19,848 research outputs found
Tramp Ship Scheduling Problem with Berth Allocation Considerations and Time-dependent Constraints
This work presents a model for the Tramp Ship Scheduling problem including
berth allocation considerations, motivated by a real case of a shipping
company. The aim is to determine the travel schedule for each vessel
considering multiple docking and multiple time windows at the berths. This work
is innovative due to the consideration of both spatial and temporal attributes
during the scheduling process. The resulting model is formulated as a
mixed-integer linear programming problem, and a heuristic method to deal with
multiple vessel schedules is also presented. Numerical experimentation is
performed to highlight the benefits of the proposed approach and the
applicability of the heuristic. Conclusions and recommendations for further
research are provided.Comment: 16 pages, 3 figures, 5 tables, proceedings paper of Mexican
International Conference on Artificial Intelligence (MICAI) 201
Finished Genome Sequence of Collimonas arenae Cal35.
We announce the finished genome sequence of soil forest isolate Collimonas arenae Cal35, which comprises a 5.6-Mbp chromosome and 41-kb plasmid. The Cal35 genome is the second one published for the bacterial genus Collimonas and represents the first opportunity for high-resolution comparison of genome content and synteny among collimonads
Transpleural systemic artery-pulmonary artery communications in the absence of chronic inflammatory lung disease. A case series and review of the literature
AIM: To describe the causes and computed tomography (CT) and angiographic appearances of transpleural systemic artery-pulmonary artery shunts in patients without chronic inflammatory lung disease and determine their best management. MATERIALS AND METHODS: All patients referred to a tertiary referral unit between January 2013 and January 2020 in whom a diagnosis of a systemic-pulmonary artery communication without underlying chronic inflammatory lung disease was subsequently made have been included in this report. Medical records and imaging findings were reviewed retrospectively. RESULTS: Ten patients (male: female ratio = 7:3; median age 42 years [range 22-70 years]) with systemic artery-pulmonary artery shunts without chronic inflammatory lung disease were identified. Five were misdiagnosed as having a pulmonary arteriovenous malformation and had been referred for embolisation. In six patients, there was either a history of accidental or iatrogenic thoracic trauma or of inflammatory disease involving the pleura, and in two patients, in whom a previous medical history could not be obtained, there were CT features suggesting previous pleural inflammatory disease. Two shunts were thought to be congenital. All individuals were asymptomatic other than one with localised thoracic discomfort that dated from the time of surgery. All patients were managed conservatively and have remained well with a median follow-up of 4.5 years (range 1-11.3 years). CONCLUSIONS: Localised transpleural systemic artery-pulmonary artery shunts in the absence of chronic inflammatory lung disease are usually related to previous thoracic trauma/intervention or abdominal or pulmonary sepsis involving a pleural or diaphragmatic surface. Congenital shunts are rare. The present study and much of the literature supports conservative management
Evaluation of chemical composition of the leaves of Ocimum gratissimum and Vernonia amygdalina
The leaves of Ocimum gratissimum and Vernonia amygdalina were analyzed for their chemical composition, minerals and vitamins. The results obtained from the analysis of the two plants were compared. The results revealed the presence of bioactive constituents comprising alkaloids (1.90 to 2.68 mg/100 g), tannins (0.04 to 0.07 mg/100g), saponins (0.06 to 2.94 mg/100 g), flavonoids (1.88 to 2.98 mg/100 g) and phenols (0.03 to 0.07 mg/100g). These plants contained ascorbic acid (241.06 to 310.62 mg/100 g), niacin (0.29 to 0.80 mg/100 g), riboflavin (0.08 to 0.09 mg/100 g) and thiamine (0.03 to 0.08 mg/100 g). These plants are good sources of minerals such as Ca, P, K, Mg, Na, Fe and Zn. The importance of these chemical constituents with respect to their roles in ethnomedicine in Nigeria was also discussed.Keywords: Bioactive compounds, Ocimum gratissimum, Vernonia amygdalin
The effect of paired corticospinalâmotoneuronal stimulation on maximal voluntary elbow flexion in cervical spinal cord injury: an experimental study
Study design: Randomised, controlled, crossover study. Objectives: Paired corticospinalâmotoneuronal stimulation (PCMS) involves repeatedly pairing stimuli to corticospinal neurones and motoneurones to induce changes in corticospinal transmission. Here, we examined whether PCMS could enhance maximal voluntary elbow flexion in people with cervical spinal cord injury. Setting: Neuroscience Research Australia, Sydney, Australia. Methods: PCMS comprised 100 pairs of transcranial magnetic and electrical peripheral nerve stimulation (0.1 Hz), timed so corticospinal potentials arrived at corticospinalâmotoneuronal synapses 1.5 ms before antidromic motoneuronal potentials. On two separate days, sets of five maximal elbow flexions were performed by 11 individuals with weak elbow flexors post C4 or C5 spinal cord injury before and after PCMS or control (100 peripheral