Scalable algorithms for software based self test using formal methods

textTransistor scaling has kept up with Moore's law with a doubling of the number of transistors on a chip. More logic on a chip means more opportunities for manufacturing defects to slip in. This, in turn, has made processor testing after manufacturing a significant challenge. At-speed functional testing, being completely non-intrusive, has been seen as the ideal way of testing chips. However for processor testing, generating instruction level tests for covering all faults is a challenge given the issue of scalability. Data-path faults are relatively easier to control and observe compared to control-path faults. In this research we present a novel method to generate instruction level tests for hard to detect control-path faults in a processor. We initially map the gate level stuck-at fault to the Register Transfer Level (RTL) and build an equivalent faulty RTL model. The fault activation and propagation constraints are captured using Control and Data Flow Graphs of the RTL as a Liner Temporal Logic (LTL) property. This LTL property is then negated and given to a Bounded Model Checker based on a Bit-Vector Satisfiability Module Theories (SMT) solver. From the counter-example to the property we can extract a sequence of instructions that activates the gate level fault and propagates the fault effect to one of the observable points in the design. Other than the user supplying instruction constraints, this approach is completely automatic and does not require any manual intervention. Not all the design behaviors are required to generate a test for a fault. We use this insight to scale our previous methodology further. Underapproximations are design abstractions that only capture a subset of the original design behaviors. The use of RTL for test generation affords us two types of under-approximations: bit-width reduction and operator approximation. These are abstractions that perform reductions based on semantics of the RTL design. We also explore structural reductions of the RTL, called path based search, where we search through error propagation paths incrementally. This approach increases the size of the test generation problem step by step. In this way the SMT solver searches through the state space piecewise rather than doing the entire search at once. Experimental results show that our methods are robust and scalable for generating functional tests for hard to detect faults.Electrical and Computer Engineerin

Extra-terrestrial construction processes - advancements, opportunities and challenges

Government space agencies, including NASA and ESA, are conducting preliminary studies on building alternative space-habitat systems for deep-space exploration. Such studies include development of advanced technologies for planetary surface exploration, including an in-depth understanding of the use of local resources. Currently, NASA plans to land humans on Mars in the 2030s. Similarly, other space agencies from Europe (ESA), Canada (CSA), Russia (Roscosmos), India (ISRO), Japan (JAXA) and China (CNSA) have already initiated or announced their plans for launching a series of lunar missions over the next decade, ranging from orbiters, landers and rovers for extended stays on the lunar surface. As the Space Odyssey is one of humanity’s oldest dreams, there has been a series of research works for establishing temporary or permanent settlement on other planetary bodies, including the Moon and Mars. This paper reviews current projects developing extra-terrestrial construction, broadly categorised as: (i) ISRU-based construction materials; (ii) fabrication methods; and (iii) construction processes. It also discusses four categories of challenges to developing an appropriate construction process: (i) lunar simulants; (ii) material fabrication and curing; (iii) microwave-sintering based fabrication; and (iv) fully autonomous and scaled-up construction processes

Qualitative and Semi Quantitative Culture Assays of Bacterial Bioburden in Chronic Non Healing Superficial Wounds Before and After Electrical Stimulation and Invitro study on the Antibacterial Effects of Electrical Stimulation.

