Cause Of Retardation Research Articles

USING THE CHARACTERISTICS OF ISLAMIC CIVILIZATION IN TEACHING SKILLS

Islam is a universal religion that encourages science and considers it obligatory for every Muslim, and has never been the cause of retardation. Any science is acceptable unless it is a flag that contradicts Islamic law and its rules. Islam honors scientists and makes them inheritors of the prophets and orders knowledge from birth to death. Civilization meaning: "living and staying in urban area and civilization of the city, which is unlike Badia, cities, villages and countryside, so named because the people attended the places and houses of homes that have a decision, remember civilization in the language it means what is the opposite of the Bedouin, means, the inhabitants of cities and villages. A manifestation of Islamic civilization: - Foundations of the system of governance in Islamic civilization, including the method of choosing the ruler and the way of governance "Koran and Sunnah, Shura and justice and guarantee freedom of the Muslim and other freedom of choice for his religion. - Islamic civilization and economic life: - Islam built an integrated economic system and organized the methods of collecting money and methods of spending as well. - Islamic civilization and its influence on education through the Quran and Sunnah encouragement to acquire science. - Islamic civilization and social impact on life: The signs of Islamic social life and organization from the first moment of the Prophet's founding in the establishment of the mosque and the organization of relations of immigrants and supporters and the conclusion of treaties with non-Muslims in society. - Science: There was a special interest in Islam with science and its types and details such as translation, medicine, mathematics, agriculture and chemistry. - Science and the Arts: It is clear that the great impact of Islamic art in all fields and during the successive Islamic eras and Islamic controversies that continue to the present time on all other civilizations and until now Western societies are affected by Islamic science and art. Key words: Islamic Civilization, Teaching Skills

Growth Failure in Children with Sickle Cell Anaemia

Abstract:-  Background Sickle cell disease is a group of inherited sickling disorders consequent upon abnormalities of haemoglobin synthesis. It is one of the common causes of retardation in both physical growth and sexual maturation in children, as a result of chronic anaemia and consequent hypoxia that occur in several organs.  Objectives To determine the anthropometric indices (weight, height and Body Mass Index) of children with sickle cell anaemia (SCA) and compare them with that of children with normal haemoglobin; haemoglobin AA (HbAA).

Інновації в розвитку аграрних підприємств Закарпатської області

The purpose. To determine nature and features of agrarian innovations for delineating directions of activation of innovative activity of agrarian factories at regional level. Methods. Monographic, calculation, mathematicalstatistical. Results. Agricultural innovation can be considered as innovation in the field of agriculture that is accompanied by deriving mercantile effect. Specificity of innovations in agrarian production is stipulated by features of agriculture where the major factor of production is the land. Innovative activity in agriculture has 4 stages: development of innovations, their approbation, testing and procreation, implementation into production. Conclusions. The most weighable cause of retardation of process of implementation of agricultural innovations is insufficient level of financial security of factories, low accessibility of credits and state support for modernizing agrarian branch, backwardness of system of data support of innovative process.

The Study on the Psycho-social Issues and Challenges of Children with Mental Retardation: A Case Study

A lot has been written about the psycho-social issues and challenges of children with mental retardation. The aim of this research is to investigate the impact of psycho-social issues and challenges of children with mental retardation. The study utilized qualitative research tools to explore the deep feelings of the participants. Purposive sampling technique and case study employed as a major study tools. The study used in-depth interview, observation and FGD. The collected data were organized and analyzed through qualitative research approach by using thematic analysis. Findings obtained from the study showed that children with mental retardation are facing different psychosocial challenges like stigma, discrimination, isolation, blame, shame, frustration, feeling of upset, self-insult, loneliness, losing respect, despairing (feeling of no hope), insult, anger and sadness. The study also found that the perception parents of children with mental retardation regarding the causes of retardation was changed from religious beliefs to possible causes of mental retardation as a result of the rehabilitation services. Further, praying, helping each other, reaction formation (insulting who insulted them), developing wishful thinking, and limiting one's interaction were some of the mechanisms explored from this study. The study finally concludes some measures to curb the negative belief systems of the communities towards the children with mental retardation. The study has a great implication for social work practice in the area of policy formulation, advocacy, community mobilization, empowerment, service provision, assessment and research in the areas of disability.

