Using artificial neural networks to identify and optimise the key parameters affecting geometry of a GMAW fillet weld

Control of Gas Metal Arc Welding (GMAW) parameters is key to maintaining good quality and consistent fillet weld geometry. The external geometry of the fillet weld can be easily measured, however the internal geometry (i.e. penetration), which is critical in determining the structural integrity of the joint, is difficult to measure without destructively testing the workpiece. Consequently the most cost effective way to ensure adequate penetration is to maintain close control of the input parameters. Furthermore if we can demonstrate tight control of the parameters and interactions that affect the joint penetration then we can increase the confidence that sufficient penetration is being achieved.Previous studies have shown that the variation in set up parameters between welders and the guidance given by industry/suppliers can vary widely and in some cases be contradictory. Also in practice there are several characteristics of the manual/semi-automatic GMAW fillet weld process that are difficult to control (e.g. gun angle, travel angle and gap) but yet have an impact on the resultant geometry.This paper will document a programme of work which has used an Artificial Neural Network (ANN) to identify the parameters, and specific interactions that have an impact on the resultant fillet weld geometry. The variables that will be assessed in this paper will include current, voltage, travel speed, gun angle, travel angle. Further follow on studies will take place to understand the impact of gap, gas flow & nozzle diameters

The gender balance of the Australian Space Research Community: a snapshot from the 15th ASRC, 2015

In recent years, the striking gender imbalance in the physical sciences has been a topic for much debate. National bodies and professional societies in the astronomical and space sciences are now taking active steps to understand and address this imbalance. In order to begin this process in the Australian Space Research community, we must first understand the current state of play. In this work, we therefore present a short ‘snapshot’ of the current gender balance in our community, as observed at the 15th Australian Space Research Conference. We find that, at this year’s conference, male attendees outnumbered female attendees by a ratio of 3:1 (24% female). This gender balance was repeated in the distribution of conference talks and plenary presentations (25 and 22% female, respectively). Of the thirteen posters presented at the conference, twelve were presented by men (92%), a pattern repeated in the awards for the best student presentations (seven male recipients vs one female). The program and organising committees for the meeting fairly represented the gender balance of the conference attendees (28% and 30% female, respectively). These figures provide a baseline for monitoring future progress in increasing the participation of women in the field. They also suggest that the real barrier is not speaking, but in enabling conference attendance and retaining female scientists through their careers – in other words, addressing and repairing the ‘leaky pipeline’

Survey Of UK Clinicians’ Approaches To Decision-Making In Neonatal Intestinal Failure

BACKGROUND: Outcomes for neonatal intestinal failure (IF) have improved significantly over the past two decades, however, there is no consensus for decision making among UK paediatric subspecialists. OBJECTIVES: The aim was to describe clinician’s attitudes to decision making in neonatal IF and examine variation between subspecialties. METHODS: Neonatologists, paediatric surgeons and gastroenterologists were surveyed electronically. They were asked if they would recommend active or palliative care or allow the parents to decide in several scenarios; or if they considered treatment morally obligatory or impermissible. RESULTS: Of 147 respondents, 81% of gastroenterologists would recommend active care (34.6% regardless of parental decision) for a term infant with total gut Hirschsprung’s compared with 46% and 33% of surgeons and neonatologists. No gastroenterologist would recommend palliation while 23% of both neonatologists and surgeons would. Similarly, 77% of surgeons and 73% of neonatologists would recommend palliation for a 28-week infant with IF and bilateral parenchymal haemorrhages compared with 27% of gastroenterologists. Prognostic estimates also varied. A term baby with IF was estimated to have a survival of >80% at 5 years by 58% of gastroenterologists compared with 11.5% and 2.7% of surgeons and neonatologists. Only 11.5% of surgeons and 2.6% of neonatologist believed a 26-week preterm with IF would have a 5-year survival >60% compared with 59% of gastroenterologists. CONCLUSION: There is substantial variation in views about outcomes and management choices both within and between specialties; with gastroenterologists being consistently more positive. This is likely to lead to unjustified variation in counselling and parental choices

The relationship between predicted peptide–MHC class II affinity and T-cell activation in a HLA-DRβ1*0401 transgenic mouse model

The HLA-DRB1*0401 MHC class II molecule (DR4) is genetically associated with rheumatoid arthritis. It has been proposed that this MHC class II molecule participates in disease pathogenesis by presenting arthritogenic endogenous or exogenous peptides to CD4(+) T cells, leading to their activation and resulting in an inflammatory response within the synovium. In order to better understand DR4 restricted T cell activation, we analyzed the candidate arthritogenic antigens type II collagen, human aggrecan, and the hepatitis B surface antigen for T-cell epitopes using a predictive model for determining peptide–DR4 affinity. We also applied this model to determine whether cross-reactive T-cell epitopes can be predicted based on known MHC–peptide–TCR interactions. Using the HLA-DR4-IE transgenic mouse, we showed that both T-cell proliferation and Th1 cytokine production (IFN-γ) correlate with the predicted affinity of a peptide for DR4. In addition, we provide evidence that TCR recognition of a peptide–DR4 complex is highly specific in that similar antigenic peptide sequences, containing identical amino acids at TCR contact positions, do not activate the same population of T cells

An Observational Study of the Etiology, clinical presentation and outcomes associated with peritonitis in Lilongwe, Malawi

