A discrete degree of freedom can be engineered to match the Hamiltonian of particles moving in a real-space lattice potential. Such synthetic dimensions are powerful tools for quantum simulation ...because of the control they offer and the ability to create configurations difficult to access in real space. Here, in an ultracold
Sr atom, we demonstrate a synthetic-dimension based on Rydberg levels coupled with millimeter waves. Tunneling amplitudes between synthetic lattice sites and on-site potentials are set by the millimeter-wave amplitudes and detunings respectively. Alternating weak and strong tunneling in a one-dimensional configuration realizes the single-particle Su-Schrieffer-Heeger (SSH) Hamiltonian, a paradigmatic model of topological matter. Band structure is probed through optical excitation from the ground state to Rydberg levels, revealing symmetry-protected topological edge states at zero energy. Edge-state energies are robust to perturbations of tunneling-rates that preserve chiral symmetry, but can be shifted by the introduction of on-site potentials.
Inhibitor of apoptosis protein (IAP)-binding proteins such as Grim, Reaper and HID have been shown to exert a critical role in regulating caspase activity in species such as D. Melanogaster. However, ...a comparable role for the mammalian homologue of second mitochondrial-derived activator of caspase/direct IAP-binding protein with low pI (Smac/DIABLO) has yet to be clearly established in vivo. Despite tremendous interest in recent years in the use of so-called Smac mimetics to enhance chemotherapeutic potency, our understanding of the true physiologic nature of Smac/DIABLO in regulating programmed cell death (PCD) remains elusive. In order to critically evaluate the role of Smac/DIABLO in regulating mammalian PCD, deficiency of caspase-3 was used as a sensitizing mutation in order to reduce aggregate levels of executioner caspase activity. We observe that combinatorial deletion of Diablo and Casp3, but neither alone, results in perinatal lethality in mice. Consistent with this, examination of both intrinsic and extrinsic forms of PCD in lines of murine embryonic fibroblasts demonstrate that loss of Smac/DIABLO alters both caspase-dependent and caspase-independent intrinsic PCD. Comparative small interfering RNA inhibition studies of X-linked inhibitor of apoptosis, cellular inhibitor of apoptosis (cIAP)-1, cIAP-2, caspase-6 and -7 in both wild-type and Casp3/Diablo DKO mouse embryonic fibroblast lineages, supports a model in which Smac/DIABLO acts to enhance the early phase executioner caspase activity through the modulation of inhibitory interactions between specific IAP family members and executioner caspases-3 and -7.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
There have been claims of early use of high-carbon steel in South India. Still, the antiquity, elemental composition and steelmaking process have not been explored adequately. The high carbon steel ...was known in the Iron Age or early historical period. However, the large-scale use of such steel was prevalent only in the medieval times. This article examines the presence of steel and its metallographic features in the iron artifacts retrieved from two archaeological sites, namely, Ambal and Vallam, Tamil Nadu, India, with occupational evidence from the Iron Age to the medieval period through a number of scientific tests. Metallographic and mechanical tests were performed to identify the morphology and measure the strength, respectively. Similarly, the chemical composition was determined to quantify the alloying elements in the material. The slag was exposed on the etched surface of the sample cut from axe. Microscopy and chemical composition analysis showed very fine bright dendrites of wüstite in the iron slag. The deterioration of samples was confirmed in microscopic and composition analysis. The result shows that the inhabitants of ancient Ambal and Vallam were equipped with iron smelting technology and had the knowledge of steelmaking in the Iron Age. (7 Figures, 1 Table, 36 References)
Abstract In addition to protective effects within the adult central nervous system (CNS), in vivo application of N -methyl- d -aspartate inhibitors such as (+) MK-801 have been shown to induce ...neurodegeneration in neonatal rats over a specific developmental period. We have systematically mapped the nature and extent of MK-801-induced neurodegeneration throughout the neonatal murine brain in order to genetically dissect the mechanism of these effects. Highest levels of MK-801-induced neurodegeneration are seen in the cerebellar external germinal layer; while mature neurons of the internal granule layer are unaffected by MK-801 treatment. Examination of external germinal layer neurons by electron microscopy, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) and bromodeoxyuridine (BrdU) labeling, and caspase-3 activation demonstrate that these neurons die through the process of programmed cell death soon after they exit from the cell cycle. Significantly, ablation of caspase-3 activity completely inhibited the MK-801-induced (and developmental) programmed cell death of external germinal layer neurons. Similar to caspase-3, inactivation of muscarinic acetylcholine receptors in vivo using scopolamine inhibited MK-801-induced programmed cell death. By contrast, the GABAergic agonist diazepam, either alone or in combination with MK-801, enhanced programmed cell death within external germinal layer neurons. These data demonstrate that, in vivo , cerebellar granule neurons undergo a dramatic change in intracellular signaling in response to molecules present in the local cellular milieu during their first 24 h following exit from the cell cycle.