INTRODUCTION : Humans are not germ free. Therefore, health is not absence of bacteria but is kindred to an elegant balance among humans, their resident or transient flora and flora of the environment. The intact skin and the mucous membrane are the most eloquent defenses for humans. Any damage or injury to integument disturbs this bastion and its equilibrium with the bacterial flora. A wound is a breach in the skin and the exposure of subcutaneous tissue following loss of skin integrity provides a moist, warm and nutritive environment that is conducive to microbial colonization and proliferation. Infection occurs when the bacteria accomplish penetration of the subcutaneous tissue and achieve an acute number. Wounds can be broadly categorized as having either an acute or chronic etiology. Irrespective of the nature of the cutaneous injury, acute wounds are expected to heal within a predictable time frame. Chronic wounds result from the disruption of the normal healing process and appear to be struck in the inflammatory phase with accumulation of excessive extra cellular matrix components and matrix proteinases. Each wound needs to be evaluated independently to assess which factors may be at play in disturbing the healing process. Local factors contributing to poor wound healing include infection, tissue hypoxia, repeated trauma, history of irradiation or the presence of necrotic tissue. Systemic factors include diabetes, ageing, malnutrition, obesity, smoking, immunodeficiency and certain medications. In this study, qualitative and semi quantitative aerobic bacterial cultural assay of tissue biopsies from chronic non healing superficial wound patients before and after electrical stimulation is compared with control. In vitro demonstration of the antibacterial effects of electrical stimulation also included in this study. AIMS AND OBJECTIVES : • To isolate and characterize the bacterial agents causing infections in chronic non healing superficial wounds. • Estimation of bacterial bio burden in the chronic non healing superficial wounds by semi quantitative culture assay before and after electrical stimulation. • To compare the effects of electrical stimulation in controlling the bacterial bio burden of chronic wounds with controls • To compare the healing rates of chronic wounds treated with and without electrical stimulation. • Clinico-Microbiological correlation of the effects of electrical stimulation on chronic non healing superficial wounds. • In vitro demonstration of antibacterial effects of electrical stimulation. MATERIALS AND METHODS : Randomized controlled Prospective study. This study was done in department of Microbiology, Stanley medical college, in association with department of plastic surgery, Govt. Stanley Hospital, Chennai. Study Period from June 2008 to May 2009. During this study period, patients with chronic non healing superficial wounds admitted to the department of Plastic surgery with various etiologies were included. Among the 38 patients selected, 36 patients had single ulcer and 2 patients each had two ulcers. All these ulcers were mostly present in the lower limbs except two ulcers which were present in the upper limbs. Out of the 40 wounds from 38 patients, 20 wounds were kept randomly in the study group and another 20 wounds were kept randomly in the control group. Study group- Electrical stimulation treatment was given for a period of 3 weeks. Control group - Without electrical stimulation only saline dressing was given for 3 weeks. None of the group was treated either with antibiotics or topical antiseptics. Inclusion Criteria: Patients with chronic superficial non healing wounds of varying etiology like diabetes, arterial, venous and pressure ulcers which do not heal in the expected time frame(about a month time) with conventional treatment like optimization of nutrition, moist dressings, debridement, infection resolution, repositioning, and off-loading of pressure. Patients of either sex with ages as and above 15 years. Patients who gave written informed consent to undergo this treatment modalities and various investigations. Patients who were not on systemic and topical antibiotics or antiseptics during this study period. Exclusion Criteria: • Patients on either systemic and topical antibiotics or antiseptics. • Malignant ulcer. • Any indication of thrombosis underlying the wound. • Chronic Osteomyelitis • Patients using cardiac pacemaker were excluded from the study. • Pregnant woman. RESULTS : All patients included in the study had wounds in the lower limbs except 2 patients who had wounds in the upper limbs. On analysis of the etiology of chronic wounds in this study, 14 diabetic ulcers; 10 arterial ulcers; 8 venous ulcers; 6 lymphatic ulcers and 2 unstable scars were present. Total number of patients included in this study were 38, among which 28were males (73.7%) and 10 were females (26.3%). Out of them, between 21- 30 years of age there were 5 males and 1 female, between 31-40 years 6 males and 1 female, between 41-50 years 8 males and 2 females, between 51-60 years 4 males and 3 females, between 61-70years 4 males and 2 females and between 71-80 years 1male and 1female. Most of the patients were in the age group between 41-50 yrs. The youngest patient was 23 years of age and the oldest was 76 years. Most of the patients with chronic ulcer were males. Out of 160 direct smears by Gram’s staining, 77smears showed positive screening in the rapid slide smear technique for Quantitative Assessment which was shown to reliably predict a critical microbial load of >1x105CFUs/ gram of tissue if a single or more micro organism was seen in the entire field under oil immersion objective by using 0.2 ml of tissue homogenate. 83 were reported as negative smear. CONCLUSION : The Microbiological profile of the chronic non healing wounds reveals a critical level of bioburden, Biofilm formation the polymicrobial flora, synergistic relationship between microorganisms and the presence of specific pathogens and their toxins all these causes a state of non healing in the chronic wounds . • Importance of quantitative microbiology is well reinforced in that it is not only helps to estimate the bioburden but also useful in the quantitative assessment of various treatment modalities out come. This also gives a clue to the clinician in deciding the timing of wound closure because the critical bacterial load of >105 CFUs /gm of tissue will badly affect the skin graft survival. • In this era of increasing multi drug resistance & hospital acquired infections; chronic non healing wound patients are clearly a high risk group for acquisition, carriage and dissemination of antibiotic resistant organisms to which antibiotic therapy should not be given merely on clinical grounds alone but it must be validated by the qualitative and quantitative microbiological assays. • The electricidal effects of electrical stimulation on the bacterial viability are clearly documented by in vivo & in vitro studies. • The electrical stimulation can be used adjunctively with other standard wound care management to enhance the wound healing

A study of serum lipid profile in normal pregnancy and pregnancy induced hypertensive disorders: a case-control study

