144. Recognizing patients in whom CT-myelography detects additional level of stenosis compared to MRI

OBJECTIVESpontaneous spinal CSF leaks are caused by abnormalities of the spinal dura mater. Although most cases are treated conservatively or with an epidural blood patch, some intractable cases require neurosurgical treatment. However, previous reports are limited to a small number of cases. Preoperative detection and localization of spinal dural defects are difficult, and surgical repair of these defects is technically challenging. The authors present the anatomical characteristics of dural defects and surgical techniques in treating spontaneous CSF leaks.METHODSAmong the consecutive patients who were diagnosed with spontaneous CSF leaks at the authors’ institution between 2010 and 2020, those who required neurosurgical treatment were included in the study. All patients’ clinical information, radiological studies, surgical notes, and outcomes were reviewed retrospectively. Outcomes of two different procedures in repairing dural defects were compared.RESULTSAmong 77 patients diagnosed with spontaneous CSF leaks, 21 patients (15 men; mean age 57 years) underwent neurosurgery. Dural defects were detected by FIESTA MRI in 7 patients, by CT myelography in 12, by digital subtraction myelography in 1, and by dynamic CT myelography in 1. The spinal levels of the defects were localized at the cervicothoracic junction in 16 patients (76%) and thoracolumbar junction in 4 (19%). Intraoperative findings revealed that the dural defects were small, circumscribed longitudinal slits located at the ventral aspect of the dura mater. The median dural defect size was 5 × 2 mm. The presence of dural defects at the thoracolumbar junction was associated with manifestation of an altered mental status, which was an unusual manifestation of CSF leaks (p = 0.003). Eight patients were treated via the posterior transdural approach with watertight primary sutures of the ventral defects, and 13 were treated with muscle or fat grafting. Regardless of the two different procedures, postoperative MRI showed either complete disappearance or significant reduction of the extradural CSF collection. No patient experienced postoperative neurological deficits. Clinical symptoms improved or stabilized in 20 patients with a median follow-up of 12 months.CONCLUSIONSDural defects in spontaneous CSF leaks were small, circumscribed longitudinal slits located ventral to the spinal cord at either the cervicothoracic or thoracolumbar junction. Muscle/fat grafting may be an alternative treatment to watertight primary sutures of ventral dural defects with a good outcome.

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"Nécessité d'une orientation esthétique": Techniques of Development in the Music of Boulez

Music Theory and Analysis (MTA) ◽

10.11116/mta.6.1.3 ◽

2019 ◽

Vol 6 (1) ◽

pp. 87-129

Author(s):

Catherine Losada

Keyword(s):

Significant Influence ◽

Major Change ◽

Compositional Process ◽

Base Materials ◽

Compositional Approach ◽

The Creation ◽

Open Work ◽

Additional Level ◽

New Perspective ◽

The 1960S

The latter part of the 1950s saw a major change in Boulez's compositional approach: Instead of creating extensive pre-compositional sketches, he increasingly reused previously composed materials as the basis for new works. The shifting aesthetics that characterized this period had a significant influence on Boulez. His works from the late 1950s explore the ideas of mobility embedded in the open work. Balancing the concept of mobility with the ideals of control that form the basis of his compositional ideology led to an economy of means and an associated emphasis on the concept of development in his compositional process. Both facilitated the creation of new works from a more limited array of base materials.<br/> Tracing the concept of development in a sample of Boulez's sketches and works from the late 1950s through the 1960s, this essay presents a preliminary typology of recurring pitch and temporal developmental techniques. By taking a bird's-eye view, I add an additional level of interpretation, emphasizing their formal function, association with aspects of middleground structure and studying their implications in terms of perception. In this way, I present a new perspective on the association between these techniques and the practice of derivation from a limited amount of material that characterizes these works.

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Utilising Flow Aggregation to Classify Benign Imitating Attacks

Sensors ◽

10.3390/s21051761 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1761

Author(s):

Hanan Hindy ◽

Robert Atkinson ◽

Christos Tachtatzis ◽

Ethan Bayne ◽

Miroslav Bures ◽

...