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A very large surface to volume ratio of nanoporous silicon (PS) produces a high density of surface states, which are responsible for uncontrolled oxidation of the PS surface. Hence it disturbs the ...stability of the material and also creates difficulties in the formation of a reliable electrical contact. To passivate the surface states of the nanoporous silicon, noble metals (Pd, Ru, and Pt) were dispersed on the PS surface by an electroless chemical method. GIXRD (glancing incidence X-ray diffraction) proved the crystallinity of PS and the presence of noble metals on its surface. While FESEM (field emission scanning electron microscopy) showed the morphology, the EDX (energy dispersive X-ray) line scans and digital X-ray image mapping indicated the formation of the noble metal islands on the PS surface. Dynamic SIMS (secondary ion mass spectroscopy) further confirmed the presence of noble metals and other impurities near the surface of the modified PS. The variation of the surface roughness after the noble metal modification was exhibited by AFM (atomic force microscopy). The formation of a thin oxide layer on the modified PS surface was verified by XPS (X-ray photoelectron spectroscopy).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Landslide susceptibility map delineates the potential zones for landslides occurrence. The paper presents a statistical approach through spatial data analysis in GIS for landslide susceptibility ...mapping in parts of Sikkim Himalaya. Six important causative factors for landslide occurrences were selected and corresponding thematic data layers were prepared in GIS. Topographic maps,satellite image,field data and published maps constitute the input data for thematic layer preparation. Numerical weights for different categories of these factors were determined based on a statistical approach and the weighted thematic layers were integrated in GIS environment to generate the landslide susceptibility map of the area. The landslide susceptibility map classifies the area into five different landslide susceptible zones i.e.,very high,high,moderate,low and very low. This map was validated using the existing landslide distribution in the area.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Aims: To conduct a prospective, community based study in an impoverished urban site in Kolkata (formerly Calcutta) in order to measure the burden of cholera, describe its epidemiology, and search for ...potential risk factors that could be addressed by public health strategies. Methods: The study population was enumerated at the beginning and end of the study period. Surveillance through five field outposts and two referral hospitals for acute, watery, non-bloody diarrhoea was conducted from 1 May 2003 to 30 April 2004. Data and a stool sample for culture of Vibrio cholerae were collected from each patient. Treatment was provided in accordance with national guidelines. Results: From 62 329 individuals under surveillance, 3284 diarrhoea episodes were detected, of which 3276 (99%) had a stool sample collected and 126 (4%) were culture confirmed cholera. Nineteen (15%) were children less than 2 years of age, 29 (23%) had severe dehydration, and 48 (38%) were hospitalised. Risk factors for cholera included a household member with cholera during the period of surveillance, young age, and lower educational level. Conclusions: There was a substantial burden of cholera in Kolkata with risk factors not easily amenable to intervention. Young children bear the brunt not only of diarrhoeal diseases in general, but of cholera as well. Mass vaccination could be a potentially useful tool to prevent and control seasonal cholera in this community.
The 3 d − 5 d based double perovskites offer an ideal playground to study the interplay between electron correlation ( U ) and spin-orbit coupling (SOC) effect, showing exotic physics. The Sr2 FeIrO6 ...is an interesting member in this family with ionic distribution of Fe3 + ( 3 d5 ) and Ir5 + ( 5 d4 ) where the later is believed to be nonmagnetic under the picture of strong SOC. Here we report a detailed investigation of structural, magnetic, and electronic transport properties along with electronic structure calculations in ( Sr1 − x Cax )2 FeIrO6 series with x from 0 to 1. While the basic interactions such as U and SOC are unlikely to be modified, a structural modification is expected due to ionic size difference between Sr2 + and Ca2 + which would influence other properties such as crystal field effect and bandwidths. While nonmonotonic changes in lattice parameters are observed across the series, the spectroscopic investigations reveal that 3 + / 5 + charge state of Fe/Ir continue till the end of the series. An analysis of magnetic data suggests similar nonmonotonic evolution of magnetic parameters with doping. Temperature dependent crystal structure as well as low temperature (5 K) magnetic structure have been determined from neutron powder diffraction measurements which further indicate site ordered moments for both Fe and Ir. The whole series shows insulating behavior with a nonmonotonic variation in resistivity where the charge transport follows the three-dimensional variable range hopping model. The electronic structure calculations show, SOC enhanced, a noncollinear antiferromagnetic and a Mott-type insulating state is the stable ground state for the present series with a substantial amount of orbital moment, but less than the spin magnetic moment, at the Ir site and the magnetocrystalline anisotropy. The calculations further show the evolution of the spin and orbital magnetic moment components across the series along with the magnetization density. The obtained results imply that the local structural modification with introduction of lower size Ca2 + has a large influence on the magnetic and transport properties, further showing a large agreement between experimental results as well as theoretical calculations.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
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