journal of Basic Sciences

Since the outbreak of the Syrian crisis in 2011, Syria has witnessed a gradual collapse of state institutions and sovereign functions, leading to a strategic vacuum in the regional security architecture of the Middle East, and creating challenges and opportunities for regional and international actors. In this context, Turkey has emerged as a pivotal actor seeking to reshape geopolitical balances in the Arab world, basing its actions on the logic of political realism, which focuses on maximizing national power and protecting national interests.
This research deals with the Turkish response to the collapse of the Syrian state through the framework of classical realism theory, through a strategic analysis that combines qualitative analysis tools and quantitative indicators. The research focuses on three main axes: Turkey's military interventions in northern Syria, its policies towards the Syrian refugee file, and the diplomatic and security tracks adopted by Ankara to strengthen its regional influence and contain threats. The results indicate that Turkey has pursued a multidimensional foreign policy that combines military deterrence, diplomatic action, and geographic repositioning, in line with its strategic priorities.
The analysis also shows that Turkish behavior has been clearly influenced by the principles of realpolitik, by focusing on maintaining regional balance, containing transnational armed organizations, and dealing with challenges arising from adverse regional expansions. In doing so, Turkey seems to have used the Syrian crisis as an opportunity to re-engineer its regional role in accordance with its supreme national interests

This research examines a poetic figure from the Umayyad era in Khorasan, who held a prominent position during her time, due to her political role with members of her Bakri tribe. He was a representative of the Bakr tribe to the rulers of his time.
The study aims to reveal the musical formation in his poetry by examining the external and internal music and explaining his most important uses of meters, rhyme, and musical phenomena in a study that came in two sections: the first came to define the poet’s life, his collection of poems, and his poetry, and the second included explaining the external and internal music in his poetry.

The aim of the current research was to measure the effectiveness of a blended learning-based training program designed to equip student teachers in the Department of Islamic Education – College of Basic Education with teaching skills. The study employed the descriptive approach during the construction of the program and utilized the experimental approach for its implementation. The research tool consisted of a teaching skills observation checklist. The research population included fourth-year student teachers, and the sample comprised 46 participants. The findings revealed statistically significant differences between the mean scores of the sample’s performance on the teaching skills observation checklist—specifically in planning, implementation, and assessment—before and after participating in the training program, with the post-test scores being significantly higher. In light of these findings, the researcher presented several recommendations, most notably: benefiting from the current study’s list of the three teaching skills when evaluating in-service teachers, and reconsidering the development of professional staff in light of these skills. Based on the results and recommendations, the researcher also proposed several further studies to be conducted on student teachers to complement the current research topic

This research dealt with another aspect of dreams, in which we draw our world, aspirations and hopes as we wish. It became clear that daydreams have many motives that this summary cannot mention in detail. The research also revealed the lofty status of fertile imagination and explained to the reader the terminological meanings of daydreams. Then it detailed the analysis of the poems of our three poets that talk about the subject of daydreams, starting with the oldest and then the oldest. The research concluded by making fair and just comparisons between our three poets, which showed us the sources of captivating beauty and demonstrated the unique places of creativity in their poems, and pointed out the virtuous and the inferior after looking with an eye of objective criticism, justice and fairness.

The current research aims to identify health beliefs among educational counselors, the significance of differences in health beliefs according to the gender variable (males - females), the health behavior of educational counselors, and the significance of differences in health behavior according to the gender variable (males - females), and to reveal the correlation between health beliefs and health behavior among educational counselors. The research community consisted of (384) One of the educational counselors working in the schools of Kut city center, and the research sample was selected, numbering (200) individuals, with (100) individuals for each of the males and females. The researcher adopted the health behavior scale of (Al-Samadi and Al-Samadi, 2011), which consists of (52) paragraphs, and built a scale to identify the health beliefs of the research sample, which consists of (21) paragraphs, and the psychometric properties of the two scales were extracted. He extracted the apparent validity of the two scales after presenting them to a group of specialists in educational and psychological sciences, and also verified the indicators of construct validity of the two scales, and extracted the stability using the methods (test-retest, and Cronbach's alpha), and then the data were analyzed statistically using the Statistical Package for Social Sciences (SPSS) and the results showed the following:
1.Educational counselors had a good level of health beliefs.
2.There were statistically significant differences in health beliefs according to the gender variable, in favor of females.
3.Educational counselors had a good level of health behavior.
4.There were statistically significant differences in health behavior according to the gender variable, in favor of females.
5.There was a significant positive correlation between the two research variables, health beliefs and health behavior.
In light of these results, the researcher reached a set of conclusions and presented several recommendations and proposals.