Separating plasticity-induced closure and residual stress contributions to fatigue crack retardation following an overload

The introduction of an overload or underload within a constant amplitude loading fatigue test leads to a retardation or acceleration of the Fatigue Crack Growth Rate (FCGR). The understanding of the causes of these effects is essential in the context of variable amplitude fatigue loading, since in principle any loading history can be represented as a sequence of overloads and underloads. In the case of overload, along with some other minor causes, the residual stress changes at the crack tip and crack closure behind the tip can be thought of as the main factors that affect the fatigue crack growth rate. Whilst this has been recognised and accepted for many decades, controversy persists regarding the relative significance and presence of these two effects, and consensus is yet to emerge. The effect of crack closure, when the baseline loading ratio is high enough, can be inhibited so that the main cause of retardation becomes doubtless the residual stress present ahead the crack tip.In the present paper we report our attempt to deconvolve the contributions of crack closure and residual stress on crack retardation following an overload. To accomplish this task we analyse the results of fatigue tests run at two baseline load ratios, namely R=0.1 and R=0.7. At the load ratio of R=0.7 the crack closure effect is not operative, as confirmed by Digital Image Correlation analysis of the crack flanks close to the tip, and post mortem fractographic analysis of crack surfaces. Therefore, for R=0.7 the compressive residual stress region created by the overload ahead of the crack tip is the sole mechanism causing crack retardation. Therefore, for R=0.7 the focus must be placed entirely on the strain field around the crack tip. To this end, line profiles along the crack bisector of elastic strain in the crack opening direction were collected at several stages of crack propagation past the overload using in situ Synchrotron X-ray Powder Diffraction (SXRPD) technique.By performing comparison between the two loading conditions (R=0.7 and R=0.1), information was extracted regarding the role of residual stress alone, and then, by subtracting this effect for the R=0.1 sample, for crack closure alone. To enable this analysis, we propose a introducing the concept of equivalent effective stress intensity factor range, ∆Keq,eff proposed by Walker. Afterwards, the SIF range reduction ratio, β, which represents the “knock down” factor with respect to the steady state growth was assessed. It is in terms of these newly introduced parameters that the magnitude and extent of the overload-induced crack growth rate retardation can be plotted, fitted and decomposed into closure and residual stress effects, respectively. It is concluded that although the residual stress effect is present at all values of the load ratio R, its effect is relatively short-lived, whilst the closure effect that is dominant at low values of R causes longer range retardation.

Vacancy‐Induced Electronic Structure Variation of Acceptors and Correlation with Proton Conduction in Perovskite Oxides

AbstractIn most proton‐conducing perovskite oxides, the electrostatic attraction between negatively charged acceptor dopants and protonic defects having a positive charge is known to be a major cause of retardation of proton conduction, a phenomenon that is generally referred to as proton trapping. We experimentally show that proton trapping can be suppressed by clustering of positively charged oxygen vacancies to acceptors in BaZrO3−δ and BaCeO3−δ. In particular, to ensure the vacancy–acceptor association is effective against proton trapping, the valence electron density of acceptors should not significantly vary when the oxygen vacancies cluster, based on the weak hybridization between the valence d or p orbitals of acceptors and the 2p orbitals of oxygen.

Vacancy‐Induced Electronic Structure Variation of Acceptors and Correlation with Proton Conduction in Perovskite Oxides

In most proton-conducing perovskite oxides, the electrostatic attraction between negatively charged acceptor dopants and protonic defects having a positive charge is known to be a major cause of retardation of proton conduction, a phenomenon that is generally referred to as proton trapping. We experimentally show that proton trapping can be suppressed by clustering of positively charged oxygen vacancies to acceptors in BaZrO3-δ and BaCeO3-δ . In particular, to ensure the vacancy-acceptor association is effective against proton trapping, the valence electron density of acceptors should not significantly vary when the oxygen vacancies cluster, based on the weak hybridization between the valence d or p orbitals of acceptors and the 2p orbitals of oxygen.

Multi-dimensional visualization of sustainable filtration

The paper determines that the cause of retardation of innovation for industrial filtration applications is commercial supposition rather than technical performance. The paper describes a multi-dimensional framework for characterizing the required filtration attributes for attaining a more sustainable filter for bespoke industrial applications. This framework appreciates the fact that bespoke applications have complex environments as such a subjective approach is taken and the results are indexed to that used commercially in the application. Paint exhaust filtration has been used as the papers' framework example and laboratory characterization of this bespoke filtration is undertaken revealing the multiple key areas of focus. This multi-dimensional approach demonstrates it is possible to utilize subjective visual characterization followed by quantitative methods as an effective facilitator of sustainable filtration re-engineering.

