Structural correlation between cuticular hydrocarbons and female contact sex pheromone of German cockroachBlattella germanica (L.)

The structural relationships between the cuticular hydrocarbons and the contact sex pheromone of the female German cockroach,Blattella germanica, were investigated. Cuticular hexane extracts were separated into hydrocarbon and ketone fractions by TLC or silicic acid column chromatography. The ketone fraction (which contains the major contact sex pheromone component) was analyzed by GC-MS before and after reduction to ydrocarbon. In addition to 3,11-dimethyl-2-nonacosanone, 3,11-dimethyl-2-heptacosanone was also identified. Females have the 3,11- and 3,9-dimethyl C27 and C29 alkanes, but only the 3,11- isomer of the dimethylketones. Inddition to the hydrocarbon components previously reported, a number of new components were characterized. Although the ratios of cuticular hydrocarbons differ among nymphs, adult males, and adult females, they have qualitatively identical hydrocarbon profiles, suggesting that the production of the contact sex pheromone results from the sex-specific oxidation of 3,11-imethylalkanes to pheromone components by the female.

Heuristic Search When Time Matters

In many applications of shortest-path algorithms, it is impractical to find a provably optimal solution; one can only hope to achieve an appropriate balance between search time and solution cost that respects the user's preferences. Preferences come in many forms; we consider utility functions that linearly trade-off search time and solution cost. Many natural utility functions can be expressed in this form. For example, when solution cost represents the makespan of a plan, equally weighting search time and plan makespan minimizes the time from the arrival of a goal until it is achieved. Current state-of-the-art approaches to optimizing utility functions rely on anytime algorithms, and the use of extensive training data to compute a termination policy. We propose a more direct approach, called Bugsy, that incorporates the utility function directly into the search, obviating the need for a separate termination policy. We describe a new method based on off-line parameter tuning and a novel benchmark domain for planning under time pressure based on platform-style video games. We then present what we believe to be the first empirical study of applying anytime monitoring to heuristic search, and we compare it with our proposals. Our results suggest that the parameter tuning technique can give the best performance if a representative set of training instances is available. If not, then Bugsy is the algorithm of choice, as it performs well and does not require any off-line training. This work extends the tradition of research on metareasoning for search by illustrating the benefits of embedding lightweight reasoning about time into the search algorithm itself.

Liquid gold from the milk bar: constructions of breastmilk and breastfeeding women in the language and practices of midwives

Midwives are the main health professional group providing support and assistance to women during the early establishment of breastfeeding. In published accounts of early breastfeeding experiences women report high levels of dissatisfaction with health professional support. To gain an understanding of this dissatisfaction, we examined the way in which midwives represent breastmilk and construct breastfeeding women in their interactions. Seventy seven women and seventy six midwives at two maternity units in NSW, Australia, participated in this study. Eighty five interactions between a midwife and a breastfeeding woman were observed and audio recorded during the first week after birth. In addition, data were collected through observation of nine parenting education sessions, interviews with 23 women following discharge, and 11 managers and lactation consultants (collected between October 2008 and September 2009). Discourse analysis was used to analyse the transcribed interactions, and interview data. The analysis revealed that midwives prioritised both colostrum and mature breastmilk as a 'precious resource', essential for the health and wellbeing of the infant and mother. References to breastmilk as 'liquid gold' were both verbal and implied. Within this discourse, the production and acquisition of 'liquid gold' appeared to be privileged over the process of breastfeeding and women were, at times, positioned as incompetent operators of their bodily 'equipment', lacking knowledge and skill in breastfeeding. In this context breastfeeding became constructed as a manufacturing process for a demanding consumer. The approach taken by midwives revealed an intensive focus on nutrition to the exclusion of relational communication and support. The findings indicate the need to challenge the current 'disciplinary' and 'technological' practices used by midwives when providing breastfeeding support and the need for a cultural change in postnatal care.

PAR(2) expression in peripheral blood monocytes of patients with rheumatoid arthritis

OBJECTIVES

Proteinase-activated receptor 2 (PAR(2)) is a G protein-coupled receptor activated by serine proteinases with proinflammatory activity. A study was undertaken to investigate the presence and functional significance of PAR(2) expression on rheumatoid arthritis (RA)-derived leucocyte subsets.

METHODS

Venous blood was obtained from patients with RA and osteoarthritis (OA) as well as healthy control subjects. Surface expression of PAR(2) on peripheral blood mononuclear cells (PBMCs) was analysed by flow cytometry and interleukin 6 (IL-6) generation by ELISA.

RESULTS

Patients with RA had elevated but variable surface expression of PAR(2) on CD14+ monocytes compared with control subjects (median (1st to 3rd quartiles) 1.76% (0.86-4.10%) vs 0.06% (0.03-0.81%), p<0.0001). CD3+ T cells showed a similar pattern with significantly higher PAR(2) expression in patients with RA compared with controls (3.05% (0.36-11.82%) vs 0.08% (0.02-0.28%), p<0.0001). For both subsets, PAR(2) expression was significantly higher (p<0.00001) in patients with high levels of disease activity: PAR(2) expression for both CD14+ and CD3+ cells correlated to C reactive protein and erythrocyte sedimentation rate. Furthermore, in a cohort of patients with newly diagnosed RA, elevated PAR(2) expression in both CD14+ and CD3+ cells was significantly reduced 3 months after methotrexate or sulfasalazine treatment and this reduction correlated significantly with the reduction in the 28-joint Disease Activity Scale score (p<0.05). PAR(2) expression on cells from patients with OA was low, similar to levels seen in control subjects. Generation of IL-6 by monocytes in response to a selective PAR(2) agonist was significantly greater in patients with RA than in patients with OA and control subjects (p<0.05).

