Phytosociological studies of mire ecosystems in eastern Canada

The vegetation of a large number of mire complexes from the eastern Canadian provinces of Nova Scotia, New Brunswick and Quebec were described and classified using the phytosociological methods of the Scandinavian and Zurich-Montpellier schools and comparison was made with similar classifications proposed for Europe

Improved Greedy Nonrandomness Detectors for Stream Ciphers

We consider the problem of designing distinguishers and nonrandomness detectors for stream ciphers using the maximum degree monomial test. We construct an improved algorithm to determine the subset of key and IV-bits used in the test. The algorithm is generic, and can be applied to any stream cipher. In addition to this, the algorithm is highly tweakable, and can be adapted depending on the desired computational complexity. We test the algorithm on the stream ciphers Grain-128a and Grain-128, and achieve significantly better results compared to an earlier greedy approach

eavesROP: Listening for ROP Payloads in Data Streams (preliminary full version)

We consider the problem of detecting exploits based on return-oriented programming. In contrast to previous works we investigate to which extent we can detect ROP payloads by only analysing streaming data, i.e., we do not assume any modifications to the target machine, its kernel or its libraries. Neither do we attempt to execute any potentially malicious code in order to determine if it is an attack. While such a scenario has its limitations, we show that using a layered approach with a filtering mechanism together with the Fast Fourier Transform, it is possible to detect ROP payloads even in the presence of noise and assuming that the target system employs ASLR. Our approach, denoted eavesROP, thus provides a very lightweight and easily deployable mitigation against certain ROP attacks. It also provides the added merit of detecting the presence of a brute-force attack on ASLR since library base addresses are not assumed to be known by eavesROP

Analysis of the Relationship Between Biology Teachers' Pupil Control Ideology and Their Classroom Practices

Educatio

Does Ability Grouping Create Undesirable Aspects for the Slow Learner?

This report is an attempt by the author to check some of the literature to see if ability grouping actually creates undersirable aspects for the slow learner. The author is interested in the slow learner since he is working with them in the classroom. Three aspects are considered in this report. These aspects are: (1) Will ability grouping insure higher academic achievement for the slow learner? (2) Can good social relationships exist between the slow learner and his peers in a school utilizing ability grouping? and (3) Can the slow learner develop desirable personal attitudes in a class�in which he is grouped for instructional purposed on the basis of ability? In the case of ability grouping insuring academic achievement, there is too little evidence to support this view. Undoubtedly something will be proven in the future, On the surface, the literature seems to agree that very little adverse effect is caused by ability grouping on the pupils' social relationships. Even though they are grouped on ability in school, this has very little or no effect on how children choose their social friends. Ability grouping does have a harmful effect on the slow learner in his quest to develop a desirable personal attitude. The slow learner often feels that he is inferior because he is set apart from the other students and therefore, he cannot develop a desirable sense of personal worth.Natural Scienc

Real circles tangent to 3 conics

In this paper we study circles tangent to conics. We show there are generically 184 complex circles tangent to three conics in the plane and we characterize the real discriminant of the corresponding polynomial system. We give an explicit example of 3 conics with 136 real circles tangent to them. We conjecture that 136 is the maximal number of real circles. Furthermore, we implement a hill-climbing algorithm to find instances of conics with many real circles, and we introduce a machine learning model that, given three real conics, predicts the number of circles tangent to these three conics

Prediction of ‘Nules Clementine’ mandarin susceptibility to rind breakdown disorder using Vis/NIR spectroscopy

