bluuebunny/crossref_metadata_2025 huggingface dataset:
DATA STRUCTURES FOR RANGE-AGGREGATION OVER CATEGORIES
Authors: RAHUL SALADI , GUPTA PROSENJIT , RAJAN K. S.
Published: December 2011

We solve instances of a general class of problems defined as follows: Preprocess a set S of possibly weighted colored geometric objects (e.g. points/orthogonal segments/rectangles) in IR d, d ≥ 1 such that given a query orthogonal range q (e.g. hyperbox/point), we can report efficiently for each distinct color c of the points in S ∩ q, the tuple [Formula: see text] where [Formula: see text] is a function (e.g. weighted sum, bounding box etc.) of the objects of color c in q.
TESTING AXION PHYSICS IN A JOSEPHSON JUNCTION ENVIRONMENT
Authors: BECK CHRISTIAN
Published: December 2011

We suggest that experiments based on Josephson junctions, SQUIDS, and coupled Josephson qubits may be used to construct a resonant environment for dark matter axions. We propose experimental setups in which axionic interaction strengths in a Josephson junction environment can be tested, similar in nature to recent experiments that test for quantum entanglement of two coupled Josephson qubits. We point out that the parameter values relevant for early-universe axion cosmology are accessible with present day's achievements in nanotechnology. We work out how typical dark matter and dark energy signals would look like in a novel detector that exploits this effect.
AB INITIO CALCULATIONS OF ELECTRONIC STRUCTURE AND OPTICAL SPECTRA OF (13-0) CARBON NANOTUBE
Authors: MOVLAROOY TAYEBEH , HOSSEINI S. M. , KOMPANY A. , SHAHTAHMASEBI N.
Published: December 2011

We present a first principle calculation on the electronic structure and the linear optical properties of (13-0) zigzag single walled carbon nanotube by using full potential linear augmented plane wave (FP-LAPW) method. It is found that zigzag (13-0) nanotube has semiconducting behavior with the band gap of 0.6 eV at Γ point. The optical spectra of (13-0) carbon nanotube have been calculated for both electric field polarizations, parallel and perpendicular to the tube axis. The dielectric function is found to be highly anisotropic and is much larger for the electric field applied along the tube axis than the perpendicular. The results show that unlike the optical absorption, the energy loss function of (13,0) SWCNT show weak anisotropy. It was also revealed that the energy loss function peaks for both electric fields happen almost at the same energies, but with rather difference in their amplitudes.
FABRICATION OF Mg/SiC NANOCOMPOSITE SURFACE LAYER USING FRICTION STIR PROCESSING TECHNIQUE
Authors: ERFAN YOONES , KASHANI-BOZORG SEYED FARSHID
Published: December 2011

Friction stir processing (FSP) was employed to incorporate nano-sized SiC particles into the surface of AZ31 magnesium substrate in order to produce surface nanocomposite layers. Characterization of the microstructure of the processed layers exhibited powders agglomeration which was found to disperse with increasing the tool rotation speed/advancing speed ratio. A uniform distribution of SiC particles with a mean particle size of ~95 nm was achieved after second FSP passes. The matrix grain size was found to decrease by increasing the tool advancing speed and number of FSP passes; however, increasing the advancing speed resulted in introduction of defects which leads to tunnels. The micro hardness value of the composite layer with uniform distribution of nano-size SiC particles was found to be almost twice of that of the AZ31 substrate.
EFFECT OF ANNEALING AND SnO2 ADDITION ON PROPERTIES OF NANOSTRUCTURED ZnO THIN FILMS
Authors: JAIN VIPIN KUMAR , KUMAR PRAVEEN , BHANDARI DEEPIKA , VIJAY Y. K.
Published: December 2011

In the present work, Zinc–Tin–Oxide (ZTO) thin films were deposited on glass substrate with varying concentration ( ZnO:SnO2 -100:0, 90:10, 70:30 and 50:50 wt.%) at room temperature by flash evaporation technique. These deposited ZTO film were annealed in vacuum to study the thermal stability and to see the effects on the structural and optical properties. The XRF spectra revealed the presence of Zinc and Tin with varying concentration in ZTO thin films. XRD results show the crystallinity of the ZTO films was improved with increasing the concentration of SnO2 and post annealing. The surface composition and oxidation state were analyzed by X-ray photoelectron spectroscopy. The variation of % composition shows as the concentration of SnO2 increases from 0 to 50%, the atomic ratio of Sn/Zn and O/Zn increases for both types of ZTO films and deficiency of oxygen has been appeared after annealing. The optical band gap was also found to be decreased for both types of films with increasing concentration of SnO2 .
MODELING OF MICRO-ELECTRO MECHANICAL SYSTEMS BASED CANTILEVER BEAM AS BIOSENSOR FOR C-REACTIVE PROTEIN
Authors: SWARRUP J. SAKTHI , VELMURUGAN V.
Published: December 2011

Micro fabricated cantilever beam smart immunosensor was modeled using "Intellisuite" software to detect nanogram level antigen. The FEM simulations were carried out with immunoglobulin antibody, IgG for the detection of C -reactive protein. The effect of geometry of the cantilever beam with different number of holes and thickness of Si piezo resistive-patch on the sensor performance and signal transduction was studied. The effect of nature of Si and CNT piezo resistive-patch on the sensor performance was also investigated. Considering the response of stress and sensitivity, CNT piezo resistive patch is more suitable for the development of smart sensor. A cantilever beam immunosensor 100 μm long, 50 μm wide and 2.4 μm thick with one hole 3 μm long and 6 μm wide in the beam and CNT piezo-patch 100 nm thick is a more promising system for the fabrication for the detection of C -reactive protein. The modeled sensor can detect CRP even at a low concentration of 11.0 ng/ml.
PHOTOPLASTIC MICROCANTILEVER SENSOR PLATFORM FOR EXPLOSIVE DETECTION
Authors: SEENA V. , FERNANDES AVIL , MUKHERJI SOUMYO , RAO V. RAMGOPAL
Published: December 2011

