1,134 research outputs found
X-ray photoemission study of NiS_{2-x}Se_x (x = 0.0 - 1.2)
Electronic structure of NiS_{2-x}Se_x system has been investigated for
various compositions (x) using x-ray photoemission spectroscopy. An analysis of
the core level as well as the valence band spectra of NiS_2 in conjunction with
many-body cluster calculations provides a quantitative description of the
electronic structure of this compound. With increasing Se content, the on-site
Coulomb correlation strength (U) does not change, while the band width W of the
system increases, driving the system from a covalent insulating state to a
pd-metallic state.Comment: 19 pages, 6 figures, To appear in Phys. Rev. B, 200
Velocity map imaging for low-energy electron-molecule collisions
The development of an experiment for velocity map imaging (VMI) of fragment ions arising from electron-molecule collisions is discussed. The angular distribution of O− from the dissociative attachment and dipolar dissociation of O2 is measured and compared with the existing data. The details of the technique and its importance to electron-molecule collisions are discussed
How to Extend the Capabilities of Space Systems for Long Duration Space Exploration Systems
For sustainable Exploration Missions the need exists to assemble systems-of-systems in space, on the Moon or on other planetary surfaces. To fulfill this need new and innovative system architecture is needed that can be satisfied with the present lift capability of existing rocket technology without the added cost of developing a new heavy lift vehicle. To enable ultra-long life missions with minimum redundancy and lighter mass the need exists to develop system soft,i,are and hardware reconfigurability, which enables increasing functionality and multiple use of launched assets while at the same time overcoming any components failures. Also the need exists to develop the ability to dynamically demate and reassemble individual system elements during a mission in order to work around failed hardware or changed mission requirements. Therefore to meet the goals of Space Exploration Missions in hiteroperability and Reconfigurability, many challenges must be addressed to transform the traditional static avionics architecture into architecture with dynamic capabilities. The objective of this paper is to introduce concepts associated with reconfigurable computer systems; review the various needs and challenges associated with reconfigurable avionics space systems; provide an operational example that illustrates the needs applicable to either the Crew Exploration Vehicle or a collection of "Habot like" mobile surface elements; summarize the approaches that address key challenges to acceptance of a Flexible, Intelligent, Modular and Affordable reconfigurable avionics space system
On two finless porpoise Neophocaena phocaenoides landed at Malpe Fishing Harbour, Udupi district, Karnataka.
Two finless porposies Neophocaenan phocaenoides were caught by purseseine and landed at Malpe Fishing Harbour On 06-11-2003. Both the animals were auctioned for Rs. 660.Enquiries with the purseseiner which brought the
porposies, revealed that they were caught from a depth
of 15 m along with the catch of sardine, mackerel and
rainbow sardine. The mesh size of the purseseine was 18 mm
Analysis of MUC4 expression in the prostatic adenocarcinoma and its pathological implications
Background: Expression of various types of mucins has been documented in several malignancies and seems to play a sentinel role in some epithelial malignancies. MUC1 and MUC4 are two transmembrane mucins that are involved in cell signalling events that drive the proliferation of cells. Therefore, mucins may be important biomarkers for early diagnosis and targeted therapy due to their frequently altered expression pattern in carcinomas. The objective of the study was to determine the expression pattern of MUC-4 in prostate cancer and to correlate the expression with clinicopathological parameters.Methods: Thirty cases of prostate carcinomas of different grades were selected from the case files of our institute for the study. Immunohistochemistry was done on all cases using monoclonal antibodies against MUC- 4 by the avidin biotin technique. The expression and pattern of staining were analyzed .Staining pattern in the adjacent benign areas were also noted.Results: Our study showed that expression of MUC4 was considerably down regulated in prostate cancer tissues when compared to normal or benign prostatic tissue. Few cases of prostate cancer showed a moderate staining while majority cases of adjacent normal areas were moderate to strongly positivity.Conclusions: The results of our study implies that MUC4 is down regulated in prostate cancer and this may be of significance for diagnostic application and tumor progression in prostate cancer. Since MUC4 is known to modulate HER2/ErbB2 signalling it may prospectively prove to be useful in prostate cancer therapy
Synaptotagmin 1 oligomers clamp and regulate different modes of neurotransmitter release
Release of neurotransmitters relies on submillisecond coupling of synaptic vesicle fusion to the triggering signal: AP-evoked presynaptic Ca2+ influx. The key player that controls exocytosis of the synaptic vesicle is the Ca2+ sensor synaptotagmin 1 (Syt1). While the Ca2+ activation of Syt1 has been extensively characterized, how Syt1 reversibly clamps vesicular fusion remains enigmatic. Here, using a targeted mutation combined with fluorescence imaging and electrophysiology, we show that the structural feature of Syt1 to self-oligomerize provides the molecular basis for clamping of spontaneous and asynchronous release but is not required for triggering of synchronous release. Our findings propose a mechanistic model that explains how Syt1 oligomers regulate different modes of transmitter release in neuronal synapses
Inhibition of Dermatophyte Fungi by Australian Jarrah Honey.