The history of the Islamic state witnessed the emergence of a number of cities outside the borders of the Arabian Peninsula. These cities have received great attention from historians in general, and from Muslim geographers and travelers in particular. Among these prominent cities is the city of Basra, which was founded by Utbah ibn Ghazwan al-Mazini in the year 14 AH/635 AD. This research deals with the study of the city of Basra as it appears in the book “Surat al-Ard” by the geographer Ibn Hawqal al-Baghdadi.
The research is divided into two main sections: The first is devoted to introducing Ibn Hawqal and his book “Surat al-Ard”, in which we discussed various aspects of his life, including his lineage, date of birth, and travels, in addition to his method of writing and his political leanings. The second section is entitled: Conditions of Basra through the book “Surat al-Ard”, in which we focused on tracing the historical dimension of the city of Basra across different time periods, highlighting the importance of its water resources, describing its landmarks, and other matters that Ibn Hawqal touched upon in his book.

Research Objective:
1.The research aims to determine the effectiveness of the flipped learning strategy in enhancing achievement and critical thinking among second-grade middle school students in science,by testing the null hypothesis:
1.There are no statistically significant differences at the (0,05) level between the mean achievement scores of the experimental and control groups who studied using the flipped learning strategy the mean scores of the control group who learned the same material through traditional methods.
2.Research population,sample,and results:
The research population consisted of all second-grade middle school students at Sh.Mohand school,totaling (52) students,who were purposefully selected.
The research sample was randomly chosen,selecting two classes (A,B) to represent the experimental and control groups,with each group consisting of (26) students,making a total of (52) students.
The sample members were matched on several variables:
Chronological age,previous achievement,intelligence level,and overall average from the previous year.
The experiment was conducted in the first semester of the 2024/2025 academic year.
Key Findings:
1.No statistically significant difference was found in the achievement test in favor of the experimental group that studied using the flipped learning strategy.

The current research aims to identify the moral elevation among kindergarten teachers, and to identify the statistical differences between two groups of kindergarten teachers according to years of experience in moral elevation. The research relied on the descriptive approach, and the current research sample consisted of (120) kindergarten teachers. In order to achieve the research objectives, the researcher built a scale (moral elevation) from three areas, each area (10) paragraphs, with a total of (40) paragraphs for the entire scale, and applied it to kindergarten teachers affiliated with the Aziziyah Education Directorate in Wasit Governorate.
The study concluded that the level of moral elevation among kindergarten teachers is available among kindergarten teachers at a statistically significant level (0.05, 0) in favor of the research sample, and this may be justified by the kindergarten teachers' possession of a high sense of humanity, helping others, and respecting different points of view. There are also statistically significant differences at a significance level (0.05) in favor of the sample of years of service from (15-25) years in moral elevation among kindergarten teachers according to years of experience. This is due to the long years of experience in which the teacher practiced the job, which made her gain experience in dealing with this age group. The researcher suggested conducting other studies in the field of moral elevation and its relationship to other variables and for different age groups and academic specializations

This research aims to examine the effectiveness of the Gradual Difficulty Strategy in the Achievement of Teaching Methods among Students of the College of Education for Humanities. To achieve this, the researcher formulated the null hypothesis, which states that there is no statistically significant difference at the 0.05 significance level between the mean scores of the experimental group students who study the teaching methods according to the gradual difficulty strategy and the mean scores of the control group students who study the same subject according to the traditional method of the achievement test. The sample size consisted of 105 students, with 50 students in the experimental group and 55 students in the control group for the academic year (2023-2024) of the first course. The researcher prepared a test for an achievement consisting of 40 items, and its validity and reliability were verified. The scale was then applied to the research sample. After analgising the data statistically, the results showed a statistically significant difference in the average scores of the achievement in favour of the experimental group.

