Erroneous Readings Research Articles

High temperature exposure of in-situ thermocouple fixed-point cells: stability with up to three months of continuous use

To categorise thermocouples in batches, manufacturers state an expected operating tolerance for when the thermocouples are as-new. In use, thermocouple behaviour can rapidly change and the tolerance becomes invalid, especially when used at high temperatures (i.e. above 1000 °C) as the processes leading to de-calibration, such as oxidation and contamination, can be very fast and lead to erroneous readings. In-situ thermocouple self-validation provides a method to track the drift and correct the thermocouple reading in real-time, but it must be shown to be reliable. Two miniature temperature fixed-point cells designed at NPL for in-situ thermocouple self-validation, the first containing a Pt-C eutectic alloy and the second containing a Ru-C eutectic alloy, have been exposed to temperatures close to their melting point for 2200 h and 1570 h, respectively, and continuously, for up to three months. Recalibration after this long-term high-temperature exposure, where a tantalum-sheathed thermocouple was always in place, is used to show that no significant change of the temperature reference point (the melting temperature) has occurred in either the Pt-C ingot or the Ru-C ingot, over timescales far longer than previously demonstrated and approaching that required by industry for practical use of the device.

Clustering of reads with alignment-free measures and quality values.

BackgroundThe data volume generated by Next-Generation Sequencing (NGS) technologies is growing at a pace that is now challenging the storage and data processing capacities of modern computer systems. In this context an important aspect is the reduction of data complexity by collapsing redundant reads in a single cluster to improve the run time, memory requirements, and quality of post-processing steps like assembly and error correction. Several alignment-free measures, based on k-mers counts, have been used to cluster reads.Quality scores produced by NGS platforms are fundamental for various analysis of NGS data like reads mapping and error detection. Moreover future-generation sequencing platforms will produce long reads but with a large number of erroneous bases (up to 15 %).ResultsIn this scenario it will be fundamental to exploit quality value information within the alignment-free framework. To the best of our knowledge this is the first study that incorporates quality value information and k-mers counts, in the context of alignment-free measures, for the comparison of reads data. Based on this principles, in this paper we present a family of alignment-free measures called Dq-type. A set of experiments on simulated and real reads data confirms that the new measures are superior to other classical alignment-free statistics, especially when erroneous reads are considered. Also results on de novo assembly and metagenomic reads classification show that the introduction of quality values improves over standard alignment-free measures. These statistics are implemented in a software called QCluster (http://www.dei.unipd.it/~ciompin/main/qcluster.html).

Integrative weaning index: New kid on the block!

