Circadian rhythm and light

قَالَ مُوسَىٰٓ أَتَقُولُونَ لِلۡحَقِّ لَمَّا جَآءَكُمۡۖ أَسِحۡرٌ هَٰذَا وَلَا يُفۡلِحُ ٱلسَّٰحِرُونَ

Moses said, ‘Is this what you say about the Truth when it comes to you? Is this sorcery? Sorcerers never prosper.’

فَلَمَّا جَآءَ ٱلسَّحَرَةُ قَالَ لَهُم مُّوسَىٰٓ أَلۡقُواْ مَآ أَنتُم مُّلۡقُونَ

When the sorcerers came, Moses said to them, ‘Throw down whatever you have.’

فَلَمَّآ أَلۡقَوۡاْ قَالَ مُوسَىٰ مَا جِئۡتُم بِهِ ٱلسِّحۡرُۖ إِنَّ ٱللَّهَ سَيُبۡطِلُهُۥٓ إِنَّ ٱللَّهَ لَا يُصۡلِحُ عَمَلَ ٱلۡمُفۡسِدِينَ

When they did so, Moses said, ‘Everything you have brought is sorcery and God will show it to be false. God does not make the work of mischief-makers right

وَٱتَّبَعُواْ مَا تَتۡلُواْ ٱلشَّيَٰطِينُ عَلَىٰ مُلۡكِ سُلَيۡمَٰنَۖ وَمَا كَفَرَ سُلَيۡمَٰنُ وَلَٰكِنَّ ٱلشَّيَٰطِينَ كَفَرُواْ يُعَلِّمُونَ ٱلنَّاسَ ٱلسِّحۡرَ وَمَآ أُنزِلَ عَلَى ٱلۡمَلَكَيۡنِ بِبَابِلَ هَٰرُوتَ وَمَٰرُوتَۚ وَمَا يُعَلِّمَانِ مِنۡ أَحَدٍ حَتَّىٰ يَقُولَآ إِنَّمَا نَحۡنُ فِتۡنَةࣱ فَلَا تَكۡفُرۡۖ فَيَتَعَلَّمُونَ مِنۡهُمَا مَا يُفَرِّقُونَ بِهِۦ بَيۡنَ ٱلۡمَرۡءِ وَزَوۡجِهِۦۚ وَمَا هُم بِضَآرِّينَ بِهِۦ مِنۡ أَحَدٍ إِلَّا بِإِذۡنِ ٱللَّهِۚ وَيَتَعَلَّمُونَ مَا يَضُرُّهُمۡ وَلَا يَنفَعُهُمۡۚ وَلَقَدۡ عَلِمُواْ لَمَنِ ٱشۡتَرَىٰهُ مَا لَهُۥ فِي ٱلۡأٓخِرَةِ مِنۡ خَلَٰقࣲۚ وَلَبِئۡسَ مَا شَرَوۡاْ بِهِۦٓ أَنفُسَهُمۡۚ لَوۡ كَانُواْ يَعۡلَمُونَ

and followed what the evil ones had fabricated about the Kingdom of Solomon instead. Not that Solomon himself was a disbeliever; it was the evil ones who were disbelievers. They taught people witchcraft and what was revealed in Babylon to the two angels Harut and Marut. Yet these two never taught anyone without first warning him, ‘We are sent only to tempt- do not disbelieve.’ From these two, they learned what can cause discord between man and wife, although they harm no one with it except by God’s leave. They learned what harmed them, not what benefited them, knowing full well that whoever gained [this knowledge] would lose any share in the Hereafter. Evil indeed is the [price] for which they sold their souls, if only they knew

وَجَآءَ ٱلسَّحَرَةُ فِرۡعَوۡنَ قَالُوٓاْ إِنَّ لَنَا لَأَجۡرًا إِن كُنَّا نَحۡنُ ٱلۡغَٰلِبِينَ

The sorcerers came to Pharaoh and said, ‘Shall we be rewarded if we win?’

وَأُلۡقِيَ ٱلسَّحَرَةُ سَٰجِدِينَ

The sorcerers fell to their knees

(And follow that which the devils falsely related against the kingdom of Solomon�) [2:102]. Muhammad ibn 'Abd al-'Aziz al-Qantari informed us> Abu'l-Fadl al-Haddadi> Abu Yazid al-Khalidi> Ishaq ibn Ibrahim> Jarir> Husayn ibn 'Abd al-Rahman> 'Imran ibn al-Harith who said: �Once as we were sitting with Ibn 'Abbas when he said: 'The devils used to eavesdrop on heaven. One of them would bring a word of truth from therein, and when he is trusted for telling the truth, he would add to it seventy lies with which he earns the hearts of people. When Solomon came to know about it, he took it and buried it beneath his throne. When he died, a devil stood in the street and said: 'Shall I guide you to Solomon's guarded treasure, the like of which he does not have?' They said: 'Yes, do'. He said: 'It is under his throne; go and unearth it'. They said: 'This is magic'. Different nations then copied it f

And they follow wa’ttaba‘ū is a supplement to nabadha ‘it cast away’ what the devils used to relate during the time of Solomon’s kingdom in the way of sorcery it is said that they the devils buried these books of sorcery underneath his throne when his kingdom was taken from him; it is also said that they used to listen stealthily and add fabrications to what they heard and then pass it on to the priests who would compile it in books; this would be disseminated and rumours spread that the jinn had knowledge of the Unseen. Solomon gathered these books and buried them. When he died the devils showed people where these books were and the latter brought them out and found that they contained sorcery and said ‘Your kingdom was only thanks to what is in here’; they then took to learning them and rejected the Scriptures of their prophets. In order to demonstrate Solomon’s innocence and in repudi

And the sorcerers came to Pharaoh saying ‘Surely a-inna read pronouncing both hamzas or by not pronouncing the second one but inserting an alif between the two in both cases there will be a wage for us if we are the victors?’

