Home About us Contact
|
Home About us Contact | ||
|
|
||
Basic Processes (basic + process)
Selected AbstractsEnduring love: A grounded formal theory of women's experience of domestic violenceRESEARCH IN NURSING & HEALTH, Issue 4 2001Margaret H. Kearney Abstract Using a grounded formal theory approach, 13 qualitative research reports were analyzed with the goal of synthesizing a middle-range theory of women's responses to violent relationships. The combined sample numbered 282 ethnically and geographically diverse women ages 16,67. Within cultural contexts that normalized relationship violence while promoting idealized romance, these women dealt with the incongruity of violence in their relationships as a basic process of enduring love. In response to shifting definitions of their relationship situations, many women moved through four phases, which began with discounting early violence for the sake of their romantic commitment ("This is what I wanted"), progressed to immobilization and demoralization in the face of increasingly unpredictable violence that was endured by the careful monitoring of partner behavior and the stifling of self ("The more I do, the worse I am"), shifted to a perspective that redefined the situation as unacceptable ("I had enough"), and finally moved out of the relationship and toward a new life ("I was finding me"). Variations in the manifestation and duration of these phases were found to be linked to personal, sociopolitical, and cultural contexts. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:270,282, 2001 [source] Elementary processes of soil,water interaction and thresholds in soil surface dynamics: a reviewEARTH SURFACE PROCESSES AND LANDFORMS, Issue 9 2004Richard S. B. Greene Abstract Elementary processes of soil,water interaction and the thresholds to these processes are important to understand as they control a range of phenomena that occur at the soil surface. In particular processes involved with wetting by rainfall that lead to particle breakdown are critical. This breakdown causes soil detachment and crust formation, which are both key elements in erosion. This paper reviews the range of approaches that have been taken in describing the processes associated with the wetting of a soil surface by rainfall. It assembles the studies that emphasize soil physics, soil chemistry, and erosion mechanics in a framework to enable a balanced consideration of important processes and management strategies to control erosion for a particular situation. In particular it discusses the factors associated with the two basic processes of soil structural breakdown, i.e. slaking and dispersion, and how these processes are critical in particle detachment, transport and surface crust formation. Besides the balance between the exchangeable cation composition and electrolyte concentration (measured as the sodium adsorption ratio (SAR) and total cation concentration (TCC) respectively) of the soil, the importance of energy input and soil organic matter content in controlling clay dispersion is emphasized. Based on the balance between these factors, the soil can be in one of three different regions, i.e. a dispersed region, a ,occulated region and one where the resilience of the soil is variable. The implications of each of these regions to soil erosion management are brie,y outlined, as are the critical roles that soil cover levels and organic matter have in controlling erosion. Finally, the relationship between various laboratory measures of aggregate stability, and corresponding ,eld erosion characteristics, is discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] From Single Grains to TextureADVANCED ENGINEERING MATERIALS, Issue 10 2009Kun Yan Abstract Structural materials, such as metals, ceramics, and their composites are most often polycrystalline. The nature, morphology, and composition of their microstructure determine in large measure the mechanical properties of the final product, and the art to design novel materials is to find particular arrangements which make them harder, more shock absorbing, heat resistant, or self-recovering upon damage and aging. The understanding of the basic processes and their interplay in a polycrystalline structure are most important for improved simulation of plastic deformation and to predict their thermo-mechanical behavior. [source] The Physiological Basis of Uterine Contractility: A Short ReviewEXPERIMENTAL PHYSIOLOGY, Issue 2 2001S. Wray In this review we discuss our current understanding of the cellular basis of uterine contractility, highlighting those areas requiring