Longer Duration Of Exposure Research Articles

Effect of duration, and temporal modulation, of monochromatic light on emmetropization in chicks

Previous experiments disagree on the effect of monochromatic light on emmetropization. Some species respond to wavelength defocus created by longitudinal chromatic aberration and become more myopic in monochromatic red light and more hyperopic in monochromatic blue light, while other species do not. Using the chicken model, we studied the effect of the duration of light exposure, modes of lighting, and circadian interruption on emmetropization in monochromatic light.To achieve this goal, we exposed one-week-old chicks to flickering or steady monochromatic red or blue light for a short (10 days) or long (17 days) duration; other chicks were exposed to white light for 10 days. Refraction and ocular biometry were measured. Activity was measured via a motion detection algorithm and an IR camera. The results showed that in both steady and flickering light, there was a greater increase in axial length and vitreous chamber depth in chicks exposed to red or white light compared to chicks exposed to blue light. With a longer duration of exposure, axial length and vitreous chamber depth differences were no longer observed, except at an intermediate time point. Chicks exposed to red light were more active during the day compared to chicks exposed to blue light. We conclude that our results indicate that with short duration monochromatic light exposure, chicks rely on wavelength defocus to guide emmetropization. With longer exposure from hatching, our results support the notion that responses to wavelength defocus can be transient and that the difference between species may be due to differences in experimental duration and/or interference with circadian activity rhythms.

Resident physicians' perceptions of ambulatory care pharmacy.

Background:Physicians’ acceptance of clinical pharmacy services is dependent on exposure to those services, with use increasing as resident physicians progress through their training. Resident physicians train within environments that have a multidisciplinary teaching and clinical care approach, working closely with other healthcare professionals. Ambulatory care pharmacists are increasingly working with resident physicians in clinic settings as part of the multidisciplinary team, and identification of resident physicians’ perceptions may influence future collaboration.Objective:The objective of this research is to evaluate the perception of ambulatory care clinical pharmacy services from the perspective of resident physicians.Methods:A statewide network of ambulatory care pharmacists was identified and received an electronic questionnaire. Pharmacists working within clinics that serve as training sites for resident physicians then completed and distributed questionnaires to the resident physicians within their clinical site. Items related to demographics and perception of involvement and interactions with clinical pharmacists.Results:Forty-five resident physicians responded from four unique clinical sites (response rate = 42%). They agreed or strongly agreed that pharmacists help patients obtain their therapeutic goals (97.8%), are able to educate patients effectively (95.6%), provide high quality care (97.8%), and do a good job helping co-manage patients (91.1%). Previous exposure to pharmacists was limited primarily to the drugstore (48.9%) and hospital (51.1%) settings. Resident physicians in the third year of training and those reporting a friend was a pharmacist, were more likely to have a positive perception of the pharmacist’s role as a resident educator (p=0.048 and p=0.044, respectively).Conclusions:Resident physicians with a longer duration of exposure and personal friendship with a pharmacist are more likely to express positive perceptions. Areas for further enhancements in this interprofessional relationship related to perceptions about pharmacist autonomy and patient relationships were identified.

Prevalence of chronic obstructive pulmonary disease among urban males in Chidambaram, Tamil Nadu

Background: Chronic obstructive pulmonary disease (COPD) is a major public health problem with increasing prevalence especially in developing countries. Different studies show higher prevalence of COPD among men compare to women across the country. Hence this study was undertaken to estimate the prevalence of COPD among men, and to find out the risk factors of COPD among males in Chidambaram. Methods: A community based cross sectional study was done in Chidambaram among males more than 30 years of age. 392 study participants were selected by cluster sampling method. A semi structured questionnaire was used to collect the background information and spirometer was used to measure FEV1 and FVC ratio. Results: The Prevalence of COPD was 15.8% in the study population. Prevalence was significantly higher among older males, smokers and study participants with long duration of ETS and occupational exposure to dust and fumes. Conclusions: There is significant association between COPD and the age, smoking status, long duration of ETS exposure and occupational exposure with p value

Corrosion behaviour of 2205 duplex stainless steel in marine conditions containing Erythrobacter pelagi bacteria