We present an ultrasensitive and cost effective polymeric microcantilever sensor platform for explosive vapor detection. These sensors were fabricated using SU-8 polymer composite materials with two transduction approaches namely (i) optical and (ii) electrical detection. The cantilevers have been characterized for their electrical and mechanical properties. The functionalization of these microcantilevers has been carried out using selective chemicals for most popular explosives such as TNT and RDX. Optical and electrical responses of respective microcantilevers to TNT and RDX vapors are also presented here.
OPTIMIZATION OF CATALYST LOADING FOR EFFECTIVE UTILIZATION OF FEED STOCK FOR CARBON NANOTUBES SYNTHESIS PROCESS
Authors: PATIL KASHINATH N. , MAHAJANI SANJAY M. , SOLANKI CHETAN S.
Published: December 2011

Carbon nanotubes (CNTs) possess range of properties which are useful in applications like, H2 storage, electrodes in fuel cell, catalyst support in chemical industry, electronic components, etc. Normally, high yield is desirable from the cost reduction point of view, hence knowledge of carbon deposition in the presence of various catalysts loading is required. In this paper, optimization of catalyst loading to obtain effective utilization of the feed stock, which obtains cost reduction of CNTs is presented. The Fe – Co metal catalyst is used in the study. The carbon precursor used in the study is C2H2 along with Ar as a carrier gas. The carbon deposition is carried out at optimized temperature of 700°C. The experiments are carried out at different concentration of the feed stocks ( C2H2 : Ar ) such as 0.06:1, to 0.28:1, so as to compare the effect of carbon loading. Since, at higher concentration, the amount of carbon generated is more, hence, sufficient catalyst should be present such that it assures the maximum utilization of the decomposed carbon. The 8.1 and 42.4 mgcatalyst is required for maximum utilization of feed stock at 30 min of precursor flow at lowest and highest concentration. It is observed that the catalyst loading shows a linear relationship with an increase in the concentration of feed stock and the time of the CNTs synthesis.
INFLUENCE OF GRAIN SIZE ON MAGNETOCALORIC EFFECT IN THE NANOCRYSTALLINELa0.8Te0.2MnO3
Authors: MAHATO RABINDRA NATH , SETHUPATHI K. , SANKARANARAYANAN V.
Published: December 2011

The nanocrystalline La0.8Te0.2MnO3samples are prepared by sol-gel method and show rhombohedral crystal structure with R3c space group at room temperature. The calculated crystallite sizes are ~55 nm, 40 nm and 25 nm for calcined at 700°C, 800°C and 900°C temperatures. The SEM images show the grain size increases as the calcination temperature increases and the values are in good agreement with that obtained from X-ray diffraction analysis. The samples undergo paramagnetic to ferromagnetic transition and follow Curie–Weiss law in the paramagnetic region. The maximum entropy change are ~3.2 J kg-1K-1, 3 J kg-1K-1and 2 J kg-1K-1for a field change of 20 kOe for 55 nm, 40 nm and 25 nm samples respectively. In the framework of Landau theory of phase transition, the experimentally observed magnetic entropy change and theoretical predicted model fits well for all the nanoparticles.
ENHANCED MAGNETIZATION IN COBALT SUBSTITUTED Ni–Zn NANOFERRITES
Authors: VARMA M. CHAITANYA , KUMAR A. MAHESH , RAO K. H.
Published: December 2011

Cobalt substituted nickel zinc ferrite nanoparticles ( Ni 0.65–x Co x Zn 0.35 Fe 2.0 O 4) X varying from 0.0 to 0.65 in steps of 0.15 have been produced using sol–gel method, with PVA as chelating agent. The phase formation of the sintered ferrite was confirmed by X-ray diffraction studies. The lattice parameter a(A°) has been calculated using Nelson–Riley method. The crystallite size has been estimated by the Williamson–Hall method using the full width at half-maximum (FWHM) of the line broadening of all the peaks. Mössbauer spectroscopy (MS) of the samples showed the clear presence of two sextets and distribution of iron over the two sites has been given. Increase in saturation magnetization with cobalt concentration with a slight decrease for x = 0.15 has been observed with the vibrating sample magnetometry study. The observed value of magnetization for Ni0.65Zn0.35Fe2O4 with a particle size of 43.5 nm has been 71 emu/gm at room temperature, which is higher than that reported for samples prepared using chemical methods of the same composition. The results have been explained on the basis of the particle size and cation distribution among various sites.
BIEXCITONIC EFFECT ON TRANSIENT NONLINEAR REFRACTION AND ABSORPTION IN A MAGNETIZED CdS QUANTUM DOTS
Authors: GOYAL SWATI , SEN PRANAY K.
Published: December 2011