Background: Pregnancy induced hypertensive disorders are one of the commonest complication of pregnancy which accounts for 12% of the maternal and perinatal mortality and morbidity. Dyslipidemias are associated with endothelial dysfunction that may result in proteinuria and hypertension which is a clinical hallmark of PIH. It affects both maternal health as well as fetal growth. Hence, this study was done to assess the role of altered lipid profile in the development of PIH.Methods: A Case Control study was conducted at the Department of Biochemistry, Kurnool Medical College and Govt General Hospital, Kurnool in collaboration with its Obstetrics Dept during the period of November 2015-2017. A total of 300 pregnant women, primigravida /multigravida with singleton pregnancy, in the age group of 18‐ 35 years with >20 weeks of gestation were included in the study. Subjects were divided into gestational hypertensives, n=39 (BP ≥140/80) and preeclamptic women, n=111 (≥140/80 and proteinuria) as cases. Age matched normotensive pregnant women, n=150 (BP 120/80) were recruited as Controls. Subjects with history of multiple pregnancies, pregnancy with congenital anomalies, chronic hypertension, diabetes mellitus, cardiac/thyroid/hepatic/renal disease, dyslipidemia were excluded. Total cholesterol, TG, HDL, LDL, VLDL were performed.Results: A comparison of these values between hypertensive and normotensive women showed a significant rise in TC, TG, LDL and VLDL. HDL-C showed a significant decrease in hypertensive women compared to normal pregnant women. LDL: HDL and TG:HDL ratios were higher in PIH group.Conclusions: The results of this study suggests an abnormal lipid metabolism, predominantly high TG concentrations and low HDL-C, which may add to the promotion of vascular dysfunction and oxidative stress seen in PIH. This association is significant in understanding the development of hypertension during pregnancy and is useful in early diagnosis and prevention of PIH

Multiple intra-renal pathological injury patterns in resistant myeloma

Renal dysfunction in patients with multiple myeloma has a heterogeneous aetiology ranging from pre-renal, intra-renal to post-renal causes. Common pathological forms of paraproteinemic disease include cast nephropathy, amyloidosis and Immunoglobulin chain deposition disease. Infrequently cryoglobulinemic glomerulonephritis and light chain proximal tubulopathy have also been described. The presence of multiple intra-renal pathological injury patterns has been described only once previously with immunoglobulin light chains. We report a patient with long standing treatment resistant multiple myeloma and new onset progressive renal failure with heavy and light-chain amyloidosis, cast nephropathy and proximal tubulopathy on renal biopsy

Current Anesthetic Care of Patients Undergoing Transcatheter Aortic Valve Replacement in Europe:Results of an Online Survey

Objectives: Transcatheter aortic valve replacement (TAVR) has become an alternative treatment for patients with symptomatic aortic stenosis not eligible for surgical valve replacement due to a high periprocedural risk or comorbidities. However, there are several areas of debate concerning the pre-, intra- and post-procedural management. The standards and management for these topics may vary widely among different institutions and countries in Europe. Design: Structured web-based, anonymized, voluntary survey. Setting: Distribution of the survey via email among members of the European Association of Cardiothoracic Anaesthesiology working in European centers performing TAVR between September and December 2018. Participants: Physicians. Measurements and main results: The survey consisted of 25 questions, including inquiries regarding number of TAVR procedures, technical aspects of TAVR, medical specialities present, preoperative evaluation of TAVR candidates, anesthesia regimen, as well as postoperative management. Seventy members participated in the survey. Reporting members mostly performed 151-to-300 TAVR procedures per year. In 90% of the responses, a cardiologist, cardiac surgeon, cardiothoracic anesthesiologist, and perfusionist always were available. Sixty-six percent of the members had a national curriculum for cardiothoracic anesthesia. Among 60% of responders, the decision for TAVR was made preoperatively by an interdisciplinary heart team with a cardiothoracic anesthesiologist, yet in 5 countries an anesthesiologist was not part of the decision-making. General anesthesia was employed in 40% of the responses, monitored anesthesia care in 44%, local anesthesia in 23%, and in 49% all techniques were offered to the patients. In cases of general anesthesia, endotracheal intubation almost always was performed (91%). It was stated that norepinephrine was the vasopressor of choice (63% of centers). Transesophageal echocardiography guiding, whether performed by an anesthesiologist or cardiologist, was used only Conclusion: The results indicated that requirements and quality indicators (eg, periprocedural anesthetic management, involvement of the anesthesiologist in the heart team, etc) for TAVR procedures as published within the European guideline are largely, yet still not fully implemented in daily routine. In addition, anesthetic TAVR management also is performed heterogeneously throughout Europe. (C) 2020 Elsevier Inc. All rights reserved

Solvent effects on lasing characteristics for Rh B laser dye.

