Ethephon induced oxidative stress in the olive leaf abscission zone enables development of a selective abscission compound.

BACKGROUND: Table olives (Olea europaea L.), despite their widespread production, are still harvested manually. The low efficiency of manual harvesting and the rising costs of labor have reduced the profitability of this crop. A selective abscission treatment, inducing abscission of fruits but not leaves, is crucial for the adoption of mechanical harvesting of table olives. In the present work we studied the anatomical and molecular differences between the three abscission zones (AZs) of olive fruits and leaves. RESULTS: The fruit abscission zone 3 (FAZ3), located between the fruit and the pedicel, was found to be the active AZ in mature fruits and is sensitive to ethephon, whereas FAZ2, between the pedicel and the rachis, is the flower active AZ as well as functioning as the most ethephon induced fruit AZ. We found anatomical differences between the leaf AZ (LAZ) and the two FAZs. Unlike the FAZs, the LAZ is characterized by small cells with less pectin compared to neighboring cells. In an attempt to differentiate between the fruit and leaf AZs, we examined the effect of treating olive-bearing trees with ethephon, an ethylene-releasing compound, with or without antioxidants, on the detachment force (DF) of fruits and leaves 5 days after the treatment. Ethephon treatment enhanced pectinase activity and reduced DF in all the three olive AZs. A transcriptomic analysis of the three olive AZs after ethephon treatment revealed induction of several genes encoding for hormones (ethylene, auxin and ABA), as well as for several cell wall degrading enzymes. However, up-regulation of cellulase genes was found only in the LAZ. Many genes involved in oxidative stress were induced by the ethephon treatment in the LAZ alone. In addition, we found that reactive oxygen species (ROS) mediated abscission in response to ethephon only in leaves. Thus, adding antioxidants such as ascorbic acid or butyric acid to the ethephon inhibited leaf abscission but enhanced fruit abscission. CONCLUSION: Our findings suggest that treating olive-bearing trees with a combination of ethephon and antioxidants reduces the detachment force (DF) of fruit without weakening that of the leaves. Hence, this selective abscission treatment may be used in turn to promote mechanized harvest of olives.

Consistent high prevalence of Exophiala dermatitidis, a neurotropic opportunist, on railway sleepers.

Environmental isolation of black yeasts potentially causing human disorders is essential for understanding ecology and routes of infection. Several Exophiala species show prevalence for man-made environments rich in monoaromatic compounds, such as creosote-treated or petroleum-stained railway sleepers. Ambient climatic conditions play a role in species composition in suitable habitats. Therefore, the aim of the present study was to establish the composition of Exophiala species in railway stations as a potential source of human infections in a subtropical region with evaluation of their antifungal susceptibility profiles. We examined 150 railway samples using cotton swabs moistened with sterile physiological saline. Black yeasts and relatives were selected on theirs colony morphology and identified based on ITS rDNA sequencing. Overall, 36 (24%) of samples were positive for black yeast-like fungi, i.e., Exophiala dermatitidis (n=20, 55.6%) was predominant, followed by E. phaeomuriformis (n=9, 25%), E. heteromorpha (n=5, 13.9%), and E. xenobiotica (n=2, 5.6%). Massive contaminations of E. dermatitidis were seen on railway sleepers on creosoted oak wood at the region close to the sea level, while in cold climates were primarily contaminated with clinically insignificant or rare human opportunists (E. crusticola). It seems that, high temperature and humidity are significant effect on species diversity. Moreover, the MIC results for all E. dermatitidis and E. phaeomuriformis strains revealed the widest range and the highest MICs to caspofungin (range 1-16mg/L, Geometric mean 4.912mg/L), and the lowest MIC for posaconazole (0.016-0.031mg/L, G mean 0.061mg/L). However, their clinical effectiveness in the treatment of Exophiala infections remains to be determined.

Effects of prone and supine positions on sleep state and stress responses in preterm infants.