Transient optical nonlinearities of semiconductor quantum dots in the strongly confined regime are studied, in which the exciton, biexciton and magnetic field effects are taken into account. The photo induced band-to-band electronic transitions are considered from both the heavy-hole (hh) and light-hole (lh) valence bands to the lowest (1s) exciton state below the fundamental absorption edge. The time dependent perturbation technique for a three-level system, under the near band gap resonant excitation regime, has been employed; with the incorporation of the relaxation and dephasing mechanisms phenomenologically. The induced polarization is calculated from where the real and imaginary parts of the third-order nonlinear optical susceptibility, responsible for the occurrence of nonlinear refraction and nonlinear absorption respectively, have been derived. The temporal and detuning spectra of nonlinear refraction and absorption; and their dependence on density of biexcitons and a moderately strong magnetic field, have been analyzed. It is observed that the nonlinear refraction and nonlinear absorption enhance with increasing magnetic field in small CdS quantum dots.
CONTROLLED GROWTH OF HIGHLY ORIENTED ZnO NANOROD ARRAY ON AMORPHOUS GLASS SUBSTRATE AND THEIR OPTICAL AND ELECTRICAL PROPERTIES
Authors: KUSHWAHA AJAY , ASLAM M.
Published: December 2011

Highly oriented zinc oxide nanorod array is fabricated on ZnO quantum dots functionalized amorphous glass substrate. Simplified aqueous based beaker-chemistry is utilized for a controlled growth of vertically oriented nanorod arrays. XRD studies exhibit (002) orientation of the nanorod arrays which are achieved by sheer control of parameters such as ZnO seed layer morphology, molarity, reaction time and deposition temperature. A lower concentration of precursor leads to the sparse nanorods alignment while a higher concentration renders a (002) oriented of nanorod array film. We find that the amorphous substrate plays no role and a pre-annealed quantum dot array leads to an oriented structure when the growth is faster and the quantum dot surface provides an optimal site for oriented growth. The photoluminescence (PL) spectra reflect a strong UV emission at 380 nm and a broad green orange emission band nearly 600 nm which is generally attributed to the defect band transition. UV-visible spectra has a sharp jump at 380 nm for the excitonic band absorptions. The DC conductivity measurement reveals that the film is a good semiconductor (order of σ = 10-7 ohm-1 cm-1) and provides a very promising platform for photovoltaic and optoelectronic device applications. The conductivity of the ZnO nanorod array becomes higher in orders of 10 with the illumination of UV light of the 350 nm wavelength.
ENGINEERING AND THERAPEUTIC APPLICATIONS OF MICROTUBULES
Authors: KAPOOR SONIA , RANJITH P. , PANDA DULAL
Published: December 2011

Living organisms are fascinating systems. The macromolecules that make up a living cell possess equally astounding structural and functional characteristics. By taking simple cues from how these biopolymers organize and work inside the cell, one can draw inspiration to utilize them outside their natural environment for several purposes. Microtubules are example of biopolymers that demonstrate extraordinary properties of hierarchical self-organization, dynamic remodeling and mechanical rigidity. Mimicking the principles and properties of microtubules and improving them have opened novel engineering avenues. In addition, due to the functions that microtubules perform during cell division, they are excellent therapeutic drug targets for anticancer agents. In this work, we describe the biological properties and functions of microtubules, and discuss their engineering and therapeutic applications.
STUDIES ON BIODEGRADATION OF CELLULOSE NANOFIBRIL REINFORCED STARCH/PVA BIOCOMPOSITE FILMS USING AEROBIC COMPOST ENVIRONMENT
Authors: MAITI SONAKSHI , MITRA DEBARATI , RAY DIPA
Published: December 2011

Starch/PVA biocomposite films reinforced with cellulose nanofibrils were prepared by solution casting method incorporating glycerol as a plasticizer. These biocomposite films along with unreinforced films were subjected to biodegradation in an aerobic compost pit. The extents of biodegradation of these films were studied in terms of persentage weight loss. The corresponding changes in the structures and properties of these biocomposites were investigated using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) study and Differential Scanning Calorimetry (DSC). The presence of fillers influenced the arrangement of the starch and PVA molecules in the film compared to that in the unreinforced film. A significant difference was observed in the nature of biodegradation of unreinforced and the reinforced films. The glass transition temperature, as observed from DSC, showed a decreasing trend, while the melting temperature showed an increasing trend after biodegradation. SEM micrographs revealed that the starch portions were consumed at a faster rate compared to polyvinyl alcohol, which was confirmed from XRD graphs also.
HYBRID SEMICONDUCTING QUANTUM DOTS–METALLIC NANOPARTICLES ARRAYS FOR POSSIBLE NANOPHOTONIC DEVICES
Authors: HARIDAS M. , BASU J. K.
Published: December 2011

Arrays of quantum dots and hybrid arrays of semiconducting quantum dots and metallic nanoparticles have wide range of potential applications from nanophotonics to quantum information processing. Creating such arrays with well-defined morphology and order over a large area is a challenge. We present a reliable method for constructing such arrays using simple self assembly technique. The reliability of the method is verified using AFM. The emission properties of such system are studied using high resolution imaging techniques and we have given the possible explanation for the observed phenomena.
Chapter 11 The record of Neoproterozoic glaciation in the Taoudéni Basin, NW Africa
Authors: Shields-Zhou G. A. , Deynoux Max , Och Lawrence
Published: December 2011