And the sorcerers fell down in prostration.

And so the sorcerers came to Fir'awn. They said: "Indeed there will be a (good) reward for us if we are the victors. (113)He said: "Yes, and moreover you will (in that case) be of the nearest (to me). (114) The Magicians convene and change Their Ropes into Snakes before Musa Allah describes the conversation that took place between Fir'awn and the magicians he collected to defeat Musa, peace be upon him. Fir'awn told them that he will reward them and give them tremendous provisions. He made them hope in acquiring what they wished for and to make them among his private audience and best associates. When they were assured of the cursed Fir'awn's promises,

And We revealed to Musa (saying): "Throw your stick," and behold! It swallowed up straight away all the falsehood which they showed (117)Thus truth was confirmed, and all that they did was made of no effect (118)So they were defeated there and returned disgraced (119)And the sorcerers fell down prostrate (120)They said: "We believe in the Lord of all that exists (121)"The Lord of Musa and Harun. (122) Musa defeats the Magicians, Who believe in Him Allah states that at that tremendous moment, in which Allah differentiated between Truth and Falsehood, He sent a revelation to His servant and Messenger Musa, peace be upon him, ordering him to throw the stick that he held in his right hand, فَإِذَا هِيَ تَلْقَفُ (It swallowed straight away) and devoured, مَا يَأْفِكُونَ (all the falsehood which they showed.) the magic that they caused the illusion with, of magic with which they caused m

حَدَّثَنَا أَبُو نُعَيْمٍ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الأَسْوَدِ، قَالَ سَمِعْتُ جُنْدَبًا، يَقُولُ اشْتَكَى النَّبِيُّ صلى الله عليه وسلم فَلَمْ يَقُمْ لَيْلَةً أَوْ لَيْلَتَيْنِ‏.‏

Narrated Jundab:The Prophet (ﷺ) became sick and did not get up (for Tahajjud prayer) for a night or two

حَدَّثَنَا ابْنُ مُقَاتِلٍ، أَخْبَرَنَا عَبْدُ اللَّهِ، أَخْبَرَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ هِنْدٍ بِنْتِ الْحَارِثِ، عَنْ أُمِّ سَلَمَةَ ـ رضى الله عنها ـ أَنَّ النَّبِيَّ صلى الله عليه وسلم اسْتَيْقَظَ لَيْلَةً فَقَالَ ‏ "‏ سُبْحَانَ اللَّهِ مَاذَا أُنْزِلَ اللَّيْلَةَ مِنَ الْفِتْنَةِ، مَاذَا أُنْزِلَ مِنَ الْخَزَائِنِ مَنْ يُوقِظُ صَوَاحِبَ الْحُجُرَاتِ، يَا رُبَّ كَاسِيَةٍ فِي الدُّنْيَا عَارِيَةٍ فِي الآخِرَةِ ‏"‏‏.‏

Narrated Um Salama:One night the Prophet (ﷺ) got up and said, "Subhan Allah! How many afflictions Allah has revealed tonight and how many treasures have been sent down (disclosed). Go and wake the sleeping lady occupants of these dwellings up (for prayers), perhaps a well dressed in this world may be naked in the Hereafter

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنِ ابْنِ شِهَابٍ، أَنَّ عُمَرَ بْنَ عَبْدِ الْعَزِيزِ، أَخَّرَ الصَّلاَةَ يَوْمًا، فَدَخَلَ عَلَيْهِ عُرْوَةُ بْنُ الزُّبَيْرِ، فَأَخْبَرَهُ أَنَّ الْمُغِيرَةَ بْنَ شُعْبَةَ أَخَّرَ الصَّلاَةَ يَوْمًا وَهْوَ بِالْعِرَاقِ، فَدَخَلَ عَلَيْهِ أَبُو مَسْعُودٍ الأَنْصَارِيُّ فَقَالَ مَا هَذَا يَا مُغِيرَةُ أَلَيْسَ قَدْ عَلِمْتَ أَنَّ جِبْرِيلَ نَزَلَ فَصَلَّى، فَصَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم ثُمَّ صَلَّى فَصَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم ثُمَّ صَلَّى فَصَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم ثُمَّ صَلَّى فَصَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم ثُمَّ صَلَّى فَصَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم ثُمَّ قَالَ ‏ "‏ بِهَذَا أُمِرْتُ ‏"‏‏.‏ فَقَالَ عُمَرُ لِعُرْوَةَ اعْلَمْ مَا تُحَدِّثُ أَوَإِنَّ جِبْرِيلَ هُوَ أَقَامَ لِرَسُولِ اللَّهِ صلى الله عليه وسلم وَقْتَ الصَّلاَةِ‏.‏ قَالَ عُرْوَةُ كَذَلِكَ كَانَ بَشِيرُ بْنُ أَبِي مَسْعُودٍ يُحَدِّثُ عَنْ أَبِيهِ‏.‏ قَالَ عُرْوَةُ وَلَقَدْ حَدَّثَتْنِي عَائِشَةُ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُصَلِّي الْعَصْرَ، وَالشَّمْسُ فِي حُجْرَتِهَا قَبْلَ أَنْ تَظْهَرَ‏.‏

