2,513 research outputs found
Predictions of Dynamic Behavior Under Pressure for Two Scenarios to Explain Water Anomalies
Using Monte Carlo simulations and mean field calculations for a cell model of
water we find a dynamic crossover in the orientational correlation time
from non-Arrhenius behavior at high temperatures to Arrhenius behavior at low
temperatures. This dynamic crossover is independent of whether water at very
low temperature is charaterized by a ``liquid-liquid critical point'' or by the
``singularity free'' scenario. We relate to fluctuations of hydrogen
bond network and show that the crossover found for for both scenarios is
a consequence of the sharp change in the average number of hydrogen bonds at
the temperature of the specific heat maximum. We find that the effect of
pressure on the dynamics is strikingly different in the two scenarios, offering
a means to distinguish between them.Comment: 10 Pages, 4 figure
Formal Verification of Safety Properties for Ownership Authentication Transfer Protocol
In ubiquitous computing devices, users tend to store some valuable
information in their device. Even though the device can be borrowed by the
other user temporarily, it is not safe for any user to borrow or lend the
device as it may cause private data of the user to be public. To safeguard the
user data and also to preserve user privacy we propose and model the technique
of ownership authentication transfer. The user who is willing to sell the
device has to transfer the ownership of the device under sale. Once the device
is sold and the ownership has been transferred, the old owner will not be able
to use that device at any cost. Either of the users will not be able to use the
device if the process of ownership has not been carried out properly. This also
takes care of the scenario when the device has been stolen or lost, avoiding
the impersonation attack. The aim of this paper is to model basic process of
proposed ownership authentication transfer protocol and check its safety
properties by representing it using CSP and model checking approach. For model
checking we have used a symbolic model checker tool called NuSMV. The safety
properties of ownership transfer protocol has been modeled in terms of CTL
specification and it is observed that the system satisfies all the protocol
constraint and is safe to be deployed.Comment: 16 pages, 7 figures,Submitted to ADCOM 201
Entropic Inequalities for a Class of Quantum Secret Sharing States
It is well-known that von Neumann entropy is nonmonotonic unlike Shannon
entropy (which is monotonically nondecreasing). Consequently, it is difficult
to relate the entropies of the subsystems of a given quantum state. In this
paper, we show that if we consider quantum secret sharing states arising from a
class of monotone span programs, then we can partially recover the monotonicity
of entropy for the so-called unauthorized sets. Furthermore, we can show for
these quantum states the entropy of the authorized sets is monotonically
nonincreasing.Comment: LaTex, 5 page
Laparoscopy and loop colostomy : a new approach to extra-peritoneal rectal injuries
Includes bibliographical references.Distal rectal washout and presacral drainage appear to have little or no influence on the morbidity and mortality in patients with low-energy trauma to the rectum. The ever-increasing popularity and obvious advantages of minimal access surgery have prompted surgeons to apply its use to a variety of surgical diseases, including trauma-related conditions. This study retrospectively reviews and examines the safety and efficacy of laparoscopy and the formation of a diverting sigmoid loop colostomy through an abdominal wall trephine, in a limited number of carefully selected patients with isolated extra-peritoneal rectal injuries. The patient is thus spared a major laparotomy wound. The value of distal rectal washout and presacral drainage in such injuries is also examined
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Intertwined Functions of Separase and Caspase in Cell Division and Programmed Cell Death.
Timely sister chromatid separation, promoted by separase, is essential for faithful chromosome segregation. Separase is a member of the CD clan of cysteine proteases, which also includes the pro-apoptotic enzymes known as caspases. We report a role for the C. elegans separase SEP-1, primarily known for its essential activity in cell division and cortical granule exocytosis, in developmentally programmed cell death when the predominant pro-apoptotic caspase CED-3 is compromised. Loss of SEP-1 results in extra surviving cells in a weak ced-3(-) mutant, and suppresses the embryonic lethality of a mutant defective for the apoptotic suppressor ced-9/Bcl-2 implicating SEP-1 in execution of apoptosis. We also report apparent non-apoptotic roles for CED-3 in promoting germ cell proliferation, meiotic chromosome disjunction, egg shell formation, and the normal rate of embryonic development. Moreover, loss of the soma-specific (CSP-3) and germline-specific (CSP-2) caspase inhibitors result in CED-3-dependent suppression of embryonic lethality and meiotic chromosome non-disjunction respectively, when separase function is compromised. Thus, while caspases and separases have evolved different substrate specificities associated with their specialized functions in apoptosis and cell division respectively, they appear to have retained the residual ability to participate in both processes, supporting the view that co-option of components in cell division may have led to the innovation of programmed cell suicide early in metazoan evolution
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