843 resultados para symptoms of boron deficiency


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The goal of this research was to determine the composition of boron deposits produced by pyrolysis of boron tribromide, and to use the results to (a) determine the experimental conditions (reaction temperature, etc.) necessary to produce alpha-rhombohedral boron and (b) guide the development/refinement of the pyrolysis experiments such that large, high purity crystals of alpha-rhombohedral boron can be produced with consistency. Developing a method for producing large, high purity alpha-rhombohedral boron crystals is of interest because such crystals could potentially be used to achieve an alpha-rhombohedral boron based neutron detector design (a solid-state detector) that could serve as an alternative to existing neutron detector technologies. The supply of neutron detectors in the United States has been hampered for a number of years due to the current shortage of helium-3 (a gas used in many existing neutron detector technologies); the development of alternative neutron detector technology such as an alpha-rhombohedral boron based detector would help provide a more sustainable supply of neutron detectors in this country. In addition, the prospect/concept of an alpha-rhombohedral boron based neutron detector is attractive because it offers the possibility of achieving a design that is smaller, longer life, less power consuming, and potentially more sensitive than existing neutron detectors. The main difficulty associated with creating an alpha-rhombohedral boron based neutron detector is that producing large, high purity crystals of alpha-rhombohedral boron is extremely challenging. Past researchers have successfully made alpha-rhombohedral boron via a number of methods, but no one has developed a method for consistently producing large, high purity crystals. Alpha-rhombohedral boron is difficult to make because it is only stable at temperatures below around 1100-1200 °C, its formation is very sensitive to impurities, and the conditions necessary for its formation are not fully understood or agreed upon in the literature. In this research, the method of pyrolysis of boron tribromide (hydrogen reduction of boron tribromide) was used to deposit boron on a tantalum filament. The goal was to refine this method, or potentially use it in combination with a second method (amorphous boron crystallization), to the point where it is possible to grow large, high purity alpha-rhombohedral boron crystals with consistency. A pyrolysis apparatus was designed and built, and a number of trials were run to determine the conditions (reaction temperature, etc.) necessary for alpha-rhombohedral boron production. This work was focused on the x-ray diffraction analysis of the boron deposits; x-ray diffraction was performed on a number of samples to determine the types of boron (and other compounds) formed in each trial and to guide the choices of test conditions for subsequent trials. It was found that at low reaction temperatures (in the range of around 830-950 °C), amorphous boron was the primary form of boron produced. Reaction temperatures in the range of around 950-1000 °C yielded various combinations of crystalline boron and amorphous boron. In the first trial performed at a temperature of 950 °C, a mix of amorphous boron and alpha-rhombohedral boron was formed. Using a scanning electron microscope, it was possible to see small alpha-rhombohedral boron crystals (on the order of ~1 micron in size) embedded in the surface of the deposit. In subsequent trials carried out at reaction temperatures in the range of 950 °C – 1000 °C, it was found that various combinations of alpha-rhombohedral boron, beta-rhombohedral boron, and amorphous boron were produced; the results tended to be unpredictable (alpha-rhombohedral boron was not produced in every trial), and the factors leading to success/failure were difficult to pinpoint. These results illustrate how sensitive of a process producing alpha-rhombohedral boron can be, and indicate that further improvements to the test apparatus and test conditions (for example, higher purity/cleanliness) may be necessary to optimize the boron deposition. Although alpha-rhombohedral boron crystals of large size were not achieved, this research was successful in (a) developing a pyrolysis apparatus and test procedure that can serve as a platform for future testing, (b) determining reaction temperatures at which alpha-rhombohedral boron can form, and (c) developing a consistent process for analyzing the boron deposits and determining their composition. Further experimentation is necessary to achieve a pyrolysis apparatus and test procedure that can yield large alpha-rhombohedral boron crystals with consistency.