AIM: The purpose of the study is to assess the influence of prone or supine position on sleep states and on withdrawal and approach reactions of preterm infants. METHODS: Thirty-two preterm infants from Meir Medical Center, Israel, mean post menstrual age 30.37±2.57, mean birth weight 1250g±313.86, participated in the study. Infants were studied during 48h. Positions (prone and supine) were alternated every 3-4h after feedings. Sleep states were assessed by Actigraph measurement and by two daily 30-min Naturalistic Observations of Newborn Behavior (NONB) to confirm sleep states and for recording the behavioral reactions (approach and withdrawal). RESULTS: In the prone position there were more approach reactions as compared to withdrawal reactions (p<.001) while in the supine position, the approach and withdrawal reactions were comparable. In the prone position more sleep patterns (deep sleep, light sleep, drowsy) were observed as opposed to more awake patterns (quiet awake, active awake and agitated fussy) that were seen in the supine position. CONCLUSIONS: Clinical implications encourage placing the preterm infant in the prone position while in the NICU. This enables important achievements such as longer periods of quality sleep, and production of adaptive self-regulatory reactions.

Sol-gel-derived composite antimony-doped, tin oxide-coated clay-silicate semitransparent and conductive electrodes.

A new form of conductive and transparent porous composite electrode is introduced. The electrode material is composed of antimony-doped, tin oxide (ATO)-coated mica platelets imbedded in sol-gel-derived silicate or methyl silicate network. The platelet clays self-align in a layered structure within the silicate film, an anisotropic construction that minimizes the ATO loading required to achieve electric percolation. Transparency and resistance as a function of clay loading is reported with typical values of 100 k Omega/square and 1.5 OD for a 20-microm-thick film. The transparency is lower as compared to sputtered ATO glasses, but this is, as far as we know, the best method for the low-temperature preparation of transparent, porous, and electrically conductive (as opposed to the amply reported ionically conductive) electrode materials. Permselectivity induced by the silicate and clay ingredients is demonstrated by permeation of positively charged methyl viologen compared to negatively charged ferricyanide. Prussian blue-modified ATO-coated platelets dispersed in sol-gel-derived silicate were used to demonstrate feasibility of a transparent and electrically conductive porous electrochromic material.

Sleep patterns and sleep disruptions in kindergarten children.

Assessed sleep patterns and sleep disruptions in kindergarten children and investigated the relation between sleep measures derived from objective and subjective evaluation methods. The sleep patterns of 59 normal kindergarten children (mean age = 5.5 years) were monitored for 4 to 5 consecutive nights by means of activity monitors (actigraph) and by means of parental daily sleep logs. The correlation between the actigraphic measures and the daily parental logs indicated that parents were accurate reporters of sleep schedule measures. However, parents were less accurate in assessing sleep quality measures, significantly underestimating the number of night-wakings and overestimating the quality of their children's sleep. Fragmented sleep was found, by means of activity monitoring, in 41% of the children.

Characteristics and outcomes of paediatric rhegmatogenous retinal detachment treated by segmental scleral buckling plus an encircling element.

PURPOSE: To evaluate the outcome of paediatric rhegmatogenous retinal detachment treated by segmental scleral buckling plus an encircling element. METHODS: A retrospective review was carried out of 15 consecutive paediatric patients (16 eyes). RESULTS: Thirteen of the 15 patients were male (87%), 2 (13%) were female. Their average age was 10.9 years (range 6-18 years; median 10 years). Retinal detachment was caused by trauma in 9 of 16 eyes (56%), high myopia in 5 of 16 eyes (31%) and had an unknown cause in 2 of 16 eyes (13%). Diagnosis was delayed by more than 1 month in 10 of 16 eyes (63%). The visual acuity was 6/60 or worse and the macula was detached on presentation in 13 of 16 eyes (81%). Two of 16 eyes (13%) had mild proliferative vitreoretinopathy. Final reattachment was achieved in all cases. Of 11 eyes with a follow-up of 6 months or more, there was improvement in visual acuity in 7 (63%), and a best-corrected visual acuity of 6/20 or better in 5 (46%). CONCLUSION: Paediatric rhegmatogenous retinal detachment is characterised by a delay in diagnosis and a high degree of macular involvement on presentation. Anatomical reattachment with segmental scleral buckling plus an encircling element was successful in all eyes, and improvement of visual acuity was achieved in one-half of the eyes which had a follow-up of 6 months or more.

Sleep patterns and sleep disruptions in school-age children.

This study assessed the sleep patterns, sleep disruptions, and sleepiness of school-age children. Sleep patterns of 140 children (72 boys and 68 girls; 2nd-, 4th-, and 6th-grade students) were evaluated with activity monitors (actigraphs). In addition, the children and their parents completed complementary sleep questionnaires and daily reports. The findings reflected significant age differences, indicating that older children have more delayed sleep onset times and increased reported daytime sleepiness. Girls were found to spend more time in sleep and to have an increased percentage of motionless sleep. Fragmented sleep was found in 18% of the children. No age differences were found in any of the sleep quality measures. Scores on objective sleep measures were associated with subjective reports of sleepiness. Family stress, parental age, and parental education were related to the child's sleep-wake measures.