further study. It is clear that the basic processes of excitation-contraction coupling lie within the myometrial cell, and that these may be modified by agonists. Pacemaker acitivity, however, remains a mystery. The contribution of extracellular calcium entry to contraction is shown to be vital, whilst the role of the sarcoplasmic reticulum remains controversial. Much current experimental focus is on pathways controlling and regulating contraction, and we discuss sensitisation mechanisms and question their role in intact uterine preparations. [source] Characteristics of skin aging in Korean men and womenINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2005J. H. Chung Introduction Korea is located between Japan and Mainland China. The people of these three countries have similar appearances and it is difficult to differentiate between them. Although the population of Asia is more than half of the total population of the Earth, the inherent characteristics of Asian skin have not been well investigated. Commercial markets for cosmetics and drugs for photoaged skin are rapidly expanding in many Asian countries. Therefore, many investigators in the field of dermatology and cosmetology have become interested in brown Asian skin. Clinical characteristics of skin aging and photoaging in Asians Skin aging can be divided into two basic processes: intrinsic aging and photoaging [1]. Intrinsic aging is characterized by smooth, dry, pale, and finely wrinkled skin, whereas photoaging, which indicates premature skin aging in chronically photodamaged skin, is characterized by severe wrinkling and irregular pigmentation. The pattern of wrinkling in Asians seems to differ from that in Caucasians. Asians have coarser, thicker and deep wrinkles, particularly in the forehead, perioral and Crow's foot areas. In contrast, Caucasians usually have relatively fine cheek and Crow's foot wrinkles. The reasons for these differences are not known and need further investigation. There are racial, ethnic and genetic differences, and differences of skin structure and function, between the brown skin of Asians and the white skin of Caucasians. As Asian skin is more pigmented, acute and chronic cutaneous responses to UV irradiation differ from those in white skin. Many people believe, based on clinical impressions, that the main process of photoaging in Asians involves pigmentary changes, rather than wrinkling. However, no study has been performed to confirm this belief. Risk factors for skin wrinkles and their relative risks in Korean skin [2] Various factors such as age, sun-exposure, and smoking are known to be important risk factors for wrinkles. However, the relative risks of each factor on wrinkles in the brown skin of Asians have not been investigated, and they could differ from those in Caucasians. An evaluation system for skin wrinkling is necessary for Asian skin [3]. Thus, we developed an eight-point photographic scale for assessing wrinkles in both Korean genders [2]. This scale can probably be applied to the populations of other Asian countries, at least to the Japanese and Chinese. The pattern of wrinkles in both genders appears to be similar. Age Age is an important risk factor for wrinkling in Asians, as in Caucasians. Korean subjects in their 60s showed a 12-fold increased risk of wrinkling, while subjects in their 70s have a 56-fold increased risk compared with young age group. UV light It is well known that the UV component in sunlight can cause and accelerate photoaging. The pigmented skin of Asian may better protect skin from acute and chronic UV damage. However, we found a strong association between sun-exposure and the development of wrinkling in Koreans. It was found that sun exposure of more than 5 h per day was associated with a 4.8-fold increased risk in wrinkling versus less than 2 h of sun-exposure in Koreans. Estrogen deficiency Korean females have more wrinkles than men, after controlling for age, sun exposure, and smoking, it was found that they have a 3.6-fold increased risk of developing wrinkles than their male counterparts [2]. It has also been reported, that the relative risk for wrinkling in women is higher than in men as for in white Caucasians [4]. The reason why women show more wrinkles remains to be determined. It is possible that a reduction in skin collagen because of estrogen deficiency in postmenopausal woman may aggravate wrinkling severity. Korean women with more than 10 years since menopause showed a 3.9-fold higher risk of wrinkling than the women 5 years of beyond menopause [5]. We demonstrated that women with