Uso de habitat, orçamento temporal e influência da maré da geomorfologia do fundo sobre o comportamento do boto Sotalia guianensis Van Bénéden, 1864 (Cetacea: Delphinidae) no Porto de Maceió - Alagoas, Brasil

The physical and environmental factors presented by each habitat and the rhythm of behavior patterns strongly influence the ecology and behavior of the all living beings. At same time this factors may provide clues about the structure of a population and its ecological balance. The organizational structure, ecology and behavior of a species appraised in a region if we know be in balance when compared to the same type of appraisal made in a degraded area can provide a clear view of how the anthropogenic influences acted on these species and what steps can be taken in order to mitigate the effects and keep the population. The region where this study was conducted is, like most areas of port, subject to intense physical and environmental degradation. With the emerging interest of change in the quality of these environments also by the companies themselves that use the port services, the proposed study aimed to characterize the use of habitat, the distribution of behavioral activities carried out throughout the day and influence of geomorphology of the bed, depth and variation of tide on the expression of the behavior of Sotalia guianensis in the port of Maceio - Alagoas. From this information will be possible establish parameters for comparison with other populations of S. guianensis and establish conservation measures for the population occurring in the port of Maceio - AL, serving also as a basis for conservation actions future performed in other port regions

Preferências e escolhas românticas entre universitários

Several studies have found different patterns of preferences to men and women for short term and long term relationship romantic partners. It is known that the preferences vary with the sex of individuals, the expected involvement level of the relationship and according to the perceptions that subjects have about themselves. In the present study, we investigate whether the preferences typically founded for sexes are also founded between Brazilian undergraduate students. We also investigated if the individuals choose partners in accord of the sex preferences and if the ideal preferences are really expressed in real choices. For these investigations, 370 undergraduate students described profiles of an ideal partner for a short-term and a long-term relationship, through the joint evaluation of nine characteristics. Each ideal s profile has been described over three simulations, in which the amount of points available to be invested were limited and gradually reduced. After the descriptions of these profiles, the participants described the current or previous partner (if they were not in a relationship) and performed a self-assessment with the same characteristics used in the description of preferences. Overall, the results obtained in several countries were observed in Brazil. For short-term relationships men prioritize physical attributes and women value physical and personal attributes. For long-term, personal traits gained in importance on masculine preferences and women emphasized personal traits and the partner disposition to acquire resources. We also identified similar preferences profiles for both sexes and that the romantic preferences reflect similarities with the own individual s characteristics, in addition to the typical sexual preferences expected for the Parental Investment Theory. When evaluated their real partners, men considerate them more physically attractive than themselves but less intelligent, good humorous and ambi tion/willing to work. Women, in turn, described their partners as good as them. Finally, we observed equivalence between characteristics of the subjects and those of its partners, this effect being more pronounced among men. The last partners were described only as less sincere. The interpretation of the most part of our results was possible from evolutionist s and socio-cultural s explanations and was discussed under the two perspectives. We conclude this study stressing that the traditional romantic preferences occur in Brazil and that the sex, the kind of relationship and the vision that people have about their own characteristics affect the preferences, which are expressed in the real partner choices

Sonhos antecipatórios: influência de um evento significativo da vigília na atividade onírica

In most cultures, dreams are believed to predict the future on occasion. Several neurophysiological studies indicate that the function of sleep and dreams is to consolidate and transform memories, in a cyclical process of creation, selection and generalization of conjectures about the reality. The aim of the research presented here was to investigate the possible adaptative role of anticipatory dreams. We sought to determine the relationship between dream and waking in a context in which the adaptive success of the individual was really at risk, in order to mobilize more strongly the oneiric activity. We used the entrance examination of the Federal University of Rio Grande do Norte (UFRN) as a significant waking event in which performance could be independently quantified. Through a partnership with UFRN, we contacted by e-mail 3000 candidates to the 2009 examination. In addition, 150 candidates were approached personally. Candidates who agreed to participate in the study (n = 94) completed questionnaires specific to the examination and were asked to describe their dreams during the examinaton period. The examination performance of each candidate in the entrance examination was provided by the UFRN to the researcher. A total of 45 participants reported dreams related to the examination. Our results show a positive correlation between performance on the examination and anticipatory dreams with the event, both in the comparison of performance on objective and discursive, and in final approval (in the group that not dreamed with the exam the rate of general approval, 22,45%, was similar to that found in the selection process as a whole, 22.19%, while for the group that dreamed with the examination that rate was 35.56%). The occurrence of anticipatory dreams reflectes increased concern during waking (psychobiological mobilization) related to the future event, as indicated by higher scores of fear and apprehension, and major changes in daily life, in patterns of mood and sleep, in the group that reported testrelated dreams. Furthermore, the data suggest a role of dreams in the determination of environmentally relevant behavior of the vigil, simulating possible scenarios of success (dream with approval) and failure (nightmares) to maximize the adaptive success of the individual

