224 research outputs found
Model of optimization of mining complex for the planning of flow of quarry production of limestone in multiple products and with elements for the analysis of the capacity
Activities in mining complexes contain multiple decisions that affect the operations of the system for the extraction, transformation, transport and storage of various subsoil components. The purpose of this research is the planning of continuous flow production systems for mixed products, in non-metallic mining extraction processes, considering bottlenecks and capacity planning. This paper presents a model for production, based on mathematical optimization, that facilitates the planning and management of operations in the area of extraction, crushing and transformation of a quarry of aggregates for construction, considering the resources and the constraints that allow to define effective strategies in the increase of the productivity of the lines of low production environment by scenarios. This research develops an analysis of bottlenecks and contrasts the nature of the production system by means of a mathematical model of optimization, which considers the capacities and balances in the flows of the Limestone production line. The mathematical model that maximizes profits can be adapted to systems of continuous flow production in mining complexes where their products are part of a reverse logistics process, analysis of alternatives of extraction, transformation and transport
A deep learning approach for intelligent cockpits: learning drivers routines
Nowadays an increasing number of vehicles are being equipped with powerful cockpit systems capable of collecting drivers’ footprints over time. The collection of this valuable data opens effective opportunities for routine prediction. With the growing ability of vehicles to collect spatial and temporal information solving the routine prediction problem becomes crucial and feasible. It is then extremely important to advance and take advantage of the capabilities of these cockpit systems. A vehicle that is capable of predicting the next destination of the driver and when the driver intends to leave to that destination can prepare the journey in advance. Previous studies tackling the next location prediction problem have made use of Traditional Markov models, Neural Networks, Dynamic models, among others. In this work, a framework based on the hierarchical density-based clustering algorithm followed by a Long Short-Term Memory (LSTM) recurrent neural network is proposed for spatial-temporal prediction of drivers’ routines. Based on real-life driving scenarios of three different users, the proposed approach achieved a test set accuracy of 96.20%, 90.23%, and 86.40% when predicting the next destination and a R2 Score of 93.69, 79.21, and 28.81 when predicting the departure time, respectively. The results indicate that the proposed architecture can be implemented on the vehicle cockpit for the assistance of the management of future trips.Programme (COMPETE 2020) and national funds, through the ADI Project Bosch & UMinho “Easy Ride: Experience is everything” , ref POCI-01-0247 FEDER-039334FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 and UIDB/00013/2020
Guillain-Barré syndrome: a century of progress
In 1916, Guillain, Barré and Strohl reported on two cases of acute flaccid paralysis with high cerebrospinal fluid protein levels and normal cell counts — novel findings that identified the disease we now know as Guillain–Barré syndrome (GBS). 100 years on, we have made great progress with the clinical and pathological characterization of GBS. Early clinicopathological and animal studies indicated that GBS was an immune-mediated demyelinating disorder, and that severe GBS could result in secondary axonal injury; the current treatments of plasma exchange and intravenous immunoglobulin, which were developed in the 1980s, are based on this premise. Subsequent work has, however, shown that primary axonal injury can be the underlying disease. The association of Campylobacter jejuni strains has led to confirmation that anti-ganglioside antibodies are pathogenic and that axonal GBS involves an antibody and complement-mediated disruption of nodes of Ranvier, neuromuscular junctions and other neuronal and glial membranes. Now, ongoing clinical trials of the complement inhibitor eculizumab are the first targeted immunotherapy in GBS
Decoration Increases the Conspicuousness of Raptor Nests
Avian nests are frequently concealed or camouflaged, but a number of species builds noticeable nests or use conspicuous materials for nest decoration. In most cases, nest decoration has a role in mate choice or provides thermoregulatory or antiparasitic benefits. In territorial species however, decorations may serve additional or complementary functions, such as extended phenotypic signaling of nest-site occupancy and social status to potential intruders. The latter may benefit both signaler and receiver by minimizing the risk of aggressive interactions, especially in organisms with dangerous weaponry. Support for this hypothesis was recently found in a population of black kites (Milvus migrans), a territorial raptor that decorates its nest with white artificial materials. However, the crucial assumption that nest decorations increased nest-site visibility to conspecifics was not assessed, a key aspect given that black kite nests may be well concealed within the canopy. Here, we used an unmanned aircraft system to take pictures of black kite nests, with and without an experimentally placed decoration, from different altitudes and distances simulating the perspective of a flying and approaching, prospecting intruder. The pictures were shown to human volunteers through a standardized routine to determine whether detection rates varied according the nest decoration status and distance. Decorated nests consistently showed a higher detection frequency and a lower detection-latency, compared to undecorated versions of the same nests. Our results confirm that nest decoration in this species may act as a signaling medium that enhances nest visibility for aerial receivers, even at large distances. This finding complements previous work on this communication system, which showed that nest decoration was a threat informing trespassing conspecifics on the social dominance, territory quality and fighting capabilities of the signaler
Hepatitis E in southern Vietnam: Seroepidemiology in humans and molecular epidemiology in pigs.