We demonstrate pulsed, photopumped multimode laser emission in the visible spectral range from rhodamine B dye dissolved in various solvents. The laser emission is characterized by a well-defined, low threshold pump power at which the emission spectral intensity dramatically increases and collapsed into several dominant laser modes with reduced mode spacing and spectral width. The modes were found to originate from the subcavities formed by the plane-parallel walls of the cuvette containing the gain medium. The cavity lasing spectral structure and the numbers of longitudinal modes were easily controlled by changing the solvents. A shift in the emission spectra has been also observed by changing the solvents will allow a limited range of tuning of laser emission wavelength. We also determined the gain coefficient and stimulated emission cross-section for the Rh B dye dissolved liquid laser system. A detailed discussion of the solvent effect in the lasing characteristics of Rh B in different solution is explained along with the computational data

Sequence Analysis of Novel Staphylococcus aureus Lineages from Wild and Captive Macaques

Staphylococcus aureus is a widespread and common opportunistic bacterium that can colonise or infect humans as well as a wide range of animals. There are a few studies of both methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolated from monkeys, apes, and lemurs, indicating a presence of a number of poorly or unknown lineages of the pathogen. In order to obtain insight into staphylococcal diversity, we sequenced strains from wild and captive individuals of three macaque species (Macaca mulatta, M. assamensis, and M. sylvanus) using Nanopore and Illumina technologies. These strains were previously identified by microarray as poorly or unknown strains. Isolates of novel lineages ST4168, ST7687, ST7688, ST7689, ST7690, ST7691, ST7692, ST7693, ST7694, ST7695, ST7745, ST7746, ST7747, ST7748, ST7749, ST7750, ST7751, ST7752, ST7753, and ST7754 were sequenced and characterised for the first time. In addition, isolates belonging to ST2990, a lineage also observed in humans, and ST3268, a MRSA strain already known from macaques, were also included into the study. Mobile genetic elements, genomic islands, and carriage of prophages were analysed. There was no evidence for novel host-specific virulence factors. However, a conspicuously high rate of carriage of a pathogenicity island harbouring edinB and etD2/etE as well as a higher number of repeat units within the gene sasG (encoding an adhesion factor) than in human isolates were observed. None of the strains harboured the genes encoding Panton–Valentine leukocidin. In conclusion, wildlife including macaques may harbour an unappreciated diversity of S. aureus lineages that may be of clinical relevance for humans, livestock, or for wildlife conservation, given the declining state of many wildlife populations

Sequence Analysis of Novel Staphylococcus aureus Lineages from Wild and Captive Macaques

Staphylococcus aureus is a widespread and common opportunistic bacterium that can colonise or infect humans as well as a wide range of animals. There are a few studies of both methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolated from monkeys, apes, and lemurs, indicating a presence of a number of poorly or unknown lineages of the pathogen. In order to obtain insight into staphylococcal diversity, we sequenced strains from wild and captive individuals of three macaque species (Macaca mulatta, M. assamensis, and M. sylvanus) using Nanopore and Illumina technologies. These strains were previously identified by microarray as poorly or unknown strains. Isolates of novel lineages ST4168, ST7687, ST7688, ST7689, ST7690, ST7691, ST7692, ST7693, ST7694, ST7695, ST7745, ST7746, ST7747, ST7748, ST7749, ST7750, ST7751, ST7752, ST7753, and ST7754 were sequenced and characterised for the first time. In addition, isolates belonging to ST2990, a lineage also observed in humans, and ST3268, a MRSA strain already known from macaques, were also included into the study. Mobile genetic elements, genomic islands, and carriage of prophages were analysed. There was no evidence for novel host-specific virulence factors. However, a conspicuously high rate of carriage of a pathogenicity island harbouring edinB and etD2/etE as well as a higher number of repeat units within the gene sasG (encoding an adhesion factor) than in human isolates were observed. None of the strains harboured the genes encoding Panton–Valentine leukocidin. In conclusion, wildlife including macaques may harbour an unappreciated diversity of S. aureus lineages that may be of clinical relevance for humans, livestock, or for wildlife conservation, given the declining state of many wildlife populations

Numerical modelling of the microwave heating behaviour of lunar regolith

The field of In Situ Resource Utilisation (ISRU) is expanding rapidly with a particular focus on developing ISRU technologies and applications to support a longer-term surface exploration of the Moon. In this respect, microwave sintering is proposed to be one of the potential fabrication methods for developing a 3D printing technique for construction processes on the Moon. Thus, understanding the behaviour of lunar regolith, available at different locations on the Moon (e.g. mare versus highlands regions), under microwave heating is crucial for developing an optimal method for microwave sintering. As the availability of real lunar regolith on Earth is highly limited, developing an appropriate numerical model of microwave heating behaviour of lunar regolith is urgently required. In this paper, three representative lunar regolith samples (selected from the database of Apollo sample collections) with pre-defined material properties have been simulated under seven input powers and three specimen sizes. This paper discusses the outcomes of these simulations and the potential contribution of the model for developing a desired 3D printing technique utilising microwave sintering of lunar regolith