Weaning covers the entire process of liberating the patient from mechanical ventilation and endotracheal tube.[1] Till date, no weaning index has been shown to accurately predict weaning success. The decision to wean a patient by clinical judgment of the physician is not always correct and is met with a high incidence of weaning failure. The challenge for critical care physicians is to balance the act of successfully weaning the patient from ventilator against the dreadful need of re-intubation. The need for accurate prediction applies to all phases of weaning, beginning with reductions in mechanical support, as patients are increasingly able to support their own breathing, followed by trials of unassisted breathing, which often precede extubation and ending with extubation.[2] An ideal weaning index should be able to discriminate between those patients who can be successfully weaned from mechanical ventilation and those who are unable to be weaned. Many factors can influence the weaning outcome: The functional parameters used as indexes of weaning, the criteria used to define failure or success, the moment at which the patients are studied, different clinical practice from unit to unit, and the different populations.[3] Esteban et al.[4] along with other Spanish Lung Failure Collaborative Group researchers introduced weaning by attempting a 2-h spontaneous breathing trial (SBT) and concluded that two-thirds of ventilated patients can be successfully discontinued from ventilator after a 2-h SBT. Based on these findings, the critical care physicians have been practicing SBT and if the patient fulfills the objective and subjective readiness criteria, the trachea is extubated. Nevertheless, around 12–25% of the patients experience respiratory insufficiency postextubation and require re-intubation.[5] Hence, this method does not have accurate predictive value. Yang and Tobin[6] in 1991 developed a new weaning index and named it rapid shallow breathing index (RSBI) and had concluded that RSBI is the single most accurate predictor of weaning success and has a predictive value of 89%. Since then, this index has been evaluated in almost 22 studies published. Lee et al.[7] suggested that RSBI could be employed more usefully as a trend monitor rather than as a spot check. Various studies have found that RSBI <105 breaths/min/L has a sensitivity, 65–96%; specificity, 0–73%; and hence only modestly predicts extubation success. Nemer et al.[8] in 2009 defined the integrative weaning index (IWI) and its predictiveness for successful weaning. The principle of IWI is to integrate three important components of breathing in a single equation: The respiratory mechanics, oxygenation, and breathing pattern. The principle that static compliance and SaO2 are directly proportional to weaning success and RSBI values are inversely proportional to weaning success have been incorporated in the equation. The authors of the present study[9] have based their study on the above-mentioned article and compared IWI with routine weaning criteria. They have shown IWI can accurately predict weaning failure even in patients who tolerate SBTs. To incorporate IWI in routine weaning prediction model, we have to understand certain important points. First, there are very limited studies on IWI and most of the studies have majority of chronic obstructive pulmonary disease patients as their study subjects. Hence, the question whether this weaning index accurately predict successful weaning in other conditions of acute respiratory failure needs a larger extrapulmonary database as the respiratory mechanics may change with the disease. Second, when the patients are in the weaning phase, calculation of static respiratory compliance with patients’ breathing spontaneously can give erroneous readings. So, to get an accurate reading, the patient's respiratory effort either has to be abolished or the patient has to voluntarily become apneic. To calculate IWI, static compliance plays a very important role and one has to be sure about the method of obtaining the correct compliance value. In the present study, the authors have done justice to the first point by enrolling patients with varied etiologies of respiratory failure although the total number of patients is less. They also have taken into account the second point by taking the digital display value of static respiratory compliance by selectively deleting the values where patient had taken respiratory effort. The positive predictive value of IWI in the study is 97%, which is almost the same as the original article which had 99%. In this present study, the authors have been able to predict statistically significant weaning success. Even with limited literature on IWI, the concept looks appealing with such high sensitivity and specificity. To make IWI as a routine predictor of weaning success could be an excellent advancement in the respiratory management, but require more studies.

An audit and suggested guidelines for in-patient blood pressure measurement.

No universally accepted guideline exists for measurement of blood pressure for patients confined to bed. The aim was to establish areas of technique that might be open to standardization to improve measurement reliability similar to those used for office BP measurements. In-patient blood pressure measurement (IPBPM) was closely observed in 100 patients in a variety of medical wards during routine vital signs observation rounds, comparing the methods observed with current office BPM guidelines. IPBPM, always taken initially with automated machines, was measured once only in 96% of patients. Around 7% patients were lying flat, 32% semi-reclined, 24% had their back unsupported, 15% crossed legs, 9% arms unsupported, 65% arm below heart level, 4% above, 36% incorrect cuff size for arm circumference, 43% bladder not centred over brachial artery and 14% had arrhythmia not documented by ward staff during the measurement. Staff and patients were conversing during 41% measurements. There is a lack of standardization of automated IPBPM technique including a failure to adhere to principles of measurement already established for office BP in a majority (97%) of patients. This may lead to potentially erroneous BP readings, which are an unreliable basis for clinical interpretation and decision making. There is a need for universal hospital-specific guidelines for IPBPM and programmes to train and monitor staff for adherence to these. Particular attention should be given to those factors well known to affect blood pressure measurement, including correct cuff size and placement, arm position and absence of talking during measurement as well as only using validated machines. Additional recommendations might include the routine use of manual BP readings where appropriate (such as with very low or irregular heart rates), BP measured in both arms on admission and the arm with the highest BP used thereafter and recording the side of IPBPM and patient position. We recommend that a task force is commissioned to develop universal guidelines for this important part of clinical assessment.