Instability of sleep patterns in children with attention-deficit/hyperactivity disorder.

OBJECTIVE: To compare the stability of the sleep-wake system of children with attention-deficit/hyperactivity disorder (ADHD) and controls by objective and subjective measures. METHOD: Thirty-eight school-age boys with diagnosed ADHD and 64 control school-age boys were examined using actigraphic monitoring and sleep diaries, over 5 consecutive nights. RESULTS: Increased instability in sleep onset, sleep duration, and true sleep were found in the ADHD group compared with the control group. Discriminant analysis revealed that children's classification (ADHD versus control) could be significantly predicted on the basis of their sleep measures. CONCLUSIONS: The findings support the hypothesis that instability of the sleep-wake system is a characteristic of children with ADHD. Given the potential negative effects of disturbed or unstable sleep on daytime functioning, it is recommended that a thorough sleep assessment be conducted when a sleep disturbance is suspected or when symptoms associated with daytime sleepiness or decreased arousal level are present.

Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine receptor D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention.

An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.

Macular ring in a patient with Terson's syndrome.

PURPOSE: To report on a pigmented finding in the macula that is unique to Terson's syndrome, and was previously described only once. METHOD: A 49-year-old man underwent vitrectomy for vitreous hemorrhage due to Terson's syndrome. During surgery the retina was exposed, and a pigmentation was noticed around the macula. Follow-up of the macular finding is presented. RESULTS: At surgery a pigmented "ring" encircling the macula was revealed. Two and six months later, the pigmented line was still noticed, and an epiretinal membrane appeared in the temporal macula. CONCLUSION: Terson's syndrome may be associated with a pigmented "ring" encircling the macula, a finding that may be a result of a detachment of the internal limiting membrane (ILM). The epiretinal membrane that was later noticed, might also be related to the damage to the ILM.

Estimating sleep patterns with activity monitoring in children and adolescents: how many nights are necessary for reliable measures?

STUDY OBJECTIVES: This study provides estimates of reliability for aggregated values from 1 to 7 recording nights for five commonly used actigraphic measures of sleep patterns, reliability as a function of night type (weeknight or weekend night), and stability of measures over several months. DESIGN AND SETTING: Data are from three studies that obtained 7 nights of actigraph data (using Mini Motionlogger actigraphs and associated validated algorithms [ASA]) on children and adolescents living at home on self-selected sleep-wake schedules. PARTICIPANTS: Participants were 169 children aged 12-60 months, and 55 adolescents aged 11-16 years. MEASUREMENTS AND RESULTS: Up to 28% of weekly recordings may be unacceptable for analysis in young participants because of illness, technical problems, and participant noncompliance; studies aiming to collect 5 nights of actigraph data should record for at least 1 full week. Reliability estimates for values aggregated over any 5 nights were adequate (> or = .70) for sleep start time, wake minutes, and sleep efficiency. Measures of sleep minutes and sleep period were less reliable and may require 7 or more nights for estimates of stable individual differences. Reliability for 1- or 2-night aggregates were poor for all measures. We found significant and high correlations between summer and fall session measures for all five variables when weekend nights were included. CONCLUSIONS: Five or more nights of usable recordings are required to obtain reliable actigraph measures of sleep for children and adolescents.

Sleep and pulmonary function in children with well-controlled, stable asthma.

The aim of this study was to assess sleep and pulmonary function in asthmatic and control children. Forty children with well-controlled, stable asthma, and 34 controls (age range: 8.2 to 15.4 years) were monitored with wrist actigraphs and peak-flow meters for 3 consecutive days. In addition, asthma severity was assessed by subjective parental and self-rating scale and symptom checklist. Asthmatic children had poorer sleep quality in comparison to their controls, as manifested in lower percentages of quiet sleep (p < .05) and increased activity level during sleep (p < .05). As expected, asthmatic children had reduced morning peak expiratory flow measures (p < .01) and a higher evening-to-morning drop in peak expiratory flow (p < .005). Peak-flow measures were significantly correlated with subjective and objective sleep measures. In the asthmatic group, sleep measures were also correlated with subjective asthma severity indices and symptom checklists. We conclude that poorer sleep is associated with reduced pulmonary function. The reduced sleep quality, coupled with subjective reports of increased fatigue and reduced alertness found in asthmatic children, suggest that these children are at risk for developing neurobehavioral deficits associated with chronic sleep loss.

