Radar remote sensing has been widely used to estimate moisture and surface roughness due to its sensitivity to the physical and geometrical parameters of the soil. There are different models to explain the relationship between radar backscattering, surface and sensor parameters. The most important of these models are the integral equation model (IEM) and the small perturbation model (SPM). Due to the complexity of these models, in order to estimate roughness and moisture a neural network is used for inversion of these models. In this article, the X-band of the SAR image is used to estimate the surface roughness. One of the innovations of this research is the use of fractal SPM model in surface roughness estimation. To evaluate the accuracy of roughness estimation from SAR image, digital terrain model (DTM) that prepared using lidar data is used. For calculation of field roughness, Euclidean geometry and fractal geometry have been used, and they have been compared with roughness estimated from SAR image using two fractal SPM and IEM models. The results of this research have shown that the best accuracy is related to the estimation of the surface roughness with the fractal SPM model, which is compared with the ground roughness measured by the fractal geometry method. The accuracy of this method is 22% better than the similar method with the IEM model. The results of this paper showed that the use of fractal physical model as well as fractal geometry significantly increases the accuracy of roughness estimation from SAR images.

AbstractBackground: Inborn errors of metabolism (IEM) are rare genetic disorders that usually cause the disease by blocking a metabolic pathway. Delayed diagnosis is usually due to nonspecific manifestations. In this study, we aim to evaluate the demographic and clinical characteristics of pediatric patients with IEM admitted in Nemazi hospital, a referral center in southern Iran.Methods: All 1-month- to 18-year-old patients who were admitted in the pediatric ward in Nemazi hospital, a referral center in southern Iran, with the diagnosis of IEM were enrolled. Patients with incomplete information were excluded. We collect demographic and clinical data including age, sex, parents’ consanguinity, family history of IEM, presenting symptoms, number of hospitalization, age of onset, and diagnosis of the disease. All the data were entered into SPSS ver.22 and analyzed.Results: 200 patients were enrolled in the study. 53.5% were male and 46.5% female. The most clinical symptoms were lethargy and vomiting. The most prevalent IEM were aminoacidopathies, organic acidemia, and mitochondrial disease. Consanguinity was seen in 57.5% of them, while the family history of metabolic diseases was observed in 16.5%. There was a statistically significant relationship between consanguinity and the type of the disease.Conclusion: The clinical symptoms of IEM are nonspecific and may be misdiagnosed as other diseases like septicemia. We should always keep IEM in mind to detect the disease earlier and prevent significant morbidities and mortality by appropriate timely treatment. Due to the prevalence of consanguinity marriage in Iran, we should also consider metabolic screening.

There is insufficient data about esophageal body dysmotility in patients with refractory gastroesophageal reflux disease (RGERD) and inadequate response to proton pump inhibitors (PPIs) treatment. This study aimed to assess esophageal motility disorder and reflux parameters among these patients by highresolution manometry (HRM) and intraluminal impedance and pH (MII‐,pH) monitoring after stopping PPI therapy. A retrospective study was conducted among 100 RGERD patients admitted to Taleghani Hospital (Tehran, Iran) for one year. More than half of them were males (55%). Their mean age was 47. 10±, 6. 92, and 50% of patients had ineffective esophageal motility (IEM). Middle, distal, and proximal esophageal pressure (MEP, DEP, and PEP), lower esophageal sphincter (LES) basal pressure (LESP), integrated relaxation pressure (IRP), distal contractile integral (DCI), large breaks, upper esophageal sphincter basal pressure (UESP), and LES length (LESL) in IEM patients were significantly lower than the patients with normal esophageal motility (P<0. 001). Furthermore, there were more patients in the IEM group with long-term and abnormal weakly acid reflux compared with the non-IEM group (P<0. 05). It seems that the evaluation of reflux parameters and esophageal motility could lead to additional insights into the pathophysiological mechanisms of RGERD. Nevertheless, further studies are suggested to evaluate the effects of esophageal motility disorders among RGERD patients.

