The Time Complexity of A* with Approximate Heuristics on Multiple-Solution Search Spaces

We study the behavior of the A* search algorithm when coupled with a heuristic h satisfying (1-epsilon1)h*

A Hole in the Heart: confronting the drive for evidence-based impact research in arts and health

The field of arts and health, and associated academic discussion, is beset by a number of interlinked challenges which make it vulnerable to academic dismissal or, at best, poor visibility. One of these is a preoccupation with developing an evidence base of impact. This is compounded by resistance to definitions, disagreement over what constitutes appropriate evidence of success, and inadequate consideration of the mechanisms of arts and health practice, as opposed to outcomes. We argue that increased attention should be paid to the description, analysis and theorising of the practice itself as the basis upon which the findings of impact studies can be understood and accepted. A literature review identifies some important emerging themes in community arts and health practice, and some lacunae in need of further investigation. We conclude that an interdisciplinary theoretical framework for the practice could make a valuable contribution to the academic status of the field.

Sleep-related falling out of bed in Parkinson's disease

BACKGROUND AND PURPOSE

Sleep-related falling out of bed (SFOB), with its potential for significant injury, has not been a strong focus of investigation in Parkinson's disease (PD) to date. We describe the demographic and clinical characteristics of PD patients with and without SFOB.

METHODS

We performed a retrospective analysis of 50 consecutive PD patients, who completed an REM sleep behavior disorder screening questionnaire (RBDSQ), questionnaires to assess for RBD clinical mimickers and questions about SFOB and resulting injuries. Determination of high risk for RBD was based on an RBDSQ score of 5 or greater.

RESULTS

Thirteen patients reported history of SFOB (26%). Visual hallucinations, sleep-related injury, quetiapine and amantadine use were more common in those patients reporting SFOB. Twenty-two patients (44%) fulfilled criteria for high risk for RBD, 12 of which (55%) reported SFOB. Five patients reported injuries related to SFOB. SFOB patients had higher RBDSQ scores than non-SFOB patients (8.2±3.0 vs. 3.3±2.0, p<0.01). For every one unit increase in RBDSQ score, the likelihood of SFOB increased two-fold (OR 2.4, 95% CI 1.3-4.2, p<0.003).

CONCLUSIONS

SFOB may be a clinical marker of RBD in PD and should prompt confirmatory polysomnography and pharmacologic treatment to avoid imminent injury. Larger prospective studies are needed to identify risk factors for initial and recurrent SFOB in PD.

Predictors of improved seminal parameters and fertility after varicocele repair in young adults

The aim of our study was to determine hormonal or biochemical markers in patients with clinically palpable left varicocele but without a history of infertility, with especial emphasis on nitric oxide, related with improved seminal parameters after varicocelectomy. Semen samples were obtained from 202 patients with left varicocele grade II or III. Nitric oxide levels in seminal plasma were determined by the Griess technique. Testicular volume was determined ultrasonographically in both testes and hormonal profile was measured. The post-operative sperm concentration increased significantly in patients with normal sperm count or moderate oligozoospermia, but we did not find an increment in sperm count in patients with mild and severe oligozoospermia after surgery. The mean percentage of normal motility significantly increased after surgery, but we did not observe a significant increment in morphologically normal sperm count and testicular volume after varicocele repair. Moreover, we did not find any correlation between nitric oxide concentrations and severity of oligozoospermia, asthenozoospermia or abnormal sperm morphology in this population. It is concluded that in the general male population, varicocele repair is not associated with an improved semen profile in all cases. We did not observe a significant correlation between nitric oxide concentrations and semen profile.

Placental growth hormone, fetal growth and the IGF axis in normal and diabetic pregnancy

Gestational diabetes mellitus (GDM) and pre-gestational diabetes are known to pose risks to the mother and developing fetus, often related to abnormal fetal growth. One potential mediator of maternal effects on fetal growth is Placental Growth Hormone (PGH). PGH is produced by the syncytiotrophoblast and found predominantly in the maternal circulation. It progressively replaces pituitary growth hormone (hGH) in the human maternal circulation from mid-gestation onwards, peaking towards term. PGH appears to be an important potential regulator of maternal insulin resistance in human pregnancy and may influence fetal growth both by modifying substrate availability and through paracrine actions in the placental bed. The details of PGH regulation remain relatively poorly understood, but current evidence does suggest a central role in growth restricted pregnancies. There is currently less evidence of a pathophysiologic role in production of the macrosomic fetal phenotype commonly seen in response to hyperglycaemia, although our recent in vitro studies do raise the possibility of feto-placental feedback as a mechanism of growth modulation.

