Abort performance for a winged-body single-stage to orbit vehicle

Optimal control theory is employed to determine the performance of abort to orbit (ATO) and return to launch site (RTLS) maneuvers for a single-stage to orbit vehicle. The vehicle configuration examined is a seven engine, winged-body vehicle, that lifts-off vertically and lands horizontally. The abort maneuvers occur as the vehicle ascends to orbit and are initiated when the vehicle suffers an engine failure. The optimal control problems are numerically solved in discretized form via a nonlinear programming (NLP) algorithm. A description highlighting the attributes of this NLP method is provided. ATO maneuver results show that the vehicle is capable of ascending to orbit with a single engine failure at lift-off. Two engine out ATO maneuvers are not possible from the launch pad, but are possible after launch when the thrust to weight ratio becomes sufficiently large. Results show that single engine out RTLS maneuvers can be made for up to 180 seconds after lift-off and that there are scenarios for which RTLS maneuvers should be performed instead of ATP maneuvers

What are the important factors in health-related quality of life for people with aphasia? A systematic review

Objective: To determine factors associated with or predictive of poor health-related quality of life (HRQL) in people with aphasia poststroke. Better understanding of these factors can allow better targeting of rehabilitation programs. Data Sources: Electronic databases, covering medical (eg, Medline, Excerpta Medica Database, Evidence-Based Medicine Reviews, Cumulative Index to Nursing and Allied Health Literature, Ovid, Allied and Complementary Medicine Database) and social sciences (eg, PsycINFO) were searched and key experts were approached. Study Selection: Studies including specific information on the HRQL of people with aphasia poststroke using validated HRQL measures or established ways of analyzing qualitative data were included. Two reviewers independently screened studies against the eligibility criteria. Data Extraction: This was undertaken independently by 2 reviewers. Discrepancies were resolved by consensus. Quantitative studies were assessed for quality with Counsell and Dennis' critical appraisal tool for systematic review of prognostic models in acute stroke; qualitative studies with the Critical Appraisal Skills Program tool for qualitative research. Data Synthesis: Fourteen research reports met the eligibility criteria. Because of their high heterogeneity, the data synthesis was narrative. The evidence is not strong enough to determine the main predictors of HRQL in people with aphasia. Still, emotional distress/depression, severity of aphasia and communication disability, other medical problems, activity limitations, and aspects of social network and support were important factors. Conclusions: Emotional distress, aphasia severity, communication and activity limitations, other medical problems, and social factors affect HRQL. Stroke HRQL studies need to include people with aphasia and report separately on them, in order to determine the main predictors of their HRQL and to identify what interventions can best address them

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Female infanticide and amniocentesis

Clinical services offering amniocentesis to inform women of the sex of their foetuses have appeared in North India in the past 10 years. They fit into cultural patterns in which girls are devalued, and some authors have seen direct links between female infanticide (assumed to have been eradicated by 1900), female neglect leading to higher infant and child mortality rates for girls, and 'female foeticide'. This paper contributes to this debate by presenting some material on the nature of female infanticide, the cultural setting of childbirth and decision-making with respect to fertility and child mortality, largely drawn from a recent research project in Bijnor District, in Uttar Pradesh, North India.

High-Throughput Techniques for the Evaluation of Fire Retardancy

As new flame retardant (FR) approaches are developed they must be evaluated with conventional FR additives, processing additives, stabilizers, and fillers. In most cases this is done in a number of polymers, and a variety of processing conditions also must be optimized. Thus the development of new FR methods is a multi-parameter problem. A full-factorial approach to developing the structure–property relationships of interest requires numerous experiments and is prohibitively labor intensive; additional methods in which the composition space can be rapidly sampled and evaluated are necessary. Several new high throughput approaches are described herein which have been correlated with conventional flammability tests

Recent changes in southern Australian frost occurrence: implications for wheat production risk

Frost damage remains a major problem for broadacre cropping, viticulture, horticulture and other agricultural industries in Australia. Annual losses from frost events in Australian broadacre agriculture are estimated at between $120million and$700million each year for this sector. Understanding the changing nature of frost risk, and the drivers responsible, are important steps in helping many producers manage climate variability and change. Our analysis, using Stevenson screen temperature thresholds of 2°C or below as an indicator of frost at ground level, demonstrates that across southern Australia, despite a warming trend of 0.17°C per decade since 1960, 'frost season' length has increased, on average, by 26 days across the whole southern portion of Australia compared with the 1960-1990 long-term mean. Some areas of south-eastern Australia now experience their last frost an average 4 weeks later than during the 1960s. The intersection of frost and wheat production risk was quantified at 60 sites across the Australian wheatbelt, with a more in-depth analysis undertaken for 15 locations across Victoria (i.e. eight sites common to both the National and Victorian assessments and seven sites exclusive to the Victorian analysis). The results of the national assessment highlight how frost-related production risk has increased by as much as 30% across much of the Australian wheatbelt, for a range of wheat maturity types, over the last two decades, in response to an increase in later frost events. Across 15 Victorian sites, sowing dates to achieve anthesis during a period with only a 10% chance of a 0°C night occurring shifted by 23 days (6 June) for the short-season variety, 20 days (17 May) for the medium-season variety and 36 days later (9 May) for the long-season variety assessed

Complex Evolutionary and Genetic Patterns Characterize the Loss of Scleral Ossification in the Blind Cavefish <i>Astyanax mexicanus</i>

<div><p>The sclera is the tough outer covering of the eye that provides structural support and helps maintain intraocular pressure. In some fishes, reptiles, and birds, the sclera is reinforced with an additional ring of hyaline cartilage or bone that forms from scleral ossicles. Currently, the evolutionary and genetic basis of scleral ossification is poorly understood, especially in teleost fishes. We assessed scleral ossification among several groups of the Mexican tetra (<i>Astyanax mexicanus</i>), which exhibit both an eyed and eyeless morph. Although eyed <i>Astyanax</i> surface fish have bony sclera similar to other teleosts, the ossicles of blind <i>Astyanax</i> cavefish generally do not form. We first sampled cavefish from multiple independent populations and used ancestral character state reconstructions to determine how many times scleral ossification has been lost. We then confirmed these results by assessing complementation of scleral ossification among the F₁ hybrid progeny of two cavefish populations. Finally, we quantified the number of scleral ossicles present among the F₂ hybrid progeny of a cross between surface fish and cavefish, and used this information to identify quantitative trait loci (QTL) responsible for this trait. Our results indicate that the loss of scleral ossification is common–but not ubiquitous–among <i>Astyanax</i> cavefish, and that this trait has been convergently lost at least three times. The presence of wild-type, ossified sclera among the F₁ hybrid progeny of a cross between different cavefish populations confirms the convergent evolution of this trait. However, a strongly skewed distribution of scleral ossicles found among surface fish x cavefish F₂ hybrids suggests that scleral ossification is a threshold trait with a complex genetic basis. Quantitative genetic mapping identified a single QTL for scleral ossification on <i>Astyanax</i> linkage group 1. We estimate that the threshold for this trait is likely determined by at least three genetic factors which may control the severity and onset of lens degeneration in cavefishes. We conclude that complex evolutionary and genetic patterns underlie the loss of scleral ossification in <i>Astyanax</i> cavefish.</p></div