Keyword(s):

Machine Learning ◽

Feature Extraction ◽

Network Traffic ◽

Cyber Attacks ◽

Detection Accuracy ◽

Computational Power ◽

Human Understanding ◽

Flow Aggregation ◽

Additional Level ◽

Attack Surfaces

Cyber-attacks continue to grow, both in terms of volume and sophistication. This is aided by an increase in available computational power, expanding attack surfaces, and advancements in the human understanding of how to make attacks undetectable. Unsurprisingly, machine learning is utilised to defend against these attacks. In many applications, the choice of features is more important than the choice of model. A range of studies have, with varying degrees of success, attempted to discriminate between benign traffic and well-known cyber-attacks. The features used in these studies are broadly similar and have demonstrated their effectiveness in situations where cyber-attacks do not imitate benign behaviour. To overcome this barrier, in this manuscript, we introduce new features based on a higher level of abstraction of network traffic. Specifically, we perform flow aggregation by grouping flows with similarities. This additional level of feature abstraction benefits from cumulative information, thus qualifying the models to classify cyber-attacks that mimic benign traffic. The performance of the new features is evaluated using the benchmark CICIDS2017 dataset, and the results demonstrate their validity and effectiveness. This novel proposal will improve the detection accuracy of cyber-attacks and also build towards a new direction of feature extraction for complex ones.

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Biomass estimates derived from sector subsampling of 360° spherical images

Forestry An International Journal of Forest Research ◽

10.1093/forestry/cpab023 ◽

2021 ◽

Author(s):

Xiao Dai ◽

Mark J Ducey ◽

Haozhou Wang ◽

Ting-Ru Yang ◽

Yung-Han Hsu ◽

...

Keyword(s):

Basal Area ◽

Sampling Errors ◽

Eastern Canada ◽

Individual Tree ◽

Inventory Costs ◽

Standard Error Estimation ◽

The Mean ◽

Biomass Ratio ◽

Spherical Images ◽

Additional Level

Abstract Efficient subsampling designs reduce forest inventory costs by focusing sampling efforts on more variable forest attributes. Sector subsampling is an efficient and accurate alternative to big basal area factor (big BAF) sampling to estimate the mean basal area to biomass ratio. In this study, we apply sector subsampling of spherical images to estimate aboveground biomass and compare our image-based estimates with field data collected from three early spacing trials on western Newfoundland Island in eastern Canada. The results show that sector subsampling of spherical images produced increased sampling errors of 0.3–3.4 per cent with only about 60 trees measured across 30 spherical images compared with about 4000 trees measured in the field. Photo-derived basal area was underestimated because of occluded trees; however, we implemented an additional level of subsampling, collecting field-based basal area counts, to correct for bias due to occluded trees. We applied Bruce’s formula for standard error estimation to our three-level hierarchical subsampling scheme and showed that Bruce’s formula is generalizable to any dimension of hierarchical subsampling. Spherical images are easily and quickly captured in the field using a consumer-grade 360° camera and sector subsampling, including all individual tree measurements, were obtained using a custom-developed python software package. The system is an efficient and accurate photo-based alternative to field-based big BAF subsampling.

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Memristors as Candidates for Replacing Digital Potentiometers in Electric Circuits

Electronics ◽

10.3390/electronics10020181 ◽

2021 ◽

Vol 10 (2) ◽

pp. 181

Author(s):

Ivo Marković ◽

Milka Potrebić ◽

Dejan Tošić

Keyword(s):

