Factors Associated with Quality of Life among People with Atrial Fibrillation: Jordan Atrial Fibrillation Registry Study.

Background and Objectives: Atrial fibrillation (AF) is a common arrhythmia that may adversely affect the quality of life (QoL). Several factors could be associated with the QoL among patients with AF; however, evidence regarding these factors is still limited and controversial. Therefore, this study aimed to identify the level of QoL and its associated factors among Jordanian patients with AF. Subjects and methods: A case study design was implemented. A sample of 620 participants were recruited from 28 outpatient clinics registered in the Jordan atrial fibrillation registry AF (JoFIB). Data on QoL were gathered through the self-reported Atrial Fibrillation Effect on Quality-of-life tool (AFEQT). A QoL questionnaire was validated in this population before starting this study. The cardiac nurse then provided the research assistant with data relating to patients' characteristics and associated comorbidities. Results: The overall AFEQT scores were positively skewed (median 21.3, IQR: 14.4-31.9). This pattern was reflected for the AFEQT sub-scales 'Symptoms' (20.8, 8.3-33.3), 'Daily activities' (16.7, 10.4-27.1), and 'Treatment concerns' (27.8, 19.4-41.7), whereas 'Treatment satisfaction' was negatively skewed (91.7, 83.3-91.7). Patients in the higher quartiles, indicating a better QoL, tended to be younger and were less likely to experience dyslipidemia, stroke, pulmonary hypertension, or other comorbidities. Over 90% of patients were currently experiencing AF, and patients with a better QoL tended to be less likely to be currently experiencing AF and more likely to have had their latest episode of AF more than a month ago (compared to less than a month ago). Age, BMI, dyslipidemia, heart failure, COPD, CAD, history of ablation, and the use of anticoagulants were significantly associated with the overall AFEQT score (R2 = 0.278). Conclusions: This study demonstrates that AF Jordanian patients had low levels of QoL. Patients in higher quartiles for the overall AFEQT score were younger, with fewer disease comorbidities and less experience of current AF episodes. Several modifiable and non-modifiable factors were associated with QoL in AF patients. Age, BMI, dyslipidemia, heart failure, COPD, CAD, history of ablation, and the use of oral anticoagulants were significantly associated with the overall AFEQT score. Healthcare providers should target these factors as indicators or interventions for which QoL is continuously monitored.

A qualitative exploration of adherence to wearing removable cast walkers in patients with diabetic foot ulcers.

OBJECTIVE: To explore adherence to wearing removable cast walkers (RCWs) among patients with diabetic foot ulcers (DFUs). METHOD: A qualitative study was conducted by interviewing patients with active DFUs and using knee-high RCWs as their offloading treatment. The interviews were undertaken at two diabetic foot clinics in Jordan, using a semi-structured guide. Data were analysed through content analysis by developing main themes and categories. RESULTS: Following interviews with 10 patients, two main key themes with a total of six categories were identified: theme 1-reporting of adherence levels was inconsistent, included two categories: i) a belief in achieving optimal adherence, and ii) non-adherence was often reported indoors; and theme 2-adherence was a consequence of multiple psychosocial, physiological and environmental factors, which included four categories: i) specific offloading knowledge or beliefs influenced adherence; ii) severity of foot disease influenced adherence; iii) social support benefitted adherence; and iv) physical features of RCWs (the usability of the offloading device) impacted adherence. CONCLUSION: Patients with active DFUs reported inconsistent levels of adherence to wearing RCWs which, after deeper investigation, seemed to be due to participants' misperceptions of the optimal adherence. Adherence to wearing RCWs also seemed to be impacted by multiple psychosocial, physiological and environmental factors.

The Validity and Reliability of Self-Reported Adherence to Using Offloading Treatment in People with Diabetes-Related Foot Ulcers.

