Online delivery and assessment during COVID-19: safeguarding academic integrity

Globally, the number of COVID-19 cases continues to rise daily despite strict measures being adopted by many countries. Consequently, universities closed down to minimise the face-to-face contacts, and the majority of the universities are now conducting degree programmes through online delivery. Remote online delivery and assessment are novel experiences for many universities, which presents many challenges, particularly when safeguarding academic integrity. For example, invigilated assessments, often considered as more secure, are not an option given the current situation and detecting any cheating would be significantly challenging. This paper reviews assessment security in the digital domain and critically evaluates the practices from different universities in safeguarding academic integrity, including associated challenges

Estimating Self-Sustainability in Peer-to-Peer Swarming Systems

Peer-to-peer swarming is one of the \emph{de facto} solutions for distributed content dissemination in today's Internet. By leveraging resources provided by clients, swarming systems reduce the load on and costs to publishers. However, there is a limit to how much cost savings can be gained from swarming; for example, for unpopular content peers will always depend on the publisher in order to complete their downloads. In this paper, we investigate this dependence. For this purpose, we propose a new metric, namely \emph{swarm self-sustainability}. A swarm is referred to as self-sustaining if all its blocks are collectively held by peers; the self-sustainability of a swarm is the fraction of time in which the swarm is self-sustaining. We pose the following question: how does the self-sustainability of a swarm vary as a function of content popularity, the service capacity of the users, and the size of the file? We present a model to answer the posed question. We then propose efficient solution methods to compute self-sustainability. The accuracy of our estimates is validated against simulation. Finally, we also provide closed-form expressions for the fraction of time that a given number of blocks is collectively held by peers.Comment: 27 pages, 5 figure

An alternative order parameter for the 4-state Potts model

We have investigated the dynamic critical behavior of the two-dimensional 4-state Potts model using an alternative order parameter first used by Vanderzande [J. Phys. A: Math. Gen. \textbf{20}, L549 (1987)] in the study of the Z(5) model. We have estimated the global persistence exponent $\theta_g$ by following the time evolution of the probability $P(t)$ that the considered order parameter does not change its sign up to time $t$. We have also obtained the critical exponents $\theta$, $z$, $\nu$, and $\beta$ using this alternative definition of the order parameter and our results are in complete agreement with available values found in literature.Comment: 6 pages, 6 figure

TravelGo Tour Management System

The tech-savvy consumer of today has high standards for the customer experience and booking of travel. According to research, online travel booking businesses struggle to convert leads and have the highest rates of cart abandonment. Therefore, to draw in potential clients, turn leads into sales, and differentiate yourself in a market as crowded as the travel sector, it is crucial to have an appealing, interesting, and user-friendly website. Travel websites are now required to bet on innovation, multi-channeling, and the newest web development trends to stay competitive in the tourist industry due to the quick change of customer behavior. Users who use websites as informational resources to organize their vacation look for a streamlined approach and experience. Before making a reservation, the tourist tries to examine various rates and holiday types to determine which is the best and most comprehensive option. The traveler makes his purchase after doing research and exploring various informational sources, such as websites for travel and vacation destinations. Websites must comply with fundamental web development requirements in order to earn the trust of visitors if they don't want to be ignore

Milk production in saanen goats treated with repeated low doses of intermediate-release insulin during early lactation

The effect of insulin administration on the productive responses of Saanen goats during early lactation was investigated. Ten of 20 adult females were subjected to subcutaneous administration of intermediate-acting insulin (0.14UI/kg body weight) at 2, 9, and 14 days postpartum. Milk yield was measured twice daily for 13 weeks and milk samples were collected to measure protein and fat contents. Plasma levels of progesterone, insulin, non-esterifies fatty acids, glucose and other metabolites were measured. Results showed a significantly increased effect of insulin treatment on the content of milk fat and protein; moreover, milk production in the first and second postpartum weeks were higher than control group. The peak of lactation in the insulin group was achieved one week earlier in comparison to the control group. In addition, the milk production rate showed lower persistency (milk yield 13 week/milk yield at peak) in the same group. During the first four weeks of postpartum, treated animals showed greater weight loss and higher non-esterified fatty acid concentration, whereas no effect was observed on the concentration of progesterone and other metabolites. The above results indicated that repeated administration of insulin in dairy goats during early lactation increase yield and qualitative components of milk, but has substantial consequences on animal productive rate and metabolic response

Magnetocaloric Effect And Evidence Of Superparamagnetism In Gda L2 Nanocrystallites: A Magnetic-structural Correlation