A study was carried on 2205 duplex stainless steel immersed in synthetic seawater with Erythrobacter pelagi bacteria for a period of time up to 63 days. Electrochemical tests and microorganism growth analysis from SEM images was used for the study. The observation showed that biofilm developed on DSS 2205 surface retarded corrosion activities at the commencing stages of the study. With increase in immersion period, the biofilm grew thicker and the corrosion rate slightly reduced. Biofilm growth and later sloughing off, and also deterioration of the solution environment and the biofilm (“presence of micro cracks”), led to an increase in corrosion rate. This was seen after a long duration of exposure (up to 56 days).From electrochemical analysis, polarization plots showed movement towards the negative and a rise in current densities accompanied with decreased impedance values. SEM images showed cracked biofilm coating after a longer period of exposure in synthetic seawater. It was concluded that corrosion activities were hindered as long as the biofilm was intact. Any deteriorations on the biofilm accelerated formation of localized corrosion sites.

The Effects of Nickel on the Structure and Functioning of a Freshwater Plankton Community Under High Dissolved Organic Carbon Conditions: A Microcosm Experiment.

In the present study, we aimed to test the protectiveness of the bioavailability-normalization procedure, with its associated hazardous concentrations for x% of the species (HCx), that is currently implemented to derive environmental threshold concentrations for nickel (Ni) in European environmental legislative frameworks. We exposed a natural plankton-dominated community to 3 constant Ni concentrations, that is, a control with no Ni added (background Ni of 1.2-4 µg/L) and the bioavailability-normalized HC5 and HC50 of 24 and 97 µg dissolved Ni/L, respectively, during a 56-d microcosm experiment under high dissolved organic carbon (DOC) conditions (DOC of 14 mg/L at test initiation). The effects of the bioavailability-normalized HC5 and HC50 values were evaluated at the levels of community structure (community composition and plankton group abundances), community functioning (measured as indirect physicochemical proxies for overnight respiration and carbon fluxes), and individual species abundances. The bioavailability-normalized HC50 treatment had clear effects (defined as effects occurring on at least 2 consecutive sampling days) on both the structure and functioning of the investigated aquatic community. Through its effect on community functioning (i.e., reduced pH and DOC), Ni also influenced its own bioavailability. Clear direct effects of Ni were observed for only 3 species (the Cyanobacteria Oscillatoria sp. 1 and the rotifers Asplanchna/Testidunela sp. and Trichocerca group similis). Most other effects occurring in the plankton community in the HC50 treatment were indirect and likely driven by the direct effect of Ni on the Cyanobacteria Oscillatoria sp. 1, which was the dominant phytoplankton species in the control microcosms. In contrast, the bioavailability-normalized HC5 did not induce clear effects on community structure and functioning endpoints: these were only affected on individual sampling days. Clear (direct) effects were observed for only 2 plankton species (the rotifer Trichocerca group similis and the Cyanobacteria Oscillatoria sp. 1), but their abundances recovered to control levels at the end of the study. In addition, a few species (1 phytoplankton and 3 zooplankton species) were affected in the HC5 treatment only on the last sampling day. It is uncertain whether these species would have shown clear effects over a longer exposure duration. Thus, our study shows that the bioavailability-normalized HC5 of Ni at high DOC induced clear effects on a few individual species. However, the overall conclusion is that the bioavailability-normalized HC5 of Ni as derived through the procedure that is currently implemented in European legislative frameworks protects against clear effects on community structure and function. Environ Toxicol Chem 2019;38:1923-1939. © 2019 SETAC.