Study the causes of growth retardation in pure breed imported calves after theileriosis in Abu-Shaeer cattle Farm /Diyala province

The aim of this study is investigated the causes of retardation in growth of purebred calves infected by Theileria annulata.Blood samples of infected group (treatment group) were taken once, and blood samples of the control group (clinically healthy) were taken also .Serum separation was done to two groups to determinate some blood factors levels as ferritin ,phosphorus ,glucose ,growth hormone ,total T3 and total T4.It was detected that mean values of serum Ferritin was significantly higher than the values of the control group and healthy animals.No significant effect of the infection on the phosphorus and T3 levels ,While there were significant depression in serum levels of glucose ,growth hormone and T4.

Array CGH in the routine diagnostic work-up of mental retardation1

Abstract Array CGH (Comparative Genomic Hybridisation) analysis has become an essential part of the diagnostic work-up of mental retardation in children. Using BAC- (Bacterial Artificial Chromosome) array CGH, a follow-up examination on chromosomally inconspicuous children with mental retardation (n=194) revealed in 20 patients (10.4%) a chromosomal imbalance as the cause of retardation. In a small pilot study on ten patients, we were able to demonstrate the benefit of applying a second, oligonucleotide-based array CGH platform as a reliable and rapid validation tool for ambiguous CGH results, in particular, if duplications were suspected (cross validation). Based on our own experience and that of other groups, a stepwise approach for the diagnosis of mental retardation in children involving a combination of BAC- and oligonucleotide array CGH as well as fluorescence in situ hybridisation (FISH) is recommended.

Detection of inherited metabolic diseases in children with mental handicap

Mental Retardation is a condition where complex interactions of intrinsic and extrinsic factors hamper mental and sometimes physical growth of the child during developmental period. This study was carried out to detect cause of Mental Retardation in 2000 cases of developmental delay by a multidisciplinary team comprising of a Pediatrician, Cytogeneticist, Biochemist, Psychologist and Speech and Occupational therapists. The causes for developmental delay are broadly divided into Genetic, Environmental and Idiopathic (no specific cause found) factors. The complete diagnosis was possible in 1192(60%) cases. Genetic factors were found in 477(23.8%) cases and environmental factors covered 692(34.6%) cases as a cause of retardation. The most common genetic cause is chromosomal abnormalities which were found in 355 (17.75%) cases. Another major group comprising of 122 (6.1%) cases was that of the disorders which follow Mendelian inheritance. Autosomal recessive conditions, which covers majority of metabolic disorders, are detected in 48(2.4%) cases. During this screening the most common inherited metabolic condition detected is Mucopolysaccharidosis, a Lysosomal Storage Disorder followed by Amino acid abnormalities like Phenylketonuria, Alkaptonuria and Tyrosinuria.

Causes of root growth retardation induced by ultraviolet-B irradiation of shoots in Barley seedlings

In barley seedlings (Hordeum vulgare L.) during two days after irradiation of shoots with UV-B (0.5 W/m2, 6 h), the rate of elongation of primary roots decreased 2–3 times compared to that in control plants. The modulus of elasticity of roots (e) increased at most twofold in 12 h after the onset of irradiation; the hydraulic conductivity (Lp) diminished by a factor of two in 12 h, and the root osmotic pressure gradually decreased by 0.08 MPa in 24 h. Changes in e and Lp were shown to be related to oxidative stress in growing roots, which was evidenced from the increase in H2O2 level up to 15-fold increase in 6 h and in activity of guaiacol peroxidase (3.5-fold in 12 h). After 48 h, the characteristics of oxidative metabolism and root characteristics e and Lp became identical in untreated and treated plants. On the third day, the rate of root growth in treated plants reached its initial value. It is concluded that the main causes of retardation of root growth under these conditions were as follows: the increase in cell wall rigidity related to formation of oxidative cross-links in the apoplast and the decrease in root osmotic pressure due to limited transport of assimilates from irradiated leaves. After the intensity of UV-B irradiation applied to shoots was enhanced (1.6 W/m2, 4 h), another physiological status of roots was observed on the 2nd day characterized by twofold increase in Lp, tenfold decreased root elongation rate, and by a progressing increase of root diameter in growing roots. The comparison of root responses induced by irradiation of shoots with the root responses to sodium salicylate and ABA suggests that both agents might participate in the transmission of signals from irradiated leaves to roots.