It was natural for the Christian entity to be influenced by the cultural heritage in general, and the prevailing culture in particular, and that it had an impact on the form of cultural life at that time, because Christians had long lived in Muslim countries and mixed with their people, and were influenced by them, and influenced them, as human nature imposed on them to fight sometimes, and to reconcile sometimes, and in times of peace, cultural interaction between them took place on a wide scale, and the nature of its division required an introduction and a preface, and five axes, the first axis dealt with: cultural interaction between Muslims and Christians in language, while the second axis dealt with: transferring Arabic sciences to Western Europe, and the third axis discussed: documenting history and other sciences, while the fourth axis discussed: scientific and religious dialogues, and the fifth axis we devoted to studying the influence of Christians by Muslim customs and traditions.

The family is one of the most powerful educational and social institutions that influence the formation of the child’s personality and modifying his behavior, as he learns from it many sound moral, social and religious values, in addition to adhering to customs and traditions that help him face the stressful events of life and solve its difficult problems and deal with them with objectivity, accuracy and realism. The family is the one that provides its children with security and warmth and provides them with continuous support, clarifies roles for them and defines responsibilities and forms of control and the system of life.
University students differ from each other according to their gender, specialization, and cultures. This difference is usually due to the diversity of their family environments to which they belong. The family also plays a major role in the progress of its children in the university stage towards academic success. However, at the same time, the student may suffer from academic boredom if the family does not contribute by providing him with an emotional and psychological climate to help him read, understand, and comprehend. Among these are the students of the kindergarten department.
School boredom is one of the most widespread educational problems among kindergarten students, and the most severe. This problem is evident in that it results in several negative effects, including the emergence of deviant behaviors and dangerous psychological and social problems, which appear in the form of a lack of desire to follow lessons and the emergence of some inappropriate behaviors such as aggression, anger, disturbing other students, lack of communication with them, a decline in the performance of tasks and work, and experiencing negative emotional states such as despair, anxiety, dissatisfaction with life, and a feeling of psychological loneliness.
In order to achieve this, the researcher set the following objectives:
1-The family climate among kindergarten students.
2-Academic boredom among kindergarten students.
3- The relationship between the family climate and academic boredom among kindergarten students.
In order to achieve the research objectives, the researcher constructed two scales, the first is the (family climate) scale, which consists of (25) items, and the (school boredom) scale, which consists of (22) items. Then, the validity and reliability coefficients were extracted for both scales, and then the scale paragraphs were distributed to a sample of (300) female students from the kindergarten department who were selected using a simple random method. After applying the scale paragraphs to the research sample, and when analyzing the sample’s answers to the scale paragraphs, the research results showed the following:
1-The research sample has a high level of family climate.
2-The research sample does not suffer from a high level of academic boredom.
3-There is a strong positive relationship between the level of family climate and academic boredom among kindergarten students.

The research addressed an important issue within the framework of Quranic sciences, which is a source of trial for Muslims in their daily.worship and prayers
When performing these prayers, they read the Qur’an, and it is the duty of every Muslim to read the Qur’an correctly and without .mistakes
They rely on the Quranic readings that have reached them through the narrators of those readings. In the Islamic countries, especially the Islamic East, we have The reading of Asim bin Abi Al-Najoud Al-Kufi depends on this Asim. If we refer to the books of men and the books of biographies, we find that he is not trustworthy among them How can you take from him the recitation of the Qur’an in our prayers? Therefore, the research dealt with this issue and concluded that the reliability of Asim in narrating the hadith differs from his reliability in the Qur’anic recitations Hence, even though the scholars of hadith said that he was not trustworthy in narrating hadith, he was trustworthy in readings. The research in this was based on several matters that .he mentioned and elaborated on in this study

The current research aims to identify the attitudes of kindergarten teachers towards the use of artificial intelligence in effective teaching in Baghdad, and the study used the descriptive approach. The study sample consisted of (100) teachers were randomly selected, from government kindergartens in Baghdad Governorate, and to achieve the objective of the study, an artificial intelligence questionnaire was built, as the questionnaire included two positive and negative sides, the first field: the attitudes of kindergarten teachers towards the use of artificial intelligence in effective teaching processes, while the negative field The second field is the challenges facing kindergarten teachers towards the use of artificial intelligence. The results of the study showed that there are great trends among kindergarten teachers towards the use of artificial intelligence applications in effective teaching processes in Baghdad Governorate, in addition to the presence of some challenges facing Riyadh teachers such as (high prices of devices, lack of infrastructure readiness, difficulty in providing the Internet), and the results also showed that there are differences between the arithmetic media, but they are statistically significant for the variables of academic achievement (bachelor's - master's) and the type of device (the

