Existence Of Day Research Articles

SAINS BUMI DAN ANTARIKSA PADA ANAK USIA DINI

The concept of science developed for the context of early childhood is so that children have insight and experience about events in their surroundings. Early childhood has a high curiosity about science. So that the process of early childhood learning about science is to develop a child's curiosity about the surrounding environment. Earth and space science is one of the fields of science for early childhood learning. The learning can be in the form of objects in the surrounding environment or natural events that occur. Therefore, it will be discussed about the concept of earth and space science in early childhood. The research method used is literature study (literature study) with relevant written sources. Earth Science covers objects and events on earth such as air, air, soil, rock, as well as natural disasters. Meanwhile, space science consists of objects in outer space, such as the sun, moon, stars, as well as the events that cause them, for example the existence of day and night, temperature differences and changing seasons. Several indicators developed at an early age related to the science of the Earth and Space area, namely knowledge of the properties of earth materials, use of vocabulary that displays day and night, observations about individual activities that can cause changes that occur in materials, observations about the weather.

Efekat dana u nedelji na južnoafričkom tržištu akcija - a garch analysis

Understanding dynamics of daily stock returns provide insight in trading opportunities available in stock markets. The purpose of the study was to examine whether day of the week effect exists in the South African equity market. Daily data from Top 40, All Shares, Basic Materials, Industrials, Consumer Goods, Health Care, Consumer Services, Telecommunications, Financials and Technology indices were collected for period 1995 to 2018. Exponential and threshold generalized auto regressive conditional heteroskedasticity models were employed to analyse day of the week anomaly. Findings of the day of the week for the mean equation revealed a positive Monday effect for aggregate indices namely Top 40 and All shares whilst the sectorial analysis showed a positive Monday effect for Basic materials, Consumer goods, Health care and Telecommunication. Furthermore, the mean equation for day of the week depicted a positive Tuesday effect for Financials sector, positive Wednesday effect for Consumer services sector and Thursday effect for Industrials and Technology sectors. The variance equation highlighted negative Monday effect for Top 40 and All shares as well as Basic materials, Consumer goods, Health care, Consumer services, Telecommunication and Financials sectors. However, Industrials sector indicated a negative Friday effect. The existence of day of the week effect nullifies the efficient market hypothesis in its weak form. In practice, it is recommended that for Mondays investors should invest in Top 40 and All shares, for Tuesday and Wednesday it would be prudent for investors to invest in Financial and Consumer services sectors respectively. Returns for Thursdays are attractive to an investor investing in the Industrial sector. An investor can reduce exposure by diversifying in the Health sector on Monday and in the by Industrial sector on Friday. Unlike previous studies that focussed on aggregate market indices, this study extended the analysis to sectors that constitute the market index.

A Study of Day of the Week Effect in Karachi Stock Exchange During Different Political Regimes in Pakistan

In this study we attempt to examine the existence of day of the week effect in Karachi Stock Exchange during the three prominent political regimes of PML-N, PPP, and PML-Q, in context of Pakistan using six sub-samples (three on basis of changing trading days, and three on basis of changing political regimes) extracted from the KSE-100 index which is the benchmark of Pakistan's equity market and is the biggest and most dynamic operational stock exchange of Pakistan having a share of about 70 percent of total stock transition. Dummy variable approach is utilized in this study to uncover the day of the week effect in trading days during the sub-samples. The study finds evidence of existence of significant day of the week effect during the PPP regime with pronounced negative first trading day returns, while no significant negative returns are discovered during the PML-N and PML-Q regimes