Viral pathogens account for a significant proportion of the burden of emerging infectious diseases in humans. The Wellcome Trust-Vietnamese Initiative on Zoonotic Infections (WT-VIZIONS) is aiming to understand the circulation of viral zoonotic pathogens in animals that pose a potential risk to human health. Evidence suggests that human exposure and infections with hepatitis E virus (HEV) genotypes (GT) 3 and 4 results from zoonotic transmission. Hypothesising that HEV GT3 and GT4 are circulating in the Vietnamese pig population and can be transmitted to humans, we aimed to estimate the seroprevalence of HEV exposure in a population of farmers and the general population. We additionally performed sequence analysis of HEV in pig populations in the same region to address knowledge gaps regarding HEV circulation and to evaluate if pigs were a potential source of HEV exposure. We found a high prevalence of HEV GT3 viral RNA in pigs (19.1% in faecal samples and 8.2% in rectal swabs) and a high HEV seroprevalence in pig farmers (16.0%) and a hospital-attending population (31.7%) in southern Vietnam. The hospital population was recruited as a general-population proxy even though this particular population subgroup may introduce bias. The detection of HEV RNA in pigs indicates that HEV may be a zoonotic disease risk in this location, although a larger sample size is required to infer an association between HEV positivity in pigs and seroprevalence in humans
Oxford Phase 3 unicompartmental knee arthroplasty: medium-term results of a minimally invasive surgical procedure
PURPOSE: In the last decade, a major increase in the use of and interest in unicompartmental knee arthroplasty (UKA) has developed. The Oxford Phase 3 UKA is implanted with a minimally invasive technique using newly developed instruments. The objective of this prospective study was to evaluate the outcome of UKA in patients with medial osteoarthritis of the knee in a high-volume unit. METHODS: Two-hundred and forty-four UKAs were performed with a minimally invasive approach. The median age was 72 (43-91) years. The median follow-up was 4.2 years (range 1-10.4 years). Fourteen patients died, and nine were considered to be lost to follow-up, but all had a well-functioning prosthesis in situ until their last follow-up. Pain, function and health-related quality of life were evaluated pre- and postoperatively using patient- and assessor-based outcome scores, as well as radiographic evidence. RESULTS: The mean Knee Society knee and function scores, WOMAC-scores, Oxford-score and VAS pain and satisfaction all improved. Nine knees required revision. Eleven patients required an additional arthroscopic procedure due to persisting pain secondary to intra-articular pathology, and four patients required manipulation under anaesthesia because of limited range of motion. The 7-year cumulative survival rate of the arthroplasty was 94.4%. A low incidence (21%) of a radiolucent line beneath the tibial component was observed at 5 years of follow-up. CONCLUSION: This study showed a high survival rate of the Oxford Phase 3 UKA. Patient satisfaction and functional performance were also very high. Major complication rate was low; in addition, the incidence of radiolucency under the tibial component, when compared to present literature, was low. When strict indication criteria are followed, excellent, durable, and in our opinion reliable, results can be expected for this procedur
Kernel Architecture of the Genetic Circuitry of the Arabidopsis Circadian System
A wide range of organisms features molecular machines, circadian clocks,
which generate endogenous oscillations with ~24 h periodicity and thereby
synchronize biological processes to diurnal environmental fluctuations.
Recently, it has become clear that plants harbor more complex gene regulatory
circuits within the core circadian clocks than other organisms, inspiring a
fundamental question: are all these regulatory interactions between clock genes
equally crucial for the establishment and maintenance of circadian rhythms? Our
mechanistic simulation for Arabidopsis thaliana demonstrates that at least half
of the total regulatory interactions must be present to express the circadian
molecular profiles observed in wild-type plants. A set of those essential
interactions is called herein a kernel of the circadian system. The kernel
structure unbiasedly reveals four interlocked negative feedback loops
contributing to circadian rhythms, and three feedback loops among them drive
the autonomous oscillation itself. Strikingly, the kernel structure, as well as
the whole clock circuitry, is overwhelmingly composed of inhibitory, rather
than activating, interactions between genes. We found that this tendency
underlies plant circadian molecular profiles which often exhibit
sharply-shaped, cuspidate waveforms. Through the generation of these cuspidate
profiles, inhibitory interactions may facilitate the global coordination of
temporally-distant clock events that are markedly peaked at very specific times
of day. Our systematic approach resulting in experimentally-testable
predictions provides insights into a design principle of biological clockwork,
with implications for synthetic biology.Comment: Supplementary material is available at the journal websit
Postdigital Dialogue
This article is a multi-authored experimental postdigital dialogue about postdigital dialogue. Fourteen authors were invited to produce their sections, followed by two author-reviewers who examined the article as a whole. Authors were invited to reflect on Petar Jandric’s book Learning in the age of digital reason (2017) or to produce completely new insights. The article also contains a summary of book symposium on Learning in the age of digital reason held at the 2017 American Educational Research Conference (AERA). The authors are tentatively confident that this article produces more knowledge than the arithmetic sum of its constituent parts. However, they are also very aware of its limits and insist that their conclusions are not consensual or homogenous. As traditional forms of research increasingly fail to describe our current reality, they present this article as an experiment and a possible starting point for developing new dialogical research approaches fit for our postdigital reality
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