Water resources in Basra Governorate are of great exceptional importance. The reason for this is that it is the driest part of Iraq and the difficulty of providing water from other sources. Basra Governorate is located at the end of the river system of Iraq. Therefore, in recent years, it has witnessed a new reality of scarcity of fresh water and its poor quality, in addition to its location within... The hot, dry desert climate. Therefore, the concentration of dissolved oxygen in the water was measured along the northern longitudinal section of the Shatt al-Arab. It became clear that the concentrations of dissolved oxygen in the water of the studied stations witnessed local and seasonal variations, as the percentage of dissolved oxygen decreased in the summer compared to the winter, and that its decrease resulted from The effect of high air temperature, which raises the temperature of the water, and this helps gases leave the water, including dissolved oxygen, as the amount of gases dissolved in the water is inversely proportional to the temperature, as well as the sewage and agricultural waste received by the population. The high concentration of dissolved oxygen in the aquatic environment is evidence of The suitability of that environment for life to live in,

The present research paper aims at Identifying the level of performance of primary school female teachers in light of the criteria of the green teaching.
In order to achieve the above objective, an observation card (research tool) was prepared to measure the performance level of teachers. The card comprised (10) criteria with (36) performance indicators which were measured by class visits.
The research sample consisted of (20) primary school teachers from schools in Baghdad which lie in Second Rusafa Directorate of Education. Ten of these teachers teach science subjects while the other ten teach social sciences (geography).
Research results showed that the research sample lacks practices for green teaching indicators of the research tool (observation card) as a whole and of each criterion individually. The only exception were the fifth criterion (change towards the green school) as well as the seventh (the green citizenship) and the ninth (the sustainable development) where each was realised as (medium) , rather than (weak).
The results also showed differences between the indicator of relative performance of the science teachers, with a realisation degree of (medium) , and that of relative performance indicator of social sciences teachers of a realisation of a (low) degree. These differences are however not statistically significant.
The two researchers put forward recommendations based on their research results, among which are the following:
- paying due attention to curricula, textbooks and cultural programmes in primary schools by including issues like the environments and sustainable deveopments which are socially and economically important.
- Planning and preparing for changes towards green schools.

The study aimed to identify organizational intelligence and its relationship to administrative motivation among secondary school principals as well as the relationship between them. The researcher adopted the descriptive approach, and the study sample consisted of (200) principals. To achieve the research objectives, the researcher built a scale (organizational intelligence), and adopted the (Radwan 2017) scale for administrative motivation after verifying its psychometric properties and adapting them to the Iraqi environment. The results showed that secondary school principals possess organizational intelligence. Secondary school principals are also characterized by administrative motivation. In addition to the existence of a positive and direct relationship between organizational intelligence and administrative motivation. The study came out with a number of recommendations and proposals

This study aims to estimate the water footprint of Kut City, the capital of Wasit Governorate, using the direct water footprint methodology, which is an analytical tool for measuring the amount of water used in various human activities. The model was applied to the residential sector, focusing on surface water sources, which supply the treatment plants that provide water to households. This was done to calculate the amount of water consumed, determine water loss, and analyze their impact on the water footprint of the city's population, comparing it with global water consumption standards.
The study relied on a review of relevant literature, official data on water consumption for the year 2024, as well as results from a field survey, which were analyzed using mathematical methods and statistical software. The results revealed a significant increase in the water footprint of Kut City's residents, which reached (1,691 liters/person/day), a level much higher than the allocated amount set by the Wasit Water Directorate (240 liters/person/day), as well as the global standard set by the World Health Organization (100-200 liters/person/day), indicating excessive water consumption in domestic uses.
The study also revealed a high percentage of water loss before it reaches the final consumer, estimated at 25%, due to technical faults, inadequate maintenance, and lack of oversight on distribution networks. Based on these findings, the study recommends adopting integrated water resource management strategies and raising community awareness about the importance of water conservation, especially in light of rapid climate changes and increasing population pressures.

The poet’s speech differed in terms of intentional and communication from the prose discourse; Because prose discourse is based on well -known communication tools, in terms of speaker, addressee and purpose, it is closer to the use of verbal verbs in the deliberations of social intentions at all levels, as they are less displaced than poetic discourse, and this made the study of poetic text more difficult than prose texts; This is due to the attachment of the speaker-the poet-and the use of words that are based on interpretation in many aspects; Because poetry is creative, its intention lies in the displacement of the language, as this aspiration makes the literary text multiple possibilities when studying it, the context in the daily discourse on its various ranks is closer to reality than it to imagination, to achieve the achievement purpose for which this or that discourse was created, and the study was applied to a poet The old is represented in his spirit, and the new in many aspects of his language and its uses, and he is the poet King Suleiman bin Suleiman Al -Nabhani.