Sleep and melatonin in infants: a preliminary study.

Sleep-wake patterns of 20 normal, healthy infants (16 girls and four boys; age range: 26-37 weeks) were recorded for a period of 1 week with a miniature activity monitor. Urine samples were extracted from the infants' disposable diapers that were collected during a 60-hour period to determine the levels of 6-sulphatoxymelatonin (aMT6s, a melatonin metabolite) using a radioimmunoassay test. Infants with "mature" secretion patterns (i.e. with an adult-like circadian rhythm) had a significantly delayed sleep-wake cycle in comparison to those with "immature" patterns. The onset of their nocturnal-sleep episode was delayed by almost 1 hour (22.1 vs. 21.2 hours; p < 0.05). Higher secretion rates of aMT6s during the evening hours (6:00-10:00 p.m.) were associated with earlier onset of nocturnal sleep (r = 0.51; p < 0.05). A delayed peak of melatonin was associated with more fragmented sleep during the night (e.g. r = 0.49; p < 0.05; for lower sleep percent). These findings suggest that melatonin plays an important role in the evolution of the sleep-wake system.

Sleep quality in children with attention deficit hyperactivity disorder: an actigraphic study.

The aim of the present study was to compare the sleep of 12 children with attention deficit hyperactivity disorder (ADHD) with that of 12 normal controls. The children were examined in their natural environment, using continuous actigraphic monitoring over several consecutive nights, as well as undergoing subjective parental reports. It was hypothesized that children diagnosed with ADHD would suffer from reduced sleep quality than children without ADHD. This hypothesis was supported by the actigraphic measures, but not supported by the subjective parental reports. It was also found that the sleep quality of the two groups differed over the course of the night, which suggests a difference in sleep architecture. Various possible explanations for these findings, their implications regarding the relationship between sleep and ADHD, and the resulting treatment ramifications are discussed, and suggestions for further research are provided.

Evaluating night wakings in sleep-disturbed infants: a methodological study of parental reports and actigraphy.

The aim of this study was to investigate the use of objective and subjective sleep measures in diagnostic assessment of night-waking problems during infancy. Infant sleep-wake measures obtained from parental daily logs were compared with objective sleep measures derived from activity monitoring during a week-long period in 66 referred infants. Reported sleep measures were significantly correlated with objective sleep measures and showed a significant level of day-to-day stability. Parents were accurate reporters of sleep-schedule measures (e.g. sleep onset, r = 0.88; sleep duration, r = 0.74; p < 0.0001). However, parents were less accurate in assessing sleep quality measures, significantly overestimating the time that their infants spent in actual sleep and underestimating the number of their night-wakings (r = 0.41 and r = 0.60, respectively; P < 0.001). It is suggested that subjective and objective measures should play a complementary role in the clinical assessment of night-waking problems in early childhood.

Newborns' sleep-wake patterns: the role of maternal, delivery and infant factors.

OBJECTIVE: The purpose of this study was to assess the sleep-wake patterns of fullterm (> or = 37 weeks) newborns and to evaluate the effects of specific factors including maternal gestational diabetes, infant size and anthropometric measures, gender, gestational age and delivery variables. METHODS: Two-hundred twenty newborns were studied in the hospital nursery for a continuous 24-h period with miniature activity monitors attached to the infants' ankles. The sample consisted of 102 infants of gestational diabetic mothers (IGDM) and 118 controls. Anthropometric measurements were obtained and maternal and infant characteristics were recorded. RESULTS: The newborns had a discernible diurnal sleep pattern and slept twice as much during the nighttime as daytime hours (P < 0.001). Higher skinfold measurements correlated significantly with increased quiet and motionless sleep (P < 0.05) for the IGDM but not for controls. Sleep of infants born at later gestational ages was characterized by increased percent of quiet and motionless sleep (P < 0.0001). No direct gender effects were identified. CONCLUSIONS: Multiple factors were associated with the sleep-wake patterns of the newborns on our study cohort including maternal glucose values during pregnancy, increased measures of adiposity in IGDM, increased gestational age, mode of delivery and delivery Sequence. Investigation of the sleep-wake characteristics of neonates using activity monitors is a noninvasive method for gaining new understanding of the relationships between sleep wake activity patterns and infant characteristics.