The Taoudéni Basin covers over 1 000 000 km
2
of the West African Craton, bounded by Pan-African orogenic belts. Four supergroups separated by craton-scale unconformities are recognized, with Neoproterozoic glaciogenic deposits occurring at the base of Supergroup 2. The Jbéliat Group occurs along a continuous, 1300-km-long, narrow belt from the Adrar region of Mauritania to the eastern limit of the Hank in Algeria and comprises thin glacial drift capped widely by periglacial polygonal structures, with more complex glacial sequences preserved in palaeo-depressions. A thicker, variously marine and continental glaciogenic succession can be found in southern parts, while fully marine, glacially influenced successions are only known from the extreme SW of the basin. The ‘triad’ sequence of diamictites overlain by barite-bearing ‘cap’ dolostones and then by green shales and/or bedded cherts (silexites) is ubiquitous and has long been used to correlate the Supergroup 1/2 boundary across the basin and into the surrounding orogenic belts. The bedded cherts commonly show a volcanic influence and are cemented by early marine calcite at their base at Adrar, Mauritania. Although fossil-based age constraints are scarce and ambiguous, regional tectonic events indicate that ‘triad’ deposition occurred between the Bassaride (665–655 Ma) and Dahomeyide (610–580 Ma) orogens. Recent U–Pb zircon studies of ignimbrite tuffs provide a minimum age for the glaciation of
c.
600 Ma. Correlation of supergroup 2 glacial deposits with the
c.
635 Ma end-Cryogenian (‘Marinoan’) glaciation is likely and is supported by limited carbon and strontium isotope data. Barite is commonly found within the cap carbonate and may relate to methane seepage and/or unusual oceanographic conditions after deglaciation. Several studies have attributed sequence complexity within the post-glacial succession to isostatic reequilibration. The Taoudéni Basin represents a rare Neoproterozoic example of terrestrial tillites and associated periglacial facies.
Chapter 16 The Chameis Gate Member, Chameis Group, Marmora Terrane, Namibia
Authors: Frimmel Hartwig E.
Published: December 2011

The Chameis Gate Member is a poorly exposed and poorly investigated diamictite in the Chameis Subterrane of the Marmora Terrane, which forms the western, completely allochthonous part of the Pan-African Gariep Belt (southwestern Namibia). Its significance lies in its position in an entirely oceanic unit, the Dernburg Formation, which is dominated by mafic volcanic rocks. The diamictite contains exotic dropstones in a mafic volcaniclastic matrix, thus providing evidence for transport by ice away from the continental margin into an oceanic environment. No direct age data are available and stratigraphic relationships are obscured by limited outcrop and intense syn-orogogenic deformation. Preliminary chemostratigraphic data obtained on carbonate rocks below and above the diamictite, imprecise Pb–Pb age data on the largely volcaniclastic silicate fraction within associated stromatolitic reef carbonates, and imprecise Ar–Ar data on early hornblende related to sea-floor metamorphism of the associated volcanic rocks all point to an age loosely constrained between 640 and 580 Ma. Based on a comparison between the tectono-stratigraphic units of the Marmora Terrane with the continental Port Nolloth Group on the one side and the Rocha Group of the Punta del Este Terrane in Uruguay on the other side of the terrane, it is suggested that the diamictite was deposited in a back-arc basin that developed in response to the 640–590 Ma volcanic arc of the Dom Feliciano Belt in southeastern Brazil and eastern Uruguay.
Chapter 19 The Ayn Formation of the Mirbat Group, Dhofar, Oman
Authors: Allen Philip A. , Rieu Ruben , Etienne James L. , Matter Albert , Cozzi Andrea
Published: December 2011

Glacial deposits are found in the Ayn Formation and Shareef Formation of the Mirbat Group close to Mirbat in Dhofar, southern Oman. The Mirbat Group is most likely a correlative of the Abu Mahara Group of the Huqf Supergroup of northern Oman. The Ayn Formation, the main subject of this chapter, comprises <400 m of mainly coarse-grained glaciogenic deposits, ponded in 2- to >8-km-wide N- to NW-oriented palaeovalleys eroded into crystalline basement, with few or no deposits preserved on intervening palaeohighs. The Shareef Formation occurs as thin, lenticular, erosional remnants beneath the unconformably overlying Cretaceous. The Ayn Formation is overlain by a thin (<3 m), discontinuous cap carbonate that passes from carbonate-cemented talus on the basin margin to stromatolitic carbonate on palaeohighs and resedimented gravity flows on palaeovalley flanks.

The Ayn Formation is younger than its youngest detrital zircons and the youngest late plutons in crystalline basement, constraining it to <
c
. 720 Ma, but its exact age is unknown. The detrital zircon population comprises exclusively Neoproterozoic sources, suggesting derivation from the juvenile Neoproterozoic crust of the Arabian area.

The composition of fine-grained matrix in glaciogenic diamictite units and of non-glacial mudstones, plotted using the chemical index of alteration (CIA), suggests strong variations in the intensity of palaeoweathering on contemporary land surfaces between the mechanical weathering-dominated Ayn Formation, and the chemical weathering-dominated overlying Arkahawl Formation, which supports the notion of major glaciation followed by rapid climatic transit as basin margins were flooded and buried with sediment during post-glacial transgression. The carbon isotopic ratio (δ
13
C) of the post-glacial carbonate is strongly variable from −3.5‰ to +5.8‰, whereas carbonate fissures in the underlying basement range between +4.1‰ and +5.7‰.

Two independent palaeomagnetic studies have yielded low palaeomagnetic latitudes for the Mirbat Group.
Chapter 23 Glacial deposits of the Bokson Group, East Sayan Mountains, Buryatian Republic, Russian Federation
Authors: Chumakov Nickolay M.
Published: December 2011

