scholarly journals Investigation of melt distribution reactions, thermobarometry and minerals chemistry of amphibols and plagioclase leucosome, melanosome and mesosome in Takab Hornblend bearing migmatites, northwestern Iran

2020 ◽  
Vol 28 (3) ◽  
pp. 735-750
Author(s):  
هاله Ghorbani ◽  
رباب Hajialioghli ◽  
محسن Moazzen ◽  
◽  
◽  
...  
Keyword(s):  
Melt Distribution ◽  
Northwestern Iran

Quantification of excess 231Pa in late Quaternary igneous baddeleyite

2020 ◽  
Vol 105 (12) ◽  
pp. 1830-1840 ◽  
Author(s):  
Yi Sun ◽  
Axel K. Schmitt ◽  
Lucia Pappalardo ◽  
Massimo Russo
Keyword(s):  
Late Quaternary ◽  
Central Italy ◽  
Direct Analysis ◽  
Weight Percent ◽  
Volcanic Field ◽  
Distribution Coefficients ◽  
Secular Equilibrium ◽  
Melt Distribution ◽  
D Values ◽  
Significant Figures

Abstract Initial excess protactinium (231Pa) is a frequently suspected source of discordance in baddeleyite (ZrO2) geochronology, which limits accurate U/Pb dating, but such excesses have never been directly demonstrated. In this study, Pa incorporation in late Holocene baddeleyite from Somma-Vesuvius (Campanian Volcanic Province, central Italy) and Laacher See (East Eifel Volcanic Field, western Germany) was quantified by U-Th-Pa measurements using a large-geometry ion microprobe. Baddeleyite crystals isolated from subvolcanic syenites have average U concentrations of ~200 ppm and are largely stoichiometric with minor abundances of Nb, Hf, Ti, and Fe up to a few weight percent. Measured (231Pa)/(235U) activity ratios are significantly above the secular equilibrium value of unity and range from 3.4(8) to 14.9(2.6) in Vesuvius baddeleyite and from 3.6(9) to 8.9(1.4) in Laacher See baddeleyite (values within parentheses represent uncertainties in the last significant figures reported as 1σ throughout the text). Crystallization ages of 5.12(56) ka (Vesuvius; MSWD = 0.96, n = 12) and 15.6(2.0) ka (Laacher See; MSWD = 0.91, n = 10) were obtained from (230Th)/(238U) disequilibria for the same crystals, which are close to the respective eruption ages. Applying a corresponding age correction indicates average initial (231Pa)/(235U)0 of 8.8(1.0) (Vesuvius) and 7.9(5) (Laacher See). For reasonable melt activities, model baddeleyite-melt distribution coefficients of DPa/DU = 5.8(2) and 4.1(2) are obtained for Vesuvius and Laacher See, respectively. Speciation-dependent (Pa4+ vs. Pa5+) partitioning coefficients (D values) from crystal lattice strain models for tetra- and pentavalent proxy ions significantly exceed DPa/DU inferred from direct analysis of 231Pa for Pa5+. This is consistent with predominantly reduced Pa4+ in the melt, for which D values similar to U4+ are expected. Contrary to common assumptions, baddeleyite-crystallizing melts from Vesuvius and Laacher See appear to be dominated by Pa4+ rather than Pa5+. An initial disequilibrium correction for baddeleyite geochronology using DPa/DU = 5 ± 1 is recommended for oxidized phonolitic melt compositions.

