Department of Basic Science

We consider preheating in models in which the potential for the inflaton is given by a fractional power, as is the case in axion monodromy inflation. We assume a standard coupling between the inflaton field and a scalar matter field. We find that in spite of the fact that the oscillation of the inflaton about the field value which minimizes the potential is anharmonic, there is nevertheless a parametric resonance instability, and we determine the Floquet exponent which describes this instability as a function of the parameters of the inflaton potential.

We study the preheating of gauge fields in a simple axion monodromy model and compute the induced entropy perturbations and their effect on the curvature fluctuations. We find that the correction to the spectrum of curvature perturbations has a blue spectrum with index ns = 5/2. Hence, these induced modes are harmless for the observed structure of the universe. Since the spectrum is blue, there is the danger of overproduction of primordial black holes. However, we show that the observational constraints are easily satisfied.

We consider reheating in a class of asymptotically safe quantum field theories recently studied in [1, 2]. These theories allow for an inflationary phase in the very early universe. Inflation ends with a period of reheating. Since the models contain many scalar fields which are intrinsically coupled to the inflaton there is the possibility of parametric resonance instability in the production of these fields, and the danger that the induced curvature fluctuations will become too large. Here we show that the parametric instability indeed arises, and that hence the energy transfer from the inflaton condensate to fluctuating fields is rapid. Demanding that the curvature fluctuations induced by the parametrically amplified entropy modes do not exceed the upper observational bounds puts a lower bound on the number of fields which the model of Ref. [1, 2] must contain. This bound also depends on the total number of e-foldings of the inflationary phase.

We study particle production at the end of inflation in kinetically driven G-inflation model and show that, in spite of the fact that there are no inflaton oscillations and hence no parametric resonance instabilities, the production of matter particles due to a coupling to the evolving inflaton field can be more efficient than pure gravitational Parker particle production.

The purpose of this study was to investigate changes that occur in pulmonary function when postural changes in the sagittal plane are made in a seated position in students. This cross sectional analytical study was done randomly on 20 boys from Iran, and the results of a forced expiratory manouvre in these young healthy subjects were compared according to body posture. Twenty able-bodied students boys (age 13.5±1.09 yr, height 158.25±5.65 cm and weight, 50.45±7.02 kg), participated in this study. Standard spirometric measurements forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow(PEF) were taken for each subject in each of 3 sitting postures: (normal, slumped and kyphotic) and standing posture. A repeated measure ANOVA and a paired t test indicated that FVC and FEV1 value in standing posture was significantly higher than other sitting postures. In slumped sitting, FVC, FEV1 and PEF significantly decreased from other sitting posture. But there was no significant difference for FVC, PEF and FEV1 between the normal and kyphotic sitting postures. The results showed that FVC, FEV1 and PEF as importance index in health of pulmonary system function, was affected by sitting posture, particularly in slumped sitting posture. Also student should prevent slumped sitting posture.

Abstract
Purpose: The aim of this study was to determine cranial & facial anthropometric Ratios and
assessment of cranial & facial development in Shirvanian kurmanj population
Materials and Methods: This cross sectional analytical study was conducted randomly on 137
boys from shirvan, with normal face patterns. Facial and cranial ratios was estimated and compared.
Data were analyzed by SPSS software. The regression line and the growth coefficient were
determined for each Parameter. Finally, the mean values of these parameters were determined.
Furthermore, the mean anthropometric measurement of Iranians was compared with Canadians.
Student-t test was used for comparing the measured values.
Results:Shirvanian kurmanj populations were have hypereuryprosopic Face and hypercephalic
Cranium form. While getting older, peoples midface height increases, face becomes more
prominent, chin becomes shorter and Face and Cranium change to Eurycephalic and
hyperleptoprosopic form respectively.
Conclusion: Approximately, all of the anthropometric measurements in Shirvanian kurmanj
population, Fars race (Resident in Mashhad) and Canadians were significantly different.
Considerable the differences in the facial and cranial anthropologic ratios and size among
Shirvanian kurmanj population, Fars race (Resident in Mashhad) and Canadians, the results
obtained from Canadian and Fars race, should not be applied as criteria for treatment plans. Due to
the wide racial combinations in Iran, studies, covering wider scope, should be conducted among
different Iranian races.

Developmental biology such as human reproduction and development are scattered throughout the Qur'an. It is only recently that the scientific meaning of some of these verses has been appreciated fully. The long delay in interpreting these verses correctly resulted mainly from inaccurate translations
and commentaries and from a lack of awareness of scientific knowledge. In the Holy Quran, God speaks about the stages of man's embryonic development. Modern embryology is a fairly recent development which has its beginning with the invention of microscope in the 17th century. However, the concept of
the human being developing in stages was not recognized until much later. But the scientists then and most Muslim and non-Muslim scholars do not even know that the Holy Quran and Sunnah [words, deeds, approvals of Prophet Muhammad (PBUH) collected by authentic narrators] had provided a
detailed description of the significant events in human development from the stages of gametes and conception until the full term pregnancy and delivery or even post partum. Actually, information in the Quran and Hadith corrected many superstitious and vague ideas about human development that were prevalent before. This article highlights different stages of formation of the human embryo along with the description of every stage of the embryonic development as mentioned in the Quran.

Abstract
Purpose: The purpose of this study is to present a cranifacial growth model using anthropometry based on changes observed in the human face.
Materials and Methods: This cross sectional analytical study was conducted randomly on 45 pepole, with normal face patterns. Facial and cranial ratios were measured and compared. Data was analyzed by SPSS software. The regression line and the growth coefficient were determined for
each Parameter. Finally, the mean values of these parameters were determined. Facial growth pattern was drawn on the basis of on the growth parameters. A anthropometric ratios were obtained on the basis of facial landmark.
Results: This research presents cranifacial growth model for young faces (2-18-years-old) using anthropometry based on changes observed in the human face that can be used as a method for growth parameters calculation. This model can also predict tailored face changes with the lapse of time.
Conclusion: This model can be used for face recognition as well, on the other hand the results of this research can be used in medical professions such as maxillofacial surgery, growth and
development studies, plastic surgery, bioengineering and non-medical fields such as shoe-making and eye glasses industries.