Assessment of tissue perfusion in the lower limb: current methods and techniques under development.

Peripheral arterial disease (PAD) affects 27 million individuals in Europe and North America.1 This condition causes a severe restriction of blood flow that can lead to critical limb ischemia (CLI), a condition characterized by rest pain, ulceration, or gangrene, which is associated with limb loss in ≈25% of cases.2 The ischemic limb can be revascularized by endovascular techniques (angioplasty/stenting) or surgical bypass. Imaging modalities, including duplex ultrasound, MR angiography, computer tomographic angiography, or intra-arterial angiography, are used to assess the extent of disease, plan intervention, and confirm the patency of major blood vessels after intervention. These techniques do not provide information about perfusion at the tissue level. An early relatively crude method for assessing ischemic limbs, venous occlusion plethysmography3 relies on the principle that the volume of the limb is dependent on the arterial inflow when venous drainage is occluded. Under resting conditions, ≤70% of blood flow to the limb is directed to skeletal muscle, with the remainder to the skin circulation.4 Venous occlusion plethysmography provides a global indication of limb perfusion but gives no anatomic information and cannot delineate segmental perfusion deficits. It is influenced by numerous factors, such as ambient temperature and arteriovenous shunting that may lead to erroneous readings. Objective measurement of limb perfusion would particularly benefit patients with CLI but most attempts at addressing this have used patients with claudication. The latter can lead to CLI but is a less severe form of PAD that is often treated conservatively and is characterized by pain only when walking as opposed to pain at rest or gangrene. An accurate, noninvasive method of measuring limb perfusion would aid the diagnosis and treatment of PAD and could be combined with conventional angiography to provide both functional …

Is Violence Sometimes a Legitimate Right? An African-American Dilemma

AbstractThe contrast, often painted in simplistic colours, between Martin Luther King Jr. and Malcolm X as civil rights campaigners bolsters an erroneous reading of the freedom struggle of African-Americans, leaving the impression that the resort to violence and self-defence propounded by Malcolm X was a purely circumstantial departure from the general strategy of the civil rights movement.In fact, both of them reflected long on the capacity of violence and a contrario of non-violence to bring about political and social transformation in the context of the extreme brutality and oppression being suffered by African-Americans. Their dilemma stemmed from an old intellectual tradition of the America of the slave period. Well before the ideas of Gandhi won over the African-American elite, and even before Henry David Thoreau laid the theoretical basis for civil disobedience, African slaves gave thought to the legitimacy and effectiveness of violence to amend their situation. The importance of the non-violent movement in the United States and the historical significance of Martin Luther King cannot be understood unless a true measure is taken of the anti-slavery struggle. While within the religious domain, the Black Church played a major role in dissuading violence, secular thought in favour of legitimate forceful rebellion also found itself confronted by a counter-argument which advanced the power of social change and resistance to injustice that non-violence could effect. This article particularly addresses the challenges to their consciences that confronted the militants of non-violence in their campaign for the abolition of slavery and notably those facing the central figure of that struggle, the former slave become the apostle of liberation, Frederick Douglass.

Proovread : large-scale high-accuracy PacBio correction through iterative short read consensus