A comparison of asthma prevalence in adolescents living in urban and semi-urban areas in northwestern Iran

2021 ◽  
pp. 1-18
Author(s):  
Zahra Sabeti ◽  
Khalil Ansarin ◽  
Ensiyeh Seyedrezazadeh ◽  
Mohammad Asghari Jafarabadi ◽  
Venus Zafari ◽  
...  
Keyword(s):  
Urban Areas ◽  
Asthma Prevalence ◽  
Northwestern Iran

scholarly journals Lake Neor reveals how mountain vegetation responded to 7000 years of hydroclimate variability in northwestern Iran

2021 ◽  
Author(s):  
Khadijeh Alinezhad ◽  
Elias Ramezani ◽  
Morteza Djamali ◽  
Arash Sharifi ◽  
Alireza Naqinezhad ◽  
...  
Keyword(s):  
Hydroclimate Variability ◽  
Northwestern Iran ◽  
Mountain Vegetation

scholarly journals Mineralogy, mineral chemistry and thermobarometry of post-mineralization dykes of the Sungun Cu–Mo porphyry deposit (Northwest Iran)

2020 ◽  
Vol 12 (1) ◽  
pp. 764-790
Author(s):  
Amin Allah Kamali ◽  
Mohsen Moayyed ◽  
Nasir Amel ◽  
Fadaeian Mohammad ◽  
Marco Brenna ◽  
...  
Keyword(s):  
Active Continental Margin ◽  
Mineral Chemistry ◽  
Quartz Diorite ◽  
Alkaline Magmatism ◽  
Porphyry Deposit ◽  
Average Percentage ◽  
The North ◽  
Northwestern Iran ◽  
Subduction System ◽  
Late Stages

AbstractThe Sungun copper–molybdenum porphyry deposit is located in the north of Varzaghan, northwestern Iran. The Sungun quartz-monzonite is the oldest mineralized intrusive body in the region and was emplaced during the Early Miocene. Eight categories of the late and unmineralized dykes, which include quartz diorite, gabbrodiorite, diorite, dacite, microdiorite and lamprophyre (LAM), intrude the ore deposit. The main mineral phases in the dykes include plagioclase, amphibole and biotite, with minor quartz and apatite and secondary chlorite, epidote, muscovite and sericite. The composition of plagioclase in the quartz diorite dykes (DK1a, DK1b and DK1c) varies from albite-oligoclase to andesine and oligoclase to andesine; in the diorite, it varies from andesine to labradorite; in the LAM, from albite to oligoclase; and in the microdiorite (MDI), it occurs as albite. Amphibole compositions are consistent with classification as hornblende or calcic amphibole. Based on their AlIV value (less than 1.5), amphibole compositions are consistent with an active continental margin affinity. The average percentage of pistacite (Ps) in epidotes formed from alteration of plagioclase and ferromagnesian minerals is 27–23% and 25–30%, respectively. Thermobarometric studies based on amphibole and biotite indicate approximate dyke crystallization temperature of 850–750℃, pressure of 231–336 MPa and high fO2 (>nickel-nickel-oxide buffer). The range of mineral compositions in the postmineralization dyke suite is consistent with a genetic relationship with the subduction of the Neotethys oceanic crust beneath the continental crust of the northwest part of the Central Iranian Structural Zone. Despite the change from calc-alkaline to alkaline magmatism, the dykes are likely related to the late stages of magmatic activity in the subduction system that also generated the porphyry deposit.

scholarly journals Epidemiological characteristics and mortality risk factors among COVID-19 patients in Ardabil, Northwest of Iran

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Davoud Adham ◽  
Shahram Habibzadeh ◽  
Hassan Ghobadi ◽  
Shabnam Asghari Jajin ◽  
Abbas Abbasi-Ghahramanloo ◽  
...  
Keyword(s):  
Clinical Presentation ◽  
Multiple Model ◽  
Shortness Of Breath ◽  
Imaging Data ◽  
Demographic Information ◽  
Runny Nose ◽  
Data Registration ◽  
Northwestern Iran ◽  
Northwest Of Iran ◽  
Epidemiological Characteristics

