606 research outputs found
TimeTrader: Exploiting Latency Tail to Save Datacenter Energy for On-line Data-Intensive Applications
Datacenters running on-line, data-intensive applications (OLDIs) consume
significant amounts of energy. However, reducing their energy is challenging
due to their tight response time requirements. A key aspect of OLDIs is that
each user query goes to all or many of the nodes in the cluster, so that the
overall time budget is dictated by the tail of the replies' latency
distribution; replies see latency variations both in the network and compute.
Previous work proposes to achieve load-proportional energy by slowing down the
computation at lower datacenter loads based directly on response times (i.e.,
at lower loads, the proposal exploits the average slack in the time budget
provisioned for the peak load). In contrast, we propose TimeTrader to reduce
energy by exploiting the latency slack in the sub- critical replies which
arrive before the deadline (e.g., 80% of replies are 3-4x faster than the
tail). This slack is present at all loads and subsumes the previous work's
load-related slack. While the previous work shifts the leaves' response time
distribution to consume the slack at lower loads, TimeTrader reshapes the
distribution at all loads by slowing down individual sub-critical nodes without
increasing missed deadlines. TimeTrader exploits slack in both the network and
compute budgets. Further, TimeTrader leverages Earliest Deadline First
scheduling to largely decouple critical requests from the queuing delays of
sub- critical requests which can then be slowed down without hurting critical
requests. A combination of real-system measurements and at-scale simulations
shows that without adding to missed deadlines, TimeTrader saves 15-19% and
41-49% energy at 90% and 30% loading, respectively, in a datacenter with 512
nodes, whereas previous work saves 0% and 31-37%.Comment: 13 page
Evaluation of antipyretic activity of alcoholic extract of Murraya koenigii leaves in rabbits
Background: The present study was carried out to evaluate the antipyretic activity of alcoholic extract of Murraya koenigii leaves in rabbits by using PGE1 induced hyperpyrexia method. We found that not much work has been done on the antipyretic effect of this plant.Methods: Laboratory breed New Zealand strains of rabbits of either sex weighing 1000-1500 gm were used in the study. The animals were divided into five groups (n=6). The rabbits of all the groups were made febrile by injecting misoprostol (PGE1) subcutaneously in the dose of 100 mcg/kg. For group 1 and 2, normal saline 2ml/kg as control and aspirin 28mg/kg as standard were given respectively. Alcoholic extract of Murraya koenigii leaves in the doses of 200, 400 and 800mg/kg were administered in remaining three groups respectively. Rectal temperatures were recorded with help of digital thermometer for every 30 min after drug treatment.Results: Alcoholic extract of Murraya koenigii produced highly significant (p<0.001) antipyretic effect in 400 and 800 mg/kg doses. But onset of action was fast with 800mg/kg dose.Conclusions: This study concludes that Alcoholic extract of Murraya koenigii has fast onset of action and also exhibited sustained anti pyretic action in New Zealand rabbits
Exposure to stress minimizes the zone of antimicrobial action: a phenotypic demonstration with six Acinetobacter baumannii strains
Aim: To phenotypically study the role of domestic environmental stress in the emergence of antimicrobial resistance in Acinetobacter baumannii. Materials and Methods: Six strains of A. baumannii were initially subjected to AST and then were exposed to various stresses (temperature, pH and random combinations). Stressed cells were subcultured and then subjected for AST. The ZOIs before and after exposure to stress were compared. Statistical analysis was done using Student t-test at p < 0.10. Results: Exposure to stresses and combination of stresses resulted in substantial reduction in the ZOIs. Stress hardening was associated with further reduction in ZOIs. Conclusion: Exposure to domestic environmental stress imparted a significant and substantial reduction in the susceptibility of A. baumannii strains to antibiotics.
DOI: http://dx.doi.org/10.5281/zenodo.118415
SafeBet: Secure, Simple, and Fast Speculative Execution
Spectre attacks exploit microprocessor speculative execution to read and
transmit forbidden data outside the attacker's trust domain and sandbox. Recent
hardware schemes allow potentially-unsafe speculative accesses but prevent the
secret's transmission by delaying most access-dependent instructions even in
the predominantly-common, no-attack case, which incurs performance loss and
hardware complexity. Instead, we propose SafeBet which allows only, and does
not delay most, safe accesses, achieving both security and high performance.
SafeBet is based on the key observation that speculatively accessing a
destination location is safe if the location's access by the same static trust
domain has been committed previously; and potentially unsafe, otherwise. We
extend this observation to handle inter trust-domain code and data
interactions. SafeBet employs the Speculative Memory Access Control Table
(SMACT) to track non-speculative trust domain code region-destination pairs.