nerve stimuli) conditioning. During contractions, supramaximal biceps brachii stimulation elicited superimposed twitches, which were expressed as a proportion of resting twitches to give maximal voluntary activation. Maximal torque and electromyographic activity were also assessed. Results: Baseline median (range) maximal torque was 11 Nm (6â41 Nm) and voluntary activation was 92% (62â99%). Linear mixed modelling revealed no significant differences between PCMS and control protocols after conditioning (maximal torque: p = 0.87, superimposed twitch: p = 0.87, resting twitch: p = 0.44, voluntary activation: p = 0.36, biceps EMG: p = 0.25, brachioradialis EMG: 0.67). Conclusions: Possible explanations for the lack of effect include a potential ceiling effect for voluntary activation, or that PCMS may be less effective for elbow flexors than distal muscles. Despite results, previous studies suggest that PCMS is worthy of further investigation
The evolution of pitch angles of spiral arms
This is the final version. Available from Oxford University Press via the DOI in this recordIn spiral galaxies, the pitch angle, α, of the spiral arms is often proposed as a discriminator between theories for the formation of the spiral structure. In LinâShu density wave theory, α stays constant in time, being simply a property of the underlying galaxy. In other theories (e.g. tidal interaction, and self-gravity), it is expected that the arms wind up in time, so that to a first approximation cot α â t. For these theories, it would be expected that a sample of galaxies observed at random times should show a uniform distribution of cot α. We show that a recent set of measurements of spiral pitch angles (Yu & Ho) is broadly consistent with this expectation.European Union FP7Science and Technology Facilities Council (STFC
The reliability of inspiratory resistive load magnitude and detection testing
Objectives: To assess the test-retest reliability of inspiratory load detection and load magnitude perception tests in healthy volunteers. Design: Cohort of convenience. Setting: Respiratory physiology laboratory. Participants: Twenty healthy adults. Interventions: On two separate occasions participants performed tests of inspiratory loading. Participants breathed through custom made resistive tubing and were asked to indicate when they detected a different resistance during inspiration. In a second test participants rated the magnitude of presented inspiratory loads using the modified Borg score. Main Outcome Measures: Intra-class Correlation Coefficient (ICC2,1) values for repeated tests of inspiratory load detection threshold and load magnitude rating. Results: ICC2,1 values ranged from 0.657â0.786 for load detection testing and 0.739 to 0.969 for rating of load magnitude. Conclusions: The tests are simple and reliable measures of inspiratory load detection and magnitude rating. They can be used in future research to determine the effectiveness of interventions to reduce the effort of breathing in health and disease
Optimal electrode position for abdominal functional electrical stimulation
Abdominal functional electrical stimulation (abdominal FES) improves respiratory function. Despite this, clinical use remains low, possibly due to lack of agreement on the optimal electrode position. This study aimed to ascertain the optimal electrode position for abdominal FES, assessed by expiratory twitch pressure. Ten able-bodied participants received abdominal FES using electrodes placed: 1) on the posterolateral abdominal wall and at the motor points of 2) the external oblique muscles plus rectus abdominis muscles, and 3) the external obliques alone. Gastric (Pga) and esophageal (Pes) twitch pressures were measured using a gastroesophageal catheter. Single-stimulation pulses were applied at functional residual capacity during step increments in stimulation current to maximal tolerance or until Pga plateaued. Stimulation applied on the posterolateral abdominal wall led to a 71% and 53% increase in Pga and Pes, respectively.compared with stimulation of the external oblique and rectus abdominis muscles (P < 0.001) and a 95% and 56% increase in Pga and Pes, respectively.compared with stimulation of the external oblique muscles alone (P < 0.001). Stimulation of both the external oblique and rectus abdominis muscles led to an 18.3% decrease in Pg.compared with stimulation of only the external oblique muscles (P = 0.040), with inclusion of the rectus abdominis having no effect on Pes (P = 0.809). Abdominal FES applied on the posterolateral abdominal wall generated the highest expiratory twitch pressures. As expiratory pressure is a good indicator of expiratory muscle strength and, thus, cough efficacy, we recommend this electrode position for all therapeutic applications of abdominal FES. NEW & NOTEWORTHY While abdominal functional electrical stimulation (abdominal FES) can improve respiratory function, clinical use remains low. This is at least partly due to lack of agreement on the optimal electrode position. Therefore, this study aimed to ascertain the optimal electrode position for abdominal FES. We show that electrodes placed on the posterolateral abdominal wall generated the highest expiratory twitch pressures. As such, we recommend this electrode position for all therapeutic applications of abdominal FES
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