Interpretation by morphological semantics is the clarification of the meaning of morphological semantics and the study of the meanings conveyed by words through their morphological structure. It addresses how letters and morphological formations affect the meanings of words. It also studies the meanings acquired by words through their morphological structure, such as root, weight, augmentation, and doubling. Its importance in language plays a significant role in understanding the Arabic language and helps in understanding the subtle meanings of words, analyzing the linguistic structure of texts, and interpreting meanings in different contexts more deeply.
I have divided this topic into three sections:
The first section: Interpretation of verbs, including: A. Simple verbs
B. Interpretation of augmented verbs, including: augmented with one letter, augmented with two letters, and augmented with three letters
The second section includes:
First: Interpretation of nouns
Second: Interpretation of derivatives, including the form fa'il (fa'il) meaning fa'il, the form fa'ul (fa'il) meaning fa'il, the form fa'ul (fa'il) for exaggeration, the form fa'il (fa'il) meaning maf'ul, and the form fa'al (fa'al) for exaggeration.
The third section, interpretation by morphological semantics, includes the istaf'ala form, the af'al form of the comparative, the fa'lan form, and the maf'ala form. This form plays a semantic role in Abu Zahra's book, Zahrat al-Tafasir (The Flower of Interpretations). This aspect was not overlooked by Abu Zahra in his interpretation of the vocabulary of the Holy Quran. He relied on morphological semantics to explain a single meaning that may have more than one connotation, clarify its other connotations, accurately understand its meanings, and analyze the linguistic structure. This semantics helps in interpreting meanings in the Quranic context. Morphological semantics enhances their ability to interpret Quranic words and sentences.

The current research aimed to know the effect of the conscious understanding guidance method in reducing sadness among orphan students, by verifying the hypotheses used in the current research using the experimental method. The research sample consisted of (16) students from Al-Mukhtar Intermediate School for Boys affiliated with Wasit Education Directorate / Azizia Education Department. They were randomly distributed into two equal groups, an experimental group and a control group. The researcher used the sadness scale that was built in the current research and consisted of (20) paragraphs. The psychometric properties of the scale were extracted. The number of sessions for the program was (12) sessions, with a session duration of (45) minutes for a period of (4) weeks, at a rate of (3) sessions per week. The research results showed the effect of the conscious understanding guidance method in reducing sadness among orphan students. In light of this, the researcher presented a set of recommendations and suggestions .

This study aimed to measure the emotional maturity of university students, and compare it according to the variables of gender and specialization among university students.To achieve the research objectives, the researcher used the descriptive research method, then reviewed previous studies and literature.The researcher adopted the scale prepared by (Al-Kubaisi, 2005), which It consists of (32) paragraphs, and extracted all the standard characteristics of the scale through apparent validity and reliability, He applied it to the research sample of (80) male and female students, using a random stratified method with equal selection from morning preliminary studies students from the College of Pharmacy and the College of Administration and Economics at the University of Baghdad for the academic year (2023 – 2024) and after processing the data statistically, the researcher reached several results.Including:-
Poor emotional maturity among university students. Because of the wars and conditions that Iraq has been subjected to and is still going through to this day, as well as the poor economic conditions, which left a negative impact on the emotional maturity of individuals and their mental health, and also found that males do not differ from females in emotional maturity due to psychological, economic and poor living pressures. In light of the results of this research, the researcher recommended including some curricula at the university level that would help develop the emotional maturity of students and enhance their optimism and hope for the future. And many scientific and social conferences and trips to alleviate the problems and emotions facing students at this stage. Intensifying counseling sessions and group counseling for students with emotional stress and those suffering from psychological pressure.