The unsteady-state interaction-by-exchange-with-the-mean (IEM) model has been derived elsewhere. That model was derived for the study of the dynamical behavior of the imperfectly micromixed continuous-flow stirred tank reactor (CSTR). In this study we have attempt to illustrate an easier method of derivation. The unsteady-state IEM model of micromixing describes a perfectly macromixed CSTR and assumes that individual fluid elements, initially segregated at the inlet, micromix by exchanging mass linearly with all fluid elements present in the reactor. Hence, the IEM model gives a mean-field description of the system where chemical reactions occur locally and mass is exchanged globally. The mean concentration is found by weighting the local concentrations according to their age in the reactor. This formulation, as presented in this paper, leads to a nonlinear integral equation for the mean concentration. Mathematically, integral equations involve "non-Markovian" or history-dependent behavior and are known, in many cases, to exhibit dynamical behavior absent from the ordinary differential equation found in the historyindependent limit

Biochemical anomalies impairing the body’s normal metabolism are referred to as inborn errors of metabolism (IEM). Early diagnosis and management can avert the otherwise harmful situation that may occur due to inborn errors. Generally, their incidence can vary from one case in every 800 to 2500 cases. Thus, understanding the genetic defects behind the clinical presentation of the disease and their early management and treatment is the need of the hour. This review article gives an overall knowledge of the types of IEM, its pathophysiology, clinical presentation, diagnosis, and management of the disease.

Background: Inborn errors of metabolism (IEM) are disorders caused by genetic mutations of the normal metabolic pathways.Objectives: The aim of this study was to investigate clinical findings and laboratory tests for IEMs to determine a proper clinical and laboratorial approach to these disorders.Methods: This descriptive study involved 180 patients with suspected IEM at the children’s medical center (CHM) in Tehran. The patients’ information was recorded in special forms, and three levels of examinations were performed. Data were subjected to frequency, percent, and chi square tests using SPSS version 17.Results: The study sample included 87 (48.3%) female patients and 93 (51.7%) male patients. The most common (20%) clinical presentation of patients with IEMs was poor feeding or failure to thrive, and the frequency of the condition in children younger than age 1 year was approximately 35%. Eighty percent of patients received a definitive diagnosis by the first and second level of examination.The most common (17%) disorders were proponic acidemia, methylmalonic acidemia (14%), and urea cycle disorder (14%).Conclusions: Considering the non-specific primary presentation of IEMs and the importance of clinical diagnosis other than specific laboratory tests, it is necessary to develop a general guide for an approach to IEM that provides appropriate management for high-risk families and infants.

Objective Inborn errors of metabolism (IEM) are rare conditions, with an overall incidence of 1 per 1000 births. Approximately 40-60% of IEM cases present with epilepsy as one of the main clinical presentations of the disease. A substantial number of these patients require timely and accurate diagnosis, besides specific treatment to prevent the irreversible outcomes. Materials & Methods In this two-year retrospective study, a total of 128 patients with documented neurometabolic disorders were selected and evaluated in Mofid Children Hospital of Tehran, Iran, using a questionnaire to investigate the prevalence of epilepsy and seizure phenotypes. The collected data were evaluated in SPSS version 23. Results Seizure was reported in 49% (63/128) of the patients. A single episode of seizure occurred in 7 (7%) patients. The prevalence of epilepsy was estimated at 42% (54/128). The most common seizure types were generalized tonic-clonic (43%), tonic (22%), and myoclonic (10%), respectively. Epilepsy was refractory in 30% (16/54) of the patients, and the mean number of administered anti-seizure drugs for refractory cases was 3. 2. Overall, 50% of refractory cases had mixed-type seizures, and 25% had generalized tonic-clonic and myoclonic seizures. Conclusion Neurometabolic disorders are rare, but treatable causes of epilepsy. A considerable number of patients (42%) in the current study presented with epilepsy as a clinical feature of IEM.