90 research outputs found

    Phish Responder: A Hybrid Machine Learning Approach to Detect Phishing and Spam Emails

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    Using technology to prevent cyber-attacks has allowed organisations to somewhat automate cyber security. Despite solutions to aid organisations, many are susceptible to phishing and spam emails which can make an unwanted impact if not mitigated. Traits that make organisations susceptible to phishing and spam emails include a lack of awareness around the identification of malicious emails, explicit trust, and the lack of basic security controls. For any organisation, phishing and spam emails can be received and the consequences of an attack could result in disruption. This research investigated the threat of phishing and spam and developed a detection solution to address this challenge. Deep learning and natural language processing are two techniques that have been employed in related research, which has illustrated improvements in the detection of phishing. Therefore, this research contributes by developing Phish Responder, a solution that uses a hybrid machine learning approach combining natural language processing to detect phishing and spam emails. To ensure its efficiency, Phish Responder was subjected to an experiment in which it has achieved an average accuracy of 99% with the LSTM model for text-based datasets. Furthermore, Phish Responder has presented an average accuracy of 94% with the MLP model for numerical-based datasets. Phish Responder was evaluated by comparing it with other solutions and through an independent t-test which demonstrated that the numerical-based technique is statistically significantly better than existing approaches

    WHICH TESTOSTERONE REPLACEMENT THERAPY?

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    SUMMARY Three different forms of testosterone (T) replacement therapy were compared; they were the intramuscular injection of mixed testosterone esters 250 mg; the subcutaneous implantation of 6 x 100 mg pellets of fused testosterone; and the oral administration of testosterone undecanoate (TU) 80 mg twice daily. Six hypogonadal males were treated with oral TU for an eight week period, during which time serial serum hormonal estimations were performed over 10 h at the initiation and after four and eight weeks of therapy. Serum T levels showed marked variability both between subjects and within the same subject on different occasions. We attribute this to variability in absorption of TU, which is formulated in oleic acid. The overall mean T level calculated from the areas under the profiles of TU was 12.0 nmol/l. Hormone responses to injected T esters were studied in nine hypogonadal males. Serum T rose to supraphysiological peak concentrations (mean 71 nmol/l) 24-48 h after an injection, followed by an exponential decay to reach baseline concentrations after 2-3 weeks. The overall calculated mean T level in subjects receiving testosterone esters 250 mgevery three weeks was 27.7 nmol/l. Subcutaneous implantation of testosterone in six hypogonadal men produced a gradual rise in serum T followed by a slow decline, with T levels remaining within the normal range for 4-5 months. The calculated overall mean T level over 21 weeks after implantation was 17.0 nmol/l. Serum oestradiol (Ez) levels remained within the normal male range throughout the study periods on both TU and T implant therapy but showed a supraphysiological peak (mean 347 pmol/l) 24-48 h after a T injection. Sa-dihydrotestosterone (DHT) levels appeared to parallel those of T on the three forms of therapy, with DHT:T ratios being highest for TU therapy. This was also true for the target organ metabolite 5a-androstane-3a, 17B-diol. At the doses studied drug costs were similar for T implantation (every 5 months) and Tester injections (every 3 weeks), but were 7-8 times higher for TU (80 mg twice a day). We conclude that T implantation remains overall the most physiological form of androgen replace

    The production of a physiological puzzle: how Cytisus adami confused and inspired a century’s botanists, gardeners, and evolutionists

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    ‘Adam’s laburnum’ (or Cytisus adami), produced by accident in 1825 by Jean-Louis Adam, a nurseryman in Vitry, became a commercial success within the plant trade for its striking mix of yellow and purple flowers. After it came to the attention of members of La Société d’Horticulture de Paris, the tree gained enormous fame as a potential instance of the much sought-after ‘graft hybrid’, a hypothetical idea that by grafting one plant onto another, a mixture of the two could be produced. As I show in this paper, many eminent botanists and gardeners, including Charles Darwin, both experimented with Adam’s laburnum and argued over how it might have been produced and what light, if any, it shed on the laws of heredity. Despite Jean-Louis Adam’s position and status as a nurseryman active within the Parisian plant trade, a surprising degree of doubt and scepticism was attached to his testimony on how the tree had been produced in his nursery. This doubt, I argue, helps us to trace the complex negotiations of authority that constituted debates over plant heredity in the early 19th century and that were introduced with a new generation of gardening and horticultural periodicals

    Does testosterone affect the normal menstrual cycle? Clin Endocrinol (Oxf

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    SUMMARY In order to throw further light on the role of androgens in the aetiology of the polycystic ovary syndrome (PCO) we have examined the effect of artificially increasing serum testosterone levels on menstrual function in a group of ovulating women. Six women were studied who had either severe premenstrual syndrome or loss of libido for which they were treated with 100 mg testosterone by S.C. implantation. All had regular menstrual cycles. For I month before implantation serum LH, FSH, oestradiol (Ez), progesterone and testosterone were measured three times per week. All women showed normal cyclical variation of LH, FSH, E? and progesterone. Following implantation, three times weekly blood samples were taken during the first and third cycles. No patient had any disturbance of menstrual pattern. All continued to show cyclical changes of LH, FSH, E? and progesterone. Serum E2 and progesterone were lower but not significantly so in the luteal phase of the treated cycles. This was despite a mean serum testosterone which rose from 1.3 to 7-1 nmol/l at the end of the third week following implantation and to 4.1 nmol/l at the end of the third month. Sex hormone binding globulin levels fell as expected by 18.5% during the first cycle. The lack of significant effect of a markedly elevated serum testosterone level on cyclical hormone changes is indirect evidence that in PCO the primary cause of the menstrual disturbance is not excessive production of ovarian or adrenal testosterone

    The dayside high-latitude trough under quiet geomagnetic conditions: Radio tomography and the CTIP model

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    The dayside high-latitude trough is a persistent feature of the post-noon wintertime auroral ionosphere. Radio tomography observations have been used to map its location and latitudinal structure under quiet geomagnetic conditions (<i>K<sub>p</sub></i>≤2) near winter solstice. The trough is also a clear feature in the ion density distribution of the Coupled Thermosphere-Ionosphere-Plasmasphere model (CTIP) under similar geophysical conditions. Comparisons of the measured and modelled distributions show that the plasma production equatorward of the trough is mainly controlled by solar radiation, but there are also other processes maintaining the equatorward trough-wall that are open to debate. The poleward trough-wall is produced by particle precipitation, but the densities are significantly overestimated by the model. At the trough minimum the observed densities are consistent with low nighttime densities convecting sunward to displace the higher daytime densities, but this is not borne out by the CTIP model. The study shows the potential of combining radio tomography and modelling to interpret the balance of the physical processes responsible for large-scale structuring of the high-latitude ionosphere, and highlights the role of tomographic imaging in validating and developing physical models
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