Brilliant X-rays using a Two-Stage Plasma Insertion Device.

Particle accelerators have made an enormous impact in all fields of natural sciences, from elementary particle physics, to the imaging of proteins and the development of new pharmaceuticals. Modern light sources have advanced many fields by providing extraordinarily bright, short X-ray pulses. Here we present a novel numerical study, demonstrating that existing third generation light sources can significantly enhance the brightness and photon energy of their X-ray pulses by undulating their beams within plasma wakefields. This study shows that a three order of magnitude increase in X-ray brightness and over an order of magnitude increase in X-ray photon energy is achieved by passing a 3 GeV electron beam through a two-stage plasma insertion device. The production mechanism micro-bunches the electron beam and ensures the pulses are radially polarised on creation. We also demonstrate that the micro-bunched electron beam is itself an effective wakefield driver that can potentially accelerate a witness electron beam up to 6 GeV.

Identification of the intermediate hosts of Habronema microstoma and Habronema muscae under field conditions.

A polymerase chain reaction (PCR)-based assay was used for the specific detection of Habronema microstoma and Habronema muscae (Nematoda, Spirurida) in order to identify the intermediate hosts of both nematode species under field conditions. A total of 1087 netted and 165 laboratory-bred flies were tested. Flies were identified as Musca domestica Linnaeus 1758, Musca autumnalis De Geer 1776, Haematobia irritans (Linnaeus 1758), Haematobia titillans (De Geer 1907) and Stomoxys calcitrans (Linnaeus 1758) (Muscidae). Genomic DNA was extracted from pools of fly heads, thoraces and abdomens, and 703 samples were subjected to a duplex two-step semi-nested PCR assay to specifically detect diagnostic regions within the ribosomal ITS2 sequence of both H. microstoma and H. muscae. Stomoxys calcitrans specimens were positive for H. microstoma DNA and M. domestica specimens were positive for H. muscae DNA. In particular, PCR-positive samples derived from both farm-netted and laboratory-bred flies. The present study represents the first evidence of the vectorial competence of different fly species as intermediate hosts of Habronema stomachworms under field conditions. We discuss the roles of S. calcitrans and M. domestica in transmitting H. microstoma and H. muscae.

Saturation and electron-beam lifetime in a storage ring free-electron laser.

We present a phenomenological treatment of free-electron laser storage ring saturation dynamics. The model includes longitudinal instabilities, Touschek intrabeam scattering, and nonzero off-energy-function contributions. The model predictions are compared with Super ACO experimental results and the agreement is shown to be satisfactory.

Suppression of the sawtooth instability in a storage ring by free-electron laser: an example of nonlinear stabilization by noise.

The stabilization of nonlinear excitations by noise is a topic of fundamental importance in many physical problems. We discuss a genuine example within the context of storage ring-free electron laser physics, by presenting a model which allows the characterization of the system evolution and the determination of the conditions leading to the suppression of instabilities of sawtooth type. The conclusions of the model are confirmed by a comparison with experimental results on the Super Aco Storage Ring-Free Electron Laser.

Improving dietary intake to prevent anemia in adolescent girls through community kitchens in a periurban population of Lima, Peru.

Peru has high rates of iron deficiency anemia. The prevalence is 35% in nonpregnant women of fertile age and 24.7% in adolescent girls in slums of periurban Lima. The major cause of anemia is low intake of dietary iron. A community-based, randomized behavioral and dietary intervention trial was conducted to improve dietary iron intake and iron bioavailability of adolescent girls living in periurban areas of Lima, Peru. Results show that there was a change in knowledge about anemia and improved dietary iron intake in the 71 girls who completed the study compared with the 66 girls in the control group. Although the 9-mo. intervention was not sufficient to improve hemoglobin levels significantly, there appeared to be a protective effect in maintaining the iron status of girls in comparison with the control group.

Defecation practices of young children in a Peruvian shanty town.