Adherence to using offloading treatment is crucial to healing diabetes-related foot ulcers (DFUs). Offloading adherence is recommended to be measured using objective monitors. However, self-reported adherence is commonly used and has unknown validity and reliability. This study aimed to assess the validity and reliability of self-reported adherence to using removable cast walker (RCW) offloading treatment among people with DFUs. Fifty-three participants with DFUs using RCWs were included. Each participant self-reported their percentage adherence to using their RCW of total daily steps. Participants also had adherence objectively measured using dual activity monitors. After one week, a subset of 19 participants again self-reported their percentage adherence to investigate test-retest reliability. Validity was tested using Pearson's r and Bland-Altman tests, and reliability using Cohen's kappa. Median (IQR) self-reported adherence was greater than objectively measured adherence (90% (60-100) vs. 35% (19-47), p < 0.01). There was fair agreement (r = 0.46; p < 0.01) and large 95% limits of agreement with significant proportional bias (ß = 0.46, p < 0.01) for validity, and minimal agreement for test-retest reliability (K = 0.36; p < 0.01). The validity and reliability of self-reported offloading adherence in people with DFU are fair at best. People with DFU significantly overestimate their offloading adherence. Clinicians and researchers should instead use objective adherence measures.

Prevalence and Associated Factors of Toenail Onychomycosis Among Patients with Diabetes in Jordan.

BACKGROUND: Toenail onychomycosis is common in patients with diabetes and it can increase the risk of secondary infections and foot complications. Despite several studies investigating the prevalence and associated factors of toenail onychomycosis from different parts of the world, there are no data from Jordan. OBJECTIVE: To determine the prevalence and the associated factors of toenail onychomycosis among patients with diabetes in Jordan. METHODS: A cross-sectional study was conducted on 375 patients with diabetes at the National Centre for Diabetes, Endocrinology, and Genetics in Amman, Jordan. Several socio-demographic and health-independent variables including foot self-care practices were collected. Toenail onychomycosis was assessed by a specimen culture and microscopic examinations. Descriptive and inferential statistics were used for data analysis. RESULTS: The prevalence of toenail onychomycosis was 57.6% (n=216). Multiple logistic regression revealed four significant associated factors; the presence of neuropathy (ß=1.87, p=0.02), being an ex-smoker (ß=2.69, p=0.01), being treated by both insulin and oral hypoglycemics drugs (ß=1.32, p=0.03), and using antibiotics in the last year (ß=1.78, p=0.02). CONCLUSION: The prevalence of toenail onychomycosis among patients with diabetes in Jordan is high. Regular foot screening and podiatric care are recommended especially among patients with diabetic neuropathy, current treatment by insulin and oral hypoglycemics drugs, previous history of smoking, and previous use of antibiotics.

Factors influencing gestational diabetes self-care among pregnant women in a Syrian Refugee Camp in Jordan.

AIM: The main objective of this study is to identify the level of self-care practices and the determinants of Gestational Diabetes Mellitus (GDM) among pregnant women residing in one of the refugee camps in Jordan. METHOD: A cross-sectional study was conducted on a convenient sample of forty women diagnosed with GDM from the high-risk maternity clinic in one of the Syrian refugee camps in Jordan. The study used the Gestational Diabetes Management Self-Efficacy Scale (GDMSES), Diabetes Knowledge (DMK) assessment, and Diabetes Self-Care Activities Questionnaire (SDSCA) to measure the variables of interest. Descriptive analysis and Multiple logistic regression were used to assess for significant factors. RESULTS: Significant associations were found between the subcategories of diet, exercise, and blood sugar control in both the self-efficacy and self-activity scales (p < 0.01, p < 0.01, p < 0.05), respectively. Two factors were associated with higher GDM self-care: diabetes knowledge and higher self-efficacy toward GDM self-care (p < 0.05). CONCLUSION: The findings of this study highlight that pregnant women with GDM who have higher levels of self-efficacy and diabetes knowledge are more likely to achieve higher levels of GDM self-care. Beside developing health promotion programs to enhance women's self-efficacy in adhering to GDM care, adequate support and relevant resources to facilitate GDM management among refugee women are recommended. Future research for identifying other potential factors affecting GDM self-care among refugees is highly recommended.

The one-year incidence of stroke in patients with atrial fibrillation in Jordan and its associated factors.

