Buffer overflow attacks & countermeasures

Often security website’ headlines read: "Buffer overflow in vendor’s product allows intruders to take over computer!” What can software engineering education do about this situation? In this document we have tried to point out how dangerous buffer overflow attacks can be and the amount of damage they are capable of incurring. We have shown several vulnerable applications both past as well as recent. The objective of this study is to take one inside the buffer overflow attack and bridge the gap between the “descriptive account” and the “technically intensive account”. The intent is to provide a logical, detailed, and technical explanation of the buffer overflow problem and the exploit that can be well understood by all. We have successfully coded several exploits and developed programs to demonstrate the effectiveness of such attacks

Antibakterijski učinak ekstrakta lista biljke Plectranthus amboinicus Benth u uzorcima voća, povrća i pilećeg mesa

The ability of acetone and ethyl acetate extracts of the leaves of a traditional Indian medicinal plant, Indian borage (Plectranthus amboinicus Benth) to prevent spoilage of artificially inoculated model food systems (cabbage and papaya) and natural microflora of chicken meat was evaluated. These extracts were able to reduce the bacterial counts in all food systems; however, the effective concentration varied with the complexity of the system (in descending order: cabbage, papaya and chicken). A probable mode of action of extracts was investigated by analyzing the changes they cause in bacterial cell wall and leakage of nucleic acid from bacterial cells. Both acetone and ethyl acetate extracts at their respective minimum inhibitory concentrations resulted in leakage of cell constituents to an extent of 40 to 80 and 60 to 95 %, respectively, compared to the control, and finally leading to disintegration of cell walls. These findings indicate the potential use of ethyl acetate and acetone extracts of Indian borage leaves in food preservation.U radu je ispitan učinak ekstrakata lišća drevne indijske ljekovite biljke Plectranthus amboinicus Benth, izoliranih pomoću acetona i etilnog acetata, na sprečavanje rasta bakterija uzročnika kvarenja inokuliranih u uzorke svježeg kupusa i papaje, te na prirodnu mikrofloru pilećeg mesa. Dobiveni su ekstrakti uspješno smanjili broj bakterija u svim uzorcima hrane, no njihova je učinkovitost ovisila o složenosti sastava uzorka, pa je najveća bila u kupusu, zatim u papaji, a najmanja u mesu. Ispitan je utjecaj ekstrakata na razgradnju stanične stijenke bakterija i otpuštanje nukleinskih kiselina u međustanični prostor. Ekstrakt lišća dobiven pomoću acetona je pri minimalnoj inhibicijskoj koncentraciji uzrokovao otpuštanje 40 do 80 % staničnog sadržaja, a ekstrakt dobiven pomoću etilnog acetata 60 do 95 % staničnog sadržaja bakterija u usporedbi s kontrolnim uzorkom, što je naposljetku uzrokovalo potpunu razgradnju stanične stijenke. Rezultati pokazuju da se ekstrakti lišća indijske biljke Plectranthus amboinicus Benth, dobiveni pomoću etilnog acetata ili acetona, mogu upotrijebiti za konzerviranje hrane

Influence of rice varieties and fertility levels on performance of rice and soil nutrient status under aerobic conditions

Scarcity of water resources in India is limiting the production of flooded rice crop. A field experiment was conducted in factorial RBD with sixteen treatment combinations including four rice varieties viz. V1: PR-115, V2: DRRH-3, V3: PAC-837 and V3: PR-121 and four fertility levels viz. F1: control (N0P0K0), F2: N, P2O5, K2O at 90: 45: 22.5 kg ha-1, F3: N, P2O5, K2O at 120:60:30 kg ha-1 and F4: N, P2O5, K2O at 150: 75: 37.5 kg ha-1 replicated thrice. The results revealed that among the different varieties, PAC-837 recorded highest plant height and number of tillers m-2 at all the growth stages. All yield attributes viz. number of effective tillers m-2, number of seeds per panicle, 1000-grain weight, spikelet sterility and grain yield, straw yield and harvest index significantly differed in different varieties and were recorded highest in PAC-837 which were however, statistically at par with DRRH-3 except grain yield and effective tillers m-2. Rice variety PAC-837 recorded highest grain yield of 45.65 q ha-1 and straw yield of 59.98 q ha-1. Among the fertility levels, number of effective tillers m-2 significantly increased up to 120: 60: 30 N-P2O5-K2O kg ha-1 thereafter nonsignificant differences were noticed. The grain and straw yield increased up to 150: 75: 37.5 N-P2O5-K2O kg ha-1 and recoded grain yield of 52.78 q ha-1 and straw yield of 73.85 q ha-1 with application of 150:75:37.5 N-P2O5-K2O kg ha-1. Nutrient application of 150: 75: 37.5 N-P2O5-K2O kg ha-1 recorded highest available N (238.16 kg ha-1), P (16.18 kg ha-1) and K (163.25 kg ha-1) in soil after harvest of the crop. Higher available nitrogen (235.28 kg ha-1), phosphorus (16.38 kg ha-1) and potassium (154.24 kg ha-1) n soil were recorded with PR-121 and lowest available major nutrients were recorded with variety PAC-837. This study would help to introduction and adaptation of new rice variety PAC-837 with application of 150: 75: 37.5 N-P2O5-K2O kg ha-1 under aerobic conditions in Shiwalik foothills region of North-Western Himalayas