In vitro chromosome doubling of African daisy, Gerbera jamesonii Bolus cv. Mini Red

A protocol for in vitro polyploidy induction was developed in Mini Red cultivar of African daisy (Gerbera jamesonii). Various concentrations of colchicine (0, 0.05, 0.1, 0.2, 0.5 and 1%) were applied with different exposure durations (2, 4 and 8 h) on 2 weeks old explants originated from in vitro induced Gerbera shoots. Murashige and Skoog (MS) medium supplemented with 8.8 μM 6-benzyladenine (BAP) plus 11.4 μM indole-3-acetic acid (IAA) were used for proliferation of the explants. Root induction occurred when proliferated colchicine-treated shoots transferred to the half strength MS medium supplemented with 3.99 μM IAA. The results of analysis based on the comparison of means revealed that increasing concentrations of colchicine led to significant reduction in survival rate of Gerbera in longer exposure durations; however we achieved the highest survival rate with polyploidy induction by using 0.1% (w/v) colchicine for 8 h. We obtained the highest percentage of tetraploid plants (53.3%) by applying 0.2% colchicine for 2 h. Direct chromosome counting method verified the duplicated chromosome number in colchicine-induced tetraploid plants (2n = 4x = 48) in comparison with intact diploid plants of Gerbera (2n = 2x = 24). Colchicine-induced tetraploid plants of Gerbera represented reduced stomata density with wider size than their diploid relatives. In vitro tetraploidy induction led to larger flower size, longer stalks, broader leaf length and width and lower shoots in Mini Red cultivar of Gerbera. The optimized polyploidy induction protocol has high commercial value and can be also applicable for in vitro micropropagation of Gerbera.

Effects of acute exposures to carbon dioxide on decision making and cognition in astronaut-like subjects

Acute exposure to carbon dioxide (CO2) concentrations below those found on the International Space Station are reported to deteriorate complex decision-making. Effective decision-making is critical to human spaceflight, especially during an emergency response. Therefore, effects of acutely elevated CO2 on decision-making competency and various cognitive domains were assessed in astronaut-like subjects by the Strategic Management Simulation (SMS) and Cognition test batteries. The double-blind cross-over study included 22 participants at the Johnson Space Center randomly assigned to one of four groups. Each group was exposed to a different sequence of four concentrations of CO2 (600, 1200, 2500, 5000 ppm). Subjects performed Cognition before entering the chamber, 15 min and 2.5 h after entering the chamber, and 15 min after exiting the chamber. The SMS was administered 30 min after subjects entered the chamber. There were no clear dose–response patterns for performance on either SMS or Cognition. Performance on most SMS measures and aggregate speed, accuracy, and efficiency scores across Cognition tests were lower at 1200 ppm than at baseline (600 ppm); however, at higher CO2 concentrations performance was similar to or exceeded baseline for most measures. These outcomes, which conflict with those of other studies, likely indicate differing characteristics of the various subject populations and differences in the aggregation of unrecognized stressors, in addition to CO2, are responsible for disparate outcomes among studies. Studies with longer exposure durations are needed to verify that cognitive impairment does not develop over time in crew-like subjects.

FAKTOR KETERPAPARAN BENZENA PADA MEKANIK DI BENGKEL SEPEDA MOTOR

The effects of benzene exposure on living things, especially animals and humans, have been studied almost throughout this century. Short exposure and long-term exposure to benzene can cause health problems until cancer occurs. One type of work that is at risk for indoor benzene exposure is the mechanic of a motorbike repair shop. This study aims to examine benzene exposure factors (source of exposure, air concentration, exposure, duration of exposure, and frequency of exposure) in AHASS mechanics in Sumbersari and Patrang Subdistricts, Jember Regency, and compare these exposure factors with threshold values (NAB) that applies. This research is a quantitative preliminary research, carried out from April to October 2017 in 5 AHASS motorcycle workshops spread in Sumbersari and Patrang Districts, Jember Regency. The sample of this study amounted to 30 people. Based on the results of the study it was found that benzene in the air 5 AHASS workshops spread in Sumbersari and Patrang Subdistricts, the main source came from the evaporation of fuel placed in open containers and through the combustion of the customer's motorcycle engine. The greatest concentration of benzene is in Workshop V which is equal to 21.887 mg / m3. Benzene can enter the mechanical body through inhalation and absorb it through the skin. The longest exposure time occurred in mechanics in Workshop W, while the longest duration of exposure was experienced by mechanics / 28th respondents. The frequency of benzene exposure is most often experienced by mechanics working at Y Workshop, which is 341 days a year. Benzene concentrations in air Workshop V, W, X, and Z exceed NAB, while benzene concentrations in air Y Workshop do not exceed or below NAB. To avoid the risk of benzene exposure to mechanics, the manager of Workshop V, W, X and Z is expected to make efforts to minimize benzene exposure through efforts to reduce benzene concentration in the air as well as efforts to reduce time, duration and frequency of exposure. In addition, further research is needed to determine the risk of benzene exposure to mechanics in AHASS Workshop and to determine the amount of reduction in concentration, time, duration, and frequency of exposure to minimize mechanical health risks due to exposure to benzene in the workplace.