Background: An elevated risk of stroke is linked to atrial fibrillation (AF). Effective care and prevention measures for individuals with AF require an understanding of the factors impacting the incidence of stroke in this population. Evidence regarding the incidence of stroke among patients with AF is insufficient in Jordan. This study aimed to determine the incidence of stroke and its associated factors among patients with AF in Jordan. Methods: The Jordan Atrial Fibrillation Registry JoFib was used to identify a total of 2020 AF patients meeting the study inclusion and exclusion criteria. Demographics, clinical characteristics, and the CHA2DS2-VASc score-based evaluation of stroke risk were extracted from the registry. Results: This study encompassed 2020 participants diagnosed with AF, with 925 (45.8%) being men and 1,095 (54.2%) women. The one-year stroke incidence among the 2020 AF patients was 3.4%. Notably, stroke incidence significantly increased with age (p = 0.04) and was associated with the history of stroke (7.4% vs. 2.7%), hypertension (3.9% vs. 1.9%), and diabetes (5.1% vs. 2.1%). In the multivariate analysis, diabetes (OR = 2.6, 95% CI: 1.5-4.4, p = 0.001) and history of stroke (OR = 2.6, 95% CI: 1.5-4.6, p = 0.001) were significantly associated with stroke incidence. Conclusion: This study emphasizes Jordan's high stroke rate among AF patients. Diabetes and prior stroke history are associated with increased odds of stroke, like all stroke patients. These results highlight the necessity for specialized management strategies among AF patients and highlight the significance of thorough risk assessment and focused interventions to reduce stroke risk in AF patients.

Cross-Cultural Adaptation and Reliability Testing of Arabic Versions of Several Diabetic Foot Psychosocial Scales.

The main aims of this study were cross-cultural adaptation and reliability testing of an Arabic version of Foot Care Confidence Scale (FCCS), Foot Care Outcomes Expectations Scale (FCOES), Patient Interpretation of Neuropathy Scales (PINS), Neuropathy-specific Quality of Life Scales (NQOLS), and offloading-related Visual Analog Scales (VAS). Two phases of translation and reliability testing were conducted in Jordan. Phase 1 included 2 forward and backward translations with 2 panel consensuses (translators, clinicians, and experts). In Phase 2, Cronbach's alpha (α) and intraclass correlation coefficient (ICC) were used to test the internal consistency and stability (test-retest) of the Arabic scales in a sample of a total of 90 Jordanian participants with diabetic foot ulcers. Phase 1 resulted in Arabic translation and cross-cultural adaptation of the study scales. Phase 2 resulted in acceptable internal consistency of the translated scales (α = 0.74-0.91), except for the PIN "self/practitioner blame" and "acute ulcer onset" scales (α = 0.57, 0.49, respectively). Test-retest results (ICC) were: FCCS (0.85); FCOES (0.78); PINS (0.043-0.85); NQOLS (0.76-0.90); and offloading-related VAS (0.43-0.90). This study showed evidence of cultural appropriateness and reliability of most of the translated scales, for possible future implementation for the Arabic population.

Differences in adherence to using removable cast walker treatment during daytime and nighttime weight-bearing activities in people with diabetes-related foot ulcers.

Aims: Patients' adherence to using knee-high offloading treatment is critical to effective healing of diabetes-related foot ulcers (DFUs). Previous studies have found that patients generally have low adherence to using removable knee-high offloading treatments, yet no study has investigated whether their adherence differs during daytime and nighttime. This study aimed to investigate the levels and factors associated with adherence to using knee-high removable cast walker (RCW) treatment during daytime and nighttime weight-bearing activities in people with DFUs. Methods: This was a secondary analysis of data collected from a multi-centre cross-sectional study investigating adherence to using knee-high RCWs among 57 participants with DFUs. All participants had multiple socio-demographic, physiological and psychosocial factors collected, before having their adherence to using RCWs during weight-bearing activity monitored over a 1-week period using the dual activity monitor method. Adherence data were categorised into daytime (06:00-18:00) and nighttime (18:00-06:00) periods and calculated separately. Multiple linear regression was used to identify factors associated with daytime and nighttime adherence. Results: Mean adherence to using RCW during weight-bearing activities in people with DFUs was higher during daytime compared with nighttime [39.9% (SD = 18.9) versus 20.4% (SD = 16.7), p < 0.001]. Factors independently associated with lower adherence during daytime were being male, longer diabetes duration, not having peripheral artery disease (PAD), and higher perceived RCW heaviness. Factors associated with lower adherence during nighttime were higher mean daytime steps, not having retinopathy and having dyslipidaemia. Conclusions: Adherence to using RCWs during weight-bearing activities reduced significantly at nighttime compared with daytime among people with DFUs, and this was associated with different factors. Interventions to improve adherence, in research and clinical practice, should incorporate methods to target daytime or nighttime adherence specifically.