Efeitos da cafeína sobre a memória de saguis (Callithrix jacchus)

Caffeine is considered the most consumed psychostimulant in the world, presenting several central and peripheral effects. In the Central Nervous System the major effect occur by its antagonistic activity at the A1 and A2a subtypes of the adenosine receptors. These receptors are responsible for the slow-wave sleep induction, and their binding, caused by the consumption of foods and beverages that contain caffeine, cause behaviors like increase of alertness, mood and locomotion. The effects of caffeine on memory are still discussed because of the diversity of experimental protocols. Also, it does not have the same effects on all stages of the processing of memory - acquisition, consolidation and recall. Thus, using the marmoset (Callitrhix jacchus) as subject, we aim to evaluate the effects of caffeine on the memory of this primate through the conditioned place preference paradigm, where the animal selects a context by presence of food. This cognitive task consists of five phases. The first phase was two sessions of pre-exposure, in which they were evaluated for preference for any compartment of the apparatus. Then, we proceeded the training, conditioning the animals to the food-present context for 8 days. Then, there was administration of caffeine or placebo (10mg/kg) for 8 consecutive days, during the pre-sleep phase, where the 20 animals were distributed in two groups: placebo and repeated. The forth phase was one day of retraining, a re-exposure of the apparatus to the marmosets followed by the administration of caffeine (for the repeated group and a new group called abstinence) or placebo (for placebo and abstinence groups). Finally, was the test where we evaluated if the subjects learned where the food was present. Moreover, in this work we evaluate the existence of differences between females and males on the task, and the locomotor activity for the experimental groups. The results showed that in the pre-exposure phase the animals were habituated on the apparatus and did not present differences for any contexts. In training, they were able to learn the conditioning task, independent of gender. For the retraining, the two groups exhibited more interactions in rewarded context than that in non-rewarded context. Nevertheless, in the locomotor activity, the repeated group moved similarly in contact with the apparatus and outside of it. In the other hand, the animals of the placebo group moved more when in contact with the apparatus. In the test phase, the marmosets under influence of caffeine presented an increase in the locomotor activity when compared with the placebo group, corroborating works that show this increase in locomotion. In the learning evaluation, the continuous and abstinence groups had a bad performance in the task in relation to the placebo and acute groups. This suggests that the prolonged administration of caffeine disrupts the memories because it affected sleep, which is largely responsible offline processing of memories

Seleção conjugal e as mulheres re-casadas no mercado de casamentos em uma comunidade de baixa renda no nordeste brasileiro

A presente pesquisa partiu de uma revisão teórica dos assuntos relacionados à seleção sexual proposta por Charles Darwin, passando para evolução dos sistemas e da psicologia do acasalamento humano. Os estudos práticos, divididos em dois momentos, foram coletados numa comunidade litorânea de baixa renda no nordeste brasileiro, na qual as mulheres tiveram pelo menos duas uniões estáveis até a data da coleta, no ano de 2008. Nas primeiras análises, foram contempladas as expectativas dessas mulheres em relação aos atributos dos parceiros. E posteriormente, o perfil e valor das mesmas entraram em perspectiva. De uma forma geral, foi constatado que as mulheres, no primeiro casamento, de fato realizam matrimônios com parceiros mais parecidos com o que consideram ideal do que os posteriores. Assim como as segundas e subseqüentes uniões apresentam uma ligeira queda no valor (no mercado de casamentos) desses homens quando comparados aos primeiros companheiros levando em consideração indicadores biosocioeconômicos como idade, escolaridade e renda (status socioeconômico).

O Núcleo genuíno lateral dorsal do tálamo do sagüi (callithrix jacchus): Pprojeção retiniana, caracterização citoarquitetônica e neuroquimica da principal estação visual primária.