The Bokson Group (Gr.) forms the platform cover in northern part of the Tuva-Mongolian Massif, south of the East Sayan Mountains. Widespread diamictites occur in the lower part of the Bokson Gr., in the Zabit Formation (Fm.). These contain erratic, faceted and striated stones along with dropstones. They have disconformable or gradual lower boundaries and conformable or transitional upper boundaries with overlying deposits. The isotopic δ
13
C
crb
curve records some maximum and minimum values as a background of insignificantly varying values (from –3 to 2‰). Maximum values (up to 5.5‰), are recorded in deposits underlying diamictites, whereas the overlying beds of the Zabit Formation (Fm.) yielded three peaks or minima down to −4‰. A fourth negative anomaly derived from the middle part of the Bokson Gr. in the lower part (close to base) of the Tabinzurt Fm. is as low as –5.7‰. The deposits underlying the diamictites contain Ediacaran (Vendian) microfossils.
Cloudina sp.
was discovered in the granule of diamictites, whereas beds just above include small shelly fossils (SSF) of the Nemakit-Daldynian type (
Cambrotubulus decurvatus
Miss.,
Anabarites trisulcatus
Miss.), which is overlain by a member with abundant fossils of the Tommotian assemblage. The diamictites represent glaciomarine deposits formed in the uppermost Ediacaran or lowermost Cambrian stage (Upper Vendian).
Chapter 26 Glacial deposits of the Baykonur Formation, Kazakhstan and Kyrgyzstan
Authors: Chumakov Nickolay M.
Published: December 2011

The Baykonur Formation extends with some interruptions for over 1700 km along the eastern and northern margins of the Upper Precambrian Syrdarya and Tarim microcontinents. The Baykonur Formation constitutes the upper part of the Ulutau Group, which lies on an erosional surface of granosyenite with a U–Pb age of 720±20 Ma and is overlain by Lower Cambrian vanadium-bearing carbonaceous-siliceous shales. The Baykonur Formation is mostly composed of diamictite with erratic and striated stones, and includes thin-bedded shale beds with lonestones (dropstones) and a ‘cap dolomite’ unit at its top. The lithological composition of this formation implies a glaciomarine origin, while its stratigraphic position suggests a Late Vendian or an Early Cambrian age (the latest Ediacaran or Early Cambrian according to scale of the International Commission on Stratigraphy).
Chapter 3 Recognition of glacial influence in Neoproterozoic sedimentary successions
Authors: Arnaud Emmanuelle , Etienne James L.
Published: December 2011

This chapter provides an overview and key references of glacial processes and resulting sedimentary products in subglacial, terrestrial proglacial and glaciomarine or glaciolacustrine settings. These settings are characterized by a wide variety of processes ranging from subglacial lodgement and deformation, ice-push and sediment remobilization, which in turn result in a wide range of products such as diamictite, conglomerate, sandstone, siltstone and mudstone. The sedimentary record of proglacial settings exhibits the most lateral and vertical variability due to the dynamic nature of ice margins and the most direct record of climatic fluctuations. Many Neoproterozoic successions, however, preserve glaciomarine deposits that can provide a more continuous and high-resolution (though indirect) record of change. This chapter will enable the reader to identify features that may be used to infer a glacial influence on the formation of ancient deposits. The chapter also outlines some of the important issues that require consideration when evaluating palaeoclimatic models for Neoproterozoic sedimentary successions. These include the equivocal significance of most commonly used proxies such as occurrence of diamictite, outsized clasts in laminated sediments, clast characteristics, lithostratigraphic trends and sequence boundaries. Careful analysis of multiple lines of sedimentary evidence, together with other proxies of climatic changes, can yield meaningful reconstructions and provide a basis for testing palaeoclimate models for this time period. A summary table outlining the characteristics of diamictite with different depositional origins is also included in order to assist with the interpretation of the Neoproterozoic sedimentary record.
Chapter 51 The glaciogenic Jequitaí Formation, southeastern Brazil
Authors: Uhlein A. , Alvarenga C. J. S. , Dardenne M. A. , Trompette R. R.
Published: December 2011

Glaciogenic deposits of the Jequitaí Formation (Fm.) are well exposed along the margins of the Serra do Cabral on the São Francisco Craton, southeastern Brazil. The Jequitaí Formation is thin (0–150 m thick), lenticular and overlies the Espinhaço Supergroup on a discrete unconformity. Sandstones show subglacial erosional structures such as grooved and striated pavements oriented ENE–WSW. The Jequitaí Fm. consists of massive and stratified diamictites with granules, pebbles and boulders of gneiss, granite, quartzite and carbonate. At the base, the diamictites are massive, whereas the upper part contains many alternating beds of clast-rich and -poor diamictites. They also contain discontinuous, fine-grained sandstones and a few laminated siltstone–mudstone intercalations. This diamictite association indicates glaciomarine sedimentation. The Jequitaí Fm. covers the São Francisco cratonic domain and its equivalent extends eastward over the Araçuaí fold belt where it is part of the metasedimentary Macaúbas Group, a thick Neoproterozoic unit with metadiamictites, quartzites and schists. The diamictite–turbidite association of the Macaúbas Group was deposited on the border of the Pan-African–Brasiliano rift as gravity flows.
Chapter 52 The Playa Hermosa Formation, Playa Verde Basin, Uruguay
Authors: Pazos P. J. , Rapalini A. E. , Bettucci L. Sánchez , Tófalo O. R.
Published: December 2011

The Playa Hermosa Formation (Fm.) (Playa Verde Basin) is a volcano-sedimentary unit that crops out in the extreme south of the Dom Feliciano Belt in Uruguay. This formation has traditionally been interpreted as non-glacial in origin, but recently it has been suggested that the lower part at least may be glacially influenced. The stratigraphic position of the Playa Hermosa Fm. and its correlation with other Neoproterozoic units of Uruguay, Argentina and southern Brazil remains in dispute. An age of
c.
580 Ma is indicated by a hornblende
39
Ar/
40
Ar age on magmatism regarded as coeval with syn-sedimentary volcanism. Preliminary palaeomagnetic data suggest a primary remanence and a mean geomagnetic pole consistent with the proposed apparent polar wander path for the Río de La Plata craton. In combination, these data suggest mid-Ediacaran glacial sedimentation in low to intermediate latitudes on the Río de la Plata craton. However, this conclusion needs to be reinforced by more thorough studies of the age and origin of the Playa Hermosa Fm.
Chapter 53 Las Ventanas and San Carlos formations, Maldonado Group, Uruguay
Authors: Pecoits Ernesto , Gingras Murray K. , Konhauser Kurt O.
Published: December 2011