Factors Associated With Self-Efficacy of Foot Self-Care Among Patients With Diabetes Attending a Tertiary Care Center in Saudi Arabia.

Several reports have shown self-efficacy to be a reliable way of predicting foot self-care behavior in patients with diabetes. However, at a global level in general, and in Saudi Arabia in particular, investigation of the factors related to self-efficacy in executing foot self-care continues to remain inadequate. This study endeavors to identify the factors associated with the self-efficacy of foot self-care among patients with diabetes in Saudi Arabia. From a tertiary diabetes care center in Saudi Arabia, 175 patients with diabetes were selected to participate in this cross-sectional study. Employing the Arabic version of the Foot Care Confidence Scale (FCCS), the principal end results and the sociodemographic, clinical, and psychosocial independent variables were collected and assessed. From the total reported FCCS score, the mean was found to be 28.1 ± 8.2. Multiple linear regression analysis indicated 2 independent factors were positively associated with a higher reported FCCS score; being middle-aged (< 60 years old) (ß=0.31, P< .01) and having a higher score on the Foot Care Outcome Expectations Scale (FCOES) (ß=0.36, P< .01). In conclusion, patients with diabetes in Saudi Arabia have a mild level of self-efficacy to perform the needed foot self-care. Therefore, this has turned the spotlight on the young or middle-aged < 60-year-old Saudi population with diabetes as the target group, making them the priority for future self-efficacy promotion programs to upgrade the level of foot self-care.

Factors Associated With Foot Self-Care in Patients With Diabetes-Related High-Risk Feet: A Cross-Sectional Design.

Foot self-care has been commonly studied among people with diabetes. Previous research on foot self-care among those with diabetes-related high-risk feet is almost unavailable or very limited. The current study aims to fill this gap and provide a contemporary unprecedented analysis of this area of specialization. To assess the levels of, and factors associated with foot self-care among people with diabetes-related high-risk feet. A multi-center cross-sectional study from Jordan assessed the foot self-care of 107 participants with diabetes-related high-risk feet. Multiple socio-demographic, physiological, and psychosocial factors were collected, and the Arabic version of the diabetes foot self-care behavior scale was used to estimate the foot self-care of the study population. A multiple linear regression model was employed to identify factors associated with foot self-care. The mean score of foot self-care was 25.4 ± 7.1 (35 is the highest) indicating ~73% of adherence to foot self-care. Factors associated with higher foot self-care were being treated at the King Abdullah University Hospital (ß = .30, P < .01) and reporting higher scores of patients' interpretations about neuropathy physical causes of foot ulcers (ß = ".22," P = .02). People with diabetes-related high-risk feet reported a relatively adequate foot self-care practice. However, clinicians are still required to enhance foot self-care among this population. Health promotion programs may benefit from engaging people in understanding the pathophysiology of diabetes-related foot ulcers to improve foot self-care practices.

Factors associated with adherence to using removable cast walker treatment among patients with diabetes-related foot ulcers.