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The national shortage of helium-3 has made it critical to develop an alternative to helium-3 neutron detectors. Boron-10, if it could be produced in macroscopic alpha-rhombohedral crystalline form, would be a viable alternative to helium-3. This work has determined the critical parameters needed for the preparation of alpha-rhombohedral boron by the pyrolytic decomposition of boron tribromide on tantalum wire. The primary parameters that must be met are wire temperature and feedstock purity. The minimum purity level for boron tribromide was determined to be 99.999% and it has been found that alpha-rhombohedral boron cannot be produced using 99.99% boron tribromide. The decomposition temperature was experimentally tested between 830°C and 1000°C. Alpha-rhombohedral boron was found at temperatures between 950°C and 1000°C using 99.999% pure boron tribromide.

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Persistent genital arousal disorder (PGAD) is characterized by physiological sexual arousal (vasocongestion, sensitivity of the genitals and nipples) that is described as distressing, and sometimes painful. Although awareness of PGAD is growing, there continues to be a lack of systematic research on this condition. The vast majority of published reports are case studies. Little is known about the symptom characteristics, biological factors, or psychosocial functioning associated with the experience of persistent genital arousal (PGA) symptoms. This study sought to characterize a sample of women with PGA (Study One); compare women with and without PGA symptoms on a series of biopsychosocial factors (Study Two); and undertake an exploratory comparison of women with PGA, painful PGA, and genital pain (Study Three)—all within a biopsychosocial framework. Symptom-free women, women with PGA symptoms, painful PGA, and genital pain, completed an online survey of biological factors (medical history, symptom profiles), psychological factors (depression, anxiety) and social factors (sexual function, relationship satisfaction). Study One found that women report diverse symptoms associated with PGA, with almost half reporting painful symptoms. In Study Two, women with symptoms of PGA reported significantly greater impairment in most domains of psychosocial functioning as compared to symptom-free women. In particular, catastrophizing of vulvar sensations was related to symptom ratings (i.e., greater severity, distress) and psychosocial outcomes (i.e., greater depression and anxiety). Finally, Study Three found that women with PGA symptoms reported some overlap in medical comorbidities and symptom expression as those with combined PGA and vulvodynia and those with vulvodynia symptoms alone; however, there were also a number of significant differences in their associated physical symptoms. These studies indicate that PGA symptoms have negative consequences for the psychosocial functioning of affected women. As such, future research and clinical care may benefit from a biopsychosocial approach to PGA symptoms. These studies highlight areas for more targeted research, including the role of catastrophizing in PGA symptom development and maintenance, and the potential conceptualization of both PGA and vulvodynia (and potentially other conditions) under a general umbrella of ‘genital paraesthesias’ (i.e., disorders characterized by abnormal sensations, such as tingling and burning).

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Mental Toughness (MT) provides crucial psychological capacities for achievement in sports,
education, and work settings. Previous research examined the role of MT in the domain of
mental health and showed that MT is negatively associated with and predictive of fewer
depressive symptoms in non-clinical populations. The present study aimed at 1) investigating
to what extent mentally tough individuals use two emotion regulation strategies: cognitive
reappraisal and expressive suppression; 2) exploring whether individual differences in
emotion regulation strategy use mediate the relationship between MT and depressive
symptoms. Three hundred sixty-four participants (M = 24.31 years, SD = 9.16) provided
self-reports of their levels of MT, depressive symptoms, and their habitual use of cognitive
reappraisal and expressive suppression. The results showed a statistically significant
correlation between MT and two commonly used measures of depressive symptoms. A small
statistically significant positive correlation between MT and the habitual use of cognitive
reappraisal was also observed. The correlation between MT and the habitual use of
expressive suppression was statistically significant, but the size of the effect was small. A
statistical mediation model indicated that individual differences in the habitual use of
expressive suppression mediate the relationship between MT and depressive symptoms. No
such effect was found for the habitual use of cognitive reappraisal. Implications of these
findings and possible avenues for future research are discussed.