Together with the Playa Hermosa Formation (Fm.), the Las Ventanas and San Carlos formations constitute the Maldonado Group, which is better developed in the southeastern part of Uruguay and covers an area of
c.
200 km
2
. The total thickness of both units (i.e. Las Ventanas and San Carlos formations) reaches
c.
1500 m, and comprises mafic and acidic volcanic rocks, pyroclastic rocks, diamictite, sandstone, conglomerate and pelite. Structurally, the Maldonado Group is extensively deformed, although variably, throughout the region. Strike–slip faults, westward-verging detachment faults, and folds with axis sub-parallel to the strike–slip planes are common features. The presence of pumpellyite, prehnite, chlorite and epidote in mafic rocks indicates very low- to low-grade metamorphic conditions. The Las Ventanas Fm. is characterized by basal conglomerate, diamictite, sandstone and siltstone that pass upwards into fine-grained rhythmites (pelite), and is the thickest unit of the Maldonado Group (
c.
1250 m). The San Carlos Formation (
c.
250 m) comprises fine-grained conglomerate, sandstone and mudstone towards the top. Both units lie on an angular unconformity above Palaeo- and Neoproterozoic basement and are overlain unconformably by late Ediacaran–lowermost Cambrian units. Reliable palaeomagnetic data indicate that the Maldonado Group accumulated at high palaeolatitudes; however, the palaeogeographical evolution of the Río de la Plata Craton during the Neoproterozoic remains conjectural. Radiometric data from intrusive bodies and cross-cutting strike–slip faults place the minimum age of the group at
c.
565 Ma, whereas basement volcanic rocks dated at 590 
± 
2 Ma interbedded with meta-sandstones hosting detrital zircons
c.
600 million years old provide the best constraint on the maximum age of deposition. Given the absence of carbonate rocks, no chemostratigraphic studies (e.g. C, O, Sr) are available.

The Las Ventanas and San Carlos formations are largely interpreted as units within a thick glacially influenced fan-delta sedimentary system formed during the early Ediacaran in a strike–slip basin. Based on stratigraphic and sedimentological characteristics it has been suggested that this succession, containing glacially influenced diamictite and dropstones, records a glacial period that occurred sometime between
c.
570 and 590 million years ago. Ongoing research is focused on establishing the precise age of deposition of the Maldonado Group and on reconstructing the tectonic evolution of the basin. Further palaeomagnetic studies will be especially useful for determining the palaeogeography of the Río de la Plata Craton during the Ediacaran and establishing its relationships with neighbouring strata hosting similar successions.
Chapter 62 The Port Askaig Formation, Dalradian Supergroup, Scotland
Authors: Arnaud Emmanuelle , Fairchild Ian J.
Published: December 2011

The Port Askaig Formation (Fm.) is a thick glaciogenic succession within the Dalradian Supergroup that consists of over 700 m of variably dolomitic diamictite, conglomerate, sandstone mudstone and minor dolomite, and is bounded by mixed siliciclastic–carbonate successions of the Islay (Lossit) and Bonahaven formations. These strata are exposed in the metamorphic Caledonides of Scotland, although excellent preservation of sedimentary structures can be found at several sites. An extensional setting for this succession has been proposed based on stratigraphic and structural arguments. The available chemostratigraphic data include the Chemical Index of Alteration, δ
13
C and Sr-isotope values. Palaeomagnetic analyses have been shown to be subject to post-depositional Caledonian overprinting. There is also continued debate over the regional palaeogeographical reconstructions of the Scottish promontory for this time period. The succession is chronologically poorly constrained with U–Pb analyses of stratigraphically much higher or lower deposits. The thick succession is thought to record glacially influenced marine sedimentation and reworking of unstable sediments in a tectonically active setting with evidence of ice-margin fluctuations. Alternative palaeoenvironmental interpretations that focus on glacial terrestrial processes and emphasize climatic influence instead of tectonic activity have also been proposed. The overlying carbonate is a lithologically diverse coastal complex and so does not fit the Neoproterozoic norm. Research has to date focused on the stratigraphic and sedimentological aspects of this succession, as well as some of the broader palaeogeographical and structural features of the Dalradian basin. Future efforts should focus on the chronological, structural and palaeogeographical constraints of this succession.
Chapter 64 Neoproterozoic glacial deposits of Tasmania
Authors: Calver Clive R.
Published: December 2011

In Tasmania, Neoproterozoic glaciogenic deposits were laid down in one or more epicratonic basins, probably situated at the eastern margin of the Australian–Antarctic craton. Rifting and volcanism took place in the late Cryogenian to early Ediacaran. On King Island, north of Tasmania, the Cottons Breccia consists of 50–200 m of diamictite, conglomerate and sandstone. Limestone and dolostone clasts are abundant in the diamictite, although carbonate is unknown in the underlying successions. The Cottons Breccia is overlain by 10 m of laminated dolostone and limestone with a negative, upward-decreasing δ
13
C profile. Rift volcanics and shallow intrusives higher in the sequence are dated at
c.
575 Ma. In NW Tasmania, two diamictite units are found in the Togari Group. The Julius River Member, 200 m thick, contains dominantly dolostone clasts and overlies a shallow-marine dolostone unit with vase-shaped microfossils and C-isotopes consistent with a mid-Cryogenian age. Some clasts in the Julius River Member contain a stromatolite (
Baicalia
cf.
B. burra
) very similar to a form that is abundant in the middle part of the Burra Group, Adelaide rift basin. The Julius River Member is immediately overlain by black shale and impure carbonate dated by Re–Os at 641±5 Ma. The younger diamictite in the Togari Group is the Croles Hill Diamictite, 70 m thick, with predominantly volcanic clasts, underlain by a shale and mafic-volcaniclastic succession and overlain by thin mudstone followed by thick rift tholeiites. At one locality this diamictite is underlain by a rhyodacite flow dated at 582±4 Ma. In southern Tasmania, diamictites are found in the Wedge River Beds and in the Cotcase Creek Formation (Fm.) (Weld River Group). Laminated siltstone with dropstones is associated with the diamictites in the Cotcase Creek Fm. The southern Tasmanian deposits are poorly constrained in age.