Phase Shifter ◽

Voltage Divider ◽

Frequency Characteristics ◽

Phase Shifters ◽

Pass Filter ◽

Electric Circuits ◽

Digital Potentiometer ◽

Memristive Circuits ◽

Parasitic Effects ◽

Additional Level

Digital potentiometers are substantial components for the design of many mixed-signal electronic circuits and systems. Their capability to program resistance value almost instantly provides hardware designers an additional level of freedom. Unfortunately, this feature is limited to DC and lower frequencies, due to parasitic effects. Nowadays, memristors as continuously tunable resistors are becoming candidates for potentiometer successors. Memristors are two-terminal non-volatile devices which have less significant parasitic effects and a wide resistance range. The memristance value can be changed on the fly. Using nanotechnology, memristor implementation has a nanoscale footprint with nanosecond transition between resistive states. In this paper, we present a comparison between the frequency characteristics of digital potentiometers and the only commercially available memristors. Memristor parasitic effects dominate at higher frequencies which extends the bandwidth. In order to present the advantages of memristive circuits, we have analyzed and implemented tunable circuits such as a voltage divider, an inverting amplifier, a high-pass filter, and a phase shifter. A commercially available memristor by KnowM Inc. is used for this purpose. Experimental results obtained by the measurements verify that a memristor has equal or better characteristics than a digital potentiometer. Memristive realizations of voltage dividers and inverting amplifiers have a wider bandwidth, while filters and phase shifters with a memristor have almost identical frequency characteristics as the corresponding realizations with a digital potentiometer.

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Regulation of Metabolic Reprogramming by Long Non-Coding RNAs in Cancer

Cancers ◽

10.3390/cancers13143485 ◽

2021 ◽

Vol 13 (14) ◽

pp. 3485

Author(s):

Assunta Sellitto ◽

Giovanni Pecoraro ◽

Giorgio Giurato ◽

Giovanni Nassa ◽

Francesca Rizzo ◽

...

Keyword(s):

Lipid Metabolism ◽

Cancer Cells ◽

Metabolic Reprogramming ◽

Metabolic Phenotype ◽

Metabolic Alterations ◽

Cell Proliferation And Differentiation ◽

Non Coding Rna ◽

Proliferation And Differentiation ◽

Non Coding Rnas ◽

Additional Level

Metabolic reprogramming is a well described hallmark of cancer. Oncogenic stimuli and the microenvironment shape the metabolic phenotype of cancer cells, causing pathological modifications of carbohydrate, amino acid and lipid metabolism that support the uncontrolled growth and proliferation of cancer cells. Conversely, metabolic alterations in cancer can drive changes in genetic programs affecting cell proliferation and differentiation. In recent years, the role of non-coding RNAs in metabolic reprogramming in cancer has been extensively studied. Here, we review this topic, with a focus on glucose, glutamine, and lipid metabolism and point to some evidence that metabolic alterations occurring in cancer can drive changes in non-coding RNA expression, thus adding an additional level of complexity in the relationship between metabolism and genetic programs in cancer cells.

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Association between indicators of livestock farming intensity and hospitalization rate for acute gastroenteritis

Epidemiology and Infection ◽

10.1017/s0950268808001647 ◽

2009 ◽

Vol 137 (8) ◽

pp. 1073-1085 ◽

Cited By ~ 13

Author(s):

Y. FEBRIANI ◽

P. LEVALLOIS ◽

G. LEBEL ◽

S. GINGRAS

Keyword(s):

Acute Gastroenteritis ◽

Water Source ◽

Hospitalization Rate ◽

Livestock Farming ◽

Zoonotic Infections ◽

Livestock Density ◽

Modifying Effect ◽

Additional Level ◽

Strength Of Association ◽

Effect Of Age

SUMMARYTo evaluate associations between indicators of livestock farming intensity (manure surplus and livestock density) and acute gastroenteritis hospitalization (AGH) rate, we conducted an ecological study on 306 selected agricultural municipalities of Quebec. We estimated the AGH rate for the period 2000–2004 from the Quebec hospital database. Multivariate Poisson regression was used to estimate the strength of association between the farming indicators and AGH with adjustment for confounders. The modifying effect of age and water source was also evaluated. Association between manure and AGH was observed in children, especially those aged 0–4 years for selected zoonotic infections [adjusted hospitalization rate ratio (aHRR) 1·93, 95% CI 1·21–3·09]. The risk ratio was higher for subjects using ground-water source. An increasing HRR trend with each additional level of poultry density was observed in children aged 0–4 years, especially forSalmonellainfections. We conclude that livestock farming intensity may be linked to bacterial acute gastroenteritis in children.

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