Dynamics of Non-visual Responses in Humans: As Fast as Lightning?

The eye drives non-visual (NV) responses to light, including circadian resetting, pupillary reflex and alerting effects. Initially thought to depend on melanopsin-expressing retinal ganglion cells (ipRGCs), classical photopigments play a modulatory role in some of these responses. As most studies have investigated only a limited number of NV functions, generally under conditions of relatively high light levels and long duration of exposure, whether NV functions share similar irradiance sensitivities and response dynamics during light exposure is unknown. We addressed this issue using light exposure paradigms spectrally and spatially tuned to target mainly cones or ipRGCs, and by measuring longitudinally (50 min) several NV responses in 28 men. We demonstrate that the response dynamics of NV functions are faster than previously thought. We find that the brain, the heart, and thermoregulation are activated within 1 to 5 min of light exposure. Further, we show that NV functions do not share the same response sensitivities. While the half-maximum response is only ∼48 s for the tonic pupil diameter, it is ∼12 min for EEG gamma activity. Most NV responses seem to be saturated by low light levels, as low as 90 melanopic lux. Our results also reveal that it is possible to maintain optimal visual performance while modulating NV responses. Our findings have real-life implications. On one hand, light therapy paradigms should be re-evaluated with lower intensities and shorter durations, with the potential of improving patients’ compliance. On the other hand, the significant impact of low intensity and short duration light exposures on NV physiology should make us reconsider the potential health consequences of light exposure before bedtime, in particular on sleep and circadian physiology.

Association between diuretic use and the risk of vertebral fracture after stroke: a population-based retrospective cohort study

BackgroundStroke is a major risk factor for osteoporosis and fractures. No study has evaluated the association between diuretic use and risk of vertebral fracture in stroke patients, although a considerable proportion of stroke patients are prescribed diuretics for hypertension. Our study aimed to investigate whether treatment with thiazides or loop diuretics affects the risk of vertebral fracture after stroke.MethodsA population-based propensity score-matched retrospective cohort study was conducted using the Taiwan National Health Insurance Research Database. Patients with a new diagnosis of stroke between 2000 and 2011 were included. After propensity score matching, 9468 patients were included in the analysis of the effect of thiazides, of who 4734 received thiazides within 2 years after stroke. To analyze the loop diuretic effect, 4728 patients were included, of who 2364 received loop diuretics. Cox proportional hazards regression models were used to calculate hazard ratios (HRs) of vertebral fractures among patients according to thiazide or loop diuretic use within 2 years following stroke. Sensitivity analyses based on the duration of thiazide or loop diuretic use were further conducted.ResultsThere was no significant difference in vertebral fracture risk between thiazide users and non-users (adjusted HR [aHR] = 1.14, 95% confidence interval [CI] = 0.88–1.47, p = 0.316). Loop diuretic users had a significantly higher vertebral fracture risk than non-users (aHR = 1.45, 95% CI = 1.06–1.98, p = 0.019). However, the sensitivity analysis revealed that short-term thiazide use (exposure duration < 90 days within 2 years after stroke) significantly increased the risk of vertebral fracture versus non-use (aHR = 1.38, 95% CI = 1.02–1.88, p = 0.039). Only short-term loop diuretic users had significantly higher risk of vertebral fracture (aHR = 1.56, 95% CI = 1.11–2.20, p = 0.011). The other two subgroups with longer exposure duration in analyses for both thiazides and loop diuretics revealed no significant effect.ConclusionsShort-term thiazide or loop diuretic use was associated with an increased risk of vertebral fracture after stroke. Further prospective clinical trials are required to confirm this finding.