Little is known about feces disposal practices, their determinants and feasibility for change, despite their importance in the control of diarrheal diseases. We report here the results of formative research for the development of an intervention to promote sanitary disposal of feces of young children. The study was conducted in a densely populated shanty town area of Lima, where water and sanitation systems are scarce. In-depth interviews were undertaken with mothers, husbands and community leaders. Group discussions were held with mothers in order to validate findings from the interviews, investigate particular topics further and explore reactions to possible intervention strategies. The principal defecation sites for young children were diapers, potties, the ground in or near the home, the hill, latrines and flush toilets. The main determinants found were the age of the child, the effort required by the method, perceptions of dirtiness and the availability of resources. Almost all children under one year of age use diapers but the high resource cost of diaper washing is a strong motivation for mothers to move their children on as early as possible. Potties were considered the most socially acceptable and 'hygienic' defecation method for children between one and three years of age. Nevertheless, defecation directly onto the ground is common at this age. Potty training is deemed to be quite difficult and the long term achievements are determined by the initial training success. In most cases, the training process is authoritative and inconsistent. The use of latrines and flush toilets is not considered appropriate for children until they are three to four years old. Based on these initial findings, a micro-trial was conducted to assess the feasibility and acceptability of promoting greater use of potties and associated practices. The results of the trial were very encouraging and provided valuable information for the design of a community-wide intervention. Our findings help explain why the emphasis given in most sanitation projects, where efforts have been concentrated on the promotion of latrines, has failed to induce their utilization by small children. Sanitation projects should incorporate interventions that will promote hygienic defecation and stool clearance practices for infants and small children.

Prediction of common bile duct stones by noninvasive tests.

OBJECTIVE: To define accurate and useful predictors of common bile duct stones (CBDS). SUMMARY BACKGROUND DATA: The ability to predict CBDS with noninvasive tests can avoid unnecessary, costly, or risky procedures. METHODS: All patients referred for examination for CBDS by endoscopic ultrasonography (EUS) from 1993-1996 were prospectively entered in a database. In a first sample selected randomly from the whole population, predictors of CBDS were determined by univariate analysis and logistic regression. Predictors were subsequently tested in that sample and in the rest of the population. A separate analysis was done for patients planned for cholecystectomy. RESULTS: Eight hundred and eighty patients (328 men, 552 women), aged 57.8 +/- 17 years (range 16-94), were included. The prevalence of CBDS was 18.8%. Age, serum levels of bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase (GGT), and alkaline phosphatase, and the existence of jaundice and fever, a dilated bile duct, and a pathologic gallbladder were found to be associated with CBDS. Logistic regression was undertaken separately for patients younger than 70 years (predictors: GGT >7 x normal; pathologic gallbladder; dilated bile duct) and older than 70 years (predictors: GGT >7 x normal; fever > 38 degrees C; dilated bile duct). Odds ratios were 3 to 6.7. The model was satisfactorily applicable to the second sample; age <70 years: chi2 = 3.3 (NS); age >70 years: chi2 = 3.8 (NS). In patients younger than age 70 and planned for cholecystectomy, the combination of the level of GGT and dilated bile duct predicted CBDS accurately. CONCLUSIONS: A simple screening of patients at risk for CBDS can be achieved with three predictive criteria adapted for the patient's age.

Recognizing the reversible nature of child-feeding decisions: breastfeeding, weaning, and relactation patterns in a shanty town community of Lima, Peru.

Researchers have normally considered weaning to be a non-reversible event. To determine the validity of this assumption, we interviewed 36 mothers of toddlers who were living in a poor shanty town of Lima, Peru. Data from 32 women were complete and used in this analysis. Mothers described their beliefs, practices, and decisions about breastfeeding, weaning, and relactation (the reintroduction of breastfeeding after weaning). We recorded attempted weaning events if the mother reported (1) purposefully not breastfeeding with the intention to wean, or (2) carrying out an action that was believed to cause the child to stop breastfeeding. Using a constant comparative approach, references to child-feeding decisions were coded, categorized, and analyzed. All mothers breastfed for at least 12 months; the median duration of breastfeeding was 25 months. There were several different patterns of child-feeding. Thirteen women never attempted to wean their children or had weaned on the first attempt. The majority (n = 19) of women, however, attempted to wean their children - some as early as 3 months of age but relactated between less than 1 day and 3 months later. Factors that influenced feeding decisions were primarily related to maternal and child health, and maternal time commitments. Children were weaned when there was a perceived problem of maternal health or time commitments and child health was not at risk of deterioration. Mothers postponed weaning because of poor child health. The primary reason for relactation was a child's negative reaction to weaning (e.g., incessant crying or refusal to eat). Personalities of the mother and child were important determinants of feeding decisions. These results demonstrate that maternal and child factors jointly influence child-feeding decisions and that these decisions are easily reversed. As relactation is culturally acceptable, health practitioners should consider recommending relactation when children have been prematurely weaned and human milk would improve their nutritional and health status.