<p>Abstract</p> <p>Introduction</p> <p>Peritonitis is a life-threatening condition with a multitude of etiologies that can vary with geographic location. The aims of this study were to elucidate the etiology, clinical presentation and outcomes associated with peritonitis in Lilongwe, Malawi.</p> <p>Methods</p> <p>All patients admitted to Kamuzu Central Hospital (KCH) who underwent an operation for treatment of peritonitis during the calendar year 2008 were eligible. Peritonitis was defined as abdominal rigidity, rebound tenderness, and/or guarding in one or more abdominal quadrants. Subjects were identified from a review of the medical records for all patients admitted to the adult general surgical ward and the operative log book. Those who met the definition of peritonitis and underwent celiotomy were included.</p> <p>Results</p> <p>190 subjects were identified. The most common etiologies were appendicitis (22%), intestinal volvulus (17%), perforated peptic ulcer (11%) and small bowel perforation (11%). The overall mortality rate associated with peritonitis was 15%, with the highest mortality rates observed in solid organ rupture (35%), perforated peptic ulcer (33%), primary/idiopathic peritonitis (27%), tubo-ovarian abscess (20%) and small bowel perforation (15%). Factors associated with death included abdominal rigidity, generalized (versus localized) peritonitis, hypotension, tachycardia and anemia (p < 0.05). Age, gender, symptoms (obstipation, vomiting) and symptom duration, tachypnea, abnormal temperature, leukocytosis, hemoconcentration, thrombocytopenia and thrombocytosis were not associated with mortality (p = NS).</p> <p>Conclusions</p> <p>There are several signs and laboratory findings predictive of poor outcome in Malawian patients with peritonitis. Tachycardia, hypotension, anemia, abdominal rigidity and generalized peritonitis are the most predictive of death (P < 0.05 for each). Similar to studies from other African countries, in our population the most common cause of peritonitis was appendicitis, and the overall mortality rate among all patients with peritonitis was 15%. Identified geographical differences included intestinal volvulus, rare in the US but the 2^ndmost common cause of peritonitis in Malawi and gallbladder disease, common in Ethiopia but not observed in Malawi. Future research should investigate whether correction of factors associated with mortality might improve outcomes.</p

Epidemiology of pediatric injury in Malawi: Burden of disease and implications for prevention

AbstractPurposePediatric injuries pose a significant health burden in sub-Saharan Africa, though historic data are too scarce to appreciate the extent of the problem. The purpose of this study is to utilize a comprehensive database to describe the epidemiology of pediatric injuries at a tertiary hospital in Malawi.MethodsData were prospectively collected on patients presenting to the emergency department for treatment of injuries from 2008 to 2010 (n = 23,625). The subset of pediatric patients (n = 7233) underwent cross-sectional analysis to examine demographics, injury environment, timing and mechanisms.ResultsPediatric patients, (0–16 years) comprised 30.6% of all trauma patients. Mean age was 7.2 years. Falls were the most common injury (43%), followed by burns (11.1%), pedestrian road traffic injuries (9.7%), foreign bodies (7.5%), and assaults (7.2%). Statistically significant differences in injury pattern were observed between gender, age groups and season. After logistic regression, predictors of fall included male gender, home setting, and rainy season, whereas predictors of burn included female gender, age 0–5 yrs, home setting, and cold season. Predictors of pedestrian injury included age 6–10 yrs, female, and roadside setting. Predictors of foreign body ingestion included age 0–5 yrs, female gender, home setting, and daytime, and predictors of assault include male gender, age 11–16 yrs, nighttime hours. All predictors were statistically significant (p < 0.05).ConclusionsThis study revealed patterns of injury based upon age, gender, location, and season. Our results may prove useful to stakeholders in injury prevention for designing, evaluating, and implementing programs to improve public safety in children in Malawi and similar resource poor nations

A prolonged outbreak of KPC-3-producing Enterobacter cloacae and Klebsiella pneumoniae driven by multiple mechanisms of resistance transmission at a large academic burn center

Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae have been recently recognized in the United States. Whole-genome sequencing (WGS) has become a useful tool for analysis of outbreaks and for determining transmission networks of multidrug-resistant organisms in healthcare settings, including carbapenem-resistant Enterobacteriaceae (CRE). We experienced a prolonged outbreak of CRE of E. cloacae and K. pneumoniae over a three-year period at a large academic burn center despite rigorous infection control measures. To understand the molecular mechanisms that sustained this outbreak, we investigated the CRE outbreak isolates using WGS. Twenty-two clinical isolates of CRE, including E. cloacae (N=15) and K. pneumoniae (N=7), were sequenced and analyzed genetically. WGS revealed that this outbreak, which seemed epidemiologically unlinked, was in fact genetically linked over a prolonged period. Multiple mechanisms were found to account for the ongoing outbreak of KPC-3-producing E. cloacae and K. pneumoniae . This outbreak was primarily maintained by a clonal expansion of E. cloacae ST114 with distribution of multiple resistance determinants. Plasmid and transposon analysis suggested that the majority of bla KPC-3 was transmitted via an identical Tn 4401 b element on part of a common plasmid. WGS analysis demonstrated complex transmission dynamics within the burn center at levels of strain and/or plasmid in association with transposon, highlighting the versatility of KPC-producing Enterobacteriaceae in their ability to utilize multiple modes to resistance-gene propagation