Bayesian Optimization of a Free-Electron Laser.

The Linac coherent light source x-ray free-electron laser is a complex scientific apparatus which changes configurations multiple times per day, necessitating fast tuning strategies to reduce setup time for successive experiments. To this end, we employ a Bayesian approach to maximizing x-ray laser pulse energy by controlling groups of quadrupole magnets. A Gaussian process model provides probabilistic predictions for the machine response with respect to control parameters, enabling a balance of exploration and exploitation in the search for the global optimum. We show that the model parameters can be learned from archived scans, and correlations between devices can be extracted from the beam transport. The result is a sample-efficient optimization routine, combining both historical data and knowledge of accelerator physics to significantly outperform existing optimizers.

Arachidonic acid metabolism and regulation of ion transport in rabbit Clara cells.

Sonicates of freshly isolated Clara cells produced thromboxane B2 (TxB2), prostaglandin (PG) D2, PGE2, PGF2 alpha, hydroxyheptadecatrienoic acid (HHT), and 12-hydroxyeicosatetraenoic acid (12-HETE) as detected using high-performance liquid chromatography (HPLC). Sonicates of Clara cells cultured on collagen matrices produced the same metabolites. Rates of [3H]arachidonic acid metabolism increased in culture, but the changes were not associated with changes in cell number. Sonicates of freshly isolated tracheal cells produced mainly 12-HETE. Cyclooxygenase products were not produced consistently. Sonicates of tracheal cultures produced significant quantities of TxB2, PGD2, PGE2, PGF2 alpha, and HHT, but 12-HETE remained the major metabolite. Equivalent short-circuit current (Ieq) across cultured Clara cell epithelia was unaffected by bilateral exposure to TxB2, PGD2, PGE2, PGF2 alpha, HHT, or 12-HETE. A minor (1%) decrease in transepithelial resistance (Rt) followed exposure to PGD2. Indomethacin had no significant effect on Rt or Ieq, but exposure of indomethacin-pretreated preparations to PGE2 revealed a minor (2%) increase in Ieq. In contrast, tracheal cell epithelia exhibited significant changes in Rt and Ieq in response to PGF2 alpha, PGE2, and HHT. These results indicate that Clara cells metabolize arachidonic acid to biologically active eicosanoids, but the resulting products do not play a major role in regulation of transepithelial ion transport by this cell type.

Philodendron--an infant death.

An 11 month old child chewed the leaves of a philodendrum plant (Araceae) and developed oropharyngeal erosions and dysphagia. Esophageal erosions of the mid third of the esophagus and on esophageal stricture at the level of the cricoid were diagnosed 16 days post ingestion. Unexpected sudden death on day 17 was attributed to vagotonia secondary to the esophageal lesions caused by philodendron leaves.

Early indicators of self-destruction in childhood and adolescence: a survey of pediatricians and psychiatrists.

This paper reports a comparison of pediatricians' and psychiatrists' opinions about screening for children and adolescents at risk for self-destruction. Fifty-nine percent of the members of the Nebraska Chapter of the American Academy of Pediatrics and 69% of the members of the Nebraska District Branch of the American Psychiatric Association completed questionnaires containing selected early indicators for self-destruction and programs for suicide prevention. Principal findings were that pediatricians placed less emphasis than child psychiatrists on major depressive disorder, younger pediatricians placed more emphasis than psychiatrists on psychosocial indicators, physicians from both groups said they usually hospitalize attention-seeking self-destructive children, and pediatricians from smaller communities expressed less confidence in referral to psychiatrists but more confidence in community-based programs. Findings suggest that a small group of children and adolescents at risk for eventual suicide may not be identified as early as the more obvious larger groups of individuals who are accident prone, who ingest toxic substances, and who come from violent families. General indicators of risk for self-destruction include substance abuse, psychosocial problems, and minor depression. Factors indicating more specific risk for suicide include escalating stress, family enmeshment, and major mental illness, particularly major depressive disorder. Postgraduate education, instruments for discriminate screening, and balanced programs for suicide prevention are suggested to improve care.

Omaha childhood blood lead and environmental lead: a linear total exposure model.

The majority of experimental and population studies of blood lead (PbB) and environmental lead, including the Omaha study, have utilized the Goldsmith-Hexter log-log or power function model. Comparison was made of the log-log model and a linear model of total exposure to describe the Omaha Study of 1074 PbBs from children ages 1-18 years as related to air (PbA), soil (PbS), and housedust (PbHD) lead. The data fit of the linear model was statistically equivalent to the power model and the predicted curves were biologically more plausible. The linear model avoids the mathematical limitations of the power model which predicts PbB zero at PbA zero. From the Omaha data, this model, ln PbB = ln (beta 0 + B1 PbA + B2 PbS + beta 3 PbHD) predicts that PbB increases 1.92 micrograms/dl as PbA increases 1.0 microgram/m3. Since PbS and PbHD increase with PbA, however, the increases in total exposure predict a PbB increase of 4-5 micrograms/dl as PbA increases 1.0 microgram/m3.

The adolescent overdose. Evaluation and referral.