Disallowed accesses wait until reaching commit to trigger well-known replay,
with virtually no change to the pipeline. Software simulations using SpecCPU
benchmarks show that SafeBet uses an 8.3-KB SMACT per core to perform within 6%
on average (63% at worst) of the unsafe baseline behind which NDA-restrictive,
a previous scheme of security and hardware complexity comparable to SafeBet's,
lags by 83% on average
Evaluation of new insecticide molecules for their effectiveness in the management of sugarcane early shoot borer, Chilo infuscatellus (Snellen)
An experiment was conducted at Zonal Agricultural Research Station, V.C farm, Mandya (Karnataka), India during 2015, to assess the chemical control of sugarcane early shoot borer (Chilo infuscatellus). Nine insecticides namely, Fipronil 0.3G, Chlorantraniliprole 0.4G, Chlorantraniliprole 18.5 SC, Spinosad 45SC, Flubendiamide 39.35SC, Cartap hydrochloride 4G, Phorate 10G, Carbofuran 3G, Chlorpyriphos 20EC, and compared with untreated (Check plot)using randomized block design with three replications. Significant differences were noticed among the treatments. Chlorantraniliprole 0.4G recorded lowest cumulative incidence (2.79 %) and highest per cent reduction over the control (85.78 %) which was followed by Cartap hydrochloride 4G (5.37% and 72.65%), Chlorantraniliprole 18.5 SC (5.95% and 75.62%), Flubendiamide 39.35SC (6.64% and 66.19%) and Fipronil 0.3G (6.83% and 65.22%) were found significantly superior in reducing the cumulative incidence of C. infuscatellus.In Co 86032 Cartap hydrochloride 4G was found to be the best insecticide in getting a highest cost benefit ratio (1:12.39). Other insecticides such as Fipronil 0.3G (1:8.84), Chlorantraniliprole 0.4G (1:6.96), Flubendiamide 39.35SC (1:5.42) and Spinosad 45SC (1:4.16) have also recorded better cost benefit ratio. Since Cartap hydrochloride 4G does not have crop label so we can recommend Fipronil 0.3G or Chlorantraniliprole 0.4G for the management of sugarcane early shoot borer
Smash Guard: A Hardware Solution to Prevent Security Attacks on the Function Return Address
A buffer overflow attack is perhaps the most common attack used to compromise the security of a host. A buffer overflow can be used to change the function return address and redirect execution to execute the attacker\u27s code. We present a hardware-based solution, called SmashGuard, to protecting the return addresses stored on the program stack. SmashGuard protects against all known forms of attack on the function return address pointer. With each function call instruction a new return address is pushed onto an extra hardware stack. A return instruction compares its return address to the address from the top of the hardware stack. If a mismatch is detected, then an exception is raised. Because the stack operations and checks are done in hardware, and in parallel with the usual execution of call and return instructions, our bestperforming implementation scheme has virtually no performance overhead. While previous software-based approaches\u27 average performance degradation for the SPEC2000 benchmarks is only 2.8%, their worst-case degradation is up to 8.3%. Apart from the lack of robustness in performance, the software approaches\u27 key disadvantages are less security coverage and the need for recompilation of applications. SmashGuard, on the other hand, is secure and does not require recompilation, though the OS needs to be modified to save/restore the hardware stack at context switches, and when function call nesting exceeds the hardware stack depth
Achieving Causal Consistency under Partial Replication for Geo-distributed Cloud Storage
Causal consistency has emerged as an attractive middle-ground to architecting cloud storage systems, as it allows for high availability and low latency, while supporting stronger-than-eventual-consistency semantics. However, causally-consistent cloud storage systems have seen limited deployment in practice. A key factor is these systems employ full replication of all the data in all the data centers (DCs), incurring high cost. A simple extension of current causal systems to support partial replication by clustering DCs into rings incurs availability and latency problems. We propose Karma, the first system to enable causal consistency for partitioned data stores while achieving the cost advantages of partial replication without the availability and latency problems of the simple extension. Our evaluation with 64 servers emulating 8 geo-distributed DCs shows that Karma (i) incurs much lower cost than a fully-replicated causal store (obviously due to the lower replication factor); and (ii) offers higher availability and better performance than the above partial-replication extension at similar costs
ROLE OF MATRA BASTI (ENEMA) OVER ABHYANGA (MASSAGE) AND SWEDA (SUDATION) IN REDUCING SPASTICITY IN CEREBRAL PALSY WITH SUDDHA BALA TAILA-A RANDOMIZED COMPARATIVE CLINICAL STUDY
Objective of the study was to assess the efficacy of Matra basti (enema) over Abhyanga (massage) and Sweda (sudation) in reducing spasticity in cerebral palsy. Study was carried out in IPD, Department of Kaumarbhritya, KLEs Shri BMK Ayurved Mahavidyalaya, Shahapur, Belgaum, Karnataka; India.30 children fulfilling diagnostic criteria between the age group of 2-12 years were included and enrolled as per computer generated block randomization into 2 groups of 15 children in each group. Group A was administered with Matra basti (enema) after local Abhyanga (massage) with Suddha bala taila and local Swedana (sudation) with Nadi sweda (type of sudation) method for a duration of 15 days. In group B spastic children were treated with Sarvanga Abhyanga (massage all over body) followed by plain Nadi sweda with Suddha bala taila. Follow up was done on 30th and 45th day of treatment. Both the procedures were helpful in reducing spasticity. Matra basti (enema) is more effective in treating the spasticity of cerebral palsy as compared to Abhyanga (massage) and Sweda, whereas Abhyanga (massage) and Sweda (sudation) is effective in treating fine motor functions. Suddha Bala taila is effective in treating Ekanga vata (monoplegia), Pakshaghata (diplegia) and other related Vata Vyadhi (neurological disorders) as attributed to its Rogaghnata (disease). Thus the procedures are effecting in reducing spasticity
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