Today, the base code of DNA is mostly determined through sequencing by synthesis as provided by the Illumina sequencers. Although highly accurate, resulting reads are short, making their analyses challenging. Recently, a new technology, single molecule real-time (SMRT) sequencing, was developed that could address these challenges, as it generates reads of several thousand bases. But, their broad application has been hampered by a high error rate. Therefore, hybrid approaches that use high-quality short reads to correct erroneous SMRT long reads have been developed. Still, current implementations have great demands on hardware, work only in well-defined computing infrastructures and reject a substantial amount of reads. This limits their usability considerably, especially in the case of large sequencing projects. Here we present proovread, a hybrid correction pipeline for SMRT reads, which can be flexibly adapted on existing hardware and infrastructure from a laptop to a high-performance computing cluster. On genomic and transcriptomic test cases covering Escherichia coli, Arabidopsis thaliana and human, proovread achieved accuracies up to 99.9% and outperformed the existing hybrid correction programs. Furthermore, proovread-corrected sequences were longer and the throughput was higher. Thus, proovread combines the most accurate correction results with an excellent adaptability to the available hardware. It will therefore increase the applicability and value of SMRT sequencing. proovread is available at the following URL: http://proovread.bioapps.biozentrum.uni-wuerzburg.de.

Testing quality of a self-monitoring blood glucose sensor with an auto-coding mechanism when used by patients versus technicians

BackgroundIn response to the problem of erroneous readings due to miscoding when performing self-monitoring blood glucose (SMBG), this study introduces a user-friendly SMBG biosensor with an innovative auto-coding module on the meter and strip. Actual users characterized the performance of the SMBG systems. MethodsA total of 105 patients were incorporated in the study and Clarke error grid analysis (EGA) was administered to evaluate the clinical accuracy of the results obtained by the patients versus the technicians. All patients used the questionnaires to comment on the use of the auto-coding sensor. ResultsIn the imprecision test, the total CV of the 5 BG levels was 2.1%. In the EGA plot, the results of the auto-coding sensor were 96.2%, both lots A and B, in zone A for the patients and 99.0% and 97.1% for the technician. The paired t-test demonstrated no statistically significant difference between the patient and technician measurements. Regression analysis also demonstrated that the measurements taken by the patients agreed with those obtained using the laboratory method. ConclusionsThe patients achieved satisfactory performance using the auto-coding SMBG sensor and derived similar results with both laboratory reference and operation by a technician.

Iterative Learning for Reference-Guided DNA Sequence Assembly From Short Reads: Algorithms and Limits of Performance

Recent emergence of next-generation DNA sequencing technology has enabled acquisition of genetic information at unprecedented scales. In order to determine the genetic blueprint of an organism, sequencing platforms typically employ so-called shotgun sequencing strategy to oversample the target genome with a library of relatively short overlapping reads. The order of nucleotides in the reads is determined by processing the acquired noisy signals generated by the sequencing instrument. Assembly of a genome from potentially erroneous short reads is a computationally daunting task even in the scenario where a reference genome exists. Errors and gaps in the reference, and perfect repeat regions in the target, further render the assembly challenging and cause inaccuracies. In this paper, we formulate the reference-guided sequence assembly problem as the inference of the genome sequence on a bipartite graph and solve it using a message-passing algorithm. The proposed algorithm can be interpreted as the well-known classical belief propagation scheme under a certain prior. Unlike existing state-of-the-art methods, the proposed algorithm combines the information provided by the reads without needing to know reliability of the short reads (so-called quality scores). Relation of the message-passing algorithm to a provably convergent power iteration scheme is discussed. To evaluate and benchmark the performance of the proposed technique, we find an analytical expression for the probability of error of a genie-aided maximum a posteriori (MAP) decision scheme. Results on both simulated and experimental data demonstrate that the proposed message-passing algorithm outperforms commonly used state-of-the-art tools, and it nearly achieves the performance of the aforementioned MAP decision scheme.

A simple method for gene phasing using mate pair sequencing.