Effects of Hydrogen Environment on Fatigue Characteristics in a Type 304 Austenitic Stainless Steel

In order to clarify the effects of hydrogen on the fatigue characteristics of an austenitic stainless steel, bending fatigue tests on plain specimens were conducted in air and in a hydrogen gas. Main results obtained are as follows. Effects of hydrogen are not clearly seen on the fatigue strain-life diagram, because the hydrogen gas environment has opposite effects to crack propagation and to crack initiation ; accelerates crack propagation, but retards crack initiation. Striation spacing or in-situobservations confirm the acceleration. The cause of retardation seems to be the lack of oxygen or water vapor in the hydrogen. Several cracks propagate in air, but only one crack occurred in hydrogen. The difference in the number of cracks is supposed to depend on the ratio of the crack initiation life to fatigue life.

Enchytraeid worms retard polycyclic aromatic hydrocarbon degradation in a coniferous forest soil

In this study the fate of naphthalene, fluorene and pyrene were investigated in the presence and absence of enchytraeid worms. Microcosms were used, which enabled the full fate of 14C-labelled PAHs to be followed. Between 60 and 70% of naphthalene was either mineralised or volatilised, whereas over 90% of the fluorene and pyrene was retained within the soil. Mineralisation and volatilisation of naphthalene was lower in the presence of enchytraeid worms. The hypothesis that microbial mineralisation of naphthalene was limited by enchytraeids because they reduce nutrient availability, and hence limit microbial carbon turnover in these nutrient poor soils, was tested. Ammonia concentrations increased and phosphorus concentrations decreased in all microcosms over the 56 d experimental period. The soil nutrient chemistry was only altered slightly by enchytraeid worms, and did not appear to be the cause of retardation of naphthalene mineralisation. The results suggest that microbial availability and volatilisation of naphthalene is altered as it passes through enchytraeid worms due to organic material encapsulation.

The effect of overload on the fatigue crack growth behaviour of 304 stainless steel in hydrogen

Fatigue crack growth (FCG) behaviour and its characteristics following tensile overloads were investigated for AISI 304 stainless steel in three different atmospheres; namely dry argon, moist air and hydrogen. The FCG tests were performed by MTS 810 servohydraulic machine. CT specimens were used for the tests and crack closure measurements were made using an extensometer. FCG rates of 304 stainless steel at both dry argon and moist air atmospheres have shown almost the same behaviour. In other words, the effect of moisture on FCG of this material is very small. However, in a hydrogen atmosphere, the material showed considerably higher crack growth rate in all regimes. In general, for all environments, the initial effect of overloads was to accelerate the FCG rate for a short distance (less than a mm) after which retardation occurred for a considerable amount of time. The main causes for retardation were found as crack blunting and a long reinitiation period for the fatigue crack. Regarding the environmental effect, the overload retardation was lowest in a hydrogen atmosphere. This low degree of retardation was explained by a hydrogen embrittlement mechanism. In a general sense, hydrogen may cause a different crack closure mechanism and hydrogen induced crack closure has come in to the picture. Scanning electron microscope and light microscope examinations agreed well with the above results.

The influence of RAFT on the rates and molecular weight distributions of styrene in seeded emulsion polymerizations

Seeded emulsion polymerizations of styrene in the presence of two reversible addition–fragmentation chain-transfer (RAFT) agents were studied. We designed the seed to be small to observe the effects of exit and, we made the seed of poly(methyl methacrylate) so that the molecular weight distributions of poly(styrene) by gel permeation chromatography could be obtained independently by UV detection. The rates were significantly retarded by the presence of a RAFT agent, with the retardation being greater with an EMA RAFT agent [2-(ethoxycarbonyl)propyl-2-yl dithiobenzoate] than with a cumyl RAFT agent (2-phenylprop-2-yl dithiobenzoate). We propose that exit from the particles after fragmentation was the main cause of retardation. In addition, the number-average molecular weight and polydispersities (broad) did not resemble the characteristic living behavior found in bulk or solution. This was a result of the continuous transportation of RAFT agent into the particles during interval II and the transportation of a small amount during interval III. A conspicuous red layer was also observed at the beginning of the polymerization. The red layer consisted of low molecular weight dormant species swollen with monomer. Once the switch from interval II to interval III occurred, the low molecular weight species coalesced to form a red coagulant. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3864–3874, 2000

A population-based study on epilepsy in mentally retarded children.