Narrated Ibn Shihab:Once `Umar bin `Abdul `Aziz delayed the prayer and `Urwa bin Az-Zubair went to him and said, "Once in 'Iraq, Al-Mughira bin Shu`ba delayed his prayers and Abi Mas`ud Al-Ansari went to him and said, 'O Mughira! What is this? Don't you know that once Gabriel came and offered the prayer (Fajr prayer) and Allah's Messenger (ﷺ) prayed too, then he prayed again (Zuhr prayer) and so did Allah's Apostle and again he prayed (`Asr prayers and Allah's Messenger (ﷺ) did the same; again he prayed (Maghrib-prayer) and so did Allah's Messenger (ﷺ) and again prayed (`Isha prayer) and so did Allah's Apostle and (Gabriel) said, 'I was ordered to do so (to demonstrate the prayers prescribed to you)?'" `Umar (bin `Abdul `Aziz) said to `Urwa, "Be sure of what you Say. Did Gabriel lead Allah's Messenger (ﷺ) at the stated times of the prayers?" `Urwa replied, "Bashir bin Abi Mas`ud narrated like this on the authority of his father." `Urwa added, "Aisha told me that Allah's Messenger (ﷺ) used to pray `Asr prayer when the sunshine was still inside her residence (during the early time of `Asr)

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا عَبَّادٌ ـ هُوَ ابْنُ عَبَّادٍ ـ عَنْ أَبِي جَمْرَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَدِمَ وَفْدُ عَبْدِ الْقَيْسِ عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالُوا إِنَّا مِنْ هَذَا الْحَىِّ مِنْ رَبِيعَةَ، وَلَسْنَا نَصِلُ إِلَيْكَ إِلاَّ فِي الشَّهْرِ الْحَرَامِ، فَمُرْنَا بِشَىْءٍ نَأْخُذْهُ عَنْكَ، وَنَدْعُو إِلَيْهِ مَنْ وَرَاءَنَا‏.‏ فَقَالَ ‏ "‏ آمُرُكُمْ بِأَرْبَعٍ، وَأَنْهَاكُمْ عَنْ أَرْبَعٍ الإِيمَانِ بِاللَّهِ ـ ثُمَّ فَسَّرَهَا لَهُمْ شَهَادَةُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ، وَأَنِّي رَسُولُ اللَّهِ، وَإِقَامُ الصَّلاَةِ، وَإِيتَاءُ الزَّكَاةِ، وَأَنْ تُؤَدُّوا إِلَىَّ خُمُسَ مَا غَنِمْتُمْ، وَأَنْهَى عَنِ الدُّبَّاءِ وَالْحَنْتَمِ وَالْمُقَيَّرِ وَالنَّقِيرِ ‏"‏‏.‏

Narrated Ibn `Abbas:"Once a delegation of `Abdul Qais came to Allah's Messenger (ﷺ) and said, "We belong to such and such branch of the tribe of Rabi'ah and we can only come to you in the sacred months. Order us to do something good so that we may take it from you and also invite to it those whom we have left behind (at home)." So he said, "I order you to do four things and forbid you from four things: To believe in Allah" - and then he explained it to them "to testify that none has the right to be worshipped but Allah and that I am Allah's Messenger (ﷺ), to establish the prayers (at the stated times), to pay the Zakat (obligatory charity), to hand me the Khumus (fifth) if you acquire spoils of war. And I forbid from (using) Dubba, Hantam, Muqaiyyar, and Naqir (all these were utensils used for the preparation of alcoholic drinks)

أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنِ ابْنِ شِهَابٍ، أَنَّ عُمَرَ بْنَ عَبْدِ الْعَزِيزِ، أَخَّرَ الْعَصْرَ شَيْئًا فَقَالَ لَهُ عُرْوَةُ أَمَا إِنَّ جِبْرِيلَ عَلَيْهِ السَّلاَمُ قَدْ نَزَلَ فَصَلَّى أَمَامَ رَسُولِ اللَّهِ صلى الله عليه وسلم ‏.‏ فَقَالَ عُمَرُ اعْلَمْ مَا تَقُولُ يَا عُرْوَةُ ‏.‏ فَقَالَ سَمِعْتُ بَشِيرَ بْنَ أَبِي مَسْعُودٍ يَقُولُ سَمِعْتُ أَبَا مَسْعُودٍ يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏ "‏ نَزَلَ جِبْرِيلُ فَأَمَّنِي فَصَلَّيْتُ مَعَهُ ثُمَّ صَلَّيْتُ مَعَهُ ثُمَّ صَلَّيْتُ مَعَهُ ثُمَّ صَلَّيْتُ مَعَهُ ثُمَّ صَلَّيْتُ مَعَهُ ‏"‏ ‏.‏ يَحْسُبُ بِأَصَابِعِهِ خَمْسَ صَلَوَاتٍ ‏.‏

It was narrated from Ibn Shihab that 'Umar bin 'Abdul-'Aziz delayed the 'Asr prayer a little. 'Urwah said to him:"Jibril came down and led the Messenger of Allah (ﷺ) in prayer." 'Umar said: "Watch what you are saying, O 'Urwah!" He said: "I heard Bashir bin Abi Mas'ud say: 'I heard Abu Mas'ud say: "I heard the Messenger of Allah (ﷺ) say: 'Jibril came down and led me in prayer, and I prayed with him, then I prayed with him, then I prayed with him, then I prayed with him, then I prayed with him - and he counted off five prayers on his fingers

أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ حَدَّثَنَا سَيَّارُ بْنُ سَلاَمَةَ، قَالَ سَمِعْتُ أَبِي يَسْأَلُ أَبَا بَرْزَةَ، عَنْ صَلاَةِ، رَسُولِ اللَّهِ صلى الله عليه وسلم قُلْتُ أَنْتَ سَمِعْتَهُ قَالَ كَمَا أَسْمَعُكَ السَّاعَةَ فَقَالَ سَمِعْتُ أَبِي يَسْأَلُ عَنْ صَلاَةِ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ كَانَ لاَ يُبَالِي بَعْضَ تَأْخِيرِهَا - يَعْنِي الْعِشَاءَ - إِلَى نِصْفِ اللَّيْلِ وَلاَ يُحِبُّ النَّوْمَ قَبْلَهَا وَلاَ الْحَدِيثَ بَعْدَهَا ‏.‏ قَالَ شُعْبَةُ ثُمَّ لَقِيتُهُ بَعْدُ فَسَأَلْتُهُ قَالَ كَانَ يُصَلِّي الظُّهْرَ حِينَ تَزُولُ الشَّمْسُ وَالْعَصْرَ يَذْهَبُ الرَّجُلُ إِلَى أَقْصَى الْمَدِينَةِ وَالشَّمْسُ حَيَّةٌ وَالْمَغْرِبَ لاَ أَدْرِي أَىَّ حِينٍ ذَكَرَ ثُمَّ لَقِيتُهُ بَعْدُ فَسَأَلْتُهُ فَقَالَ وَكَانَ يُصَلِّي الصُّبْحَ فَيَنْصَرِفُ الرَّجُلُ فَيَنْظُرُ إِلَى وَجْهِ جَلِيسِهِ الَّذِي يَعْرِفُهُ فَيَعْرِفُهُ ‏.‏ قَالَ وَكَانَ يَقْرَأُ فِيهَا بِالسِّتِّينَ إِلَى الْمِائَةِ ‏.‏

Shu'bah said:"Sayyar bin Salamah, narrated to us, he said: 'I heard my father ask Abu Barzah about the prayer of the Messenger of Allah (ﷺ).' I said: 'Did you really hear him?' He said: 'As I can hear you now.' He said: 'I heard my father ask about the prayer of the Messenger of Allah (ﷺ).' He said: 'He would not mind if he delayed it - meaning 'Isha' until midnight, and he did not like to sleep before it or speak after it.'" Shu'bah said: "Then I met him later on and asked him. He said: 'He used to pray Zauhr when the sun had passed its zenith, and (he would pray) 'Asr and a man could walk to the farthest point in Al-Madinah and the sun would still be clear and hot. And Maghrib, I do not know the time he mentioned.' After that I met him and asked him, and he said: 'He used to pray Fajr then after the prayer a man could regarding it, sitting next to him, look at the face of someone he knew and he could recognize it.' He said: 'And he used to recite in it between sixty and one hundred (verses)

وعبادته التي هو مشغول بها لا ينتقل إلى غيرها ولا يفتر عنها لا يستكبرون عن عبادته ولا يستحسرون يسبحون الليل والنهار لا يفترون ومفتاح مزيد الدرجات هي الصلوات

وينبغي أن لا ينفصل من طرف عرفة إلا بعد الغروب ليجمع في عرفة بين الليل والنهار وإن أمكنه الوقوف يوم الثامن ساعة عند إمكان الغلط في الهلال فهو الحزم وبه الأمن من الفوات

الباب الأول في فضيلة الأوراد وترتيبها في الليل والنهار

يشير إلى أنه غير متطلع إلى الأوقات بل هو مع الذي يقدر الليل والنهار

فهذا سؤال جاهل ظالم ضال مفرط في الجهل والظلم والضلال لأن خلق الأضداد والمتقابلات هو من كمال الربوبية كالليل والنهار والحر والبرد واللذة والألم والخير والشر والنعيم والجحيم

خلفة لمن أراد أن يذكر أو أراد شكورا} [الفرقان: 62]، أي يخلف أحدهما الآخر ليتدارك في أحدهما ما فات في الآخر. ### $ 2 - بيان عدد أوراد الليل والنهار وترتيبها

Diagnosis of circadian rhythm sleep disorders.: Insomnia and excessive sleepiness are common in the investigation of sleep-disordered breathing. Circadian rhythm sleep disorders are perhaps the most often overlooked conditions in the differential diagnosis of these symptoms. Circadian rhythm sleep disorders manifest as misalignment between the sleep period and the physical/social 24-h environmental cycle. The two most prevalent circadian rhythm sleep disorders are delayed sleep phase (common in adolescents) and advanced sleep phase (common in

Intrinsic circadian period of sighted patients with circadian rhythm sleep disorder, free-running type.: Background: Circadian rhythm sleep disorder, free-running type (FRT), is an intractable sleep disorder in which sleep and wake times progressively delay each day even in normal living environments. This disorder severely affects the social functioning of patients because of periodic nighttime insomnia, excessive daytime sleepiness, and a high rate of comorbid psychiatric disorders. Although abnormal regulation of the biological clock is suspected, the pathophysiology of FRT has yet to be elucida

Identification of a Preliminary Plasma Metabolome-based Biomarker for Circadian Phase in Humans.: Measuring individual circadian phase is important to diagnose and treat circadian rhythm sleep-wake disorders and circadian misalignment, inform chronotherapy, and advance circadian science. Initial findings using blood transcriptomics to predict the circadian phase marker dim-light melatonin onset (DLMO) show promise. Alternatively, there are limited attempts using metabolomics to predict DLMO and no known omics-based biomarkers predict dim-light melatonin offset (DLMOff). We analyzed the human

Home dim light melatonin onsets with measures of compliance in delayed sleep phase disorder.: The dim light melatonin onset (DLMO) assists with the diagnosis and treatment of circadian rhythm sleep disorders. Home DLMOs are attractive for cost savings and convenience, but can be confounded by home lighting and sample timing errors. We developed a home saliva collection kit with objective measures of light exposure and sample timing. We report on our first test of the kit in a clinical population. Thirty-two participants with delayed sleep phase disorder (DSPD; 17 women, aged 18-52 years)

