2,262 research outputs found
Mothers' Depression and Parenting Efficacy among Economically Disadvantaged Korean Women: Test of a Mediation Model
This study examined the relationships between life stressors (acute stress, chronic stress, and parental stress) and maternal depression as they relate to parenting self-efficacy among economically disadvantaged Korean women. The present investigation was based on the premise that parenting behavior develops as the result of multiple factors, including stressors, which combine to produce a final effect. The family stress model was expanded to include an examination of socio-environmental stresses as factors that might impair parenting through negative effects on maternal psychological functioning. In addition, parental stress was added as a stressor contributing to parenting quality. The study also investigated the effects of maternal depression on parenting efficacy as a predictor and mediator.The study aimed to assess: (a) the relationship between mothers' stressors (acute, chronic, and parental stress) and parenting self-efficacy while controlling for income, mother's education, mother's job status and total support; (b) the relationships between mothers' stressors and maternal depression; (c) the relationship between maternal depression and parenting self-efficacy; and (d) a mediating effect of maternal depression on the relationship between mothers' stressors and parenting self-efficacy.The study design was cross-sectional, and employed a convenience sampling method. The study participants were Korean mothers of children ages 3-5 in 12 daycare centers in Seoul, Korea. A total of 429 individuals participated in this study and data on 408 cases were analyzed.The results showed that socio-environmental stress and parental stress could result in depression and a low level of parenting self-efficacy among Korean mothers. Although income was an important variable, chronic stress and parental stress were found to be even more influential variables on maternal depression and parenting self-efficacy. This study found that the lower the income, the more vulnerable the mother was to stress, and it also showed that chronic stressors had more influence on maternal depression for low-income mothers than for middle-class mothers. This study showed that the mental health of low-income mothers mediated the relationship between chronic stress and parenting. To maximize effective parenting under high-stress conditions, mothers need to first protect their own psychological well-being against environmental contexts. For the welfare of the children, attention must be shown to the mental health of mothers and their welfare. Policy development and management for these issues are desperately needed in Korea
Photodesorption of specific organic compounds from titanium dioxide particles in aqueous media
This study investigates the photodesorption of organic compounds (beef extract, peptone, humic acid, tannic acid, sodium lignin sulphonate, sodium lauryl sulphate, arabic gum powder and arabic acid) from TiO2 (1 g/L in water, pH 7). After a period to reach adsorption equilibrium, photodesorption experiments were conducted in a recirculated reactor at a constant flow rate of 150 mL/min with a UV light intensity of 24 W. Photodesorption was observed only for sodium lauryl sulphate (50%), sodium lignin sulphonate (43.47%), beef extract (20.35%) and tannic acid (10.5%) indicating that photodesorption is specific to some organic compounds but not to all. Using liquid chromatography-organic carbon detection, untreated beef extract and sodium lignin sulphonate were found to contain significant amounts of humic substances (∼1,000 g/mol), which decreased in concentration after dark phase adsorption, while a significant increase in low molecular weight (<350 g/mol) concentrations was observed after photodesorption. UV-treated sodium lauryl sulphate photodesorbed to give both higher molecular weight (HMW) and lower molecular weight (LMW) organics. Thus, the HMW fractions of organic compounds decomposed into smaller compounds after UV irradiation, which subsequently desorbed from TiO2 surface. However, untreated tannic acid contained a larger proportion of LMW acids, which shows a high adsorption affinity to TiO2 during adsorption and poorly desorbs upon irradiation. © 2013 © 2013 Balaban Desalination Publications. All rights reserved
Preparation and characterisation of titanium dioxide produced from Ti-salt flocculated sludge in water treatment
During the past few years, titanium salts were investigated as alternative coagulants for the removal of organic matter of different molecular sizes in contaminated water. The flocculation efficiency of Ti-salt was comparable to those of FeCl3 and Al2(SO4)3 salts, commonly used coagulants. Incinerated sludge-TiO2 showed higher surface area and photocatalytic activity than commercially available TiO2. Metal-doped forms were produced by adding coagulant aids such as iron (Fe-), aluminium (Al-) and (Ca-) calcium salts during Ti-salt flocculation to increase pH. Ca- and Al- doped TiO2 showed very high photocatalytic activity compared to Fe-doped TiO2. When tested in a pilot scale plant for treatment of dye wastewater to check practical feasibility of the novel process, the removal ratio of the chemical oxygen demand was comparable to those of commonly used coagulants but the settling of sludge was faster. The TiO2 generated after sludge incineration showed a high photocatalytic activity for degradation of volatile organic compounds and increased the rate of hydrogen production by water photosplitting. TiCl4 coagulant and TiO2 produced from different water sources with different concentrations had low acute toxicity compared to heavy metals and commercial TiO2 when examined based on D. Magna mortality. This paper presents the production, characterisation and the photoactivity of TiO2 produced from Ti-salt flocculated sludge. Different case studies are discussed to highlighted recent advances in this field
Macular Infarction Associated with Reactive Arthritis