a history of HRT have a significantly lower risk, more specifically, one fifth of the risk of facial wrinkling relative to those who had no history of HRT. Interestingly, we found that wrinkle severity significantly increased with an increasing number of full term pregnancies. The relative risk for severe wrinkling is increased by approximately 1.8-fold per full term pregnancy. Smoking It is known that smoking causes skin wrinkling in Caucasians, and that it plays no role in Blacks [6, 7]. Koreans with have a smoking history of more than 30 pack years showed a more than 2.8-fold increased risk of wrinkles [2]. The relative risks of wrinkles associated with a 30,50 pack-years history of smoking were 2.8- and 5.5-fold, respectively. Dyspigmentation in Asian skin To follow pigmentary changes, six photographic standards for both genders were developed for Korean skin, to produce a 6-point scale [2, 8]. Hyperpigmented spots, mostly lentigines, were prominent among women, while seborrheic keratosis tended to be more prominent in men. Seborrheic keratosis in Korean men Seborrheic keratoses (SKs) are benign cutaneous tumors. They have diverse clinical and histopathological appearances and are very common in the elderly (over 50 years old). The etiology of SKs is not well understood, although patients with a great number of lesionsshow a familial trait with an autosomal dominant pattern, and human papilloma virus has been suggested as possible cause because of verrucous appearance of the lesions. Exposure to sunlight has been suggested to be a risk factor for SKs. However, there is still some debate in terms of the role of sunlight. Recently, we have investigated the clinical characteristics of SKs and relationship between SKs and sunlight exposure in Korean males [9]. The prevalence of SKs in Koreans increases with age; it rose from 78.9% at 40 years, to 93.9% at 50 years and 98.7% in those over 60 years. Exposed areas, i.e. the face, neck and dorsum of the hands, demonstrate a significant increase in the prevalence of SKs by decade, whereas partly exposed areas, although SKs tended to increase in prevalence with age, this trend was not significant. When the estimated body surface area (BSA) is taken into account, the number of SKs on both the face and dorsum of the hands (0.51 ± 0.08 per 1% BSA) was over-represented compared with the trunk. SKs were also concentrated on the neck (0.38 ± 0.07 per 1% BSA) and in the V-area (0.47 ± 0.09 per 1% BSA). Outer forearms also showed 3-fold more SKs per unit area than neighboring arms and inner forearms, which are classified as partly exposed area (0.09 ± 0.02, 0.03 ± 0.01, respectively). The total area covered by SKs on exposed area also became significantly larger with aging than on intermittently exposed areas. These results indicate that exposure to sunlight might be related to SK growth. Our results indicated that excessive sun exposure is an independent risk factor of SKs. After controlling for age, smoking, and skin type, subjects with a sun exposure history of more than 6 hours per day showed a 2.28-fold increased risk of having severe SKs (n , 6) compared with those exposed for less that 3 h per day. These findings indicated that sun-exposure may play an important role in SK development. In summary, SKs are very common in Korean males and represent one of the major pigmentary problems. SKs concentrate on exposed skin, especially on the face and dorsum of the hands. Both age and lifetime cumulative sunlight exposure are important contributing factors and may work in a synergistic manner. Conclusion Many people tend to believe that wrinkles are not a prominent feature of Asian photoaged skin, and that dyspigmentation is a major manifestation in Asian skin. Contrary to this impression, wrinkling is also a major problem in the photoaged skin of Asians, and Korean people showing severe pigmentary changes usually tend to have severe wrinkles. In conclusion, the wrinkling patterns and pigmentary changes of photoaged skin in East Asians differ from those of Caucasians, and the relative risks of aggravating factors may be different from those of Caucasian skin. References 1.,Gilchrest, B.A. Skin aging and photoaging: an overview. J. Am. Acad. Dermatol. 21, 610,613 (1989). 2.,Chung, J.H. et al. Cutaneous photodamage in Koreans: influence of sex, sun exposure, smoking, and skin color. Arch. Dermatol. 137, 1043,1051 (2001). 3.,Griffiths, C.E. et al. A photonumeric scale for the assessment of cutaneous photodamage. Arch. Dermatol. 128, 347,351 (1992). 4.,Ernster, V.L. et al. Facial wrinkling in men and women, by smoking status. Am. J. Public Health. 