BackgroundRecessive genes cause disease when both copies are affected by mutant loci. Resolving the cis/trans relationship of variations has been an important problem both for researchers, and increasingly, clinicians. Of particular concern are patients who have two heterozygous disease-causing mutations and could be diagnosed as affected (one mutation on each allele) or as phenotypically normal (both mutations on the same allele). Several methods are currently used to phase genes, however due to cost, complexity and/or low sensitivity they are not suitable for clinical purposes.MethodsLong-range amplification was used to select and enrich the target gene (CYP21A2) followed by modified mate-pair sequencing. Fragments that mapped coincidently to two heterozygous sites were identified and used for statistical analysis.ResultsProbabilities for cis/trans relationships between heterozygous positions were calculated along with 99% confidence intervals over the entire length of our 10 kb amplicons. The quality of phasing was closely related to the depth of coverage and the number of erroneous reads. Most of the error was found to have been introduced by recombination in the PCR reaction.ConclusionsWe have developed a simple method utilizing massively parallel sequencing that is capable of resolving two alleles containing multiple heterozygous positions. This method stands out among other phasing tools because it provides quantitative results allowing confident haplotype calls.

The effect of baseline pressure errors on an intracranial pressure-derived index: results of a prospective observational study.

BackgroundIn order to characterize the intracranial pressure-volume reserve capacity, the correlation coefficient (R) between the ICP wave amplitude (A) and the mean ICP level (P), the RAP index, has been used to improve the diagnostic value of ICP monitoring. Baseline pressure errors (BPEs), caused by spontaneous shifts or drifts in baseline pressure, cause erroneous readings of mean ICP. Consequently, BPEs could also affect ICP indices such as the RAP where in the mean ICP is incorporated.MethodsA prospective, observational study was carried out on patients with aneurysmal subarachnoid hemorrhage (aSAH) undergoing ICP monitoring as part of their surveillance. Via the same burr hole in the scull, two separate ICP sensors were placed close to each other. For each consecutive 6-sec time window, the dynamic mean ICP wave amplitude (MWA; measure of the amplitude of the single pressure waves) and the static mean ICP, were computed. The RAP index was computed as the Pearson correlation coefficient between the MWA and the mean ICP for 40 6-sec time windows, i.e. every subsequent 4-min period (method 1). We compared this approach with a method of calculating RAP using a 4-min moving window updated every 6 seconds (method 2).ResultsThe study included 16 aSAH patients. We compared 43,653 4-min RAP observations of signals 1 and 2 (method 1), and 1,727,000 6-sec RAP observations (method 2). The two methods of calculating RAP produced similar results. Differences in RAP ≥0.4 in at least 7% of observations were seen in 5/16 (31%) patients. Moreover, the combination of a RAP of ≥0.6 in one signal and <0.6 in the other was seen in ≥13% of RAP-observations in 4/16 (25%) patients, and in ≥8% in another 4/16 (25%) patients. The frequency of differences in RAP >0.2 was significantly associated with the frequency of BPEs (5 mmHg ≤ BPE <10 mmHg).ConclusionsSimultaneous monitoring from two separate, close-by ICP sensors reveals significant differences in RAP that correspond to the occurrence of BPEs. As differences in RAP are of magnitudes that may alter patient management, we do not advocate the use of RAP in the management of neurosurgical patients.

Baseline pressure errors (BPEs) extensively influence intracranial pressure scores: results of a prospective observational study

BackgroundMonitoring of intracranial pressure (ICP) is a cornerstone in the surveillance of neurosurgical patients. The ICP is measured against a baseline pressure (i.e. zero - or reference pressure). We have previously reported that baseline pressure errors (BPEs), manifested as spontaneous shift or drifts in baseline pressure, cause erroneous readings of mean ICP in individual patients. The objective of this study was to monitor the frequency and severity of BPEs. To this end, we performed a prospective, observational study monitoring the ICP from two separate ICP sensors (Sensors 1 and 2) placed in close proximity in the brain. We characterized BPEs as differences in mean ICP despite near to identical ICP waveform in Sensors 1 and 2.MethodsThe study enrolled patients with aneurysmal subarachnoid hemorrhage in need of continuous ICP monitoring as part of their intensive care management. The two sensors were placed close to each other in the brain parenchyma via the same burr hole. The monitoring was performed as long as needed from a clinical perspective and the ICP recordings were stored digitally for analysis. For every patient the mean ICP as well as the various ICP wave parameters of the two sensors were compared.ResultsSixteen patients were monitored median 164 hours (ranges 70 – 364 hours). Major BPEs, as defined by marked differences in mean ICP despite similar ICP waveform, were seen in 9 of them (56%). The BPEs were of magnitudes that had the potential to alter patient management.ConclusionsBaseline Pressure Errors (BPEs) occur in a significant number of patients undergoing continuous ICP monitoring and they may alter patient management. The current practice of measuring ICP against a baseline pressure does not comply with the concept of State of the Art. Monitoring of the ICP waves ought to become the new State of the Art as they are not influenced by BPEs.