DAY OF THE WEEK EFFECT AND STOCKMARKET VOLATILITY: FURTHER EVIDENCE FROMMALAYSIA EXCHANGE

This paper examines the day of the week anomalies at the Malaysian Exchange during various economic situations. In particular, the paper looks at the existence of day of the week effect for various indices, the popular benchmark Composite Index, the broader based Emas Index, smaller capital based Second Board Index, Financial Index of the Main Board and one of the newly created sectoral index of Trade and Services. Three estimation models are used to investigate the presence of daily effect in these indices: the Ordinary Least Squares regression (OLS), Box and Jenkins ARIMA and the GARCH(p,q) models for capturing changing volatility in the stock returns. The OLS results reveal negative Monday mean returns for each of the indices for the whole sample period. As expected during the Asian Economic Crisis period, the mean returns are negative for each day of the week, with Thursday recording the largest negative returns. Negative mean returns on Monday are not generally observed for each of the indices in recent years (during the World Economic Crisis and the following Recovery Period). When the changing volatility in the financial market is taken into account, the Monday negative returns remain significant during the whole sample period.

GELİŞMEKTE OLAN ÜLKELERDE AYIN GÜN ETKİSİ

The aim of this study is to test the existence of day of the month effect at Istanbul, Bovespa, Merval , Shanghai and Sensex stock markets whether investors have chance to benefit from these abnormal returns. In the study, emerging markets from Asia-Pacific and America are chosen and results are compared to Turkish stock index. Daily percentage returns of each market are calculated starting from the first transaction day to the December 31, 2012. 31 hypotheses for each of five markets are tested by using Z statistics. Results show that positive and negative abnormal returns exist at all of the five stock markets.

Effectiveness of the anaesthetic MS-222 in gilthead seabream, Sparus aurata: Effect of feeding time and day–night variations in plasma MS-222 concentration and GST activity

Feeding time is a potent zeitgeber capable of synchronising behavioural and physiological daily rhythms in fish. However, the effect of feeding time on the daily rhythm of drugs toxicity and/or effectiveness remains unexplored to date. In this paper we investigated the day/night variations in the effectiveness of an anaesthetic commonly used in fish (Tricaine, MS-222) in a teleost of great chronobiological and aquaculture interest (gilthead seabream). To this end, fish were kept under LD 12:12 and fed at mid-light (ML), mid-darkness (MD) or random times (RD). The time needed to induce anaesthesia (reduction of locomotor activity) during MS-222 exposure (65mg/L) as well as the recovery period were investigated at ML and MD in the three experimental groups using specialised video tracking software. In addition, daily rhythms of GST activity in the liver (as an indicator of detoxification processes) and plasma MS-222 concentration (related to uptake) were determined. The results revealed that MS-222 effectiveness in the ML group was higher during the day than at night (significant reduction of activity after 3min vs. 5min) whereas in the MD group, the daily variation of MS-222 effectiveness was inverted (significant reduction of activity after 7min at ML vs. 2min at MD), suggesting that feeding time can shift the day–night variations in the effectiveness of MS-222. Hepatic GST also seemed to be affected by feeding time: in fish fed at MD or RD this enzyme activity showed significant differences during the day, and the highest levels were found at different times of the day in each group. Plasma MS-222 concentrations were higher at ML (142.4±12.8ng/ml) than at MD (96.3±10.9ng/ml) (t-Student, p<0.05). These results suggest that the daily variation in MS-222 concentration following exposure might be involved, among other factors, in the existence of day–night variations in the effectiveness of this anaesthetic. Furthermore, manipulation of the feeding schedule can be used to modify the daily variations in MS-222 effectiveness, which has basic as well applied implications for optimising anaesthesia protocols in fish aquaculture.

EL PAPEL DE LA OBSERVACIÓN EN LA FORMALIZACIÓN DE CONCEPTOS A PARTIR DE LA CONTRIBUCIÓN DE LA ASTRONOMÍA. CASO PARTICULAR: NUESTRA ESTRELLA EL SOL