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Purpose. To identify stroke survivors with symptoms of poststroke depression and the extent of psychiatry needs and care they have received while on physiotherapy rehabilitation. Participants. Fifty stroke survivors (22 females and 28 males) at the outpatient unit of Physiotherapy Department, University of Nigeria Teaching Hospital, Enugu, who gave their informed consent, were randomly selected. Their age range and mean age were 26–66 years and 54.76 ± 8.79 years, respectively. Method. A multiple case study of 50 stroke survivors for symptoms of poststroke depression was done with Beck’s Depression Inventory, mini mental status examination tool, and Modified Motor Assessment Scale. The tests were performed independently by the participants except otherwise stated and scored on a scale of 0–6. Data were analyzed using -test for proportional significance and chi-square test for determining relationship between variables, at p < 0.05. Results. Twenty-one (42.0%) stroke survivors had symptoms of PSD, which was significantly dependent on duration of stroke ( = 21.680, df = 6, and p = 0.001), yet none of the participants had a psychiatry review. Conclusions. Symptoms of PSD may be common in cold compared to new cases of stroke and may need psychiatry care while on physiotherapy rehabilitation.

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Attention Deficit Hyperactivity Disorder is a neurodevelopmental disorder correlated with a decrease in brain dopamine and an increase in behavioral symptoms of hyperactivity and impulsivity. This experiment explored how tartrazine (Yellow #5) impacts these symptoms. After tartrazine administration to Spontaneously Hypertensive Rats (SHR), dopamine concentrations in regions of brain tissue were measured using Enzyme-Linked Immunosorbent Assay analysis. Behavioral testing with a T-maze and open field test measured impulsivity and hyperactivity, respectively. Results indicate that dietary tartrazine increases hyperactive behaviors in the SHR. However, results do not indicate a relationship between dietary tartrazine and brain dopamine. No conclusions regarding the relationship between dietary tartrazine and impulsivity were drawn.

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Nitrogen (N) is an essential plant nutrient in maize production, and if considering only natural sources, is often the limiting factor world-wide in terms of a plant’s grain yield. For this reason, many farmers around the world supplement available soil N with synthetic man-made forms. Years of over-application of N fertilizer have led to increased N in groundwater and streams due to leaching and run-off from agricultural sites. In the Midwest Corn Belt much of this excess N eventually makes its way to the Gulf of Mexico leading to eutrophication (increase of phytoplankton) and a hypoxic (reduced oxygen) dead zone. Growing concerns about these types of problems and desire for greater input use efficiency have led to demand for crops with improved N use efficiency (NUE) to allow reduced N fertilizer application rates and subsequently lower N pollution. It is well known that roots are responsible for N uptake by plants, but it is relatively unknown how root architecture affects this ability. This research was conducted to better understand the influence of root complexity (RC) in maize on a plant’s response to N stress as well as the influence of RC on other above-ground plant traits. Thirty-one above-ground plant traits were measured for 64 recombinant inbred lines (RILs) from the intermated B73 & Mo17 (IBM) population and their backcrosses (BCs) to either parent, B73 and Mo17, under normal (182 kg N ha-1) and N deficient (0 kg N ha-1) conditions. The RILs were selected based on results from an earlier experiment by Novais et al. (2011) which screened 232 RILs from the IBM to obtain their root complexity measurements. The 64 selected RILs were comprised of 31 of the lowest complexity RILs (RC1) and 33 of the highest complexity RILs (RC2) in terms of root architecture (characterized as fractal dimensions). The use of the parental BCs classifies the experiment as Design III, an experimental design developed by Comstock and Robinson (1952) which allows for estimation of dominance significance and level. Of the 31 traits measured, 12 were whole plant traits chosen due to their documented response to N stress. The other 19 traits were ear traits commonly measured for their influence on yield. Results showed that genotypes from RC1 and RC2 significantly differ for several above-ground phenotypes. We also observed a difference in the number and magnitude of N treatment responses between the two RC classes. Differences in phenotypic trait correlations and their change in response to N were also observed between the RC classes. RC did not seem to have a strong correlation with calculated NUE (ΔYield/ΔN). Quantitative genetic analysis utilizing the Design III experimental design revealed significant dominance effects acting on several traits as well as changes in significance and dominance level between N treatments. Several QTL were mapped for 26 of the 31 traits and significant N effects were observed across the majority of the genome for some N stress indicative traits (e.g. stay-green). This research and related projects are essential to a better understanding of plant N uptake and metabolism. Understanding these processes is a necessary step in the progress towards the goal of breeding for better NUE crops.

