ПІДХОДИ ДО БЕЗПЕКИ ХМАРО-ОРІЄНТОВАНОГО МОБІЛЬНОГО НАВЧАННЯ

The paper attempts to outline the security issues in the development and application of cloud-based mobile learning. A brief definition of the mobile learning, its components and related technologies and devices is given. The specific characteristics of social media, big data and cloud computing are summarized in relation with their integration in the mobile learning and its transformation to a cloud-based environment. The main security threats to this type of learning are pointed out and some recommendations for providing security learning are given are given.В статье делается попытка выделить проблемы безопасности при разработке и применении мобильной учебы с применением облачных технологий. Сделано короткое определение мобильной учебы, ее компонентов, сопутствующих технологий и устройств. Обобщены особенности социальных медиа, больших данных и облачных  технологий  в отношении к их интеграции  в мобильную учебу и трансформацию в облачной среде. Определены основные угрозы для безопасности такого вида учебы и предоставлены некоторые рекомендации для обеспечения безопасности учебы. У статті робиться спроба окреслити проблеми безпеки при розробці та застосуванні мобільного навчання з застосуванням хмарних технологій. Зроблено коротке визначення мобільного навчання, його компонентів, супутніх технологій та пристроїв. Підсумовані особливості соціальних медіа, великих данних та хмарних  технологій  у відношенні до їх інтеграції  у мобільне навчання та трансформацію в хмарному середовищі. Визначені основні загрози для безпеки такого виду навчання та надані деякі рекомендації для забезпечення безпеки навчання

Large scale fabrication of environmentally benign nanoparticles from lignin for use as delivery vehicles of active ingredients

Our group previously introduced a new class of environmentally-benign nanoparticles (EbNPs) with cores made of biodegradable lignin (Nature Nanotech., 10, 817, 2015). Unlike traditional inorganic nanoparticles, the environmentally benign nanoparticles made of lignin can degrade after they have been used, so there is no potential for toxic impact on the environment or humans. The lignin core nanoparticles are synthesized through flash precipitation, but until recently they were only produced in mL-scale batches. We have developed a semi-continuous system featuring a recycle loop, making it possible to produce such nanoparticles in practical quantities for industrial applications. We investigated the role of each variable in our process to determine how we can control the size of our EbNPs and the final concentration of the EbNP suspensions. Because of the turbulent flow in the system, we found that the range of possible flow rates did not have any impact on our final size. The amount of anti-solvent added to the medium also had no effect on our final EbNP size distribution, revealing that we have continuous nucleation throughout each run instead of the LaMer mechanism, which would result in growth of existing particles with the addition of more lignin. This allows effective control of the resulting nanoparticle size through the starting concentration of lignin in acetone. Then, by altering our anti-solvent volume, we can control the final NP concentration of our solution. Please click Additional Files below to see the full abstract

Effect of interface states on spin-dependent tunneling in Fe/MgO/Fe tunnel junctions

The electronic structure and spin-dependent tunneling in epitaxial Fe/MgO/Fe(001) tunnel junctions are studied using first-principles calculations. For small MgO barrier thickness the minority-spin resonant bands at the two interfaces make a significant contribution to the tunneling conductance for the antiparallel magnetization, whereas these bands are, in practice, mismatched by disorder and/or small applied bias for the parallel magnetization. This explains the experimentally observed decrease in tunneling magnetoresistance (TMR) for thin MgO barriers. We predict that a monolayer of Ag epitaxially deposited at the interface between Fe and MgO suppresses tunneling through the interface band and may thus be used to enhance the TMR for thin barriers.Comment: 4 pages, 3 eps figures (2 in color), revtex

Single-access transumbilical laparoscopic appendectomy using curved reusable instruments: an initial report of three cases.