The thalamus plays an important role in the sensorial processing information, in this particular case, the visual information. Several neuronal groups have been characterized as conductors and processors of important sensorial information to the cerebral cortex. The lateral geniculate complex is one to them, and appears as a group very studied once it is responsible, in almost all totality, for the processing of visual information. Among the nuclei that constitute the lateral geniculate complex we highlight the dorsal lateral geniculate nucleus of the thalamus (DLG), the main thalamic relay for the visual information. This nucleus is located rostral and lateral to medial geniculate nucleus and ventral to thalamic pulvinar nucleus in most of the mammals. In the primates humans and non-humans, it presents as a laminate structure, arranged in layers, when observed in coronal sections. The objective of this work was to do a mapping of the retinal projections and a citoarchictetonic and neurochemical characterization of DLG in the marmoset (Callithrix jacchus), a New World primate. The retinal projections were traced by anterograde transport of subunit b of cholera toxin (CTb), the citoarchicteture was described by Nissl method, and to neurochemical characterization immunohistochemicals technical were used to examine the main neurotransmitters and neuroatives substances present in this neural center. In DGL of marmoset thalamus, in coronal sections labeled by Nissl method, was possible to visualize the division of this nucleus in four layers divided in two portions: magnocellular and parvocellular. The retinal projections were present being visualized fibers and terminals immunorreactives to CTb (IR-CTb) in the DLG ipsilateral and contralateral. And through the immunohistochemicals techniques was observed that DLG contain cells, fibers and/or terminals immunoreactives against neuronal nuclear protein, subunits of AMPA 15 glutamate receptors (GluR1, GluR2/3, GluR4), choline acetyltransferase, serotonin, glutamic acid decarboxylase, binding calcium proteins (calbindin, parvalbumin and calretinin), vasopressin, vasoactive intestinal polypeptide, and an astrocyte protein, glial fibrillary acidic protein.

Estrutura da Comunidade de Lagartos de um remanescente de mata atlântica do Estado do Rio Grande Do Norte, Brasil.

As part of a broader project, Diversity and Distribution Patterns of Floristic and Faunistic composition of remnants of Potiguar s Atlantic Forest, as subsidies to conservation , that subsidizes a group of institutional research, This study aimed to evaluate the structure of the assemblage of lizards a remnant of the of the northern Atlantic Forest, identifying ecological factor (s) that contribute to the coexistence of sympatric species. Additionally, we studied the thermal ecology and thermoregulatory behavior of umbrophily and heliophily species live the Parque Estadual Mata da Pipa (PEMP), a remnant of Atlantic forest located in the Tibau do Sul municipality of, Rio Grande do Norte State, Brazil. It is one of the largest remnants of the Atlantic Forest and has an area of approximately 290 ha. The study was performed by four excursions to the field for 20 days each, when active search and pitfalls traps were used to record and colleted specimens in different habitats of the area. We recorded the presence of 19 species of lizards, of which seven are typical of forest areas, three are endemic Atlantic Forest, these two northern and one are new record for the Rio Grande do Norte. The use of resources, the results showed that phylogenetically related species do not always use a similar way the resources available; the feeding niche was the segregated component of the species that overlapped extensively in the use of space and vice versa. To examine the thermal ecology and thermoregulatory behavior of Kentropyx calcarata and Coleodactylus natalensis, we recorded the clocal temperature (Tc), oh the substrate (Ts) and of the air (Ta) to investigate what of these are the source of heat more important to the temperature s body of these lizards. Behavioral observations were conducted to analyze strategies to optimize the acquisition of heat. The air temperature explained most strongly to variation in body temperature of K. calcarata, while the temperature of the substrate to C. natalensis. As for the behavioral observations, they confirmed that K. calcarata is an active thermoregulatory; C. natalensis is a passive thermoregulatory.

Atividade multimodal no córtex sensorial primário de ratos.

The currently accepted model of sensory processing states that different senses are processed in parallel, and that the activity of specific cortical regions define the sensorial modality perceived by the subject. In this work we used chronic multielectrode extracellular recordings to investigate to which extent neurons in the visual and tactile primary cortices (V1 and S1) of anesthetized rats would respond to sensory modalities not traditionaly associated with these cortices. Visual stimulation yielded 87% of responsive neurons in V1, while 82% of S1 neurons responded to tactile stimulation. In the same stimulation sessions, we found 23% of V1 neurons responding to tactile stimuli and 22% of S1 neurons responding to visual stimuli. Our data supports an increasing body of evidence that indicates the existence multimodal processing in primary sensory cortices. Our data challenge the unimodal sensory processing paradigm, and suggest the need of a reinterpretation of the currently accepted model of cortical hierarchy.