INTRODUCTION: Adherence to using knee-high offloading treatment is critical for healing diabetes-related foot ulcers (DFUs). However, few studies have investigated patients' adherence to using knee-high offloading treatment. We aimed to investigate the levels and factors associated with adherence to using knee-high removable cast walker (RCW) treatment among patients with DFUs. RESEARCH DESIGN AND METHODS: In this multicenter cross-sectional study, we investigated adherence to using knee-high RCWs in 57 participants with DFUs. All participants were clinically examined for multiple sociodemographic, physiological, and psychosocial factors. Each participant's adherence level to using RCWs was then objectively measured using dual activity monitors (attached to the wrist and RCW) over a 1-week period. Multiple linear regression was undertaken to determine those factors independently associated with adherence levels. RESULTS: The mean adherence level to using RCWs was 33.6% (SD 16.5) of weight-bearing activity. Factors independently associated with lower adherence levels were being male, longer diabetes duration, not having peripheral artery disease (PAD), and having higher perceived RCW heaviness (p≤0.05). No associations were found with psychosocial factors. CONCLUSIONS: Patients with DFUs adhered to using their RCWs on average for only a third of their prescribed weight-bearing treatment duration. Factors linked to lower RCW adherence levels were being male, longer diabetes duration, not having PAD, and perceived heavier RCWs. These findings highlight the importance of using gold standard non-removable knee-high offloading device treatment. Furthermore, these findings suggest, when gold standard devices are containdicated, that these factors be considered when prescribing the second choice RCW offloading treatment to optimise adherence. Regardless, further longitudinal studies are needed to confirm these factors.

MEASUREMENT OF THE ACTIVITY CONCENTRATIONS OF GAMMA EMITTING RADIONUCLIDES IN TOOTHPASTE SAMPLES AND ASSESSMENT OF THE CORRESPONDING ANNUAL EFFECTIVE DOSES.

It is inevitable that we are exposed to radiation daily from various sources and products that we consume on daily basis. The use of toothpaste for oral hygiene is one of the most common daily practices by humans and yet very little data are available regarding its radiation content. In this work, we investigated the concentrations of gamma emitting radionuclides in toothpaste samples consumed in Jordan. 40K and 226Ra were detected in almost one-third of the samples, whereas 228Ra was detected in nearly half of them. The corresponding activity concentrations in the detected samples were in the ranges of 68.7-154.2, 4.6-14.1 and 1.3-10.0 Bq/kg, respectively. Dose assessment of accidental ingestion of toothpaste for children and adults was made, and its contribution to the annual effective dose was found to be very minimal with maximum doses of ~2.9 and 1.3 µSv for children and adults, respectively.

ASSESSMENT OF THE RADIOACTIVITY OF GAMMA EMITTERS IN BABY FORMULA FOR DIFFERENT AGE GROUPS AND BABY CEREAL CONSUMED IN JORDAN.

In the present work, different brands of baby formula and cereal consumed in Jordan were analyzed for their radioactivity content. The activity concentrations of 40K varied with the designated age group in formula with the average concentrations being (in Bq/kg): 160.2 ± 33.5, 219.0 ± 35.0 and 265.2 ± 56.3 for the age groups of 0-6 months, 6-12 months and 1-3 years, respectively. 226Ra was not detected in any of the samples, while 232Th was detected in nearly half the samples with concentrations ranging from 0.22 to 0.82 Bq/kg. 137Cs was detected in only two samples with concentrations of 0.94 and 3.15 Bq/kg. The concentrations of 40K and 232Th in cereal were in the ranges of 23-294 and 0.49-1.48 Bq/kg, respectively. The resulting committed dose was assessed and found in the range of 154-613 µSv, with insignificant contribution from 137Cs, which is within the worldwide range but generally higher than the worldwide average of 290 µSv.

ESTIMATION OF THE ORGAN AND EFFECTIVE DOSE TO PATIENTS UNDERGOING MEDICAL DIAGNOSTIC X-RAY EXAMINATIONS IN SAUDI ARABIA.

Quantifying the radiological risk from diagnostic radiography is essential for patients' safety. Effective dose is considered the best quantity to determine the stochastic risk associated with the radiological examinations. Therefore, the present work investigated organ and effective dose for adult patients in the most common type of X-ray examinations, such as the chest (PA/LAT), abdomen (AP) and lumbar spine (AP/LAT) projections. The PCXMC version 2 Monte Carlo program was used to estimate the organ and effective dose for 547 patients who underwent a radiographic examination at the King Abdulaziz Hospital, Saudi Arabia. The results showed wide variation in organ doses. The largest organ dose in each X-ray examination were 2.72 mGy for the spleen in the lumbar spine (LAT), 1.98 mGy for the urinary bladder in the lumbar spine (AP), 0.40 mGy for the spleen in the chest (PA), 0.11 mGy for the kidney in the chest (LAT) and 1.78 mGy for the testicles in the abdomen (AP) examinations. Values for the effective dose were estimated for each investigated X-ray examination, and the results were compared with the published values available in the literature. The obtained values for effective dose were relatively lower than those reported by the European Commission and the United Nations Scientific Committee on the Effects of Atomic Radiation for the same examinations. The results presented here will help establish a database that will be useful for future comparisons and monitoring in radiographic procedures.

