833 research outputs found

    Finally eating soup with a knife? A historical perspective on the US Army's 2006 counterinsurgency doctrine

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    In 2006, the US Army adopted a new counterinsurgency (COIN) doctrine, Field Manual 3-24. The doctrine establishes new guidelines for conducting operations such as those currently taking place in Afghanistan and Iraq, where its validity is being tested. It is also a turning point in the US Army’s doctrinal approach to such operations as it fully embraces the “small war” approach to COIN. Earlier post-Vietnam Army doctrine has had an ambivalent view of the small war approach, which is contrary to the Army’s traditional preference for fighting big-scale, conventional wars. While earlier post-Vietnam COIN doctrines have used the conflicts in Vietnam and El Salvador as models, FM 3-24 takes into account many other possible forms of insurgency as well. It also recognizes more clearly the key role of popular legitimacy and accets a potentially much more extensive degree of Army involvement. Furthermore, FM 3-24 wholeheartedly argues that political concerns should take precedence over strictly military ones when applying force. COIN operations are viewed as a long-term commitment. The doctrine may help to fill a gap in US military capabilities, but this ultimately requires a change in the Army’s mindset and in US national strategic culture

    Joint DOA and Multi-Pitch Estimation Using Block Sparsity

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    In this paper, we propose a novel method to estimate the fundamental frequencies and directions-of-arrival (DOA) of multi-pitch signals impinging on a sensor array. Formulating the estimation as a group sparse convex optimization problem, we use the alternating direction of multipliers method (ADMM) to estimate both temporal and spatial correlation of the array signal. By first jointly estimating both fundamental frequencies and time-of-arrivals (TOAs) for each sensor and sound source, we then form a non-linear least squares estimate to obtain the DOAs. Numerical simulations indcate the preferable performance of the proposed estimator as compared to current state-of-the-art methods

    A new method for normalized interpretation of antimicrobial resistance from disk test results for comparative purposes.

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    Objective To evaluate a calibration method for disk diffusion antibiotic susceptibility tests, using zone diameter values generated in the individual laboratory as the internal calibrator for combinations of antibiotic and bacterial species. Methods The high-zone side of zone histogram distributions was first analyzed by moving averages to determine the peak position of the susceptible population. The accumulated percentages of isolates for the high zone diameter values were calculated and converted into probit values. The normal distribution of the ideal population of susceptible strains was then determined by using the least-squares method for probit values against zone diameters, and the ideal population was thereby defined, including mean and standard deviation. Zone diameter values were obtained from laboratories at the Karolinska Hospital (KS) and Växjö Hospital (VX), and from two laboratories (LabA, LabB) in Argentina. The method relies on well standardized disk tests, but is independent of differences in MIC limits and zone breakpoints, and does not require the use of reference strains. Resistance was tentatively set at below 3 SD from the calculated, ideal mean zone diameter of the susceptible population. Results The method, called normalized interpretation of antimicrobial resistance, was tested on results from the KS and VX clinical microbiology laboratories, using the disk diffusion method for antimicrobial susceptibility tests, and for two bacterial species, Staphylococcus aureus and Escherichia coli. In total, 114 217 test results were included for the clinical isolates, and 3582 test results for control strains. The methodology at KS and VX followed the standard of the Swedish Reference Group for Antibiotics (SRGA). Zone diameter histograms for control strains were first analyzed to validate the procedure, and a comparison of actual means with the calculated means showed a correlation coefficient of r = 0.998. Results for clinical isolates at the two laboratories showed an excellent agreement for 54 of 57 combinations of antibiotic and bacterial species between normalized interpretations and the interpretations given by the laboratories. There were difficulties with E. coli and mecillinam, and S. aureus and tetracycline and rifampicin. The method was also tested on results from two laboratories using the NCCLS standard, and preliminary results showed very good agreement with quality-controlled laboratory interpretations. Conclusions The normalized resistance interpretation offers a new approach to comparative surveillance studies whereby the inhibition zone diameter results from disk tests in clinical laboratories can be used for calibration of the test

    An Adaptive Penalty Approach to Multi-Pitch Estimation

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    This work treats multi-pitch estimation, and in particular the common misclassification issue wherein the pitch at half of the true fundamental frequency, here referred to as a sub-octave, is chosen instead of the true pitch. Extending on current methods which use an extension of the Group LASSO for pitch estimation, this work introduces an adaptive total variation penalty, which both enforce group- and block sparsity, and deal with errors due to sub-octaves. The method is shown to outperform current state-of-the-art sparse methods, where the model orders are unknown, while also requiring fewer tuning parameters than these. The method is also shown to outperform several conventional pitch estimation methods, even when these are virtued with oracle model orders

    "Sån naturlig grej att man måste väl ta p-piller liksom." -Resonemang kring preventivmedel av heterosexuella i parrelationer.

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    Abstract Authors: Maria Kronvall, Sofia Kuczkowski Titel:”Such a natural thing, that you have to be on the pill.” –Reflections on contraceptives among heterosexuals in relationships. Supervisor: Tove Harnett Assessor: David Hoff The aim of this study was to examine attitudes and preferences regarding contraceptives among heterosexuals in relationships. It examines how men and women choose contraceptives and why they make these choices in their relationship. We have interviewed 11 women and men in the ages between 21-33. 10 of them were interviewed as couples. All of the interviews were semi-structured and we followed a structure of different themes during the interviews. The informants were asked to describe their experiences with different contraceptives, and how they decided on their current method. We have organized the informants' answers in different categories such as; safety, side effects, cost and comfort. We found that most of the couples did not make their decision about contraceptives together as a result of a discussion. The priorities and the choices were mostly made by the women and they were also the ones who mainly took the responsibility and initiative regarding contraceptives. The majority of the women in this study had used birth control pills at some point in their current relationship. Most of the women felt skeptic and worried about taking hormones, but some continued to use the pill anyway. Compared to their girlfriends, the men talked very little about worrying. The women changed to another kind of birth control pill or tried a different method only if they experienced negative side effects, or were strongly against taking hormones. Condoms were only used as a second choice and in many cases as a last resort. It was mostly seen as a temporary contraceptive in periods of being single, or in the beginning of a relationship. Both men and women agreed with the perception that men don't like to use condoms. Men who see condoms as a long term contraceptive were seen as exceptions

    Sparse Multi-Pitch and Panning Estimation of Stereophonic Signals

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    In this paper, we propose a novel multi-pitch estimator for stereophonic mixtures, allowing for pitch estimation on multi-channel audio even if the amplitude and delay panning parameters are unknown. The presented method does not require prior knowledge of the number of sources present in the mixture, nor on the number of harmonics in each source. The estimator is formulated using a sparse signal framework, and an efficient implementation using the ADMM is introduced. Numerical simulations indicate the preferable performance of the proposed method as compared to several commonly used multi-channel single pitch estimators, and a commonly used multi-pitch estimator

    Little difference between minimum inhibitory concentrations of Mycobacterium tuberculosis wild-type organisms determined with BACTEC MGIT 960 and Middlebrook 7H10

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    AbstractThe MIC wild-type (WT) distribution for Mycobacterium tuberculosis in BACTEC 960 MGIT is not defined, which may result in poor reproducibility for drug susceptibility testing (DST), as several DST methods with different breakpoints are in use. In a comparison between MGIT and Middlebrook 7H10 medium of seven first- and second-line drugs, including 133 MIC determinations of 15 WT isolates, we found an agreement of 91.7% within ± one MIC dilution step. The results confirm the agreement in MIC testing between 7H10 and MGIT and indicate that breakpoints could be harmonized in order to avoid misclassification
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