Improving gas hydrate saturation estimates using P-wave velocity log data by incorporating XRD-data for detailed matrix-mineralogy definition

Logging-while-drilling (LWD) and wire-line (WL) velocity data from the second Korean Ulleung Basin Gas Hydrate Drilling Expedition in 2010 (UBGH2) were used to predict gas hydrate saturations using the effective medium theory (EMT) at four representative sites: We used Sites UBGH2-10 and UBGH2-6 where gas hydrate occurs mostly within strata-bound sandy turbidite layers. Sites UBGH2-2_1 and UBGH2-2_2 are used to investigate a typical cold vent setting and fracture-dominated systems. We first use a new technique to correct the LWD velocity data within the shallower portions of the borehole (typically upper 60–100 m below seafloor, mbsf) where the nature of soft sediments often results in erroneous low velocity readings of the LWD tool around values between 1350 m/s and 1400 m/s. Using the Vertical Seismic Profile (VSP) data, a smooth background velocity trend is defined, onto which the LWD data is projected. After this correction, the LWD velocity data of all four sites were used to estimate gas hydrate saturation values using the EMT for a 2-phase mineral-assemblage of 90% clay and 10% quartz only, as well as a detailed mineralogy based on the core XRD data. Both these estimates are then compared to the estimates from the electrical resistivity data using an empirical Archie-analysis. The results from EMT and Archie are on average the same, when gas hydrate occurs as a pore-filling medium within thick sediment layers of homogenous nature, such as that encountered at Site UBGH2-10 where saturations are about 60% of the pore space in an interval of 124–128 mbsf. If gas hydrate occurs in thin sand layers where the thickness of the layer is at or smaller than the vertical resolution of the velocity logging tool, Archie-based results are higher than the EMT-based results due to the higher resolution of the resistivity logging-tool. In cold vent settings with fracture-dominated gas hydrate settings (such as that investigated at Sites UBGH2-2_1 and 2-2_2). Archie-based results are non-reliable and strongly over-estimated due to the anisotropic effect of near-vertical hydrate-filled fractures. In such cold vent settings, velocity-based techniques using the EMT are the preferred method to estimate the gas hydrate saturations. At Site UBGH2-2_1, hydrate saturations are on average 5–10% of the pore-space and even lower at Site UBGH2-2_2 (less than 5% on average).

Thermal, mechanical and chemical influences on the performance of optical fibres for distributed temperature sensing in a hot geothermal well

Structural well-bore integrity is an important issue for sustainable provision of geothermal energy. Raman scattering based fibre optic distributed temperature sensing (DTS) can help to monitor the status of a well and therefore help to optimize expensive work-over activities. This study reports on the installation of a fibre-optic cable in the cemented annulus behind the anchor casing in the high temperature geothermal well HE-53, Hellisheiði geothermal field, SW Iceland. Although the cable has been damaged during the installation, temperature data could be acquired during the entire length of installation down to 261.3 m. Temperature measurements were performed during the installation in spring 2009, during the onset of a flow test in summer 2009 and after a 8.5 month shut-in period in summer 2010. During the flow test, maximum temperatures of 230 °C were measured after 2 weeks fluid production. Using optical time domain reflectometry (OTDR), attenuation measurements at 850 and 1,300 nm enabled to identify mechanical, thermal, and chemical degradation along the optical fibre. The observed degradation led to erroneous temperature readings and limits, due to the optical budget of the DTS system, the accessible length of the fibre. The characteristics and the influence of the different degradation mechanisms on the accuracy of the DTS measurements are discussed and recommendations for an optimized installation are given.