[Laparoscopic surgery in gynecology. Experience at the Luis Castelazo Ayala Hospital]. / Cirugía ginecológica laparoscópica. Experiencia en el Hospital Luis Castelazo Ayala.

The purpose of the present study was to demonstrate the various applications of the laparoscopic surgery in the field of gynecology. 40 patients who were submitted to laparoscopic surgery were studied and divided into 5 groups accordingly to the surgical procedure: adhesiolysis, surgery of ovarian tumors, hysterectomy, surgery of the Fallopian tube and myomectomy. All the patients had a preoperative study and once completed they were selected for laparoscopic surgery. The laparoscopic procedure was able to solve the gynecologic pathology. The mean overall surgical time was of 66.8 min with a maximum time of 180 and a minimum of 30 min, accordingly to the groups the surgical mean times were as follows: 1) adhesiolysis 111 min 2) ovarian surgery 69 min 3) hysterectomy 113 min 4) tubal surgery 60 min and 5) myomectomy 58 min. There were no surgical complications and they all had a brief hospitalization period and a fast return to active life. All procedures were done with a bipolar cautery. We conclude that laparoscopic surgery is a useful resource for the resolution of the majority of the benign gynecologic pathology and when indicated in the proper way there is no rise in the morbid-mortality, and offers a short hospitalization period and a quick return to active life.

Ipriflavone and low doses of estrogens in the prevention of bone mineral loss in climacterium.

Estrogen replacement therapy can counteract all postmenopausal symptoms. While low estrogen doses (0.15-0.30 mg of conjugated estrogens/day) can counteract neurovegetative and psychological symptoms, higher estrogen doses (at least 0.625 mg of conjugated estrogens/day) are required to prevent bone mineral loss in postmenopausal women. However, if contra-indications to high estrogen doses exist, drugs other than estrogens can represent a suitable treatment for postmenopausal osteoporosis both alone or in combination with low estrogen doses. Experimental and clinical data have shown that ipriflavone is effective in the treatment of established postmenopausal osteoporosis. With the purpose of evaluating whether ipriflavone is able to enhance estrogen activity on bone metabolism, 133 postmenopausal women were randomly submitted to the treatment with: (1) placebo; (2) 0.15 mg/day of conjugated estrogens; (3) 0.30 mg/day of conjugated estrogens; (4) 0.15 mg/day of conjugated estrogens plus 600 mg/day of ipriflavone; (5) 0.30 mg/day of conjugated estrogens plus 600 mg/day of ipriflavone. One g/day of calcium supplementation was given to all women. In all subjects bone mineral density was measured before and after 6 and 12 months of treatment at the distal radius by dual-photon absorptiometry. A moderate decrease of bone mineral density was evidenced in women submitted to placebo or to estrogen therapy alone. By contrast, an increase of BMD was measured after 12 months of treatment in the women treated with 0.15 (not significant) or 0.30 mg/day (P < 0.01) of conjugated estrogens associated with ipriflavone. Both dosages of conjugated estrogens were able to induce a significant reduction of neurovegetative symptoms. The increase of bone density obtained with the combination of conjugated estrogens with ipriflavone demonstrates that this combination improves the effects of low estrogen doses on bone mass representing a satisfactory approach in the prevention and treatment of all symptoms related to the climacteric syndrome.

Direct evidence that eseroline possesses morphine-like effects.