85, 78,82 (1995). 5.,Youn, C.S. et al. Effect of pregnancy and menopause on facial wrinkling in women. Acta Derm. Venereol. 83, 419,424 (2003). 6.,Kadunce, D.P. et al. Cigarette smoking: risk factor for premature facial wrinkling. Ann. Intern. Med. 114, 840,844 (1991). 7.,Allen, H.B., Johnson, B.L. and Diamond, S.M. Smoker's wrinkles? JAMA. 225, 1067,1069 (1973). 8.,Chung, J.H. Photoaging in Asians. Photodermatol. Photoimmunol. Photomed. 19, 109,121 (2003). 9.,Kwon, O.S. et al. Seborrheic keratosis in the Korean males: causative role of sunlight. Photodermatol. Photoimmunol. Photomed. 19, 73,80 (2003). [source] Biomass accumulation and clogging in trickle-bed bioreactorsAICHE JOURNAL, Issue 10 2004Ion Iliuta Abstract Excessive biomass formation in two-phase flow trickle-bed bioreactors induces clogging and leads to the progressive obstruction of the bed that is accompanied with a buildup in pressure drop and flow channeling. Currently, physical models linking the two-phase flow to the space-time evolution of biological clogging are virtually nonexistent. An attempt has been made with this contribution to fill in this gap by developing a unidirectional dynamic multiphase flow model based on the volume-average mass, momentum, and species balance equations. Phenol biodegradation by Pseudomonas putida as the predominant species immobilized on activated carbon was chosen as a case study to illustrate the consequences of formation of excessive amounts of biomass. Furthermore, in developing the transient model, the following basic processes were assumed to occur and have been accounted for in the mathematical model: oxygen transport from gas into liquid bulks, phenol, and oxygen transport from the liquid phase to the biofilm surface, simultaneous diffusion and reaction of phenol and oxygen within biofilm, as well as their simultaneous diffusion and adsorption within the porous supporting particles. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2541,2551, 2004 [source] Colloid-Associated contaminant transport in porous media: 1.AICHE JOURNAL, Issue 10 2002Experimental studies Many studies have identified colloid-associated transport of contaminants as an important mechanism of contaminant migration through groundwater. It is a complex phenomenon in porous media involving several basic processes such as adsorption of contaminants, release and migration of colloidal fines, and entrapment of fines at the pore constrictions. The effects of these basic processes on the contaminant transport are studied. Column experiments are conducted to study the effects of the mobilization and migration of colloidal fines, kaolin on the transport of contaminant, and Ni2+ metal ion through the sand beds containing kaolin particles under both nonplugging and plugging conditions. As reported in literature, colloidal fines can facilitate the contaminant transport when they migrate with the flow. In the absence of migration, kaolin-sand beds retard Ni2+ transport in comparison to sand beds due to their higher adsorption capacity, but the sand-kaolin composite bed acts like an inefficient adsorption column with percentage saturation (which is in general below 25%). It is interesting to note that under plugging conditions, which can be induced by using a lower bead size to particle-size ratio, the breakthrough curves are more flattened and delayed at a higher kaolin content of the bed. [source] The Sacred and the Search for Significance: Religion as a Unique ProcessJOURNAL OF SOCIAL ISSUES, Issue 4 2005Kenneth I. Pargament Although many social scientists have assumed that religion can be reduced to more basic processes, there may be something unique about religion. By definition, religion has a distinctively meaningful point of reference, the sacred. Empirically, studies also suggest that religion may be a unique: form of motivation; source of value and significance; contributor to mortality and health; source of coping; and source of distress. These findings point to the need for: theory and research on the sacred; attention to the pluralization of religious beliefs and practices; evaluation of individual and social interventions that address spiritual problems and apply spiritual resources to their resolution; and collaboration between psychological and religious groups that draws on their unique identities and strengths. [source] Recombination, repair and replication in the pathogenic Neisseriae: the 3 R,s of molecular genetics of two human-specific bacterial pathogensMOLECULAR MICROBIOLOGY, Issue 1 2003Kimberly A. Kline