Abstract Background Coronavirus disease highly contagious, is prevalent in all age and sex groups infecting the respiratory system. The present study seeks to investigate the epidemiology and effective factors in mortality of patients with COVID-19 in Ardabil province, northwestern Iran. Methods In a retrospective study, the hospitalized patients with laboratory-diagnosed COVID-19 between February to August 2020 were enrolled. The data registration portal was designated according to Iranian Ministry of Health and Medical Education guidelines. In this portal, demographic information, clinical presentation, laboratory and imaging data were registered for patients in all hospitals in the same format. The Hosmer-Lemeshow strategy was used for variable selection in a multiple model. Results Of the patients involved 2812(50.3%) were male and 150 (2.7%) had contact with a confirmed case of COVID-19 in the last 14 days. Pre-existing comorbidity was reported in 1310 (23.4%) patients. Of all patients, 477(8.5%) died due to COVID-19. the result of the multiple logistic regression model indicated that after adjusting for other factors, higher age (OR = 3.11), fever or chills (OR = 1.61), shortness of breath (OR = 1.82), fatigue (OR = 0.71), headache (OR = 0.64), runny nose (OR = 1.54), Skeletal muscle pain (OR = 1.53), hospitalization (OR = 5.66), and hospitalization in ICU (OR = 5.12) were associated with death. Conclusions Hospitalization had the strongest effect on mortality followed by hospitalization in ICU, and higher age. This study showed that having some extra-pulmonary symptoms in contrast with pulmonary symptoms can predict as good prognostic factors.

ASSESSMENT AND MONITORING OF NATURAL ATMOSPHERIC HAZARDS (HEAVY RAINFALL) IN THE CITIES OF NORTHWESTERN IRAN USING SATELLITE DATA

2021 ◽  
Vol 16 (2) ◽  
pp. 423-436
Author(s):  
Leila ABDOLALIZADEH ◽  
◽  
Ahmad FATAHI ◽  
Mostafa DASTORANI ◽  
Vahid SAFARIAN ◽  
...  
Keyword(s):  
Satellite Data ◽  
Heavy Rainfall ◽  
Assessment And Monitoring ◽  
Northwestern Iran

Association study of rs17782313 polymorphism near MC4R gene with obesity/overweight, BMI, and hedonic hunger among women from Northwestern Iran

2021 ◽  
pp. 1-12
Author(s):  
Mahan Narjabadifam ◽  
Morteza Bonyadi ◽  
Seyed Abbas Rafat ◽  
Reza Mahdavi ◽  
Fereshteh Aliasghari
Keyword(s):  
Medical Condition ◽  
Sequencing Data ◽  
Mc4r Gene ◽  
Melanocortin 4 Receptor ◽  
Group Methods ◽  
Pcr Rflp ◽  
Hedonic Hunger ◽  
Hardy Weinberg Equilibrium ◽  
Northwestern Iran ◽  
Different Populations

BACKGROUND: Obesity, as a medical condition, results from interactions between environmental and genetic factors. The rs17782313 polymorphism, located 188kb downstream of the Melanocortin 4 Receptor (MC4R) gene, is one of the essential candidate genetic markers that has shown the highest association with obesity in different populations. OBJECTIVE: This study aimed to investigate the possible associations of rs17782313 polymorphism near the MC4R gene with obesity/overweight, body mass index (BMI), and hedonic hunger among women from the Iranian Azeri ethnic group. METHODS: Five hundred sixty-three women, composed of 396 patients with obesity/overweight and 167 unrelated healthy controls, were genotyped for the rs17782313 polymorphism by applying the polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) method. RESULTS: This population was in Hardy-Weinberg equilibrium (P = 0.878). The study confirmed a significant association of rs17782313 with obesity, where subjects carrying the C/C genotype had higher odds of obesity (OR = 2.681, P = 0.005, 95%CI:1.340–5.365). Also, C allele carriers have statistically significantly higher BMI scores than those carrying the T allele (P = 0.029). However, no significant associations were found among PFS scores and genotypic/allelic groups of rs17782313 polymorphism (P = 0.368). CONCLUSIONS: Our findings suggest that rs17782313 polymorphism is strongly associated with obesity and BMI but not with hedonic hunger among Northwest Iran women. Moreover, the sequencing data analysis in several homozygous and heterozygous carriers of the C allele led to identifying a novel frameshift variant with TCT deletion (rs534212081) in the 166 upstream of rs17782313, which has not been reported so far.

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