Introduction: The continuous evolution of laparoscopic surgery and the ambition of better cosmetic results raise the need for less invasive procedures. The umbilicus represents a natural scar and constitutes a wellhealing site of access to the peritoneal cavity. Single-access Transumbilical Laparoscopy (SATL) is gaining popularity and can be an alternative surgical treatment for acute appendicitis. We report three cases of SATL appendectomy using curved reusable instruments.Patients and methods: Three female patients, wanting minimal scarring (mean age - 30 years) were admitted to our hospital in April 2015 with acute abdominal pain in the right iliac area. A SATL appendectomy was performed using a standard 11-mm reusable trocar for a 10-mm, 30°- angled, rigid scope and curved reusable instruments according to DAPRI (Karl Storz-Endoskope, Tuttlingen, Germany) placed transumbilically.Results: Neither a conversion to open surgery nor an insertion of extraumbilical trocars was necessary. The mean operative time was 101.6 +/- 24.66 minutes and the mean blood loss 6.66 +/- 11.54 mL. The mean scar length was 16.66 +/- 0.57 mm. No intraoperative complications were registered and the use of minimal pain killers allowed the discharge after 2 or maximum 4 days. After three months of follow-up no late complications occurred and the umbilical scar was not visible.Conclusion: In young and scarless-demanding females with acute appendicitis SATL appendectomy can be performed safely and offers the possibility of surgical treatment without a visible scar

Limiting the resectability in locally advanced primary or rec urrent carcinoma of the colon

Purpose: The terms of ‘unresectable`, ‘inoperable` and ‘incurable` cancer/patient are widely used but not clearly defined and thus subject to significant subjectivity. Where is the limit of ‘resectability` of colorectal cancer - the criteria are variable and not precisely defined yet. Locally advanced lesion may vary from visible intimately adhered to the surrounding tissue, i.e. marginal, ‘border` resectable tumour to one that directly macroscopically engages adjacent critical structures. This paper presents the experience of other foreign authors with their results in the determination of the tumour as resectable or unresectable as well as own clinical experience in this field.Material and methods: The study covered the patients with colorectal cancer who were operated in the Clinic of Surgery during a period of 9 years and retrospectively analyzed.Results: Out of a total of 1051 surgeries on the occasion of colorectal cancer, advanced disease constituted 28,6% or 301 patients. Of them, 52,5% were localized in different parts of the colon. Fifty-eight combined resections were performed as in 7 of them (recurrent tumours) R1 was accomplished, i.e. a non-radical result. A total of 117 cases were assessed intraoperatively as non-radical surgery and palliative procedures were performed such as resections (with or without restoration of the intestinal passage, but in the case of M1), bypass anastomoses, or simple interruption of the passage. .Conclusion: Many of the world`s leading surgical centres adopt the tactics of ‘adequate aggressive behaviour` for locally advanced primary and recurrent colorectal cancer. In determining the reasonable balance between aggressive approach and the so-called meaningless ‘surgical exorbitance` there is strive to adhere to the view that failure to achieve R0-resection planed in such an operation as well as leading performance or a combination of factors such as advanced age, severe co-morbidities, presence of complicated forms of colorectal cancer, urgent intervention and data of generalization of the malignant process undermine the performance of aggressive block removal of tumour formation. However, adequate pre- and intraoperative assessment and surgical experience should avoid ‘exaggerated` intraoperative status of locally advanced tumou

FLORA, MYCOTA AND VEGETATION OF KUPENA RESERVE (RODOPI MOUNTAINS, BULGARIA)

The paper represents results from recent complex studies of flora, mycota and vegetation within the Kupena Reserve (Rodopi Mts, Bulgaria). Twenty three species, referred to 2 divisions, 4 classes and 16 families are recorded for the bryoflora. The vascular flora is presented by 368 species from 57 families, 121 of which are considered as medicinal plants. Eighty seven species of larger ascomycetes and basidiomycetes are found and reported for first time in the reserve. Four of them are of a high conservation value. The vegetation cover is consisted of mixed and monodominant deciduous and coniferous forests, as well as of mire, riverbank and mesic grasslands. Thirteen types of habitats according to the Habitats Directive classification have been recorded within the reserve

Ballistic anisotropic magnetoresistance

Electronic transport in ferromagnetic ballistic conductors is predicted to exhibit ballistic anisotropic magnetoresistance (BAMR) - a change in the ballistic conductance with the direction of magnetization. This phenomenon originates from the effect of the spin-orbit interaction on the electronic band structure which leads to a change in the number of bands crossing the Fermi energy when the magnetization direction changes. We illustrate the significance of this phenomenon by performing ab-initio calculations of the ballistic conductance in ferromagnetic Ni and Fe nanowires which display a sizable BAMR when the magnetization changes direction from parallel to perpendicular to the wire axis