CONCLUSIONS

These findings are consistent with a pathogenic role for PAR(2) in RA.

Hospital stay amongst patients undergoing major elective colorectal surgery: predicting prolonged stay and readmissions in NHS hospitals

AIM

Reduced hospital stay confers clinical and economic benefits for patients and healthcare providers. This article examines the length of stay and consequent bed resource usage of patients undergoing elective excisional colorectal surgery in English NHS trusts.

METHOD

All patients undergoing elective colorectal resections for malignancy between 1996 and 2006 in English NHS trusts were included from the Hospital Episode Statistics data set. Unifactorial and multifactorial analyses were performed to identify independent predictors of prolonged stay and 28-day readmission.

RESULTS

Over the 10-year period, 186,013 patients underwent elective colorectal procedures in 181 NHS trusts. About 2.893 b million bed days were utilized for elective colorectal surgery. Admission stay was shorter following colonic surgery than following rectal surgery (median 11 vs 13 days, P < 0.001). A 2-day decrease in median stay was observed over the 10-year period for both colonic and rectal procedures. Readmissions within 28 days of discharge were higher following rectal excision than following colonic surgery (9.4 vs 7.6%, P < 0.001). Multiple logistic regression analyses revealed the following independent predictors of prolonged hospital stay: distal (vs proximal) bowel resection, benign pathology, open technique, increasing age, comorbidity, social deprivation and low provider volume status. Independent predictors of 28-day readmission included distal bowel resection, benign diagnosis, young age, social deprivation and high provider volume status.

CONCLUSION

Patients of advanced age, with associated comorbidities, and those living in areas of social deprivation are at increased risk of prolonged stay. Targeted pre-emptive discharge planning and enhanced use of laparoscopic surgery could improve bed resource utilization.

Best-First Heuristic Search for Multicore Machines

To harness modern multicore processors, it is imperative to develop parallel versions of fundamental algorithms. In this paper, we compare different approaches to parallel best-first search in a shared-memory setting. We present a new method, PBNF, that uses abstraction to partition the state space and to detect duplicate states without requiring frequent locking. PBNF allows speculative expansions when necessary to keep threads busy. We identify and fix potential livelock conditions in our approach, proving its correctness using temporal logic. Our approach is general, allowing it to extend easily to suboptimal and anytime heuristic search. In an empirical comparison on STRIPS planning, grid pathfinding, and sliding tile puzzle problems using 8-core machines, we show that A*, weighted A* and Anytime weighted A* implemented using PBNF yield faster search than improved versions of previous parallel search proposals.

A review of instruments developed to measure outcomes for carers of people with mental health problems

OBJECTIVE

Community-based care for mental disorders places considerable burden on families and carers. Measuring their experiences has become a priority, but there is no consensus on appropriate instruments. We aimed to review instruments carers consider relevant to their needs and assess evidence for their use.

METHOD

A literature search was conducted for outcome measures used with mental health carers. Identified instruments were assessed for their relevance to the outcomes identified by carers and their psychometric properties.

RESULTS

Three hundred and ninety two published articles referring to 241 outcome measures were identified, 64 of which were eligible for review (used in three or more studies). Twenty-six instruments had good psychometric properties; they measured (i) carers' well-being, (ii) the experience of caregiving and (iii) carers' needs for professional support.

CONCLUSION

Measures exist which have been used to assess the most salient aspects of carers outcome in mental health. All require further work to establish their psychometric properties fully.

Spinocerebellar ataxia type 8 in Scotland: frequency, neurological, neuropsychological and neuropsychiatric findings

OBJECTIVES

The objectives of this study were to: (i) establish whether the spinocerebellar ataxia type 8 (SCA 8) expansion is associated with ataxia in Scotland; (ii) test the hypothesis that SCA 8 is associated with neuropsychological impairment; and (iii) review neuroradiological findings in SCA 8.

METHODS

The methods included: (i) measurement of SCA 8 expansion frequencies in ataxic patients and healthy controls; (ii) comprehensive neuropsychological assessment of patients with SCA 8 and matched controls, neuropsychiatric interview; and (iii) comparison of patient and matched control magnetic resonance imaging (MRI) scans.

RESULTS

(i) 10/694 (1.4%) unrelated individuals with ataxia had combined CTA/CTG repeat expansions >100 compared to 1/1190 (0.08%) healthy controls (P < 0.0005); (ii) neuropsychological assessment revealed a dysexecutive syndrome among SCA 8 patients, not readily explained by motor or mood disturbance; neuropsychiatric symptoms occurred commonly; (iii) cerebellar atrophy was the only salient MRI abnormality in the patient group.

CONCLUSIONS

The SCA 8 expansion is associated with ataxia in Scotland. The disorder is associated with a dysexecutive syndrome.