Relations Between Adjacency and Modularity Graph Partitioning

In this paper the exact linear relation between the leading eigenvector of the unnormalized modularity matrix and the eigenvectors of the adjacency matrix is developed. Based on this analysis a method to approximate the leading eigenvector of the modularity matrix is given, and the relative error of the approximation is derived. A complete proof of the equivalence between normalized modularity clustering and normalized adjacency clustering is also given. Some applications and experiments are given to illustrate and corroborate the points that are made in the theoretical development.Comment: 11 page

Resource guarding in dogs, causes and preventive methods

Hundaggression är ett allvarligt problem dels i form av nedsatt välfärd hos hunden som uppvisar aggressivt beteenden, dels för omgivningen då det kan leda till bitskador på människor och andra djur. Detta gör att hundaggression är bland det farligaste problembeteende hos hundar som ägare står inför. En vanlig orsak bakom aggressivitet hos hund är resursförsvar som innebär att hunden på olika sätt vaktar föremål, personer eller platser som har ett stort värde för hunden, t ex mat eller leksaker som hunden inte vill bli av med. Det är årligen tusentals människor som får uppsöka sjukhus i Sverige efter att de blivit hundbitna, där det år 2017 var 3 819 personer som behövde vård för sina skador orsakad av hundbett. Resursförsvar kan ta sig uttryck som olika former av aggressiva beteenden gentemot både ägare och andra hundar. Detta har stark negativ påverkan på relationen mellan hund och ägare, samt negativ påverkan på välfärden hos andra djur som resursförsvaret riktas mot. Att leva med hund som uppvisar resursförsvar kräver ofta avancerade kunskaper för att lösa beteendeproblematiken. Tidigare forskning från Beaver (1982) hänvisar till att resursförsvaret beror på svaga ledare, medan nyare forskning tyder på att resursförsvar inte har något med rangordning eller dominans att göra, snarare kan hårda metoder snarare förvärra resursförsvaret hos hunden. Syftet med den här studien var att ta reda på orsaker till resursförsvar hos hundar samt hur man som ägare kan förebygga att beteendet uppkommer och vad man kan ta till för åtgärder om problemet väl uppstår. Vidare var syftet även att få förståelse för hur ägare upplever resursförsvar riktat mot andra hundar eller människor. Metoden för denna studie var en enkätundersökning riktad till hundägare med hundar som uppvisade resursförsvar. Ägarna fick svara på frågor rörande i hur stor sträckning hunden uppvisade olika typer av försvarsbeteenden och vem/vilka försvaret riktades mot. Ägarna fick även svara på frågor gällande vad som triggar hunden och hur ägaren hanterar, samt förebygger hundens resursförsvar. Resultatet tyder på att de flesta hundägare uppfattar att hundens resursförsvar inte medför ett stort problem och att många vet hur de ska agera för att hunden inte ska uppvisa försvarsbeteenden, samt hur de ska agera om hunden väl uppvisar försvarsbeteendet. De flesta hundägare ansåg att det bästa sättet att hantera beteendet var genom positiv förstärkning, som att ignorera hundens beteende eller utöva byteshandel. Mat (73,6 4%) och föremål (59,69 %) var de resurser som flesta ägare angav att deras hundar försvarade. 48,8% av hundarna riktade försvaret enbart mot andra hundar medan 38% av hundarna riktade resursförsvaret mot både hundar och människor. De främsta triggerns för hundarna var om personen/hunden försökte ta resursen från hunden (52,21 %) samt om personen/hunden gick mot hunden/resursen (49,56 %). Några av svaren varför ägaren trodde att hunden uppvisar resursförsvar förklarades bland annat bero på genetik, osäkerhet, sjukdom samt att de blivit av med resurser tidigare och därmed utvecklat resursförsvaret.Dog aggression is a fundamental problem that can lead to bite injuries in humans, which is among the most dangerous behavior problem in dogs that owners face. The behavior is a form of aggression that has a strong impact on the relationship between dog and owner. This also has an impact on both the dog and the dog’s welfare, if the dog exhibits resource guarding against other dogs. Dog bite injuries lead to hospital visits for thousands of people in Sweden each year, 3819 people needed treatment for their injuries caused by dog bites. Living with a dog that exhibit resource guarding often requires advanced knowledge to solve the problem, and in several cases needs help from professional trainers. Previous research indicates that resource guarding is due to weak leaders, while more recent research suggests that resource guarding has nothing to do with rank or dominance, that harsh methods can worsen resource guarding in the dog. The purpose of this study was therefore to find out the cause of the resource guarding, how to prevent the behavior from occurring and to find out what measures can be taken if the problem does arise. The aim was also to gain an understanding of how the owner experiences resource guarding directed at other dogs and/or people. The method chosen for this study was a survey aimed to dog owners with resource guarding dogs. The contenders of the survey had to answer various questions to evaluate the extent to which the dog displayed diverse types of resource guarding behavior, who the defense was directed at (people and/or other dogs/animals), what triggers the dog and open questions to get an idea of how owners manage the dog's resource guarding and how they prevent it. The result suggests that most dog owners do not perceive that the dog's resource guarding entails a major problem and that many know how prevent that the dog does not display the behavior. Most dog owners agreed that the best way to deal with the behavior was through positive methods, such as ignoring the dog or bartering. Food (73.64%) and objects (59.69%) were the resources most owners indicated their dogs defended. 48.8% of the dogs directed the defense only at other dogs, while 38% of the dogs directed the resource defense at both dogs and people. The main triggers for the dogs were if the person/dog tried to take the resource from the dog (52.21%) and if the person/dog went towards the dog/resources (49.56%). Some of the answers why the owner thought the dog showed resource guarding were explained to be due, among other things, to genetics, insecurity, illness and that they lost resources and therefore developed resource defense