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Objectives. Recent literature indicates variance in psychosocial treatment preferences for negative symptoms of schizophrenia. Attempts at defining therapeutic aims and outcomes for negative symptoms to date have not included major stakeholder groups. The aim of the present study was to address this gap through qualitative methods. Design. Thematic Analysis was applied to qualitative semi-structured interview data to gather the opinions of people who experience negative symptoms, carers, and healthcare professionals. Participants were recruited from two mental health sites (inpatient/community) to increase generalisability of results. Ten people participated in the research. Methods. Semi-structured interview scripts were designed utilising evidence from the review in Chapter 1 of effective psychosocial intervention components for specific negative symptoms. Interviews were audio recorded and transcribed verbatim. Thematic analysis was employed to analyse data. Results. A common theme across groups was the need for a personalised approach to intervention for negative symptoms. Other themes indicated different opinions in relation to treatment targets and the need for a sensitive and graded approach to all aspects of therapy. This approach needs to be supported across systemic levels of organisation with specific training needs for staff addressed. Conclusions. There is disparity in treatment preferences for negative symptoms across major stakeholders. The findings suggest an individualised approach to intervention of negative symptoms that is consistent with recovery. Implementation barriers and facilitators were identified and discussed. There remains a need to develop a better understanding of treatment preferences for patients.

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Purpose: To compare signs and symptoms of dry eye in keratoconus (KC) patients versus healthy subjects. Methods: A total of 15 KC patients (KC group, n = 15 eyes) and 16 healthy subjects (control group, 16 eyes) were enrolled in this study. The Schirmer I test with no anesthetic, tear break-up time (TBUT), corneal staining characteristics, and ocular surface disease index (OSDI) scores were evaluated for both groups. Impression cytology, combined with/scanning laser confocal microscopy (LCM), was performed to evaluate goblet cell density, mucin cloud height (MCH), and goblet cell layer thickness (CLT). Finally, tear concentrations of di-adenosine tetraphosphate (Ap4A) were assessed. Results were statistically analyzed using Shapiro–Wilk and non-parametric Wilcoxon rank sum tests. Statistical significance was set at p < 0.05. Results: KC patients had lower tear volumes and greater corneal staining than did healthy subjects (p < 0.05). OSDI scores were 44.96 ± 8.65 and 17.78 ± 6.50 for the KC and control groups, respectively (p < 0.05). We found no statistically significant differences in TBUT between groups. Impression cytology revealed lower goblet cell densities in KC group patients versus control group subjects (84.88 ± 32.98 and 128.88 ± 50.60 cells/mm,2 respectively, p < 0.05). There was a statistically significant reduction in MCH and CLT in KC group patients compared with control group subjects. Ap4A tear concentrations were higher in KC group patients than in control group subjects (2.56 ± 1.10 and 0.15 ± 0.12 µM, respectively, p < 0.05). Conclusions: The parameters evaluated in this study indicate that KC patients suffer greater symptoms of dry eye and greater tear instability, primarily due to the decreased mucin production in their tears, than do healthy patients with no KC.

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The increased prevalence of iron deficiency among infants can be attributed to the consumption of an iron deficient diet or a diet that interferes with iron absorption at the critical time of infancy, among other factors. The gradual shift from breast milk to other foods and liquids is a transition period which greatly contributes to iron deficiency anaemia (IDA). The purpose of this research was to assess iron deficiency anaemia among infants aged six to nine months in Keiyo South Sub County. The specific objectives of this study were: to establish the prevalence of infants with iron deficiency anaemia and dietary iron intake among infants aged 6 to 9 months. The cross sectional study design was adopted in this survey. This study was conducted in three health facilities in Keiyo South Sub County. The infants were selected by use of a two stage cluster sampling procedure. Systematic random sampling was then used to select a total of 244 mothers and their infants. Eighty two (82) infants were selected from Kamwosor sub-district hospital and eighty one (81) from both Nyaru and Chepkorio health facilities. Interview schedules, 24-hour dietary recall and food frequency questionnaires were used for collection of dietary iron intake. Biochemical tests were carried out by use of the Hemo-control photochrometer at the health facilities. Infants whose hemoglobin levels were less than 11g/dl were considered anaemic. Further, peripheral blood smears were conducted to ascertain the type of nutritional anaemia. Data was analyzed using the Statistical Package for Social Sciences (SPSS) computer software version 17, 2009. Dietary iron intake was analyzed using the NutriSurvey 2007 computer software. Results indicated that the mean hemoglobin values were 11.3± 0.84 g/dl. Twenty one percent (21.7%) of the infants had anaemia and further 100% of peripheral blood smears indicated iron deficiency anaemia. Dietary iron intake was a predictor of iron deficiency anaemia in this study (t=-3.138; p=0.01). Iron deficiency anaemia was evident among infants in Keiyo South Sub County. The Ministry of Health should formulate and implement policies on screening for anaemia and ensure intensive nutrition education on iron rich diets during child welfare clinics.