Accelerated Life Testing of Concrete based on Three-parameter Weibull Stochastic Approach

Due to the time-varying characteristics of the durability of a concrete structure, a long duration of exposure and monitoring in natural conditions is required. The present research provided the indoor accelerated life testing of concrete, which simulated the special natural environments in the Xining area, including solar radiation, dry-wet circulation, freeze-thaw cycle, and salt corrosion. The measured dynamic modulus was taken as an evaluation index for the durability of concrete, and the change of the relative dynamic modulus of the specimen was studied. Meanwhile, a two-parameter Weibull distribution and three-parameter Weibull distribution were proposed based on the stochastic analysis method in order to assess the durability of concrete structure. It has been observed that the indoor accelerated life testing of concrete can make up for the shortcomings of long-term exposure under natural conditions. The variation of the relative dynamic modulus can effectively reflect the durability of the concrete degradation process. By contrasting two methods of stochastic analysis, the three-parameter Weibull distribution method is better to fit the accelerated life data of concrete specimens and to evaluate the durability of concrete structures during service.

Temporal Cognition Can Affect Spatial Cognition More Than Vice Versa: The Effect of Task-Related StimulusSaliency.

Cognition of space and time affect each other; a line with longer length appears to be longer in exposure duration (space on time), and a line with longer exposure duration appears to be longer in length (time on space). This cognitive interaction is known to be asymmetric; the effect of space on time is larger than that of time on space. We conjectured that this asymmetry is not intrinsic but may depend on the saliency of relevant signals. Participants were asked to judge the visual exposure duration of lines that varied in length or the lengths of the lines with different exposure times. The ranges of task-relevant and -irrelevant stimulus values were the same in the spatial and temporal tasks. Task difficulty was also evaluated by subjective rating. We found that duration affected the judgment of length more than vice versa, when the spatial task was significantly more difficult than the temporal task. Together with our previous results that showed the opposite effect, our conjecture is supported that the saliency of stimuli should affect the balance of interactions.

Comparative Studies on the Effect of Noise and Electromagnetic Fields on Rabbit Blood

This study have shown the comparison between the effect exposure to the noise and electromagnetic waves radiation on rabbit. Environmental noise and electromagnetic fields are a known stressful factor that induces alterations of various physiological responses in the exposed individuals. The electromagnetic field applied was generated by using an antenna installed at the laboratory of Islamic University of Gaza. The mobile system used in Gaza is GSM with frequency equals 900 MHz. The antenna place at 20 cm away from the animals such that the whole body exposed to the electromagnetic field on the days of the test the rabbits were brought to the laboratory. The experiment was conducted at Gaza strip laboratory. Twenty two adult male rabbit were used throughout the study. Rabbits were randomly divided into three groups. The first group consists of ten rabbits (w1000-1200gm) served as the control group. During the course of the study the animals were housed in pairs in the animal house with food and water and kept under standard environmental conditions for light (12: 12 h light: dark cycle) temperature (27°C). The second group was subjected to the noise levels (60-70 dB) for 18 days. The animals were exposed to noise product from generator with 1KW and dimension of 1200 mmx1100 mmx1300 mm. They exposure for 3-4 hour in each day. The third one of animals were exposed to split dose of electromagnetic field with constant power in the range from (1.4–4.7) mw/cm2 and electric field with the range (60-130) V/m. The treated animals were subjected to electromagnetic field for eight hours then rest eight hours without exposure. The process of exposure and rest for the same time interval were repeated for two weeks. Animals from both control and experimental groups were decapitated at the end of the experiment. Blood samples were collected in 10 ml plain tubes for serum preparation. The effect of electromagnetic exposure is greater than noise one in urea, uric acid, creatinine, Alpha., AST, ALT and PLT. Exposure to noise caused increase triglycerides, white blood cell counts, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. It was found to be directly related to the duration of exposure, the intensity and the characteristics of the noise with loud intermittent noise and longer duration of exposure producing more analgesia.