The effects of some antibiotics and lipopolysaccharide on oxidative burst and phagocytosis of neutrophils

The determination of phagocytosis (P) and oxidative burst (OB) in unfractionated blood is a rapid and sensitive flow cytometric method for quantifying neutrophil activation, and was modified for single laser systems by using propidium iodide labeled Staphylococcus aureus (S.aureus) as a quantitative measure of phagocytosis and simultaneously the green fluorescence of oxidized 2'7' dichlorofluorescein diacetate was used to measure oxidative burst. Propidium-iodide labels dead organisms by intercalation with the DNA of the dead organism. This assay was characterized with respect to the stimulatory activity of bacterial lipopolysaccharide (LPS) on OB and P and to determine the effects of lipopolysaccharide and different antibiotics on oxidative burst and phagocytosis by polymorphonuclear leukocytes (PMNL) using a FACS 440 flow cytometer. Blood from healthy donors was pre-incubated with log doses of bacterial LPS (0.1 ng/ml - 1000 ng/ml) or sterile pyrogen-free saline at 37 °c from 0-120 minutes. LPS increased both phagocytosis and oxidative burst in a dose-dependent manner (up to 62 and 121 percent respectively) at all time points tested, and this effect on P and OB could be detected even with no pre- incubation. This LPS - induced phagocytic activity could be blocked by the addition of polymyxin B (10 μg/ml) during preincubation. The priming effect of LPS was maximal at 45 minutes. P and OB were inhibited by pre-incubation with EDTA at doses greater than 1000 μg/ml (60 and 80 percent inhibition) respectively. These observations are consistent with the exquisite sensitivity of the neutrophil to endotoxin. Blood from healthy subjects was subjected to different concentrations of antibiotics, or sterile pyrogenfree saline at 37 °c from O to 120 minutes. The antibiotics used were the following: Ceftriaxone, ciprofloxacin, clindamycin, doxycycline, enoxacin, imipenem, norfloxacin, pefloxacin, teicoplanin, tetracycline and vancomycin. Blood from healthy subjects was exposed to concentrations of the above antibiotics ranging from 0.1 to 200 μg/ml for 60 minutes. EDTA and bacterial LPS used as system controls demonstrated dose-dependent inhibition and increase respectively. Doxycycline showed inhibition of both parameters, while pefloxacin enhanced and tetracycline inhibited oxidative burst. The remaining antibiotics showed no doserelated modulation of either oxidative burst or phagocytosis. The method described provides an environment that mimics physiological conditions; is a rapid and sensitive assay not requiring separation of white cells; and simultaneously measures two neutrophil functions. It can evaluate neutrophil response to immunomodulatory and chemotherapeutic agents in a physiological milieu. The necessity of using pyrogen - free reagents in any study of neutrophil function is re-emphasized

Fast Incremental SVDD Learning Algorithm with the Gaussian Kernel

Support vector data description (SVDD) is a machine learning technique that is used for single-class classification and outlier detection. The idea of SVDD is to find a set of support vectors that defines a boundary around data. When dealing with online or large data, existing batch SVDD methods have to be rerun in each iteration. We propose an incremental learning algorithm for SVDD that uses the Gaussian kernel. This algorithm builds on the observation that all support vectors on the boundary have the same distance to the center of sphere in a higher-dimensional feature space as mapped by the Gaussian kernel function. Each iteration involves only the existing support vectors and the new data point. Moreover, the algorithm is based solely on matrix manipulations; the support vectors and their corresponding Lagrange multiplier $\alpha_i$'s are automatically selected and determined in each iteration. It can be seen that the complexity of our algorithm in each iteration is only $O(k^2)$, where $k$ is the number of support vectors. Experimental results on some real data sets indicate that FISVDD demonstrates significant gains in efficiency with almost no loss in either outlier detection accuracy or objective function value.Comment: 18 pages, 1 table, 4 figure

Peak Criterion for Choosing Gaussian Kernel Bandwidth in Support Vector Data Description

Support Vector Data Description (SVDD) is a machine-learning technique used for single class classification and outlier detection. SVDD formulation with kernel function provides a flexible boundary around data. The value of kernel function parameters affects the nature of the data boundary. For example, it is observed that with a Gaussian kernel, as the value of kernel bandwidth is lowered, the data boundary changes from spherical to wiggly. The spherical data boundary leads to underfitting, and an extremely wiggly data boundary leads to overfitting. In this paper, we propose empirical criterion to obtain good values of the Gaussian kernel bandwidth parameter. This criterion provides a smooth boundary that captures the essential geometric features of the data

Learning Management System Berbasis Cloud sebagai Alternatif Pembelajaran Bagi Guru Sekolah Menengah Pertama

The purpose of this paper is to see an increase in the knowledge of Majelis Guru Mata Pelajaran (MGMP) of Kabupaten Lima Puluh Kota after a training of Cloud-based Learning Management System (LMS) using Moodlecloud and ask their opinions about the use of LMS in learning in their Subjects. The experimental design used to see the increase in the knowledge of the participants in this training was pre-experimental using the one-group pre-test post-test design. The teachers involved in the training were 15 people. Their opinion on the use of LMS for learning was asked through a questionnaire. The data shows that there is an increase in the teacher's knowledge in managing LMS using Moodlecloud, and from the questionnaire it appears that they agree that the use of LMS in their learning is interesting, practical, motivating and easy to use. From the interviews, it was also concluded that they were very enthusiastic in using this media as an additional alternative to their respective subject learnin