Expressão de zif268 no cérebro do lagarto Tropidurus Hispidus após exploração de um ambiente enriquecido.

In the present work, we investigated behavioral changes associated with the increase in Zif268 protein expression within telencephalic areas of the tropical lizard Tropidurus hispidus that correspond to the mammalian hippocampus (HC). We used 13 male individuals of this species, collected at the Federal Agrotechnical School of Rio Grande do Norte, under SISBIO license number 19561-1. Four animals had their brains removed and were submitted to a Western blot with antibodies for the Zif268 protein. The remaining animals were separated in two different groups: a control group (n=4) and an exploration group (n=5). Animals from the exploration group were exposed to an enriched environment with many sensory cues novel to them. Control group animals stayed in the environment they were already habituated to. After 90 min from the onset of exposure to the new environment, animals from both groups were submitted to intracardiac perfusion with fixative, and the brains were removed, cryoprotected and frozen. After that, brains were sectioned at 20 μm and the sections were subjected to immunohistochemistry for the Zif268 protein. We verified that the Zif268 protein is likely conserved in the brain of T. hispidus, which showed antigenicity for the antibody anti-Zif268 made in mammals. In animals from the exploration group, we detected an increase of the Zif268 protein in the Septum, Striatum, Dorsoventricular Area and in cortical areas corresponding to the HC. This increase was proportional to the amount of environmental exploration, with maximum positive correlation in the hippocampal subareas Medial Cortex (R = 0.94 and p = 0.004) and Dorsomedial Cortex (R = 0.92 and p = 0.006). The data corroborate the notion that the reptilian hippocampus, as well as the mammalian HC, plays an important role in spatial exploration.

A influência do status social no forrageio de itens camuflados e avermelhados em sagüis (Callithrix jacchus) cativos

Seeing colors can be advantageous, because they are an important signal for providing information about the environment, such as the location of food. However, not every animals sees these chromatic signals in the same way. In primates, the group of Plathyrrhini has polymorphic sex-linked vision with males always dichromats and dichromats or trichromats females. Studies indicate that trichromats during foraging would benefit by seeing better than dichromats ripe fruits against the green foliage background. On the other hand, dichromats appear to distinguish camouflaged insects better than trichromats. The marmoset (Callihtrix jacchus) is a neotropical primate species that have color vision polymorphism. This species establishes family groups with highly reproductive bias, with breeding females often having preferential access to food. This work aims to study whether the social context influences the foraging ability of camouflaged and red items in groups of C. jacchus. Four groups of captive marmosets were presented to four food tasks, involving difficult, easy, reddish and camouflaged food targets. Foods were presented in a concentrated and dispersed manner, to check whether there was monopolization of the resources by the dominant subjects and if this would affect the ability of individuals to find the food targets. Success was measured by latency to food acquisition and number of targets consumed. Males and females differed in their foraging success for camouflaged and reddish items, although this difference has not appeared in all situations and experimental conditions. In general males were more successful for detecting camouflaged items while females succeeded more in identifying reddish items. There were no differences in foraging success between individuals of different social status, however, there were differences in the success of consumption of food items for different situations when food was concentrate compared with dispersed food. Taken as a role, there was a greater difficulty in detecting food items when they were presented in concentrated arrangement, which is supposed to be related to a higher difficulty to approach and stay near the food. Although it appears that there was no direct competition seems to have group's indirect influence on the detection of food items and foraging success of individuals, affecting mainly those items more difficult to detect