Chronometric and other evidence suggests correlation of the Julius River Member, Cottons Breccia and Croles Hill Diamictite with the Sturt, Elatina and Gaskiers glacial phases, respectively. However, a glacial origin for the Julius River Member and Croles Hill Diamictite remains uncertain.
Chapter 68 Billy Springs glaciation, South Australia
Authors: Jenkins Richard J. F.
Published: December 2011

An interval several hundred metres thick in the lower part of the late Ediacaran Billy Springs Formation (Fm.) of the NE Flinders Ranges, South Australia, includes both diamictic levels, ‘dropstones’ and isolated ‘stone-clusters’ in a thin-bedded, silty or fine sandy matrix, which is commonly laminated. Slumping at a variety of scales is prevalent, but extensive panels of ‘right-way-up’, moderately dipping beds host dropstones, which disturbed the laminae. It is difficult to explain laminated sediments peppered with dropstones other than by ice-rafting, and the stone-clusters comply with sinking pieces of ice loaded with debris. Although common reworking occurred in channels, larger erratics in this material are out of hydrodynamic equilibrium. Deposition occurred offshore on an unstable slope.

Isotopic δ
13
C
carb
measurements show a strong negative excursion through the preceding Wonoka Fm., and several further similar negative excursions in the Billy Springs Fm. This record shows similarities to that of Ediacaran carbonates on the Yangtze platform, south China. Compilation based on a survey of palaeomagnetic data for Gondwana continents, Baltica and Laurasia permits a possible palaeogeography indicating a relatively high palaeolatitude at the time of deposition. Indications of age are imprecise but may be comparable with, or younger(?) than the
c.
580 Ma Gaskiers Fm. of Newfoundland.
Chapter 7 Neoproterozoic glacial palaeolatitudes: a global update
Authors: Evans D. A. D. , Raub T. D.
Published: December 2011

New stratigraphic, geochronological and palaeomagnetic constraints allow updates to be made to a synthesis of Neoproterozoic glacial palaeolatitudes, including modifications to some reliability estimates. The overall pattern of a Neoproterozoic climatic paradox persists: there is an abundance of tropical palaeolatitudes and near to complete absence of glaciogenic deposits demonstrably laid down between latitudes of 60° and 90°. In addition to 12 units with palaeolatitude estimates that are somewhat reliable, estimates with moderate to high reliability now include Konnarock (less than 10° from the palaeo-equator), Elatina, Rapitan, Mechum River, Grand Conglomerat (10–20°), Upper Tindir, Puga (20–30°), Nantuo, Gaskiers (30–40°) and Walsh (40–50°). Among these, Elatina, Upper Tindir and Nantuo are considered to have the highest reliability, all with estimates of low to moderate palaeolatitude. The Elatina result stems from sedimentary rocks with quantitative correction of inclination-shallowing effects, and the Upper Tindir result stems from data collected from igneous rocks that are precisely coeval with the glacial deposits. Despite continuing debate on the global character of Neoproterozoic ice ages, their pan-glacial extent (ice extending to low latitude in a low-obliquity world) is well demonstrated.
Constitutive expression of a Mg2+-inhibited K+ current and a TRPM7-like current in human erythroleukemia cells
Authors: Mason Michael J. , Schaffner Catherine , Floto R. Andres , Teo Quok An
Published: December 2011

Whole cell patch-clamp experiments were undertaken to define the basal K+ conductance(s) in human erythroleukemia cells and its contribution to the setting of resting membrane potential. Experiments revealed a non-voltage-activated, noninactivating K+ current. The magnitude of the current recorded under whole cell conditions was inhibited by an increase in free intracellular Mg2+ concentration. Activation or inactivation of the Mg2+-inhibited K+ current (MIP) was paralleled by activation or inactivation of a Mg2+-inhibited TRPM7-like current displaying characteristics indistinguishable from those reported for molecularly identified TRPM7 current. The MIP and TRPM7 currents were inhibited by 5-lipoxygenase inhibitors. However, inhibition of the MIP current was temporally distinct from inhibition of TRPM7 current, allowing for isolation of the MIP current. Isolation of the MIP conductance revealed a current reversing near the K+ equilibrium potential, indicative of a highly K+-selective conductance. Consistent with this finding, coactivation of the nonselective cation current TRPM7 and the MIP current following dialysis with nominally Mg2+-free pipette solution resulted in hyperpolarized whole cell reversal potentials, consistent with an important role for the MIP current in the setting of a negative resting membrane potential. The MIP and TRPM7-like conductances were constitutively expressed under in vivo conditions of intracellular Mg2+, as judged by their initial detection and subsequent inactivation following dialysis with a pipette solution containing 5 mM free Mg2+. The MIP current was blocked in a voltage-dependent fashion by extracellular Cs+ and, to a lesser degree, by Ba2+ and was blocked by extracellular La3+ and 2-aminoethoxydiphenyl borate. MIP currents were unaffected by blockers of ATP-sensitive K+ channels, human ether-à-go-go-related gene current, and intermediate-conductance Ca2+-activated K+ channels. In addition, the MIP current displayed characteristics distinct from conventional inwardly rectifying K+ channels. A similar current was detected in the leukemic cell line CHRF-288-11, consistent with this current being more generally expressed in cells of leukemic origin.
Effects of variations in intragastric volume on blood pressure and splanchnic blood flow during intraduodenal glucose infusion in healthy older subjects
Authors: Vanis Lora , Gentilcore Diana , Lange Kylie , Gilja Odd Helge , Rigda Rachael S. , Trahair Laurence G. , Feinle-Bisset Christine , Rayner Christopher K. , Horowitz Michael , Jones Karen L.
Published: December 2011

