressing p21 a potent cell cycle regulator.

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Universidade Estadual de Campinas . Faculdade de Educação Física