Utilization of Pervious Concrete in CO2 Capturing to Control Environmental Impact of Portland Cement

The cement industry is a main producer of greenhouse gases that is responsible for 5–7% of CO2 emissions. Therefore, it is important to find a method to reduce the concentration of this gas in the environment especially in places such as tunnels. This work aims to use pervious concrete to capture CO2 from the environment and transform it to calcium carbonate inside its matrix. The pervious concrete exposed at 7, 14, and 28 days age to 25 and 50% concentration of CO2 for a period of 2 and 4 hours to study the extent of carbonation inside this concrete. In addition to that, the effects of carbonation on compressive strength, weight change, CO2-uptake and change in permeability were studied. The results showed that higher concentration of CO2 and longer exposure periods caused deeper penetration of carbonation. The maximum recorded CO2 uptake by pervious concrete occurs when it was exposed to higher CO2 % and longer duration of exposure at the age of 7 days.

The effects of electromagnetic fields on cultured human retinal pigment epithelial cells.

A great deal of evidence has confirmed that electromagnetic fields (EMFs) can affect the central nervous system. In this study, cultured neonatal human retinal pigment epithelial (hRPE) cells were exposed to pulsed EMF of 1 mT intensity and 50 Hz frequency 8 h daily for 3 days. In addition to cell proliferation and cell death assays, immunocytochemistry for RPE65, PAX6, nestin, and cytokeratin 8/18 proteins were performed. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was performed for NES, PAX6, RPE65, and ACTA2 gene expression. Exposed hRPE cells did not demonstrate significant change in terms of cytomorphology, cell proliferation, or cell death. Protein expression of PAX6 was decreased in treated cells compared to controls and remained unchanged for RPE65, cytokeratin 8/18, and nestin. Gene expressions of NES, RPE65, and PAX6 were decreased in treated cells as compared to controls. Gene expression of ACTA2 did not significantly change. In conclusion, viability of cultivated neonatal hRPE cells did not change after short exposure to a safe dose of pulsed EMF albeit that both gene and protein expressions of retinal progenitor cell markers were reduced. Whether longer exposure durations that are being constantly produced by widely-used electronic devices may induce significant changes in these cells, needs further investigation. Bioelectromagnetics. 39:585-594, 2018. © 2018 Wiley Periodicals, Inc.

Influence of calcium nitrate on morphology and corrosion characteristics of ammonium phosphate treated Aluminum coating deposited by arc thermal spraying process

In present study Al coating was deposited by arc thermal spraying process thereafter treated with different concentration of Ammonium phosphate mono basic (NH4H2PO4) and 0.1 M calcium nitrate [Ca(NO3)2] to fill the porosity. Impedance values of treated coating was increased at longer duration of exposure in artificial ocean water due to transformation of Brushite and Ammonium Aluminum hydrogen phosphate hydrate into metastable and sparingly soluble gypsum and Aluminum phosphate. 0.1 M Ca(NO3)2 has positive influenced with 1 M NH4H2PO4 on formation of compact and crystalline morphology as well as corrosion resistance of Al coating.

Physiological and anatomical responses of calendula (Calendula officinalis L.) cultivars to heat-stress duration

ABSTRACTIt is necessary to identify the heat-tolerant cultivars of bedding plants in order to cope with the challenges of the global warming. The physiological and anatomical responses of four calendula cultivars (Candyman’, ‘Zen’, ‘Indian Prince’, and ‘Pacific Beauty’) to four duration levels (0, 7, 14 and 21 days) of heat stress (in a mean range of 35–42°C), were investigated after their establishment under greenhouse conditions. The results indicated that calendula cultivars displayed different responses to various heat duration levels in most parameters. Although the gas exchange of ‘Candyman’ was the highest in control treatment, it showed a considerable reduction in all levels of stress durations. In contrast, ‘Indian Prince’ maintained gas exchange and chlorophyll content and exhibited the most resistance to heat stress among others, especially for longer duration exposure, which might be resulted from the greater soluble sugar content, higher stomatal density, and thicker leaves. Experiment to assess cell membrane thermostability showed heat stress resulted in significant increase in electrolyte leakage percentage as the incubation temperature of all cultivars was increased. However, the least membrane stability was observed in ‘Zen’, indicating the higher sensitivity of this cultivar to heat-stress conditions in comparison to three other cultivars.