Superficial dermatophyte infections, commonly known as tineas, are the most prevalent fungal ailment and are increasing in incidence, leading to an interest in alternative treatments. Many floral honeys possess antimicrobial activity due to high sugar, low pH, and the production of hydrogen peroxide (H2O2) from the activity of the bee-derived enzyme glucose oxidase. Australian jarrah (Eucalyptus marginata) honey produces particularly high levels of H2O2 and has been found to be potently antifungal. This study characterized the activity of jarrah honey on fungal dermatophyte species. Jarrah honey inhibited dermatophytes with minimum inhibitory concentrations (MICs) of 1.5-3.5% (w/v), which increased to ≥25% (w/v) when catalase was added. Microscopic analysis found jarrah honey inhibited the germination of Trichophyton rubrum conidia and scanning electron microscopy of mature T. rubrum hyphae after honey treatment revealed bulging and collapsed regions. When treated hyphae were stained using REDOX fluorophores these did not detect any internal oxidative stress, suggesting jarrah honey acts largely on the hyphal surface. Although H2O2 appears critical for the antifungal activity of jarrah honey and its action on fungal cells, these effects persisted when H2O2 was eliminated and could not be replicated using synthetic honey spiked with H2O2, indicating jarrah honey contains agents that augment antifungal activity
Boron Ion Interaction with pnp Bipolar Power Transistor and Displacement Damage Effects on its Electrical Characteristics
AbstractBipolar junction transistors used in switching and amplification applications is examined for their electrical performance after irradiation with 60 MeV boron ions of different fluence. Unirradiated device base current is 5.97×10-5 A while it is 9.03×10-4 A after irradiation with a fluence of 1×1012 ions/cm2. For unirradiated device collector current is 1.22×10-3 A and is 7.31×10-4 A after irradiation to a fluence of 1×1012 ions/cm2. Base current increases whereas collector current decreases after irradiation with a fluence of 1×1012 ions/cm2. The magnitude of decrease in collector current is approximately same as that of the increase in base current, showing the leakage of the collector current due to irradiation. The output collector gain of the unirradiated transistor is 20.5 after irradiation to a fluence of 1×1012 ions/cm2 it has reduced to 0.81. The capacitance measurements for base-emitter junction show that for the unirradiated and irradiated samples, linearity of the curves indicate uniformity of shallow doping concentration. The built in potential (Vbi) for unirradiated device is 2.69V and after irradiation it is 2.52V. The device is also studied for activation energy, trap concentration and capture cross-section of deep levels are studied using deep-level transient spectroscopy (DLTS) technique. Majority carrier trap level is observed with energy Ev+0.784eV
The Paternal Component of the ‘‘Healthy Migrant’’ Effect: Fathers’ Natality and Infants’ Low Birth Weight
This study examines the predictors of birth outcomes among women of European and African ancestry and considers the birthplace of the babies’ fathers (foreign born vs. native born) as a protective factor. This is a secondary data analysis of 146,431 singleton births among women of European and African ancestry, both native-born and foreign-born, in a 21 birth hospital region of Central New York State from 1996 to 2003. Foreign born fathers were found to have 15% fewer low birth weight infants than US-born fathers, after controlling for the race and birthplace of the mother, tobacco use and Medicaid. Although this secondary data analysis does not allow us to determine the social determinants of the better birth outcomes among infants of foreign born fathers, it does demonstrate that fathers matter and that foreign born fathers are associated with reduced low birth weight in their infants
Influence of Environmental Factors on Growth Rate of Crassostrea madrasensis (Preston) in Suspended Culture
Growth response of Crassostrea madrasensis to varying environmental factors in
the Mulki estuary of Karnataka was investigated from April 2004 to March 2005. Temperature,
salinity, pH, particulate organic matter (POM), particulate inorganic matter
(PIM), total particulate matter (TPM) and chlorophyll a (Chl a) levels were correlated
with growth in shell length. Marked seasonal patterns in growth rate were observed in
relation to changes in environmental factors. Growth curve indicated a rapid phase
(16.21±1.2 mm month-1) initially (May-June) followed by a slow phase (0.8±0.52 mm
month-1) coinciding with the drop in salinity (August-September). Considering the temporal
variations of environmental factors, their influence on growth rate was analysed
seasonally. The growth rate was significantly correlated with Chl a concentrations in all
the seasons. A pronounced seasonal cycle was noticed in Chl a levels resulting from
blooms in pre-monsoon (April-May) and post-monsoon (October) seasons
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