Guidelines are provided for distinguishing between an accidental overdose, a suicidal gesture, and an attempted suicide. Emergency physicians are the primary contacts for overdosed adolescents and are responsible for both the acute medical care and the initial psychosocial evaluation. The physician must refer the patient to the appropriate acute and long-term support programs that facilitate the process of maturation.

Postoperative protection for the external ear.

The postoperative dressing is an integral part of an otoplasty. The dressing should fit securely, provide protection, and be comfortable for the patient to wear. Wrestling headgear can be used to fill these needs.

Early ambulation after skin grafting of depressed wounds of the leg.

Silicone molds can be fitted precisely to skin grafted, depressed surgical defects of the leg and can be secured in place with a tight-fitting elastic support. The gravitational effect and resultant edema under the skin graft can be reduced. Earlier ambulation and better results than have been reported in the past can be obtained.

Adolescent self-poisoning: a nine-year followup.

A 9-year followup was made of 47 adolescents initially hospitalized at ages 12 to 18 years in a psychiatric facility because of severe psychosocial dysfunction associated with an intentional self-poisoning. No deaths were disclosed as determined by an extensive telephone interview (15 subjects), report by the family (9 subjects), or death certificate search. The 15 subjects interviewed (14 females, 1 male) reported a total of 47 suicide gestures with a peak frequency at ages 14 to 15. There was a sharp decline after age 18, supporting the concept that self-poisoning is an age-related mode of expression. All subjects considered themselves better adjusted, with greater life satisfaction and improved interpersonal relationships; 80% had completed high school, and 93% were capable of stable employment. Functional adaptation was independent to the number of repeat poisonings or of the initial psychiatric diagnosis. All subjects attributed benefits to multiple support systems, particularly a strong relationship with at least one emotionally mature person, a more favorable environment--usually accomplished by moving out of their parents' house--achievement of education and employment skills, and economic independence.

Trends in childhood poisoning: a collaborative study 1970, 1975, 1980.

A collaborative study of 273 treated poisonings at three regional poison control centers showed a significant decrease in salicylism from 19% of all cases in 1970 to 9% in 1975 and 11% in 1980. A temporal correlation with safety packaging was also seen in the decrease in poisonings by household products from 36% and 42% of all treated poisonings in 1970 and 1975 to 21% in 1980. Poisonings by non-salicylate medications increased from 45% to 68% of treated ingestions. Therapeutic mishaps were relatively constant at 27%, 20% and 20% of all poisonings by medications. In children under one year of age 59% of medicinal poisonings were therapeutic mishaps, significantly higher than the 27% incidence for ages 1 to 5 years. Therapeutic mishaps and ingestions of household products resulted in significantly longer hospitalizations than accidental ingestion of medications. Additional data from two other regional centers permitted analysis of a total of 47 cases of treated salicylism. Therapeutic mishaps showed a possible upward trend from 27% of salicylate poisonings in 1970 to 36% in 1980. Almost all of the therapeutic mishaps with salicylates involved repeated overdose; 18 of the 19 mishaps due to other medications were allergic reactions.

Erythrocyte nucleotides in children--increased blood lead and cytidine triphosphate.

The erythrocyte nucleotides of 25 children, 1-5 years old, with normal and increased blood leads, were assayed by anion-exchange high-performance liquid chromatography. Red blood cells of the 12 children with blood lead (PbB) below 30 micrograms/dl (20.3 +/- 6 micrograms/dl, mean +/- S.D.) had normal levels of activity of pyrimidine 5'-nucleotidase (P5N) and their erythrocytes were virtually free of pyrimidine nucleotides except for small amounts of UMP and UDP. The purine nucleotides, predominantly ATP and GTP, were present at values similar to adults. In the 13 children with PbB 30-72 micrograms/dl (45.3 +/- 14.3 micrograms/dl), total cytidine phosphates (CMP, CDP, CTP) were significantly (P less than 0.001) increased from trace values to 8.31 +/- 6.21 nmoles/10(10) erythrocytes. The purine nucleotides were unchanged. P5N activity was 143.3 +/- 22.0 units/g hemoglobin in children with PbB less than 30 micrograms/dl and 75.4 +/- 24.2 units (P less than 0.001) in the high lead subjects. There was a logarithmic correlation of erythrocyte cytidine phosphates with PbB (r = 0.89, P less than 0.001) and an inverse correlation of cytidine phosphates with ln P5N activity (r = 0.59, P less than 0.001), of ln P5N with PbB (r = 0.64, P less than 0.001) and of ln P5N with ln erythrocyte zinc protoporphyrin (Protoporphyrin IX) (r = 0.57, P less than 0.001).

Parental perceptions of enuresis. A collaborative study.

Of 1,379 children 4 years of age and older who were patients in nine medical centers across the country, 346 (25.1%) were found to be enuretic. Their parents considered heavy sleeping and emotional problems as the main causes of enuresis in children; physical causes rarely were believed to be important. "Waking up the child" from sleep to urinate and "talking about the problem" were the main methods that parents used to treat enuresis. Very few used medication. Parents with a grade school level of education punish bed-wetting children at twice the rate of high school- and college-educated parents. Physicians need to be more aware that enuresis is an important problem for parents and that there are many widely held beliefs about cause and management.