Sustainable utilization of quartz sandstone mining wastes:Chloride and corrosion resistance

There has been growing interest to reduce the use of conventional natural aggregates to promote sustainability in construction industry. In this study, quartz sandstones are substituted for natural igneous coarse aggregates in concrete and tested for chloride and corrosion resistance. The results indicate that the depth of chloride penetration increases with increasing quartz sandstone substitution, with similar depth of penetration to that of the control mixture observed up to approximately 20% replacement by volume. Results from corrosion potential measurements indicate no significant corrosion occurring in specimens made with either natural or coarse aggregates after 180 days of ponding.</p

Electron acceleration by a short laser beam in the presence of a long-wavelength electromagnetic wave

A scheme for laser-induced acceleration of an electron injected initially at an angle to the direction of a short-wavelength laser is investigated, where an additional long-wavelength electromagnetic wave is introduced to achieve high energy gain. Due to the beating effect of the electromagnetic waves, the electron can gain additional energy. Some computational results are presented to estimate the electron energy gain by the proposed scheme, where the gain increases by increasing the difference of the wavelengths.open9

Wigner delay time from a random passive and active medium

We consider the scattering of electron by a one-dimensional random potential (both passive and active medium) and numerically obtain the probability distribution of Wigner delay time ($\tau$). We show that in a passive medium our probability distribution agrees with the earlier analytical results based on random phase approximation. We have extended our study to the strong disorder limit, where random phase approximation breaks down. The delay time distribution exhibits the long time tail ($1/\tau^2$) due to resonant states, which is independent of the nature of disorder indicating the universality of the tail of the delay time distribution. In the presence of coherent absorption (active medium) we show that the long time tail is suppressed exponentially due to the fact that the particles whose trajectories traverse long distances in the medium are absorbed and are unlikely to be reflected.Comment: 13 pages RevTex, 5 EPS figures included, communicated to PR

Effect of methonolic extract of Vitex negundo on haloperidol induced catalepsy in albino mice

Background: Plants are being used in traditional medicine since history of mankind. The knowledge of these medicinal plants has accrued in the course of many centuries leading to medicinal systems in India such as Ayurveda, Unani and Siddha. Objective: In the present study, we evaluated the anticataleptic efficacy of Vitex negundo, a polyherbal formulation in haloperidol induced catalepsy in mice.Methods: Five groups (n=6) of male albino mice were used in the study. Catalepsy was induced by i.p. administration of haloperidol (1 mg/kg). The degree of catalepsy (cataleptic score) was measured as the time the animal maintained an imposed posture. We compared the anticataleptic efficacy of Vitex negundo (50, 100, 200 mg/kg) with standard received Pheniramine maleate 10 mg/kg, i.p.Results: In vehicle treated animals, haloperidol (1 mg/kg. i.p.) produced the maximum catalepsy at 180 min (46.78±3.78 min). Standard treated as Pheniramine maleate 10 mg/kg, i.p. shows maximum at 120 min. 19.24±1.32. Test herb, i.p. Methanolic extract of Vitex negundo (50, 100, 200 mg/kg, i.p.) significantly potentiated haloperidol induced catalepsy at each time interval, in a dose dependent manner. At dose 50, 100 and 200mg/kg, extract of Vitex negundo (Linn.) roots showed maximum cataleptic score 12.34±0.78, 14.43±0.43 and 15.43±0.67 min, respectively at 120 minutes in haloperidol treated animals.Conclusions: The present study indicates that the methanolic extract of Vitex negundo reduces haloperidol-induced catalepsy in mice