Prevalence and Associates of Foot Deformities among Patients with Diabetes in Jordan.

OBJECTIVES: To determine the prevalence of, and factors associated with, people with foot deformities, among patients with diabetes in Jordan. METHODS: A cross-sectional study was conducted on 1000 diabetic participants recruited from the National Center for Diabetes, Endocrinology, and Genetics in Jordan. Participants had their feet clinically examined to detect the following foot deformity outcomes: Hallux valgus, claw/hammer toe, prominent metatarsal heads, limited joint mobility, pes cavus, Charcot foot, and amputations. Sociodemographic and health variables were also collected from participants' interviews, medical records, or clinical examination. Logistic regression was used to analyse associations between variables and each foot deformity outcome. RESULTS: Of the 1000 diabetic patients: Hallux valgus was found in 17.4%, claw\hammer toe in 16%, prominent metatarsal head in 14.2%, limited joint mobility in 9.4%, pes cavus in 3.2%, Charcot foot in 2.1%, and amputations in 1.7%. Hallux valgus was associated with gender (p=0.012), age (p<0.01) and shoe choices (p=0.031); claw\hammer toe was associated with age (p=0.04), retinopathy (p<0.001), sensory and painful neuropathy (p<0.001); limited joint mobility was associated with age only (p=0.001); Charcot foot was associated with glycemic control (p=0.016), hypertension (p<0.000), sensory neuropathy (p<0.001), and painful neuropathy (p<0.001); and, amputations were associated with duration of diabetes (p<0.043), sensory neuropathy (p=0.001), and painful neuropathy (p=0.001). CONCLUSION: Prevalence of different foot deformities in Jordan variedbetween 1.7% - 17.4%. Sociodemographic factors such as age, gender and shoes choices or presence of diabetes-related microvascular complications (neuropathy and retinopathy) or hypertension were independently associated with foot deformities among the Jordanian diabetic population.

Assessment of Patient Radiation Dose during Conventional Diagnostic X-ray Examinations in Three Public Hospitals in Northern Jordan using TLDs.

This study aims to measure entrance surface doses during routine chest and abdomen x-ray examinations of adult and child patients. Radiation dose measurements were performed using thermoluminescent dosimeters TLD-100s in three major public hospitals in northern Jordan on a total of 100 patients. Wide variations in entrance surface doses were observed within and between hospitals, which might be attributed to significant variations of the selected exposure parameters. For adult patients, the results have shown that the majority of entrance surface dose values from both chest and abdomen examinations were within recommended values of diagnostic reference levels. For child patients, the mean entrance surface dose from chest examinations in three age groups were 0.131 mGy (0-1 y), 0.136 mGy (1-5 y), and 0.191 mGy (5-10 y). These values were considered relatively high compared to the European reference levels and published results in the literature. However, for abdomen examinations, entrance surface dose values were relatively lower than European reference levels. Patient effective doses were estimated using a PCXMC 2.0 Monte Carlo program. The results for both adults and children were found to be relatively lower than the values reported by international publications. Due to the wide variations of entrance surface dose and the higher radiation doses delivered to child patients, this study recommends implementing a quality assurance program in such hospitals to achieve optimization between good image quality and minimum dose according to the as low as reasonably achievable principle. Moreover, the results of this work will provide a useful base for establishing local diagnostic reference levels for chest and abdomen examinations in Jordan.

The role of polarization interactions in the wrapping/unwrapping of nucleosomal DNA around the histone octamer: implications to gene regulation.