Este trabajo presenta una estrategia pedagógica para el desarrollo de la observación como método de investigación en estudiantes de básica primaria, con el fin de promover la comprensión de fenómenos físicos, a partir de la exploración de las características básicas del Sol. Su objetivo principal es potencializar los dispositivos básicos de aprendizaje en estudiantes de primaria, a partir del desarrollo de actividades que promuevan un adecuado desenvolvimiento de los niños dentro y fuera del entorno escolar. Se busca trabajar a partir del reconocimiento y la constante observación de ideas en torno al sol que han construido los estudiantes e introducir relaciones que posibiliten un dialogo desequilibrante entre maestro-estudiante y estudiante-estudiante sobre fenómenos relacionados al sol como lo son: las sombras, porque hay día y noche, la apariencia y composición del sol, entre otras. Al mismo tiempo, posibilitar la incorporación de material de trabajo de las ciencias físicas básicas, junto con actividades artísticas que apoyen el desarrollo del razonamiento espacial y lógico, en búsqueda de estimular a los estudiantes hacia el conocimiento de elementos en astronomía y que ellos logren dar razón de fenómenos que suceden a su alrededor y encontrar respuestas de sucesos que se den en su quehacer cotidiano.

Examining The Day Of The Week Effect In Istanbul Stock Exchange (ISE)

The existence of day of the week effect for Istanbul Stock Exchange (ISE) was analyzed on the basis of ISE-100 index returns, the returns of all stocks traded in ISE and market capitalization based portfolio returns during 1995-2008. In line with the previous findings, the results of the study presented that the ISE-100 index, ISE traded stocks and market capitalization based portfolios had significant negative Monday and significant positive Thursday and Friday returns.

MS-222 toxicity in juvenile seabream correlates with diurnal activity, as measured by a novel video-tracking method

Fish are frequently exposed to anaesthetics since their use is necessary in several aquaculture procedures. The aim of this study was to investigate the existence of day–night differences in the toxicity and effectiveness of a common fish anaesthetic (MS-222) in juvenile gilthead seabream ( Sparus aurata), determining the induction time of anaesthesia and subsequent recovery by a novel video-recording system. Our results showed that MS-222 toxicity was significantly higher at ML (mid-light) (LC50 = 85.5 mg/L) than at MD (mid-darkness) (LC50 = 107.6 mg/L) (trimmed Spearman-Karber method). In addition, when fish were exposed to a sublethal but effective MS-222 concentration (65 mg/L), 7 min passed before a 50% reduction in swimming activity was observed at ML compared to the 9 min required at MD. As regards recovery, fish showed activity levels similar to basal levels 10 min after MS-222 removal at ML, but only 6 min at MD. These results indicated that both toxicity and effectiveness were higher during the day than at night, coinciding with the diurnal activity pattern displayed by seabream, which should be taken into account when designing and applying daily protocols for anaesthesia in aquaculture.

La contaminacion atmosferica como factor de riesgo: El caso de Madrid

En estas notas analizamos los tres aspectos más importantes de la contaminación atmosférica en Madrid. Que podemos resumir en:- las variaciones entre el in viemo y e! verano, entre e! comienzo y fin de la semana y a lo largo dei día;-las diferencias espaciales con zonas de alta contaminación en e! centro y otras con niveles medi os y bajos en Ia periferia y cerca de espacios arbolados;- laexistencia de días con valores críticos, especialmente en inverno y asociados a situaciones de gran estabilidad.

On the existence of days with extraordinary geomagnetic lunar tide

The lunar daily variation, L, in the geomagnetic horizontal field, H, at Huancayo on 2517 quiet days with disturbance character figure Cp ⩽ 0.5 has been analysed. On 487 individual days L has been separated from the diurnal variation. Classes of L are defined objectively and quantitatively and the definitions are applied to the study of the characteristics of L on the 487 days. It is found that the magnification of L tends to vary from hour to hour on the same day. The existence of Big L days near the December solstice has been confirmed and they are also found to occur near the Equinoxes. Days have been found on which the phase of L is completely reversed. Some of these days are shown on which the inversion of L conspicuously modifies the diurnal variations. These Inverse L days exist near the December solstice as well as near the Equinoxes and they are more numerous than Big L days. It is suggested that the extraordinary L effects are caused by modifications in the oscillations of the upper atmosphere.