The use of diffuse reflectance visible and near infrared (Vis/NIR) spectroscopy was explored as a non-destructive technique to predict ‘Nules Clementine’ mandarin fruit susceptibility to rind breakdown (RBD) disorder by detecting rind physico-chemical properties of 80 intact fruit harvested from different canopy positions. Vis/NIR spectra were obtained using a LabSpec® spectrophotometer. Reference physico-chemical data of the fruit were obtained after 8 weeks of storage at 8 °C using conventional methods and included RBD, hue angle, colour index, mass loss, rind dry matter, as well as carbohydrates (sucrose, glucose, fructose, total carbohydrates), and total phenolic acid concentrations. Principal component analysis (PCA) was applied to analyse spectral data to identify clusters in the PCA score plots and outliers. Partial least squares (PLS) regression was applied to spectral data after PCA to develop prediction models for each quality attribute. The spectra were subjected to a test set validation by dividing the data into calibration (n = 48) and test validation (n = 32) sets. An extra set of 40 fruit harvested from a different part of the orchard was used for external validation. PLS-discriminant analysis (PLS-DA) models were developed to sort fruit based on canopy position and RBD susceptibility. Fruit position within the canopy had a significant influence on rind biochemical properties. Outside fruit had higher rind carbohydrates, phenolic acids and dry matter content and lower RBD index than inside fruit. The data distribution in the PCA and PLS-DA models displayed four clusters that could easily be identified. These clusters allowed distinction between fruit from different preharvest treatments. NIR calibration and validation results demonstrated that colour index, dry matter, total carbohydrates and mass loss were predicted with significant accuracy, with residual predictive deviation (RPD) for prediction of 3.83, 3.58, 3.15 and 2.61, respectively. The good correlation between spectral information and carbohydrate content demonstrated the potential of Vis/NIR as a non-destructive tool to predict fruit susceptibility to RBD

Gastro-protective and anti-acidic effects of Corchorus trilocularis Linn against diclofenac-induced gastric ulcers.

Ethnopharmacological RelevanceCorchorus trilocularis Linn leaves are consumed as green leafy vegetables that are boiled and used as relish, or potherb by some rural communities in Eastern Africa for the treatment of stomach ulcers.Aim: This study investigated the gastro-protective effects of Corchorus trilocularis Linn (local name ‘mrenda’), a popularly consumed vegetable in Kenya, on diclofenac-induced gastric ulcers and established its possible mechanisms of action.Methods: In the in-vivo study, thirty six Sprague dawley rats of either sex weighing 150-200 grams were randomly assigned into a normal control (distilled water), negative control (distilled water plus diclofenac sodium), treatment (200 and 400 mg/kg Corchorus trilocularis Linn plus diclofenac sodium), positive control group (omeprazole plus diclofenac sodium), or comparison group (400 mg/kg aqueous leaf extract of spinach). The ulcer index, total acidity, volume, pH of gastric secretions, and gastric morphology were assessed. In the in-vitro anti-acidity study, a rat stomach was perfused with Kreb’s solution and the pH of the mucosal perfusate measured using a digital pH meter for 1 hour after exposure to histamine, acetylcholine, or pre-treatment with 400 mg/kg of the extract prior to addition the acid secretagogues.Results: The extract, significantly reduced the ulcer index and total acidity in comparison to the diclofenac group. The high dose extract also increased the gastric pH and had cytoprotective effects. However, it did not significantly affect the volume of gastric secretions. In the in-vitro study, the extract significantly inhibited histamine and acetylcholine stimulated gastric acid secretions as analyzed by the areas under curve for pH against time.Conclusions. The gastro-protective effects of Corchorus trilocularis Linn against diclofenac induced gastric ulcers are; therefore, mediated through preservation of the gastric mucosal barrier, increase in gastric pH, and inhibition of gastric acid secretion through the histamine H2 and acetylcholine M3 extracellular pathways on the parietal cell

New horizons at L’Anse aux Meadows

The UNESCO World Heritage site of L’Anse aux Meadows (LAM) in northern Newfoundland is the only undisputed site of pre-1492 presence of Europeans in the Americas. In August 2018, we undertook fieldwork at LAM to sample the peat bog 30 m east of the Norse ruins for a multiproxy paleoenvironmental assessment of Norse settlement. Instead, we encountered a new cultural horizon. Here we report our fieldwork at this iconic site and a Bayesian analysis of legacy radiocarbon data, which nuance previous conclusions and suggest Norse activity at LAM may have endured for a century. In light of these findings, we reflect on how the cultural horizon, containing nonnative ecofacts, may relate to indigenous or Norse activities