Improved chromosome doubling of parthenogenetic haploid plants of cucumber (Cucumis sativus L.) using colchicine, trifluralin, and oryzalin

An effective chromosome doubling protocol was established in essential garden crop of cucumber (Cucumis sativus L.) Cv. Hi Power. The different concentrations of colchicine (0, 250, 500, 750, and 1500 mg/L), oryzalin (0, 5, 15, 25, 50, 75, and 150 mg/L) and trifluralin (0, 5, 15, 25, 50, 75, and 150 mg/L) were applied on parthenogenesis-induced haploid nodal and shoot tip explants of cucumber for 18 and 38 h in three independent factorial experiments. Increasing concentrations of applied antimitotic agents led to the significant reduction in the survival rate of both shoot tip and nodal explants, especially in longer exposure duration. Three ploidy levels including haploid, mixoploid, and doubled haploid were regenerated form both explant types treated with colchicine, oryzalin, and trifluralin. Flow cytometry analysis proved successful chromosome doubling of haploid plants. Based on the results obtained, the highest number of regenerated doubled haploid plants (92.31%) and fruit set (86.21%) were related to immersion of nodal explants in 50 mg/L oryzalin for 18 h. The highest doubled haploid regeneration for colchicine and trifluralin antimitotic agents were 58.33 and 83.33%, respectively. The leaf size of doubled haploid plants was larger than their correspond haploids. The optimized chromosome doubling protocol would be applicable for doubled haploid production in garden crops of Cucurbitaceae family, which is recalcitrant to the spontaneous doubling, and also for in vitro polyploidy induction studies.

Pediatric frostbite: A 10-year single-center retrospective study

ObjectiveTo describe frostbite (freezing cold injured tissue) in children and intrinsic (psychological and behavioral) and extrinsic (meteorological and safety hazard) factors related to the injury. MethodsRetrospective chart review of children <18 years old referred to a regional pediatric hospital for frostbite, to determine the demographics, environment, and risk factors related to injuries. Results47 patients met the inclusion criteria. Median age was 15 years (IQR 12–16). All injuries occurred between November and March. 49% were admitted to the hospital and frostbite was associated with use of alcohol (53%), cigarettes (34%), marijuana (23%), and symptoms of depression (with and without suicidal ideation) (32%). Frostbite injury treated with conservative wound management presented at <−6°C and injury that underwent surgical procedures occurred at temperatures ≤−23°C (p=0.001). Longer exposure duration also significantly increased the likelihood of a surgical procedure (p<0.001). Intoxication and lack of supervision were two common factors, with lack of supervision at time of injury most common among patients 0–12 years (64%), and intoxication most common among patients ages 13–17 (61%). ConclusionFrostbite injuries in children begins at temperatures <−6°C; with risk of tissue loss increasing at temperatures below −23°C. Lack of supervision and intoxication are major risk factors for frostbite in children. Two-thirds of younger children were unsupervised, whereas intoxication was frequently related to frostbite in adolescents. Both of these factors can be addressed through an education-based prevention program.

Inequalities in the control of the occupational exposure in France to carcinogenic, mutagenic and reprotoxic chemicals.

Our study examined the social disparities that exist in the implementation of protection measures for occupational exposure to carcinogenic, mutagenic and reprotoxic agents in France, and its aim was to identify which types of employees/jobs require priority action. We analyzed data from the 2010 French national cross-sectional survey of occupational hazards. The availability of the various collective and individual protections was explored. The associations of job and company characteristics with protective measures were studied by multilevel regressions. Effective collective protection measures were implemented in 25% of the exposure situations. Managers and intellectual professionals, who accumulated lower CMR exposure prevalences, durations, and intensities than blue-collar workers, benefited the most from effective collective protections. The availability of effective collective protection measures was not influenced by the size of the company. The presence of a Committee for health, safety, and work conditions, as well as intervention of occupational health and safety officers in the past 12 months were associated with a lower exposure intensity, but not with the implementation of more protection measures. Longer exposure durations were associated with more effective collective protection. Substantial discrepancies were observed in exposure levels and protection measures as a function of the characteristics of employees' jobs and the companies that they work for. The main priority in regard to prevention should be a focus on unskilled workers, since their collective protection still appears to be insufficient, while their exposure lengths and intensities were the most substantial.