A randomized controlled trial with bright light and melatonin for the treatment of delayed sleep phase disorder: effects on subjective and objective sleepiness and cognitive function.: Delayed sleep phase disorder (DSPD) is a circadian rhythm sleep disorder. Patients with DSPD have problems initiating sleep if they go to bed at a conventional time, and they often have problems waking at desired times. If they rise early in the morning, they usually experience severe sleepiness during morning hours. In the present study, we investigated the short- and long-term effects on measures of subjective and objective sleepiness and cognitive function of bright light and melatonin treatm

Light-induced changes of the circadian clock of humans: increasing duration is more effective than increasing light intensity.: Study objectives: To evaluate the effect of increasing the intensity and/or duration of exposure on light-induced changes in the timing of the circadian clock of humans. Design: Multifactorial randomized controlled trial, between and within subject design Setting: General Clinical Research Center (GCRC) of an academic medical center Participants: 56 healthy young subjects (20-40 years of age) Interventions: Research subjects were admitted for 2 independent stays of 4 nights/3 days for treatment

Laparoscopic skills and cognitive function are not affected in surgeons during a night shift.

Objective: To monitor surgeons' performance and cognition during night shifts. Design: Surgeons were monitored before call and on call (17-hour shift). Psychomotor performance was assessed by laparoscopic simulation and cognition by the d2 test of attention. The surgeons performed the laparoscopic simulation and the d2 test of attention at 8 a.m. before call and at 4 a.m. on call. Sleep was measured by wrist actigraphy and sleepiness by the Karolinska sleepiness scale. Setting: Department of Surgery at Herlev Hospital, Denmark. Participants: Overall, 30 interns, residents, and attending surgeons were included and completed the study. One participant was subsequently excluded owing to myxedema. Results: The surgeons slept significantly less on call than before call. There was increasing sleepiness on call; however, no significant differences were found in the precall laparoscopic simulati…

matched on Sleep Disorders, Circadian Rhythm (mesh), Actigraphy (mesh), Actigraphy (keyword)

Thermoregulatory and endocrine responses to light pulses in short-day acclimated social voles (Microtus socialis).

In mammals, nocturnal light pulses (NLP) have been demonstrated to affect physiology and behavior. However, the impact of NLP as a stressor has been less broadly examined. The purpose of this study was to examine the effect of NLP (three 15 min 450 lux light pulses) during each scotophase on both thermoregulation and endocrine stress responses under short-day (SD; 8L:16D) acclimation. Voles were acclimated to either SD (SD voles) or SD+NLP (NLP voles). Resistance to cold was estimated by measurements of body temperature (T(b)) during cold exposure (5 degrees C). Daily rhythms of energy expenditure (calculated from oxygen consumption), urine production, and urinary adrenaline and serum cortisol levels were measured. T(b) values of SD voles were generally unaffected by the cold stimulus, whereas in NLP voles, resistance to cold was markedly lowered. While SD- and NLP voles showed similar u…

matched on Circadian Rhythm (mesh), Light (mesh)

Melatonin and its agonists: an update.

The pineal hormone melatonin is able to shift the timing of circadian rhythms, including the sleep-wake cycle, and to promote sleep. Melatonin agonists with similar properties have therapeutic potential for the treatment of circadian rhythm sleep disorders. Depression is specifically targeted by agomelatine, which is also a serotonin-2C (5-HT(2C)) antagonist.

matched on Melatonin (mesh), circadian (text)

Sleep deprivation among adolescents in urban and indigenous-rural Mexican communities.

Comparing the nature of adolescent sleep across urban and more isolated, rural settings through an ecological, cross-cultural perspective represents one way to inform sleep nuances and broaden our understanding of human development, wellbeing and evolution. Here we tested the Social Jetlag Hypothesis, according to which contemporary, urban lifestyles and technological advances are associated with sleep insufficiency in adolescents. We documented the adolescent sleep duration (11-16 years old; X̅ = 13.7 ± 1.21; n = 145) in two small agricultural, indigenous and one densely urban context in Mexico to investigate whether adolescents in socio-ecologically distinct locations experience sleep deprivation. Sleep data was assembled with actigraphy, sleep diaries and standardized questionnaires. We employed multilevel models to analyze how distinct biological and socio-cultural factors (i.e., pub…

matched on Circadian Rhythm (mesh), chronotype (text)

Association between Chronotype and Sleep Quality among Chinese College Students: The Role of Bedtime Procrastination and Sleep Hygiene Awareness.

Chronotype and sleep quality have been shown to play significant roles in influencing people's physical and mental health. The current study focuses on examining the relationship between chronotype and sleep quality among Chinese college students and exploring the mediating role of bedtime procrastination and the moderating role of sleep hygiene awareness. A sample of 2822 college students (female = 71.4%) aged between 17 and 29 years (M = 19.77, SD = 1.41) were included and completed the measures of the Pittsburgh Sleep Quality Index (PSQI), Morningness-Eveningness Questionnaire (MEQ), Bedtime Procrastination Scale (BPS) and Sleep Hygiene Awareness Scale (SHAS). The results showed that evening-type students reported the lowest sleep quality and highest levels of bedtime procrastination. In contrast, the highest sleep quality and lowest levels of bedtime procrastination were shown by mor…

matched on Circadian Rhythm (mesh), chronotype (text)

Evening chronotype, alcohol use disorder severity, and emotion regulation in college students.