A 53-year-old woman visited the Department of Rheumatology with a chief complaint of a 3-day history of fever and chills and also presented with pain occuring in both knees at the time of outpatient visit. Based on rheumatologic and hematological lab studies, ultrasonography, and a needle aspiration biopsy of the articular cavity, the patient was diagnosed with reactive arthritis. On hospitalization day 3, consultation with the Department of Ophthalmology was requested regarding decreased visual acuity lasting for 3 days. Upon ophthalmologic examination, the corrected visual acuity was 0.1 in the right eye and 0.05 in the left eye. Upon slit lamp microscopy, there were no abnormal findings in the anterior segment. Upon fundus examination, however, there were yellow-white lesions in the macular area of both eyes. Fluorescein angiographywas performed to assess the macular lesions, and the findings were suggestive of macular infarction in both eyes. Due to a lack of other underlying disease, a past surgical history, and a past history of drug administration, the patient was diagnosed with macular infarction in both eyes associated with reactive arthritis. To date, there have been no other such cases reported. In a patient with reactive arthritis, we experienced a case of macular infarction in both eyes, which occurred without association with a past history of specific drug use or underlying disease. Herein, we report our case, with a review of the literature
The Rice Paradox: Multiple Origins but Single Domestication in Asian Rice
The origin of domesticated Asian rice (Oryza sativa) has been a contentious topic, with conflicting evidence for either single or multiple domestication of this key crop species. We examined the evolutionary history of domesticated rice by analyzing de novo assembled genomes from domesticated rice and its wild progenitors. Our results indicate multiple origins, where each domesticated rice subpopulation (japonica, indica, and aus) arose separately from progenitor O. rufipogon and/or O. nivara. Coalescence-based modeling of demographic parameters estimate that the first domesticated rice population to split off from O. rufipogon was O. sativa ssp. japonica, occurring at ∼13.1–24.1 ka, which is an order of magnitude older then the earliest archeological date of domestication. This date is consistent, however, with the expansion of O. rufipogon populations after the Last Glacial Maximum ∼18 ka and archeological evidence for early wild rice management in China. We also show that there is significant gene flow from japonica to both indica (∼17%) and aus (∼15%), which led to the transfer of domestication alleles from early-domesticated japonica to proto-indica and proto-aus populations. Our results provide support for a model in which different rice subspecies had separate origins, but that de novo domestication occurred only once, in O. sativa ssp. japonica, and introgressive hybridization from early japonica to proto-indica and proto-aus led to domesticated indica and aus rice
Successful treatment of central retinal artery occlusion using hyperbaric oxygen therapy
Central retinal artery occlusion (CRAO) is considered an ophthalmologic emergency. The prognosis of this disease is very poor. Currently, there is no generally effective therapy available to treat CRAO. Hyperbaric oxygen therapy (HBOT) can increase the volume of oxygen delivered to the ischemic retinal tissue until spontaneous or assisted reperfusion occurs. We report the case of a patient who experienced sudden visual loss due to CRAO that was treated with HBOT. The patient was an 81-year-old woman who presented with CRAO in her right eye (OD). She exhibited “hand motion” visual acuity before treatment. She underwent three sessions of HBOT at a pressure of 2.8 atmospheres absolute, performed over 3 days. After 4 days in hospital, her visual acuity improved to 0.4 (OD) for far vision and 0.5 (OD) for near vision. Her vision was stable without the supply of oxygen; therefore, she was discharged
Valsalva Retinopathy Associated With an Oratorical Contest
A 17-year-old man presented to us with a chief complaint of decreased visual acuity accompanied by central scotoma. There was nothing unusual in his medical history other than a recent oratorical contest. At the time of initial diagnosis, the corrected visual acuity was 20/20 in the right eye and 20/100 in the left eye. No significant findings were apparent on ophthalmic evaluation. On fundoscopy, there was a dumbbell-shaped macular bleed with a well-defined margin in the left eye. The clinical course was closely monitored along with drug therapy. Four weeks post presentation, the pre-retinal hemorrhage had nearly resolved. On fluorescein angiography, no significant findings were observed. In the left eye, the corrected visual acuity had improved to 20/25. Valsalva retinopathy is a pathology that occurs when a sudden increase in intra-thoracic pressure or abdominal pressure occurs in an otherwise healthy person. Here we report a case of Valsalva retinopathy occurring following an oratorical contest along with a review of the relevant literature
Casimir forces on a silicon micromechanical chip
Quantum fluctuations give rise to van der Waals and Casimir forces that
dominate the interaction between electrically neutral objects at sub-micron
separations. Under the trend of miniaturization, such quantum electrodynamical
effects are expected to play an important role in micro- and nano-mechanical
devices. Nevertheless, utilization of Casimir forces on the chip level remains
a major challenge because all experiments so far require an external object to
be manually positioned close to the mechanical element. Here, by integrating a
force-sensing micromechanical beam and an electrostatic actuator on a single
chip, we demonstrate the Casimir effect between two micromachined silicon
components on the same substrate. A high degree of parallelism between the two
near-planar interacting surfaces can be achieved because they are defined in a
single lithographic step. Apart from providing a compact platform for Casimir
force measurements, this scheme also opens the possibility of tailoring the
Casimir force using lithographically defined components of non-conventional
shapes
Hypofractionated High-Dose Intensity-Modulated Radiotherapy (60 Gy at 2.5 Gy per Fraction) for Recurrent Renal Cell Carcinoma: A Case Report
A patient with renal cell carcinoma (RCC) developed synchronous bone metastasis with metachronous relapses to the bone and renal fossa. The primary lesion was initially removed surgically, and the metastatic bone lesions and locally recurrent tumours were treated by a high-fractional dose and high-total-dose intensity-modulated radiotherapy (IMRT, 60 Gy at 2.5 Gy per fraction) without significant side effects. All the grossly relapsed tumors underwent complete remission (CR) within a short time after IMRT. To date, CR has been maintained for more than two years. This case study reports the successful treatment of radioresistant RCC using a new scheme that involves a fractionation regimen with a high precision radiotherapy
- …