Summary Most of the detailed mechanisms that have been established for the molecular biological processes that mediate recombination, repair and replication of DNA have come from studies of the Escherichia coli paradigm. The human specific pathogens, Neisseria gonorrhoeae and N. meningitidis, are Gram-negative bacteria that have some molecular processes that are similar to E. coli and others that appear to be divergent. We propose that the pathogenic Neisseriae have evolved a specialized collection of molecular mechanisms to adapt to life limited to human hosts. In this MicroReview, we explore what is known about the basic processes of DNA repair, DNA recombination (genetic exchange and pilin variation) and DNA replication in these human specific pathogens. [source] Special issue: Physics of Organic SemiconductorsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2004Wolfgang Brütting This special issue of physica status solidi (a) gives an overview of our present-day knowledge of the physics behind organic semiconductor devices, ranging from the growth of organic layers and crystals, their electronic properties at interfaces, their photophysics and electrical transport properties to the application in organic field-effect transistors, photovoltaic cells and organic light-emit-ting diodes. Guest Editor of the present issue is Wolfgang Brütting, professor at the University of Augsburg, where he leads a research group working on organic semiconductors, their physical and materials properties, and the understanding of the basic processes in these materials and devices. The cover picture is an angular plot of the anisotropy of the charge carrier mobility , in the a,b plane of a rubrene single crystal, probed on an elastomeric rubber stamp field-effect transistor device. The black and red squares correspond to the values of , extracted from the linear and saturation regimes of the transistor operation, respectively. More information can be found in the Review Article by R. W. I. de Boer et al. [1]. [source] Electrical study of InAs/GaAs quantum dots with two different environmentsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2008M. Kaniewska Abstract Unusually complex spectra have been obtained for InAs/GaAs quantum dot (QD) structures when studied as a function of applied bias by deep level transient spectroscopy (DLTS). In spite of their complexity, basic processes for electron escape from the QDs have been recognized. We show that due to the variety of transitions involving direct tunneling and more complex thermal transitions, due to QD size fluctuations, and environmental dependent QD carrier population, measurement conditions have to be carefully suited for characterizing transport properties of the QDs. Additionally, on the basis of results of a comparative study under chosen measurement conditions, we conclude that the states of the InAs QDs shift towards the middle of the energy gap if the QDs are capped with a Ga-rich InGaAs insertion. It explains a red-shift of the emission wavelength that was found by photoluminescence measurements (PL). (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Hydrogels as smart biomaterialsPOLYMER INTERNATIONAL, Issue 9 2007ich Kope Abstract Hydrogels were the first biomaterials rationally designed for human use. Beginning with the pioneering work of Wichterle and Lím on three-dimensional polymers that swell in water, we review the design, synthesis, properties, and applications of hydrogels. The field of hydrogels has moved forward at a dramatic pace. The development of suitable synthetic methods encompassing traditional chemistry to molecular biology has been used in the design of hydrogels mimicking basic processes of living systems. Stimuli-sensitive hydrogels, hydrogels with controlled degradability, genetically engineered poly(amino acid) polymers reversibly self-assembling in precisely defined three-dimensional structures, and hybrid polymers composed of two distinct classes of molecules are just some examples of these exciting novel biomaterials. The biocompatibility of hydrogels and their applications from implants to nanomaterials are also reviewed. Copyright © 2007 Society of Chemical Industry [source] Working memory interference during processing texts and pictures: Implications for the explanation of the modality effectAPPLIED COGNITIVE PSYCHOLOGY, Issue 2 2010Ralf Rummer Auditory text presentation improves learning with pictures and texts. With sequential text,picture presentation, cognitive models of multimedia learning explain this modality effect in terms of greater