Delivery of a brief motivational intervention to patients with alcohol-related facial injuries: role for a specialist nurse

In this paper we focus on providing an alcohol screening and intervention service within maxillofacial surgery. Two trained nurses screened patients with alcohol-related facial injuries who attended maxillofacial outpatient clinics, and gave brief motivational interventions to those who had been drinking to a hazardous level. Patients were followed up at 3 and 12 months after the intervention. 195/249 patients (78%) drank to a hazardous level. One hundred and ninety-five patients received an intervention. Duration of intervention was between 5 and 65 minutes. Reasons for refusal to participate included lack of interest or time, and the main reason for exclusion was length of time since injury. The follow up rate was 103 (53%) at 3 months and 134 (69%) at 12 months.

CONCLUSIONS

The high level of hazardous drinking among people with facial trauma suggests a clear need for alcohol screening and intervention. It is feasible for nursing staff to deliver brief interventions in a busy maxillofacial trauma clinic.

EULAR evidence-based recommendations on the management of systemic glucocorticoid therapy in rheumatic diseases

OBJECTIVE

To develop evidence-based recommendations for the management of systemic glucocorticoid (GC) therapy in rheumatic diseases.

METHODS

The multidisciplinary guideline development group from 11 European countries, Canada and the USA consisted of 15 rheumatologists, 1 internist, 1 rheumatologist-epidemiologist, 1 health professional, 1 patient and 1 research fellow. The Delphi method was used to agree on 10 key propositions related to the safe use of GCs. A systematic literature search of PUBMED, EMBASE, CINAHL, and Cochrane Library was then used to identify the best available research evidence to support each of the 10 propositions. The strength of recommendation was given according to research evidence, clinical expertise and perceived patient preference.

RESULTS

The 10 propositions were generated through three Delphi rounds and included patient education, risk factors, adverse effects, concomitant therapy (ie, non-steroidal anti-inflammatory drugs, gastroprotection and cyclo-oxygenase-2 selective inhibitors, calcium and vitamin D, bisphosphonates) and special safety advice (ie, adrenal insufficiency, pregnancy, growth impairment).

CONCLUSION

Ten key recommendations for the management of systemic GC-therapy were formulated using a combination of systematically retrieved research evidence and expert consensus. There are areas of importance that have little evidence (ie, dosing and tapering strategies, timing, risk factors and monitoring for adverse effects, perioperative GC-replacement) and need further research; therefore also a research agenda was composed.

Upregulation of peroxisome proliferator-activated receptor gamma coactivator gene (PGC1A) during weight loss is related to insulin sensitivity but not to energy expenditure

AIMS/HYPOTHESIS

We investigated whether skeletal muscle peroxisome proliferator-activated receptor gamma coactivator-1 (PGC1A; also known as PPARGC1A) and its target mitofusin-2 (MFN2), as well as carnitine palmitoyltransferase-1 (CPT1; also known as carnitine palmitoyltransferase 1A [liver] [CPT1A]) and uncoupling protein (UCP)3, are involved in the improvement of insulin resistance and/or in the modification of energy expenditure during surgically induced massive weight loss.

MATERIALS AND METHODS

Seventeen morbidly obese women (mean BMI: 45.9 +/- 4 kg/m(2)) were investigated before, and 3 and 12 months after, Roux-en-Y gastric bypass (RYGB). We evaluated insulin sensitivity by the euglycaemic-hyperinsulinaemic clamp, energy expenditure and substrate oxidation by indirect calorimetry, and muscle mRNA expression by PCR.

RESULTS

Post-operatively, PGC1A was enhanced at 3 (p = 0.02) and 12 months (p = 0.03) as was MFN2 (p = 0.008 and p = 0.03 at 3 and 12 months respectively), whereas UCP3 was reduced (p = 0.03) at 12 months. CPT1 did not change. The expression of PGC1A and MFN2 were strongly (p < 0.0001) related. Insulin sensitivity, which increased after surgery (p = 0.002 at 3, p = 0.003 at 12 months), was significantly related to PGC1A and MFN2, but only MFN2 showed an independent influence in a multiple regression analysis. Energy expenditure was reduced at 3 months post-operatively (p = 0.001 vs before RYGB), remaining unchanged thereafter until 12 months. CPT1 and UCP3 were not significantly related to the modifications of energy expenditure or of lipid oxidation rate.

CONCLUSIONS/INTERPRETATION

Weight loss upregulates PGC1A, which in turn stimulates MFN2 expression. MFN2 expression significantly and independently contributes to the improvement of insulin sensitivity. UCP3 and CPT1 do not seem to influence energy expenditure after RYGB.

Nuclear spin switch in semiconductor quantum dots

We show that by illuminating an InGaAs/GaAs self-assembled quantum dot with circularly polarized light, the nuclei of atoms constituting the dot can be driven into a bistable regime, in which either a thresholdlike enhancement or reduction of the local nuclear field by up to 3 T can be generated by varying the pumping intensity. The excitation power threshold for such a nuclear spin "switch" is found to depend on both the external magnetic and electric fields. The switch is shown to arise from the strong feedback of the nuclear spin polarization on the dynamics of the spin transfer from electrons to the nuclei of the dot.