The evening chronotype is strongly associated with greater alcohol use, though mechanisms underlying this association are not well understood. The current study evaluated emotion regulation as a potential mechanism linking evening chronotype and alcohol use. Participants were 81 undergraduate students. Chronotype was assessed using the Composite Scale of Morningness (CSM). Alcohol use disorder severity was assessed using the Alcohol Use Disorder Identification Test (AUDIT). Participants recorded daily sleep patterns using an online diary for seven days. Participants then completed a standardized laboratory emotion regulation task. Self-reported affect, high-frequency heart rate variability (HF-HRV), and pre-ejection period (PEP) were measured throughout the task. Sleep duration on non-free days (defined as days when sleep was restricted by morning obligations such as work or school) was …

matched on Circadian Rhythm (mesh), chronotype (text)

An in-depth look into the association between morningness-eveningness and well-being: evidence for mediating and moderating effects of personality.

Morningness-eveningness and standard personality traits are associated with well-being but few studies have directly compared the two types of construct as correlates of life satisfaction. Influences on well-being common to both chronotype and personality may include shared biological bases for depression and sleep disturbance, tendencies toward social jetlag, and emotion-regulation mechanisms. The current study tested mediation and moderation hypotheses in a sample of 379 Polish adults. The first hypothesis was that conscientiousness and emotional stability traits would mediate the relationship between morningness and life satisfaction. Consistent with previous results, morningness, the two personality traits, and satisfaction tended to be mutually positively correlated. A multiple mediation analysis showed that both traits partially mediated the morningness-satisfaction association. Da…

matched on Circadian Rhythm (mesh), chronotype (text)

Late chronotype is associated with enhanced amygdala reactivity and reduced fronto-limbic functional connectivity to fearful versus happy facial expressions.

Increasing evidence suggests late chronotype individuals are at increased risk of developing depression. However, the underlying neural mechanisms that confer risk are not fully understood. Here, fifty healthy, right-handed individuals without a current or previous diagnosis of depression, family history of depression or sleep disorder underwent functional magnetic resonance imaging (FMRI). Participants completed an implicit emotion processing task (gender discrimination) including happy and fearful facial expressions. Linear effects of chronotype on BOLD response in bilateral amygdala were tested for significance using nonparametric permutation tests. Functional connectivity between amygdala and prefrontal cortex was also investigated using psychophysiological interaction (PPI) analysis. A significant negative correlation between BOLD response and chronotype was observed in bilateral am…

matched on Circadian Rhythm (mesh), chronotype (text)

Chronotype and depressive symptoms in students: An investigation of possible mechanisms.

Individuals with an evening chronotype are at increased risk of experiencing emotional problems, including depressive symptoms. However, the mechanisms underlying these associations remain unclear. The present study aimed to determine whether poor sleep quality, substance use and cognitive emotion regulation difficulties - which have been implicated in the etiology of depression - mediate the relationship between chronotype and depressive symptoms in a student sample, which was assessed cross-sectionally and after 1 year. A total of 742 Dutch students (75% women, mean age 21.4 ± 2.9 years) completed the Quick Inventory of Depressive Symptomatology, the Morningness-Eveningness Questionnaire, the Pittsburgh Sleep Quality Index, a questionnaire assessing alcohol, caffeine, tobacco and cannabis use, the Cognitive Emotion Regulation Questionnaire and the Behavioral Inhibition/Activation Scale…

matched on Circadian Rhythm (mesh), chronotype (text)

Reduced Effective Emotion Regulation in Night Owls.

Previous research has demonstrated a clear link between late chronotype and depression. The vulnerability factors underpinning this link, however, are unclear. Here the relationship between two specific emotion regulation strategies, cognitive reappraisal and expressive suppression, and chronotype was investigated using multiple regression. Two hundred and forty participants (age range 18-80, 189 females) completed validated self-report questionnaires assaying chronotype, neuroticism, depressive symptomatology, sleep quality, and emotion regulation. Eveningness was associated with increased expressive suppression, and morningness was associated with increased cognitive reappraisal after controlling for age, gender, depressive symptomatology, neuroticism, and sleep quality. Trait expressive suppression and reduced cognitive reappraisal are known to increase depression risk. Our results su…

matched on Circadian Rhythm (mesh), chronotype (text)

Associations between chronotypes and psychological vulnerability factors of depression.

Chronotypes have been associated with psychopathology. The eveningness chronotype has been consistently linked with depressed states or depressive disorder, but the underlying mechanism remains unclear. Prior studies have shown associations between chronotype and personality traits that are linked to depression (e.g. neuroticism), but other psychological vulnerability factors have not been previously investigated in relation to chronotypes. The aim of this study was to examine the association between chronotypes, depression and psychological risk factors of depression (namely, cognitive reactivity and worry), in a large cohort of depressed patients and healthy individuals. We used data from the Netherlands Study of Depression and Anxiety (n = 1654), which includes 1227 clinically diagnosed individuals with a lifetime diagnosis of depression and 427 healthy controls. We assessed cognitive…

matched on Circadian Rhythm (mesh), chronotype (text)

CHRONOTYPE ASSOCIATIONS WITH DEPRESSION AND ANXIETY DISORDERS IN A LARGE COHORT STUDY.

Background: The chronotype, being a morning or an evening type, can influence an individual's psychological health. Studies have shown a link between depressed mood and being an evening type; however, most studies have used symptom scales and not diagnostic criteria, and confounding factors such as sleep patterns and somatic health factors have often not been considered. This study aims to examine the association between chronotype and depressive (major depressive disorder (MDD), dysthymia) and anxiety (generalized anxiety disorder, panic disorder, agoraphobia, and social phobia) disorders diagnosed using clinical interviews, while taking into account relevant sociodemographic, clinical, somatic health, and sleep parameters. Methods: Data from a large cohort, the Netherlands Study of Depression and Anxiety were used (n = 1,944), which included 676 currently depressed and/or anxious patie…

matched on Circadian Rhythm (mesh), chronotype (text)

Sleep and Physiological Dysregulation: A Closer Look at Sleep Intraindividual Variability.

