Further studies on the relationship between IRSL and BLSL at relatively high temperatures for potassium-feldspar from sediments

In optical dating of potassium-feldspar, the luminescence signals can be stimulated by both infrared (IR) light and blue light (BL). To develop reliable dating methods using different stimulation light sources for feldspars, it is important to understand the sources of the traps associated with the infrared stimulated luminescence (IRSL) and blue light stimulated luminescence (BLSL) and their relationship. In this study, we explored the luminescence characteristics of IRSL and BLSL at different stimulation temperatures (from 60 °C to 200 °C) and their relationship based on five sets of experiments, i.e. post-IR BLSL, post-BL IRSL experiments, pulse annealing test, dose-response test and laboratory fading rate test. Our results suggest that the luminescence characteristics of IRSL and BLSL and their relationship are dependent on stimulation temperature. For IR stimulation at a relatively high temperature of 200 °C, at least two components of IRSL signals are involved in the process. One component of IRSL signals can be easily bleached by BL stimulation at 60 °C, while the other is relatively hard to be bleached by BL stimulation at 60 °C. The two components have different luminescence properties, such as thermal stability, dose-response and laboratory fading rate

Seismotectonic analyses of Karachi Arc, Southern Kirthar Fold Belt, Pakistan

In this study geomorphological and seismotectonic analyses were carried out in Karachi arc area, southernPakistan to locate relatively safe areas from earthquakes disasters. Karachi arc is the southern extremity of the Kirtharmountain chain that occupies a major part of southern Pakistan and is comprised of a number of narrow, elongatedmountain ranges, i.e. Laki, Kirthar, Khud, Pab and Mor ranges. Based on geomorphological and seismotectonicanalyses Karachi arc area has been divided into three parts. These parts are northern, frontal and southern part. Thenorthern part of Karachi arc is seismically active where minor to moderate (3-5.9Mb) earthquakes occurred. Somebasement structures in Sehwan area seem to be still active and affected by the present-day transpressional stress field.The frontal part of Karachi arc is also active as manifested by the existence of active faults in Jhimpir, Surjan andMeting areas. These embryonic structures in the eastern part of the Arc are indicators of active deformation of Karachiarc. Presently the active deformation is taking place in frontal and northern parts of the arc, while the southern part thathas experienced deformation prior to Quaternary time is inactive and is relatively stable geoblock. The instrumental andhistoric seismicity record of the adjoining areas of Karachi arc show that the area has experienced light to moderateseismic events (4-5.9) with occasional occurrence of strong and major earthquakes. Any major or strong event in Katchrift zone, Makran subduction zone and Ornach-Nal fault zone may cause intensity of VII to VIII in Karachi arc area aswell as Karachi city of environmental seismic intensity scale 2007

Secure and Efficient HB-CM Entity Authentication Protocol

The simple, computationally efficient LPN-based HB-like entity authentication protocols have attracted a great deal of attention in the past few years due to the broad application prospect in low-cost pervasive devices. At present, the most efficient protocol is HB$^\#$, which is proven to resist the GRS attack under the conjecture that it is secure in the DET-model. In this paper, we introduce an innovative HB-CM$^-$ protocol, which significantly reduces the storage requirement while maintaining the same level of communication cost. We develop the concept of equivalence class, and present HB-CM$^-$ reductionist proof that overcomes an inherent limitation in the HB$^\#$ security proof. In fact, HB$^\#$ is only provably resistant to partial instances of GRS attack, while we prove that HB-CM$^-$ can prevent the full GRS attack except one trivial case. In addition, we propose a new noise mode for all HB-like protocols in order to thwart the latest OOV man-in-the-middle attack, which can effectively compromise all current HB-like protocols with the basic Bernoulli nose mode. The HB-CM$^-$ protocol along with the proposed noise mode constitutes our final protocol: HB-CM

Episodic Uplift along a Quaternary Fault, A Signature of Active Deformation in Frontal Part of Karachi Arc, Southern Pakistan

The southern part of Kirthar Fold Belt represents a divergent wrench regime marked by open arcuate structures, collectively called as Karachi Arc. The frontal part of Karachi Arc is being actively deformed. The active deformation is manifested by the neotectonic features recorded in the recent sediments. Frontal part of northern Karachi Arc has been investigated to locate Earthquake Environmental Effects (EEE) in Bizan Dhoro area northwest of Hyderabad. A linear structure in Bizan Dhoro area at frontal part of northern Karachi Arc has been investigated. The structure was interpreted in front of Laki Range with the help of LANDSAT ETM and SPOT Images. The lineament on ground is represented by a NNW oriented linear topographic step in the peneplain alluvial fans. The frontal peneplain of Laki Range is constituted by the alluvial fans composed of clast supported gravel ranging from pebble-to-boulder in size laid down by Bizan Dhoro and its tributaries. Four new generations of alluvial fans have been recognized across the lineament which suggests that the area has experienced at least three episodes of uplift along the topographic step named as Bizan Dhoro Fault. Electric resistivity tomography across Bizan Dhoro fault and evidences of tectonic geomorphology revealed that it is a capable reverse fault dipping at an angle of 60° towards west which has experienced at least three events after deposition of Quaternary alluvial fans. No brittle deformation however could be recorded in the gravels. Bizan Dhoro fault is an embryonic structure that depicts active deformation of foreland parallel to the fold and thrust belt

AMPK exerts dual regulatory effects on the PI3K pathway

BACKGROUND AMP-activated protein kinase (AMPK) is a fuel-sensing enzyme that is activated when cells experience energy deficiency and conversely suppressed in surfeit of energy supply. AMPK activation improves insulin sensitivity via multiple mechanisms, among which AMPK suppresses mTOR/S6K-mediated negative feedback regulation of insulin signaling. RESULTS In the present study we further investigated the mechanism of AMPK-regulated insulin signaling. Our results showed that 5-aminoimidazole-4-carboxamide-1 ribonucleoside (AICAR) greatly enhanced the ability of insulin to stimulate the insulin receptor substrate-1 (IRS1)-associated PI3K activity in differentiated 3T3-F442a adipocytes, leading to increased Akt phosphorylation at S473, whereas insulin-stimulated activation of mTOR was diminished. In 3T3-F442a preadipocytes, these effects were attenuated by expression of a dominant negative mutant of AMPK α1 subunit. The enhancing effect of ACIAR on Akt phosphorylation was also observed when the cells were treated with EGF, suggesting that it is regulated at a step beyond IR/IRS1. Indeed, when the cells were chronically treated with AICAR in the absence of insulin, Akt phosphorylation was progressively increased. This event was associated with an increase in levels of phosphatidylinositol -3,4,5-trisphosphate (PIP3) and blocked by Wortmannin. We then expressed the dominant negative mutant of PTEN (C124S) and found that the inhibition of endogenous PTEN per se did not affect phosphorylation of Akt at basal levels or upon treatment with AICAR or insulin. Thus, this result suggests that AMPK activation of Akt is not mediated by regulating phosphatase and tensin homologue (PTEN). CONCLUSION Our present study demonstrates that AMPK exerts dual effects on the PI3K pathway, stimulating PI3K/Akt and inhibiting mTOR/S6K.National Institutes of Health (CA118918, GM057959