The opiate-like effects of eseroline, a physostigmine derivative, were studied in different tests. The antinociceptive effect of eseroline given s.c. and intracerebrally could be detected in the rat hot plate test and was reversed by naloxone. The apparent pA2 values of naloxone demonstrated with eseroline and morphine were found to be equal, suggesting an effect on similar receptors. Eseroline also had opiate agonist activity on the isolated longitudinal muscle strip of guinea pig ileum and isolated nictitating membrane of the cat: presynaptically, it inhibited the contractions evoked by stimulation and its effect was antagonized by naloxone. Eseroline reduced acetylcholine release from the myenteric plexus of the longitudinal muscle strip when the cholinesterases had been inhibited by physostigmine. In addition, it was also found that eseroline antagonized the inhibitory effect of normorphine in the longitudinal muscle strip and potentiated the effect of exogenous acetylcholine on smooth muscle, both effects being attributed to its anticholinesterase activity. The analgesic effect of eseroline was not related to its anticholinesterase activity.

Reversible inhibition of acetylcholinesterase by eseroline, an opioid agonist structurally related to physostigmine (eserine) and morphine.

The action of eseroline--(3aS,8aR)-1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethylpyrrolo[2,3-b]indo l-5-ol--salicylate was tested on preparations of ChE from different sources and on the longitudinal muscle of guinea-pig ileum. While eseroline is eseroline is extremely weak-acting on horse serum BuChE (Ki = 208 +/- 42 microM), it is a rather strong competitive inhibitor of AChE's, its Ki being 0.15 +/- 0.08 microM, 0.22 +/- 0.10 microM and 0.61 +/- 0.12 microM in electric eel, human RBC and rat brain, respectively. Eseroline inhibitory action in AChE in independent of the duration of pre-incubation and appears fully developed in less than 15 sec. This action is also rapidly reversible; after pre-incubation followed by dilution, maximum enzymic activity is regained within 15 sec. The electrically-evoked contractions of the longitudinal strip were inhibited by concentrations of eseroline in the range 0.2-15 microM, while they were increased by concentrations over 20 microM. In the same preparation, without electrical stimulation, but in the presence of naloxone, eseroline induced contractions at concentrations higher than 5 microM. This effect was antagonized by atropine. The inhibitory activity of eseroline parallels, as regards selectivity, potency and kinetics, that of the phenolic anticurare agent edrophonium, while it differs markedly from that of physostigmine.

Eseroline: a new antinociceptive agent derived from physostigmine with opiate receptor agonist properties. Experimental in vivo and in vitro studies on cats and rodents.

We report that eseroline, until now thought devoid of any biological action, is a potent antinociceptive agent. Its antinociceptive action is stronger than that of morphine in all tests studied and, though shorter lasting than that of the latter, has a latency of only a few minutes by subcutaneous route. Eseroline, like morphine and enkephalins, inhibits the electrically evoked twitches of the mouse vas deferens and of the guinea-pig ileum. Eseroline, moreover, releases 5-hydroxytryptamine from cat brain cortex in way similar to that of morphine and physostigmine.

Effects of morphine, physostigmine and raphe nuclei stimulation on 5-hydroxytryptamine release from the cerebral cortex of the cat.

1. The release of 5-hydroxytryptamine (5-HT) from the cerebral cortex and caudate nucleus of brainstem-transected cats and from the cerebral cortex of rats anaesthetized with urethane was determined by radioenzymatic and biological assay. 2. The stimulation of nucleus linearis intermedius of raphe doubles the basal 5-HT release in the caudate nucleus and increases it 3 fold in the cerebral cortex. The effects of the electrical stimulation of the raphe are potentiated by chlorimipramine. 3. Brain 5-HT release is greatly increased by morphine hydrochloride (6 mg/kg i.v.) and by physostigmine (100 microgram/kg i.v.), but not by DL-DOPA (50 mg/kg i.v.). 4. It is suggested that the 5-HT releasing action of physostigmine can contribute to some of its pharmacological effects such as the analgesic effect so far attributed exclusively to its indirect cholinomimetic activity. 5. The 5-HT releasing action of physostigmine seems unrelated to its anticholinesterase activity.