Study objectives: Variable daily sleep (ie, higher intraindividual variability; IIV) is associated with negative health consequences, but potential physiological mechanisms are poorly understood. This study examined how the IIV of sleep timing, duration, and quality is associated with physiological dysregulation, with diurnal cortisol trajectories as a proximal outcome and allostatic load (AL) as a multisystem distal outcome. Methods: Participants are 436 adults (Mage ± standard deviation = 54.1 ± 11.7, 60.3% women) from the Midlife in the United States study. Sleep was objectively assessed using 7-day actigraphy. Diurnal cortisol was measured via saliva samples (four/day for 4 consecutive days). AL was measured using 23 biomarkers from seven systems (inflammatory, hypothalamic-pituitary-adrenal axis, metabolic glucose and lipid, cardiovascular, parasympathetic, sympathetic) using a vali…

matched on Circadian Rhythm (mesh), Actigraphy (mesh)

Diurnal cortisol pattern, eating behaviors and overweight in low-income preschool-aged children.

This study examined, among children, the associations among chaos in the home, diurnal cortisol patterns, eating behaviors and being overweight. Participants included 331 low-income children aged 3-4years. Mean salivary cortisol-intercept (representing morning peak, 60min since waking) and cortisol-slope (representing diurnal decline after peak) were calculated using mixed models from samples obtained across 3days. Parents reported chaos in the home by questionnaire and responded to the Children's Eating Behavior Questionnaire, generating subscales Food Responsiveness (FR), Emotional Overeating (EO), Enjoyment of Food (EF), and Satiety Responsiveness (SR). Body mass index was categorized as overweight vs. not. Path analysis evaluated associations among chaos, cortisol patterns, eating behaviors, and weight status. Children living in more chaotic homes had lower morning cortisol levels, c…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

How stable are diurnal cortisol activity indices in healthy individuals? Evidence from three multi-wave studies.

Background: Indices of cortisol activity, including the cortisol awakening response (CAR), diurnal slope, and cortisol output across the day (total daily output), are often studied as mechanistic indicators that could link stress with health. Yet there is a paucity of data speaking to their temporal features, particularly whether they behave in a more state- or trait-like manner across time. Methods: To address this issue, data from 3 studies were used to assess CAR, diurnal slope and total daily output stability over different age groups and time spans: 130 healthy children and adolescents collected salivary cortisol samples 5 times/day (1, 4, 9 and 11h after wake) over 2 days at 5 visits spaced 6 months apart (Study 1); 147 adolescent girls collected saliva 6 times/day (wake, 1, 4, 9 and 14 h after wake) for 2 days at 3 visits, each a year apart (Study 2); and 47 healthy, primarily mid…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

Processing of emotional reactivity and emotional memory over sleep.

Sleep enhances memories, particularly emotional memories. As such, it has been suggested that sleep deprivation may reduce posttraumatic stress disorder. This presumes that emotional memory consolidation is paralleled by a reduction in emotional reactivity, an association that has not yet been examined. In the present experiment, we used an incidental memory task in humans and obtained valence and arousal ratings during two sessions separated either by 12 h of daytime wake or 12 h including overnight sleep. Recognition accuracy was greater following sleep relative to wake for both negative and neutral pictures. While emotional reactivity to negative pictures was greatly reduced over wake, the negative emotional response was relatively preserved over sleep. Moreover, protection of emotional reactivity was associated with greater time in REM sleep. Recognition accuracy, however, was not as…

matched on Circadian Rhythm (mesh), Polysomnography (mesh)

Aging diurnal rhythms and chronic stress: Distinct alteration of diurnal rhythmicity of salivary alpha-amylase and cortisol.

The present study assessed diurnal profiles of salivary alpha-amylase (sAA), proposed as a marker of autonomic activity, and salivary cortisol in competitive ballroom dancers as well as age- and sex-matched controls to investigate age-related changes of basal activity and potential chronic psychosocial stress-related alterations. According to the Allostatic Load (AL) hypothesis of a cumulative wear and tear of the body we expected to see physiological accumulation of the effects of stress and age especially pronounced in older dancers. Dancers and controls collected five saliva samples throughout the day. Daily overall output of sAA was elevated in older adults while there was no effect of age on mean cortisol levels. Alterations of diurnal rhythms were only seen in younger male dancers showing a flattened diurnal profile of sAA and younger dancers and female older dancers showing a blun…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

Prospective prediction of major depressive disorder from cortisol awakening responses in adolescence.

Levels of the stress-sensitive hormone cortisol increase dramatically in the first 30-40min after waking, an effect known as the cortisol awakening response (CAR). There is considerable cross-sectional evidence that psychosocial stress is associated with an increased CAR, and the CAR has been found to be altered in the presence of stress-related diseases, including major depressive disorder (MDD). To date, no prospective longitudinal studies have examined whether individual differences in the CAR serve as a premorbid risk factor for MDD. In a sample of 230 late adolescents, clinical diagnoses of MDD were predicted from the CAR as well as other indicators of basal cortisol functioning gathered 1 year earlier, including: waking cortisol levels, bedtime cortisol levels, the size of the CAR, average cortisol, and the slope of the diurnal cortisol rhythm across the waking day. Age and gender,…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

Abnormal cortisol levels during the day and cortisol awakening response in first-episode psychosis: the role of stress and of antipsychotic treatment.