Caracterização do ciclo sono/vigília de professores do ensino médio em natal/rn

In the school environment is fundamental the knowledge about the sleep-wake cycle (SWC), because we find children and adolescents with excessive sleepiness and learning difficulties. Furthermore, teachers with high demand and with different work schedule, which may contribute to changes in SWC. The aim of this study was to describe the SWC of high school teachers in Natal/RN. Habits and knowledge about sleep, chronotype, SWC, daytime sleepiness, sleep quality and job satisfaction were described in 98 high school teachers from public and private school. These parameters were compared according to the characteristics of work, family structure and gender. Data collection was performed with the use of questionnaires in two stages: 1) "health and sleep" (general characterization of sleep habits), Horne & Ostberg questionnaire (characterization of chronotype), Epworth Sleepiness Scale and the Index of Pittsburg Sleep Quality, 2) The sleep diary for 14 days. From the results, we observe that the teachers woke up and went to bed earlier in the week and showed a reduction of time in bed around 42min comparing to weekend. This reduction in time in bed during the week was accompanied by an increase in nap duration on weekend. In addition the teachers woke up earlier on Saturdays than on Sundays, probably due to housework and leisure. The teachers' knowledge about sleep was low in relation to individual differences and effect of alcoholic beverages on sleep, and high in the consequences of sleep deprivation. The differences found in comparisons on the characteristics of work, family structure and gender were punctual, except concerning the work schedule. The teacher who started work in the morning and finished in the night, woke up earlier, went to bed later and had less time in bed, when compared to teachers who work only in two shifts. In addition, teachers with late chronotypes who begin the work in the morning had a greater irregularity in the wake up time compared to teachers with earlier and intermediate chronotypes. Half of teachers have excessive sleepiness, which was positive correlated with work dissatisfaction. In general, teachers showed IPSQ averages equivalent to poor sleep quality and the women showed worst averages. From the results, it is suggested that the SWC of teachers varies according to work schedule, leading to irregularity and partial sleep deprivation in the week, although these responses vary according to chronotype. These changes are accompanied by excessive daytime sleepiness and poor sleep quality. However, it is necessary to expand the sample to clarify the influence of variables related to work, family structure and gender together

Estimativa populacional e uso do hábitat do boto-cinza (Sotalia guianensis) no litoral sul do Rio Grande do Norte

Four areas are known as of frequent usage by Guiana dolphins (Sotalia guianensis) in the south coast of Rio Grande do Norte state, northeast Brazil: Tabatinga, Pipa, Lagoa de Guaraíras and Baia Formosa. This extension of 40 km of shoreline is under increasing anthropogenic impacts due to continuous development of the coastal areas and vessel traffic. The objective of this study was to investigate aspects of population biology and habitat use of the population of Sotalia guianensis in the south coast of Rio Grande do Norte. It was applied the photo-identification technique and posterior methods of capture-recapture for population estimation (POPAN extension in MARK). The distribution, movement and site fidelity of the dolphins were analyzed trough the geographic information system (GIS) and group characteristics and behavior trough non-parametric statistics. Field work was conducted on board a 10m motor vessel from March 2008 to March 2009. Photo-identification effort was 329h with 113h of direct observation of the dolphins. The population estimatives for each area: Tabatinga: 75 (63-92); Pipa 105 (88-129); Lagoa de Guaraíras: 27 (18-54) e Baia Formosa: 112 (89-129) individuals. Total population estimative was: 223 (192 a 297). High site fidelity was detected for only part of the population (<15%) as low site fidelity and transients individuals were also detected (>20%). It was observed frequent movements between Tabatinga, Lagoa de Guaraíras and Pipa, but not Baía Formosa. This suggests a division in two communities along this shore extension: one in Pipa and other in Baía Formosa. Group size was small, most groups with up to 10 dolphins. The areas were use intensively, only in Lagoa de Guaraíras dolphins were not seen in all field trips. Lagoa de Guaraíras is an area used by small groups exclusively for foraging. In Tabatinga and Pipa dolphins concentrated close to the shore, in the inner sector of the area and the main activity is also foraging. Significant larger groups were seen in socializing behavior but there was no difference in group size between the inner and external sectors of the area. The presence of calves and juveniles were significant greater in the inner areas of Tabatinga and Pipa, confirming the hypothesis that these beaches are also used for parental care. In Baia Formosa dolphins concentrated in the outer sector and foraging was also predominant. Significant larger groups were seen in the outer sector, mainly engaged in mixed behaviors of travel/foraging, possibly in some kind of group foraging. Calves and juveniles were significant more present in the outer sector where group size was also larger. In general there was no difference in area usage and period of the day. Sotalia guianensis has characteristics that make the species vulnerable to human activities such as small population concentrated in patches of suitable habitats restrict to coastal areas. We hope that this study bring new information for the species and help for the adequate management of the area in order to assure the presence of the dolphins as well as its behavior pattern and gene flow betweencommunities.