visuo-spatial working memory load with visual as compared to auditory texts. Visual texts are assumed to demand the same working memory subsystem as pictures, while auditory texts make use of an additional cognitive resource. We provide two alternative assumptions that relate to more basic processes: First, acoustic-sensory information causes a retention advantage for auditory over visual texts which occurs no matter if a picture is presented or not. Second, eye movements during reading hamper visuo-spatial rehearsal. Two experiments applying elementary procedures provide first evidence for these assumptions. Experiment 1 demonstrates that, regarding text recall, the auditory advantage is independent of visuo-spatial working memory load. Experiment 2 reveals worse matrix recognition performance after reading text requiring eye movements than after listening or reading without eye movements. Copyright © 2008 John Wiley & Sons, Ltd. [source] Epidermal kinetic alterations required to generate the psoriatic phenotype: a reappraisalCELL PROLIFERATION, Issue 3 2010T. Simonart Objectives:, Although there have been major advances in understanding immunopathogenesis of psoriasis, the basic processes causing psoriatic morphology remain to be identified. Materials and methods:, Our group has designed a systematic review of studies (1962,2009) on keratinocyte kinetics in psoriasis. We obtained data from MEDLINE, PubMed, Current Contents, reference lists and specialist textbooks. A general equation for evolution of the differentiated epidermis has been analysed. Necessary conditions for observed qualitative change in homeostasis between normal skin and established psoriatic lesions were determined. Results and discussion:, Increase in the number of cell divisions (or imbalance in symmetric division rates of committed progenitor cells) and/or decrease in physiological apoptosis in the germinative compartment, together with feedback loops that limit thickening of the skin, are required to generate psoriatic morphology, that is, to increase the absolute size but decrease relative size of the differentiated cell compartment with respect to the germinative compartment. [source] Mechanisms and consequences of persistence of intracellular pathogens: leishmaniasis as an exampleCELLULAR MICROBIOLOGY, Issue 6 2008Christian Bogdan Summary Lifelong persistence after clinical cure of the primary infection is a characteristic feature of many intracellular pathogens, including viruses, bacteria and protozoa. The underlying mechanisms are complex and range from the passive protection against toxic effector molecules of the host and the remodelling of intracellular compartments as safe niches to the active modulation of the immune response at multiple levels. Parasites of the genus Leishmania have been particular helpful in unravelling some of the basic processes and form therefore the centre of the discussion. [source] Measurement of time-resolved autofluorescenceACTA OPHTHALMOLOGICA, Issue 2008D SCHWEITZER Purpose Functional alterations are first signs of reversible pathologic processes. Whereas microcirculation studies metabolism globally, autofluorescence of endogenous fluorophores has the potential for description of cellular basic processes. Therefore, a discrimination of fluorophores is required in the tissue. Methods Besides excitation and emission spectra, the fluorescence lifetime after short-time excitation is a promising substance-specific mark. Using the opto-mechanical system of a HRA II (Heidelberg Engineering), a fluorescence lifetime mapper was developed. Picosecond pulse-lasers (448nm, 468nm, 100ps FWHM, 80MHz) can be used for excitation and the emission will be detected in 2 spectral ranges (490-560nm, 560-700nm). The dynamic fluorescence will be detected in time-correlated single photon counting (SPC 150, Becker/Hickl, Berlin). An on line image registration is realised by simultaneously detected infrared images during measuring time. Approximating the fluorescence decay by 3-exponential model function, images (lifetime and amplitudes), histograms, and cluster diagrams can be calculated for interpretation. Results Examples are given for healthy subjects, AMD patients (non-exudative, exudative, geographic atrophy), diabetic retinopathy, and oedema. Measurements of excitation and emission spectra as well as lifetimes are performed of expected substances and of anatomical ocular structures for comparison. Conclusion Fluorescence lifetime measurement at the eye is a new method for evaluation of functional metabolic state. [source] | ||||||||||||||||||||||