The inclusion of polarization interactions in nucleic acids and proteins have been recognized as a major improvement both in our understanding of these systems and in the accuracy of current calculations and simulations. Recently, we have investigated the role of these interactions in DNA A-tracts bending using a Monte Carlo simulation approach developed by Jarque and Buckingham, which allows the explicit calculation of the polarization energy at the microscopic level as a function of the interionic distance for two charges embedded in a polarizable medium. Here, we investigate the role of polarization interactions in providing a framework for understanding the wrapping/unwrapping of nucleosomal DNA. The effective electrostatic potential energy is found to decrease as the nucleosomal DNA minor groove width is decreased. This results in bending of DNA which gives rise to its folding, with narrow minor grooves facing in toward the octamer. Changes in the structure of the nucleosome, through its intrinsic dynamics, ATP-dependent remodeling factors or covalent modifications of the histone tails, and/or in the strength of hydration would exert profound effects on the strength of the polarization interactions and thereby could modulate the folding of DNA and the transcription process. These considerations have led us to suggest a potential epigenetic mechanism according to which the grip of DNA on the histone core could be controlled by the width of the minor groove in conjunction with the local compactness of the nucleosome and the strength of hydration.

DNA A-tracts bending: polarization effects on electrostatic interactions across their minor groove.

Bending by the DNA A-tracts constitutes a contentious issue, suggesting deficiencies in the physics employed so far. Here, we inquire as to the importance in this bending of many-body polarization effects on the electrostatic interactions across their narrow minor groove. We have done this on the basis of the findings of Jarque and Buckingham who developed a procedure based on a Monte Carlo simulation for two charges of the same sign embedded in a polarizable medium. Remarkably, the present analysis reveals that for compact DNA conformations, which result from dynamic effects, an overall attractive interaction operates between the phosphate charges; this interaction is especially strong for the narrow minor groove of the A-tracts, suggesting a tendency for DNA to bend toward this groove. This tendency is in agreement with the conclusions of electrophoretic and NMR solution studies. The present analysis is also consistent with the experimental observations that the minor groove is much more easily compressible than the major groove and the bending propensity of the A-tracts is greatly reduced at "premelting" temperatures. By contrast, the dielectric screening model predicts a repulsion between the phosphate charges and is not consistent with the aforementioned bending tendency or experimental observations.

A STUDY OF THE RADIOACTIVITY IN THE DUST STORM EVENT OF APRIL 2015 IN ARABIAN PENINSULA.

Gulf countries are often affected by dust storms which have a significant influence on the environment and public health. The present work examines the radioactivity content in the intense dust storm occurred over Gulf countries on 1 April 2015. The results showed that the average value of 137Cs in dust samples (±SD) is 14.4 ± 1.6 Bq/kg, which is almost two orders of magnitude larger than those in soil samples. 7Be was detected with a considerable amount only in dust samples. The activity concentrations of the natural radionuclides (234,238U, 228,230,232Th, 226,228Ra and 40K) in dust samples were found to be approximately two to three times higher than the corresponding values in soil samples, which is attributed to the abundance of the finest particle size in the dust samples. Also, the activity ratios and the correlations between the detected radionuclides were investigated to assess the origin and activities associated with any variation of the radionuclides in the environment. Moreover, the total annual effective dose due to ingestion of dust was estimated to be 89.7 and 34.9 nSv for infants and adults, respectively, which is well below the world average internal dose of 290 µSv. The main contributor to the annual effective dose was 228Ra, which contributes ~69.6 and 43.3% for infants and adults, respectively, followed by: 226Ra ¼ 232,230,228Th > 234,238U > 40k, 137Cs ¼ 7Be.

Assessment of the committed effective dose due to the 210Po intake from fish consumption for the Arabian Gulf population.

This study aims to assess the committed effective dose due to the intake of 210Po from the consumption of fish in Arabian Gulf countries. Twenty different kinds of fish, which represent the most common fish species consumed in the Arabian Gulf countries, were analyzed using alpha spectrometer technique. 210Po activity concentrations in fish samples were found to vary over a wide range from 0.1 to 14.7 Bq kg-1 fresh weight. This variation of 210Po concentrations between various type of fish samples might be attributed to the feeding type pattern and the size of fish. The annual committed effective dose due to ingestion of 210Po in fish species for adults in the Arabian Gulf countries was estimated and found to vary from 38 µSv in Bahrain to 85 µSv in Oman with an average value of 59 µSv. These values are considered relatively high compared to those reported in some other regions. However, it is still much lower than the world average ingestion dose due to natural radiation sources.