Technical note: Evaluation of data loggers for measuring lying behavior in dairy calves

Lying behavior might indicate how the animal interacts with its environment and is an important indicator of cow and calf comfort. Measuring behavior can be time consuming; therefore, behavioral recording with the help of loggers has become common. Recently, the Hobo Pendant G data logger (Onset Computer Corp., Bourne, MA) was validated for measuring lying behavior in cows but no work to date has validated this logger for measuring lying behavior in calves. The objective of this study was to test the accuracy of the Hobo Pendant G data logger for measuring total lying time and frequency of lying bouts in dairy calves. In 2 experiments (experiment 1: thirty-seven 2-h observation periods; experiment 2: nineteen 24-h observation periods), we tested the effect of 2 different recording intervals, the effect of attachment to different legs, and the effect of removing short, potentially erroneous readings. We found an excellent relationship when comparing the 30-s and 60-s recording intervals. For total lying time and bout frequency, the highest correlation was found when the logger was attached to the hind legs and recording was conducted with a 60-s sampling interval. In experiment 2, average total lying time was 1,077±54min/24h (18.0±0.9h/24h), with an average frequency of 19.4±4.5 bouts per day. Predictability, sensitivity, and specificity for experiment 2 were >97% using the 60-s recording interval and removing single readings of lying or standing from the data set compared with direct observation as reference. The data logger accurately measured total lying time and bout frequency when the sampling interval was ≤60s and short readings of lying and standing up to 1min were converted into the preceding behavior. The best results were achieved by attaching the logger to the right hind leg.

Erroneous blood pressure readings in a patient with Multiple Hereditary Exostoses

SummaryA 15 year old male with Multiple Hereditary Exostoses (MHE) developed what appeared to be profound hypotension shortly after induction of anaesthesia. All other clinical parameters, including skin color, breath sounds, heart rate, peripheral pulses, oxygen saturation and end‐tidal carbon dioxide were normal. When the cuff of the automated blood pressure device was removed and reapplied elsewhere, the blood pressure reading was normal. Examination of the original location of the cuff revealed an exostosis on the medial aspect of the proximal humerus, which had prevented the automated blood pressure device from detecting the pulsation of the artery. Had a preoperative examination of the limb been done, it may have resulted in using a different location for blood pressure monitoring, and prevented the erroneous readings. Additional issues of concern to the anaesthetist in patients with Multiple Hereditary Exostoses are discussed.

Henna dye: A cause of erroneous pulse oximetry readings

Pulse oximetry is a noninvasive and continuous monitoring of the pulsed saturation of hemoglobin oxygen. Because of its simplicity and usefulness, it is part of monitoring recommended for any anesthesia in the operating room. Different factors may limit the use of this monitoring. We report a case of difficulty monitoring by the presence of henna in a patient scheduled for general anesthesia in prone position.

Quality-filtering vastly improves diversity estimates from Illumina amplicon sequencing.

High-throughput sequencing has revolutionized microbial ecology, but read quality remains a significant barrier to accurate taxonomy assignment and alpha diversity assessment for microbial communities. We demonstrate that high-quality read length and abundance are the primary factors differentiating correct from erroneous reads produced by Illumina GAIIx, HiSeq, and MiSeq instruments. We present guidelines for user-defined quality-filtering strategies, enabling efficient extraction of high-quality data from, and facilitating interpretation of Illumina sequencing results.