The religious factor is one of the important factors that play a significant role in population growth, especially in areas where there are religious symbols and landmarks where certain worship and rituals are practiced that contribute to increasing population attraction towards them. It is clear that some areas that grew and developed had their beginnings due to religious reasons, as is known in the Kingdom of Saudi Arabia, such as (Makkah Al-Mukarramah and Medina Al-Munawwarah) , (Al-Quds Al-Sharif) in the State of Palestine, (Najaf Al-Ashraf, Karbala Al-Muqaddas and Al-Rawdah Al-Kadhimiya) in Iraq and other cities. These places have become areas of population attraction, which contributes to the development of other sectors related to population growth, such as urban growth and the expansion of cities with their various activities, such as educational, health, commercial and entertainment services. The research focused on the shrine of the great Sayyid Taj Al-Din (may God be pleased with him) in the Taj Al-Din district as a model of the impact of tourism on urban development in that geographical area.

Using humor in many different semiotic genres has gained popularity in various contexts. The effects and roles of humor have been largely studied by the scholarly mind. This paper therefore attempts to look into what the outcomes are of using humor in different semiotic genres particularly in advertisements within the Iraqi EFL context. A sample of 150 EFL students from Iraq has therefore been selected to take part in the study. They have been piloted with a smaller group of participants. A questionnaire, data collection instrument along with a pre-test, were used to gather information for this study. The theoretical framework for this study was fashioned based on an inquiry into the levels at which the use of humor permeated the genres under investigation. Results of mean scores obtained from participants showed that humor had been widely been employed in advertisements. It was also indicated that offensive language was seen more use in advertisements.

A simple, accurate, and sensitive spectrophotometric determination of nitrite in meat samples has been suggested. The main reaction for the suggested determination was occupied of nitrite ions in the diazotization of sulphacetamide in an acidic medium to produce the diazonium salt which immediately coupled with resorcinol reagent to produce a soluble and stable colored azo dye has maximum absorption at 494 nm. The present method is suitable for the estimation of nitrite ion from 2.5 to 75 µg/25ml. The molar absorptivity and Sandell sensitivity of the formed azo dye are 2.392 x 104 l. mol.-1 cm-1 and 0.00192 µg.cm-2, respectively. The method has been applied to estimate nitrite in various meat samples and the results obtained are satisfactory(with the range of analytical errors). The results of the applied standard addition method in the estimation of nitrite in various meat samples indicated that the present method is free from interferences of the additives added to packaged meat cans and preservatives.

This study investigates how the rotation of peristaltic flow of nonlinear thermal radiation affects hybrid nanomaterials that are passed via a porous medium within a conduit. This process takes place while applying a magnetic field in an inclined tapered canal and thinking about the impact of the magnetohydrodynamic (MHD) field. The governing equation is examined through the application of long-wavelength assumptions and low Reynolds approximations. We carried out an analytical investigation using the Mathematica (11.3) software. The graphs illustrate the phenomenon of trapping circular bubbles in relation to flow lines, velocity, temperature, and pressure gradient. Hybrid nanomaterial nanoparticles are also employed for their impacts. Water serves as the base liquid, while the nanoparticles consist of polystyrene and graphene oxide. The findings demonstrate that velocity rises with an increase in fluid rotation Ω, whereas the pressure gradient diminishes. The temperature rises with an increase in the heat absorption parameter β , whereas it declines with an increase in the thermal slip parameter γ

N-acetyl-5-methoxy tryptamine, the basic chemical that makes up melatonin, is a hormone that regulates the circadian cycle. Naturally, the human body produces melatonin. Melatonin production rises in the evening, resulting in a state of wakefulness during the day and sleep at night. In addition to interacting with melatonin receptors (MT1 and MT2), melatonin is a potent antioxidant and plays a part in cell cycle regulation. A common chemical found in practically all living things, including bacteria and humans, is melatonin. In vertebrates, melatonin is centrally generated by the pineal gland, a neuroendocrine organ, in addition to being produced in peripheral tissues and functioning as an autocrine and paracrine signal. Regardless of the species under consideration, the pineal hormone melatonin is always generated at night, and the length of the night has a direct impact on both the production of this hormone and the duration of its secretory events. The primary hormonal systemic integrative activity of melatonin, whose synthesis is closely correlated with the light/dark cycle, is to synchronize physiological and behavioral adaptations to the geophysical day and season. Its daily production regularity, the difference between day and night concentrations, and specially designed modes of action all influence the circadian signal. Melatonin primes the day adaptation responses through prospective effects that will only manifest during the day, when melatonin is not present, and coordinates the night adaptive physiology through immediate effects during its daily secretory episode. The central nervous and endocrine systems are similarly primed for the upcoming seasons by the yearly history of the duration of the daily melatonin secretory event.