The correlation between structural and magnetic properties of GdAl2, focusing on the role played by the disorder in magnetic ordering and how it influences the magnetocaloric effect (MCE) are discussed. Micrometric-sized particles, consisting of nanocrystallites embedded in an amorphous matrix, were prepared by a mechanical milling technique and characterized by means of x-ray diffraction, scanning and high-resolution transmission electron microscopy as well as magnetic measurements as a function of an applied external magnetic field and temperature. The results show that the average particle size is just slightly diminished (≈7%) with the milling time (between 3 and 13 h), whereas the average crystallite size undergoes an expressive reduction (≈43%). For long milling times, structural disorders mostly associated with crystallite size singularly affect the magnetic properties, leading to a large tablelike MCE in the temperature range between 30 and 165 K. Below 30 K, nanocrystallites with dimensions below a given critical size cause an enhancement in the magnetic entropy change related to superparamagnetic behavior. In contrast, for low milling times, relative cooling power values are improved. These striking features along with the small magnetic hysteresis observed make the milled GdAl2 a promising material for application in the magnetic refrigeration technology. Finally, a discussion in an attempt to elucidate the origin of the spin-glass states previously reported in the literature for mechanically milled GdAl2 samples for very long times (400 and 1000 h) is presented. © 2016 American Physical Society.93

Cholesterol-functionalized carvedilol-loaded PLGA nanoparticles: anti-inflammatory, antioxidant, and antitumor effects

The inflammation has been identified as factor of tumor progression, which has increased the interest and use of molecules with anti-inflammatory and antioxidant activities in the cancer treatment. In this study, the antioxidant, anti-inflammatory, and antitumor potentials of carvedilol was explored in a different approach. The cholesterol (CHO) was investigated as facilitated agent in the action of carvedilol-loaded nanoparticles. Different formulations exhibited spherical and stable nanoparticle with mean diameter size < 250 nm. The cholesterol changed the copolymer-drug interactions and the encapsulation efficiency. The in vitro cancer study was performed using murine colorectal cancer cell line (CT-26) to observe the cell viability and apoptosis on MTS assay and flow cytometry, respectively. The experiments have demonstrated that cholesterol improved the performance of drug-loaded nanoparticles, which was much better than free drug. The in vivo inflammation peritonitis model revealed that carvedilol-loaded nanoparticles increased the level of glutathione and leukocyte migration mainly when the functionalized drug-loaded nanoparticles were tested, in a lower dose than the free drug. As hypothesized, the experimental data suggest that cholesterol-functionalized carvedilol-loaded PLGA nanoparticles can be a novel and promising approach in the inflammation-induced cancer therapy since showed anti-inflammatory, antioxidant, and antitumor effects.Graphical abstractRadiolog

Adsortividade do herbicida "Zeta" em solos de variadas texturas

To estimate the herbicide rate which inhibits 50% (I50) of the growth of bioindicator plants in soils of different textures and organic matter levels, which could interfere on the bioactivity of the tested herbicide, a completely randomized experiment was carried out with seven treatments (0, 50, 100, 150, 200, 250 and 300 g a.i./ ha) and four replications, in five kinds of soil textures. The analyzed parameters were: total fresh biomass, dry shoot biomass and dry root biomass of the sorghum plants. According to the results, it can be concluded that in sandy soils the herbicide shows a great vertical mobility, and that high levels of AP+ in the soil can minimize the herbicide effect on plants. The experiment also has shown that the higher the level of active clays and of organic matter in the soil, the higher the rate of herbicide required for a given weed control level.Com o objetivo de estimar a dose do herbicida "Zeta" que inibe 50% I50) do crescimento de plantas bioindicadoras em solos com diferentes texturas e teores de matéria orgânica, podendo estes ter uma influência marcante sobre a bioatividade do herbicida testado, utilizou-se o delineamento experimental inteiramente casualizado com 7 tratamentos (0, 50, 100, 150, 200, 250 e 300 g i.a./ha) e 4 repetições, sendo os tratamentos dispostos em 5 tipos de texturas de solo. Os parâmetros avaliados foram: biomassa fresca total, biomassa seca da parte aérea e biomassa seca do sistema radicular das plantas de sorgo. De acordo com os resultados obtidos pode-se concluir que em solos com textura tendendo à arenosa o herbicida apresenta uma grande mobilidade vertical, e que altos teores de AP+ no solo podem mascarar, de certa forma, a atuação do herbicida na planta. Em linhas gerais, o experimento permitiu inferir que quanto maior os teores de argilas ativas e de matéria orgânica presentes no solo, maior a dose do herbicida requerida para um dado controle percentual de plantas daninhas

Agricultura familiar, multifuncionalidade da agricultura e ruralidade: interfaces de uma realidade complexa.

Nas últimas décadas, assistimos à revitalização do debate em torno da agricultura familiar pela incorporação das discussões sobre as múltiplas funções da agricultura num rural que não pode mais ser visto como domínio exclusivo da atividade agrícola e dos agricultores. No contexto brasileiro, acreditamos que essa discussão deva ser permeada pela análise de como processos diferenciados de distribuição fundiária e desenvolvimento econômico e o tipo de agricultura resultante geram ruralidades específicas com características como, no caso da agricultura familiar, a manutenção de práticas sociais e de trabalho marcadas pelas relações de parentesco e vizinhança presentes numa sociedade de interconhecimento. Partindo desse princípio, este trabalho analisa a agricultura familiar de um bairro rural do município de Ouro Fino - MG, sua herança histórica e sua participação na criação de uma paisagem natural e humana que muito contribui para a atratividade da região