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The purpose of this research was to determine if a multi-component consultation intervention was effective in improving pragmatic performance in students with ADHD. Participants for this study consisted of 7 children for whom 3 data points were obtained by a parent or 2 data points by a teacher. Changes in pragmatic performance were measured by comparing reports provided by parents or teachers pre- and post- intervention. Descriptive analysis procedures were completed to summarize changes in pragmatic behavior. Results revealed the mean overall change in pragmatic behavior for children in the MCC condition (Χ=1.133) was greater than the change seen in the CAU condition (.334) after 2 months of intervention as per parent reported data. Data indicated improvement in each behavior but incongruence between teachers and parents was found. Results support the hypothesis that the multi-component consultation intervention is effective in improving the pragmatic language performance of children with ADHD.

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Phytoremediation studies have been conducted in an area contaminated by heavy metals, located in Piracicaba - SP, Brazil. This area was contaminated accidentally by the addition of auto scrap shredding to the soil and was limed later to reduce heavy metal mobility in the environment. Previous characterization showed that it also presents high concentration of boron, which has limited the initial plant development of some species. As sunflower plants require a high boron supply and the literature describes its use in the phytoremediation of soils contaminated with heavy metals under some conditions, the aim of this work was to evaluate its potential for the remediation of this area. In the present study, the results of preliminary tests are presented, aiming at the evaluation of sunflower plant germination and its initial development when cultivated in the contaminated soil described. Two sunflower hybrids were sown in soils treated with different rates of boron and in the soil from the contaminated area in study. The results showed that sunflower plants had a normal initial development, even in the soil from the contaminated area. Therefore, sunflower is a promising crop and further studies will be developed to evaluate the sunflower efficiency in phytoextraction or phytostabilization of heavy metals in areas where boron contamination also occurs, as is the case in the study area.

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CDKL5 (cyclin-dependent kinase-like 5) deficiency disorder (CDD) is a rare and severe neurodevelopmental disease that mostly affects girls who are heterozygous for mutations in the X-linked CDKL5 gene. The lack of CDKL5 protein expression or function leads to the appearance of numerous clinical features, including early-onset seizures, marked hypotonia, autistic features, and severe neurodevelopmental impairment. Mouse models of CDD, Cdkl5 KO mice, exhibit several behavioral phenotypes that mimic CDD features, such as impaired learning and memory, social interaction, and motor coordination. CDD symptomatology, along with the high CDKL5 expression levels in the brain, underscores the critical role that CDKL5 plays in proper brain development and function. Nevertheless, the improvement of the clinical overview of CDD in the past few years has defined a more detailed phenotypic spectrum; this includes very common alterations in peripheral organ and tissue function, such as gastrointestinal problems, irregular breathing, hypotonia, and scoliosis, suggesting that CDKL5 deficiency compromises not only CNS function but also that of other organs/tissues. Here we report, for the first time, that a mouse model of CDD, the heterozygous Cdkl5 KO (Cdkl5 +/-) female mouse, exhibits cardiac functional and structural abnormalities. The mice also showed QTc prolongation and increased heart rate. These changes correlate with a marked decrease in parasympathetic activity to the heart and in the expression of the Scn5a and Hcn4 voltage-gated channels. Moreover, the Cdkl5 +/- heart shows typical signs of heart aging, including increased fibrosis, mitochondrial dysfunctions, and increased ROS production. Overall, our study not only contributes to the understanding of the role of CDKL5 in heart structure/function but also documents a novel preclinical phenotype for future therapeutic investigation.