The postprandial reduction in blood pressure (BP) is triggered by the interaction of nutrients with the small intestine and associated with an increase in splanchnic blood flow. Gastric distension may attenuate the postprandial fall in BP. The aim of this study was to determine the effects of differences in intragastric volume, including distension at a low (100 ml) volume, on BP and superior mesenteric artery (SMA) blood flow responses to intraduodenal glucose in healthy older subjects. BP and heart rate (HR; automated device), SMA blood flow (Doppler ultrasound), mesenteric vascular resistance (MVR), and plasma norepinephrine of nine male subjects (65–75 yr old) were measured after an overnight fast on 4 separate days in random order. On each day, subjects were intubated with a nasoduodenal catheter, incorporating a duodenal infusion port, and orally with a second catheter, incorporating a barostat bag, positioned in the fundus. Each subject received a 60-min ( t = 0–60 min) intraduodenal glucose infusion (3 kcal/min) and gastric distension at a volume of 1) 0 ml (V0), 2) 100 ml (V100), 3) 300 ml (V300), or 4) 500 ml (V500). Systolic BP fell ( P < 0.05) during V0, but not during V100, V300, or V500. In contrast, HR ( P < 0.01) and SMA blood flow ( P < 0.001) increased and MVR decreased ( P < 0.05) comparably on all 4 days. Plasma norepinephrine rose ( P < 0.01) in response to intraduodenal glucose, with no difference between the four treatments. There was a relationship between the areas under the curve for the change in systolic BP from baseline with intragastric volume ( r = 0.60, P < 0.001). In conclusion, low-volume (≤100 ml) gastric distension has the capacity to abolish the fall in BP induced by intraduodenal glucose in healthy older subjects without affecting SMA blood flow or MVR. These observations support the concept that nonnutrient gastric distension prior to a meal has potential therapeutic applications in the management of postprandial hypotension.
Gastrointestinal Neoplasia Associated with Bowel Parasitosis: Real or Imaginary?
Authors: Peterson Michael R. , Weidner Noel
Published: December 2011

Several parasitic species are well known to have carcinogenic properties, namely;Schistosoma hematobium(squamous cell carcinoma of the bladder) and the liver flukesOpisthorchisandChlonorchis(cholangiocarcinoma). A large number of parasites are known to colonize the gastrointestinal tract. We sought to review the evidence that implicates these parasites in gastrointestinal neoplasia.Schistosoma japonicum, which is endemic primarily in east Asia, has been shown in multiple studies to convey a mildly increased risk of colorectal adenocarcinoma. The data supporting a causative role forSchistosoma mansoniin colorectal or other neoplastic processes are less convincing, limited primarily to small case-control studies and case series. Reports of possible associations between other gastrointestinal parasites (e.g.,E. histolyticaandA. lumbricoides) and neoplasia may be found in the literature but are limited to individual cases. We conclude that, other thanS. japonicumand to a lesser extentS. mansoni, there is little evidence of an association between gastrointestinal parasites and neoplasia.
Autophagy in Inflammatory Diseases
Authors: Choi Alexander J. S. , Ryter Stefan W.
Published: December 2011

Autophagy provides a mechanism for the turnover of cellular organelles and proteins through a lysosome-dependent degradation pathway. During starvation, autophagy exerts a homeostatic function that promotes cell survival by recycling metabolic precursors. Additionally, autophagy can interact with other vital processes such as programmed cell death, inflammation, and adaptive immune mechanisms, and thereby potentially influence disease pathogenesis. Macrophages deficient in autophagic proteins display enhanced caspase-1-dependent proinflammatory cytokine production and the activation of the inflammasome. Autophagy provides a functional role in infectious diseases and sepsis by promoting intracellular bacterial clearance. Mutations in autophagy-related genes, leading to loss of autophagic function, have been implicated in the pathogenesis of Crohn's disease. Furthermore, autophagy-dependent mechanisms have been proposed in the pathogenesis of several pulmonary diseases that involve inflammation, including cystic fibrosis and pulmonary hypertension. Strategies aimed at modulating autophagy may lead to therapeutic interventions for diseases associated with inflammation.
Existence Results for Stochastic Semilinear Differential Inclusions with Nonlocal Conditions
Authors: Vinodkumar A. , Boucherif A.
Published: December 2011

We discuss existence results of mild solutions for stochastic differential inclusions subject to nonlocal conditions. We provide sufficient conditions in order to obtain a priori bounds on possible solutions of a one-parameter family of problems related to the original one. We, then, rely on fixed point theorems for multivalued operators to prove our main results.
On the Weak Solution of a Semilinear Boundary Value Problem without the Landesman‐Lazer Condition
Authors: Sanni Sikiru Adigun
Published: December 2011

We prove the existence of weak solution to a semilinear boundary value problem without the Landesman‐Lazer condition.