First-episode psychosis (FEP) patients show hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, but the mechanisms leading to this are still unclear. The aim of this study was to investigate the role of stress and antipsychotic treatment on diurnal cortisol levels, and on cortisol awakening response, in FEP. Recent stressful events, perceived stress and childhood trauma were collected in 50 FEP patients and 36 healthy controls using structured instruments. Salivary cortisol was obtained at awakening, at 15, 30, and 60min after awakening, and at 12 and 8pm. Patients experienced more recent stressful events, perceived stress and childhood trauma than controls (p<0.001). Patients had a trend for higher diurnal cortisol levels (p=0.055), with those with less than two weeks of antipsychotics showing significantly higher cortisol levels than both patients with more than two weeks o…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

The development of regulatory functions from birth to 5 years: insights from premature infants.

This study examined physiological, emotional, and attentional regulatory functions as predictors of self-regulation in 125 infants followed 7 times from birth to 5 years. Physiological regulation was assessed by neonatal vagal tone and sleep-wake cyclicity; emotion regulation by response to stress at 3, 6, and 12 months; and attention regulation by focused attention and delayed response in the 2nd year. Executive functions, behavior adaptation, and self-restraint were measured at 5 years. Regulatory functions showed stability across time, measures, and levels. Structural modeling demonstrated both mediated paths from physiological to self-regulation through emotional and attentional processes and direct continuity between vagal tone and each level of regulation. Results support the coherence of the regulation construct and are consistent with neurobiological models on self and consciousn…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

Cortisol diurnal rhythm and stress reactivity in male adolescents with early-onset or adolescence-onset conduct disorder.

Background: Previous studies have reported lower basal cortisol levels and reduced cortisol responses to stress in children and adolescents with conduct disorder (CD). It is not known whether these findings are specific to early-onset CD. This study investigated basal and stress-induced cortisol secretion in male participants with early-onset and adolescence-onset forms of CD. Methods: Forty-two participants with early-onset CD, 28 with adolescence-onset CD, and 95 control subjects participated in the study. They collected saliva across the day to assess their cortisol awakening response and diurnal rhythm. Subsequently, salivary cortisol was measured before, during, and after a psychosocial stress procedure designed to elicit frustration. Cardiovascular activity and subjective mood states were also assessed during stress exposure. Results: There were no group differences in morning cort…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

Daytime sleepiness and functional impairment in Alzheimer disease.

Objective: Daytime sleep has been noted to accompany dementing illness and is more pronounced as dementia severity increases. Although acknowledged by caregivers, sleepiness during the daytime is among the least troublesome of sleep behaviors described in Alzheimer Disease (AD) patients. The purpose of this study was to examine whether patient and spouse/caregiver reports of daytime sleepiness in AD were associated with lower functional status in those patients. Methods: The authors utilized the Epworth Sleepiness Scale to assess reported daytime sleepiness and a modification of the Lawton and Brody scale to assess functional status in a group of 137 AD patients. The authors also examined typical bedtimes and wakeup times via questionnaire. Results: Higher levels of daytime sleepiness were associated with greater impairments in functional status. These results were independent of level o…

matched on Sleep Disorders, Circadian Rhythm (mesh), Disorders of Excessive Somnolence (mesh)

Prospective cohort study of the risk of prostate cancer among rotating-shift workers: findings from the Japan collaborative cohort study.

Shift workers have been reported to have an increased risk of some cancers. However, the risk of prostate cancer in shift workers is not known to have been examined previously. This study prospectively examined the association between shift work and risk of prostate cancer incidence among 14,052 working men in Japan enrolled in a large-scale prospective cohort. A baseline survey was conducted between 1988 and 1990. Subjects were asked to indicate the most regular work schedule they had undertaken previously: day work, rotating-shift work, or fixed-night work. During 111,974 person-years, 31 cases of prostate cancer were recorded. The Cox proportional hazards model was used to estimate the risk, with adjustments for age, family history of prostate cancer, study area surveyed, body mass index, smoking, alcohol drinking, job type, physical activity at work, workplace, perceived stress, educ…

matched on Circadian Rhythm (mesh), Work Schedule Tolerance (mesh)

Sleep facilitates consolidation of emotional declarative memory.

Both sleep and emotion are known to modulate processes of memory consolidation, yet their interaction is poorly understood. We examined the influence of sleep on consolidation of emotionally arousing and neutral declarative memory. Subjects completed an initial study session involving arousing and neutral pictures, either in the evening or in the morning. Twelve hours later, after sleeping or staying awake, subjects performed a recognition test requiring them to discriminate between these original pictures and novel pictures by responding "remember,""know" (familiar), or "new." Selective sleep effects were observed for consolidation of emotional memory: Recognition accuracy for know judgments of arousing stimuli improved by 42% after sleep relative to wake, and recognition bias for remember judgments of these stimuli increased by 58% after sleep relative to wake (resulting in more conser…

matched on Circadian Rhythm (mesh), Wakefulness (mesh)

A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative?

Study objectives: The purposes of this study were to compare the benefits of different length naps relative to no nap and to analyze the electroencephalographic elements that may account for the benefits. Design: A repeated-measures design included 5 experimental conditions: a no-nap control and naps of precisely 5, 10, 20, and 30 minutes of sleep. Setting: Nocturnal sleep restricted to about 5 hours in participants' homes was followed by afternoon naps at 3:00 PM and 3 hours of postnap testing conducted in a controlled laboratory environment. Participants: Twenty-four healthy, young adults who were good sleepers and not regular nappers. Measurements and results: The 5-minute nap produced few benefits in comparison with the no-nap control. The 10-minute nap produced immediate improvements in all outcome measures (including sleep latency, subjective sleepiness, fatigue, vigor, and cogniti…

matched on Circadian Rhythm (mesh), Disorders of Excessive Somnolence (mesh)