O efeito da dessincronização circadiana sobre o metabolismo

The lost of phase relationship between rhythms and behaviour can, and often do, undesirable consequences. The purpose os study was to ascertain the effect of circadian desynchronization in T22 about metabolism of wistar rats. The subjects consisted of 24 animals separated in two groups: control (n=12) T24 with 8 weeks of aged and experimental group (n=12) T22, also with 8 weeks of aged. Both the groups were subject to register of locomotor actitivity, body temperature, body weight and food intake in all the experiment. And more, both the groups were subject to food deprivation, running in treadmill and forced swimming. The results show rhythm of locomotor activity and body temperature desynchronized. Dont exist diference in body weight between both the groups (T24 = 386,75±40,78g e T22 380,83±44,28g) . However, the food intake was different between the phases, light and dark, in intergroup and intragroup. The body temperature was not different in food deprivation. The same ocurred for running in treadmill and forced swimming. Since similar alterations occur in shift workers, it is proposed that the experimental paradigm presented in this manuscript is a useful model of shift work. That is, alterations in activity/rest cycles and consummatory behavior can affect the health of organism

Transferência de alimento aos infantes de Callithrix jacchus em uma situação de escassez de recurso alimentar

The genus Callithrix, like other marmosets, presents a cooperative breeding system, characterized by the contribution of parents and non-breeding individuals of the social group in the care of infants. This care is provided through lactation, transport, supervision of infants and food transfers. In this study, we investigated the care of offspring in Callithrix jacchus through the food transfers in family groups under conditions of abundance and scarcity of food resources. We also attempted to verify the relationship between the participation of individuals in the transport of infants and in the food sharing. We observed four families at the Núcleo de Primatologia of the Universidade Federal do Rio Grande do Norte, in a total of seven infants, six twins and a single infant. Each infant was observed twice a week, from 1st to 20th week of life using the methods focal continuous and focal instantaneous sampling with one minute intervals. The observations were carried by 10 minutes and beginning with the supply of food for each family. Two families were tested under conditions of scarcity of food resources (experimental condition) and two others were subjected to conditions of abundant food, both conditions with restricted access to food supply. The condition of food scarcity did not influence the rate of food sharing with the infants that, in general, was considered low. All shares observed were passive sharings. Only one family showed higher levels of food begging, probably due to the loss of the mother during the period of lactation of her offspring. In this family, the dominant and subadult males were primarily responsible for the food sharing. The experimental condition influenced the distance of infants in relation to food source, so the infants in families that received abundant food remained closer to the source. However, it is believed that the place of food consumption was not influenced by experimental condition. There was no relationship between the participation of individuals in the transport and food sharing with their young. Therefore, it is suggested that, in general, the transfer of food in C. jacchus is characterized by tolerance to the demands of caregivers, represented by the passive sharing. Rates of sharing with infants were low, probably due to intra-group competition for food generated by the experiment.

Avaliação do padrão do ciclo sono-vigília e a cognição em estudantes de medicina com diferentes esquemas de horários de aulas

The sleep patterns of students entering the university, is accompanied by many factors that can lead to changes in sleep habits, such as academic demands, new social opportunities, reduced parental care and irregular teaching schedules. The irregular pattern of sleep-wake cycle is usually accompanied by several daytime consequences, for example, reduced levels of motivation, performance, concentration, alertness and mood as well as increased fatigue and sleepiness.Thus, there are numerous reasons to support the fact that these students may suffer damage in their academic performance. The aim of this study was to evaluate the sleep-wake cycle (SWC) and cognition in medical students with different schemes teaching schedules. One group started classes at 08am, while the other started at 07am. We analyzed the data from 88 volunteers, 39 from each group. However, only those who participated in both stages of the study (n = 78) underwent cognitive testing. For subjective evaluation of the SWC was used questionnaires to check the quality of sleep, chronotype, daytime sleepiness and sleep habits. For objective evaluation was used actigraphy. For cognitive assessment was used the test MoCA (Montreal Cognitive Assessment). The results indicate that the group has class earlier had a greater irregularity of the SWC and a worse performance in cognitive testing. There was a difference between the schedules the week and weekend in the subjective variables, bedtime, wake up and sleep duration in both groups. The objective variables, time in bed showed difference between the schedules the week and weekend to the group started class at 08am and the variables bedtime, get up time, actual sleep time, time in bed and wake bouts in the class at 07am. In the cognitive test, there were differences between the groups in overall score and in the areas of executive function and memory recall. Thus, it is suggested that the class starting time may cause irregularity of the SWC and the irregularity may cause mild cognitive impairment. Moreover, cognitive testing MoCA was sensitive to detect differences among students, although the difference between the schedules is small