This study presents data on cumulative risk of seizures, cause, comorbidity, and remission of epilepsy among mentally retarded (MR) children followed until the age of 22 years. A total of 151 MR children were identified at the age of 8 or 9 years by screening four birth cohorts of 12,882 children born from 1969 to 1972 in the Finnish province of Kuopio. Information about epilepsy was gathered longitudinally when children were 9 to 10, 17, and 22 years old. The guidelines for epidemiological studies on epilepsy proposed by the International League Against Epilepsy were followed. By the age of 10 years, 29 of the 151 MR children (19%) had epilepsy. The cumulative risk for epilepsy at 22 years was 21%. The probability of developing epilepsy was increased fivefold in severely MR children compared with mildly MR children, i.e., in 27 of the 77 severely MR children (35%) versus 5 of the 74 mildly MR children (7%). Postnatal causes of mental retardation or association with cerebral palsy increased the risk for epilepsy, especially in the mildly MR children. When these risk factors were not present, the mildly MR children exhibited only a 3% risk for epilepsy, whereas the respective risk was about 10-fold in severe mental retardation. The cumulative probability of epilepsy being in remission for 5 years by the age of 22 was 32%. The cumulative risk of epilepsy varies according to the severity and the cause of the retardation as well as the presence of additional disabilities. The cumulative probability of epilepsy remission tended to increase with age.

The influence of RAFT on the rates and molecular weight distributions of styrene in seeded emulsion polymerizations

Seeded emulsion polymerizations of styrene in the presence of two reversible addition-fragmentation chain-transfer (RAFT) agents were studied. We designed the seed to be small to observe the effects of exit and, we made the seed of poly(methyl methacrylate) so that the molecular weight distributions of poly(styrene) by gel permeation chromatography could be obtained independently by UV detection. The rates were significantly retarded by the presence of a RAFT agent, with the retardation being greater with an EMA RAFT agent [2-(ethoxycarbonyl)propyl-2-yl dithiobenzoate] than with a cumyl RAFT agent (2-phenylprop-2-yl dithiobenzoate). We propose that exit from the particles after fragmentation was the main cause of retardation. In addition, the number-average molecular weight and polydispersities (broad) did not resemble the characteristic living behavior found in bulk or solution. This was a result of the continuous transportation of RAFT agent into the particles during interval II and the transportation of a small amount during interval III. A conspicuous red layer was also observed at the beginning of the polymerization. The red layer consisted of low molecular weight dormant species swollen with monomer. Once the switch from interval II to interval III occurred, the low molecular weight species coalesced to form a red coagulant.

Apoptotic Death of Cerebellar Neurons in Primary Culture Prepared from Neonatal Rats Exposed to Methylmercury in Utero.

A single dose of methylmercury at 10 or 15 mg Hg/kg body weight (p.o.) does not have an apparent adverse effect on adult rats. However, when primary cerebellar cells were prepared from neonatal rats exposed to methylmercury in utero by administering methylmercury to pregnant rats on day 18 of gestation, cerebellar neurons died after a certain lag time with morphological changes characteristic to apoptosis : formation of apoptotic vesicles, disappearance of neurites and condensation of nuclear chromatin and internucleosomal cleavage of chromatin DNA. The apoptotic death of cerebellar neurons required diffusible factor (s) released from the methylmercury-loaded cells, which can also induce the death of cerebellar neurons from control animals. Cerebellar weight gain during the 10 d after birth was also retarded by the prenatal exposure to methylmercury. These results indicate that prenatal exposure to methylmercury at maternal doses which do not induce apparent abnormality in adult rats brings about an accumulation of methylmercury in cerebellar neurons sufficient to induce apoptotic death of those cells, which may be a cause of retardation of cerebellar development during early postnatal stage.

High-resolution studies of C 60 films by scanning tunnelling microscopy

Scanning tunnelling microscopic studies of C 60 films containing conducting islands, under ambient conditions, have revealed the characteristic FCC lattice of the C 60 clusters with intermolecular distances in various planes along different crystallographic directions closely matching with the diffraction data. The diameter of the cluster is close to 0.71 nm, i.e. the value given by the positions of the carbon atoms on the C 60 shell, and not influenced by their Ti-electron lobes. The studies have revealed the nanometric defect structures in the C 60 lattice which are found consistent with the FCC structure. The cage morphology of the buckyballs in the form of hexagons and pentagons forming the well-known icosahedral structure of the C 60 molecule has been resolved in the finest details with bond lengths in a fair accord with the reported data. The resolved structure forming the lattice shows an orientational disorder which has been frozen from a state in which each molecule at the ambient tem perature is undergoing a rotational motion which is uncorrelated with the motion of its neighbour, in conformity with diffraction and NMR results. Various possible causes of retardation and freezing of the rotational diffusion, relevant to the samples studied are discussed which also include the distortions in the carbon cages detected in the present study.