Cortisol Levels as Predictors of Short- and Long-Term Adrenal Function After Endonasal Transsphenoidal Surgery for Pituitary Adenomas and Rathke's Cleft Cyst

Corticotropin (adrenocorticotropic hormone [ACTH]) deficiency due to transsphenoidal pituitary adenomectomy or Rathke’s cleft cysts extirpation is fairly low, mainly due to its monoclonal prevalence expression. It represents 20% of the cases, contrasting with other hypophyseal hormones, such as, antidiuretic hormone (arginine vasopressin), thyrotropin (thyroid-stimulating hormone), gonadotropins (follicle-stimulating hormone or luteinizing hormone) and growth hormone (GH) that may reach up to 40% to 50%. When low ACTH is found, it is generally permanent and close monitoring is vital. Statistics vary widely depending on tumor size and location, including the surgeon’s experience and/or compromise achieved by the medical team involved in this kind of process as well. Cortisol is of most importance, because a drop of circulating levels in the first 24 hours may be life-threatening, if replacement is not ensured with opportunity. Difficulties usually arise while attempting to establish the diagnosis and in delineating prognosis of hypocortisolism, which commonly relies on the accuracy of cortisol and corticotropin (ACTH) quantitative methods and/or qualitative clinical assessment. Preservation of ACTH/cortisol secretion when a tumor blockades the infundibulum or by surgical extension is not totally understood, albeit fragments of pituitary functional tissue have been found in neighboring zones like the ethmoid sinus or nasopharynx. A single morning or random serum cortisol quantitation in many cases do not necessarily correlate with impairment in cortisol secretion by the adrenal while attempting to evaluate intactness of the hypothalamic-pituitary-adrenal axis after a pituitary tumor removal. Nonetheless, the finding of a random serum cortisol 20 g/dL can rule out the possibility of adrenal insufficiency, whereas a concentration of cortisol 20 g/dL makes imperative a thorough investigation of adrenal deficit. Blood pressure monitoring and serum or urinary electrolytes (Na and K) with clinical assessment are effective auxiliary elements for diagnosis of hypocortisolism. It is important to bear in mind that circulating cortisol is transported by a cortisol-binding globulin (CBG), susceptible to cross react with other steroids like estrogen or testosterone or become altered in cases of liver disease (acute hepatitis) or hyperthyroidism able to induce high levels of cortisol, making necessary eventually to perform 24-hour urinary collections in order to obtain reliable amounts of free cortisol. Other sources for cortisol analysis that have proved to be useful are those in saliva or hair. Amounts of cortisol measured in saliva seem to be more accurate and specific because cross-reacting CBG is absent; however, experience under circumstances of surgical hypocorticotropism is scarce. Measurements of cortisol in hair apparently provide information to estimate time of tissue exposure to concentrations of cortisol. Potentially, this might be helpful in determining the quantities of hormonal replacement that need reduction or when to decide its withdrawal. Most methods currently available for measuring serum cortisol levels are automated immunoassays or by chemiluminescence, both susceptible to variations derived from cross-reacting material contained in biological fluids and consequently prone to erroneous readings.

Self-Enabled “Error-Free” Switching Circuit for Spin Transfer Torque MRAM and Logic

Spin transfer torque (STT) is one of the most promising switching approaches for magnetic tunnel junction (MTJ) nanopillars to build up innovative nonvolatile memory and logic circuits. It presents low critical current (e.g., <; 100 μA at 65 nm), simple switching scheme, and fast-speed; however, it suffers from a number of reliability issues like stochastic switching effects, process voltage temperature (PVT) variations, and erroneous reading etc. The mainstream solution is to enlarge the write pulse duration to reduce error rate, which sacrifices the speed and low power advantages. In this paper, we present a new switching circuit for STT memory and logic, allowing “error-free” as the switching operation becomes deterministic benefiting from the self-enabled mechanism. The switching power efficiency can be also improved thanks to a shorter switching duration. By using an accuracy spice model of STT-MTJ and CMOS 65 nm design-kit, mixed simulations have been performed to demonstrate its high-reliable write/read operations and evaluate its potential area, power, and speed performance.