FENOMENA ANOMALI MUSIMAN INDEKS HARGA SAHAM DI INDONESIA

This Research aims to obtain empirical evidence about the existence of anomaly seasonal effects on market returns on a daily and monthly basis on the IHSG and the LQ-45 Index in Indonesia throughout January 2015 untill September 2020. The diversity of arguments and research results regarding the phenomenon of seasonal anomalies in stock returns derived from previous studies make this phenomenon interesting to study. We analyze daily stock returns by using the Kruskal Wallis test, while the average monthly return is analyzed using the one-way Anova. The findings show that the phenomenon of stock anomaly returns according to the daily pattern of the week (day of the week effect) and the monthly pattern (month of the year effect) on IHSG and the LQ-45 Index are not proven within the range research from January 2015 to September 2020. The results of stock price forecasting provide benefits in supporting investors to develop their investment strategies. Futhermore, this information is also important to choose and determine which stocks should be bought and sold. In addition to investors, this information is also useful for management to monitor the pattern of stock price movements, so that they can plan, formulate strategies and take anticipatory steps based on possible threats that could arise.Keywords :Anomaly Seasonal Effect, day of the week effect, month of the year effect, market Return

An examination of calendar anomalies: evidence from the Thai stock market

PurposeThe study examines the existence of calendar anomalies, including the day-of-the-week (DOW) effect and the January effect, in the Stock Exchange of Thailand.Design/methodology/approachUsing daily stock returns from March 2014 to March 2019, the study performs regression analysis to examine predictable patterns in stock returns, the DOW effect and the January effect, respectively.FindingsThere is strong evidence of a persistent monthly pattern and weekday seasonality in the Thai stock market. Specifically, Monday returns are negative and significantly lower than the returns on other trading days of the week, and January returns are positive and significantly higher than the returns on other months of the year.Practical implicationsThe findings offer managerial implications for investors seeking trading strategies to maximize the possibility of reaching investment goals and inform policymakers regarding the current state of the Thai stock market.Originality/valueFirst, the study investigates calendar anomalies in the Thai stock market, specifically the DOW effect and the January effect, which have received relatively little attention in the literature. Second, this is the first study to examine calendar anomalies in the Thai stock market across different groups of companies and stock trading characteristics using a range of composite indexes. Furthermore, the study uses data during the period 2014–2019, which should provide up-to-date information on the patterns of stock returns in Thailand.

Biodiversity Patterns of Macroinvertebrate Assemblages in Natural and Artificial Lentic Waters on an Oceanic Island

The Azorean islands have been historically affected by human activities, mainly due to the combined effects of habitat degradation and fragmentation, and the introduction of exotic species. We here aim to analyze the role of environmental characteristics and spatial descriptors in supporting regional biodiversity of macroinvertebrates by considering natural ponds and artificial tanks. After the monthly variation of macroinvertebrate assemblages was assessed in three temporary and two permanent ponds in the Azorean island of Terceira during a complete inundation-desiccation annual cycle, the assemblage differences of 12 ponds (three temporary and nine permanent ponds) and 8 closely-located artificial tanks were analyzed across a range of landscape disturbances. Macroinvertebrate assemblages were found to differ according to hydroperiod and sampled months. Although the former explained the highest variance, macroinvertebrate differentiation by hydroperiod was also dependent on the study month. Our results also revealed a consistent monthly pattern of species replacement. However, the contribution of nestedness to the macroinvertebrate β-diversity was notable when temporary ponds were close to desiccation, probably indicating a deterministic loss of species due to the impoverished water conditions of the ponds facing desiccation. When the macroinvertebrate assemblages were analyzed in relation to physico-chemical variations and spatial descriptors, the artificial tanks were not clearly segregated from the natural ponds, and only differentiated by pH differences. In contrast, those natural ponds exhibiting high concentrations of total phosphorous (likely signs of anthropization) also discriminated the ordination of ponds in a distance-based redundancy analysis, and showed impoverished assemblages in comparison with well-preserved ponds. The macroinvertebrate assemblages of the natural ponds showed a significant spatial pattern, but this spatial influence was not significant when tanks and ponds were considered together. Our results suggest that tanks may act as possible reservoirs of biodiversity during the desiccation period of temporary ponds, but are unable to establish successful populations. These fishless permanent tanks can complement the conservation of a biodiversity that is largely maintained by the pristine high-altitude natural ponds. The establishment of a guideline for conservation management that also considers the artificial tanks is necessary to benefit the local and regional Azorean macroinvertebrate diversity.

THE CLINICAL EPIDEMIOLOGY OF NOROVIRUS INFECTION IN CHILDREN WITH DIARRHEA AT REGIONAL PUBLIC HOSPITAL DR.SOETOMO

Background: Norovirus has become a major cause of severe outbreaks of gastroenteritis since the discovery of the rotavirus vaccine, with the main symptom being diarrhea. Until now, research on the epidemiological analysis of norovirus has not been carried out at Regional Public Hospital (RSUD) Dr. Soetomo, Surabaya. Purpose: This study aims to provide clinical epidemiology data and an analysis of norovirus infections in children with diarrhea at Regional Public Hospital (RSUD) Dr. Soetomo, Surabaya, Indonesia, including the prevalence of norovirus infection in each age group and sex, its clinical appearance, and its seasonal variation. Methods: A cross-sectional study was conducted in children aged 1–60 months hospitalized for diarrhea in RSUD Dr. Soetomo between April 2013 and March 2014. Identification of the virus in the stool was done by norovirus enzyme immunoassay Quick NaviTM Noro2. The proportion, age, sex, clinical symptoms, and patterns of the norovirus seasonal data were calculated. Results: Norovirus was detected in 64 samples (19%) of the 340 stool samples, with a mean patient age of 11.75 months; it was mostly found in patients less than 24 months of age (95%), and 64% were male. The monthly pattern of norovirus infection was mostly found in November, followed by May and April. The clinical symptoms were fever (72%), vomiting (66%), bloating (59%), abdominal cramps (34%), perianal inflammation (27%), abdominal distension (16%), and seizures (8%). Conclusion: The prevalence of norovirus was found to be high in patients with diarrhea aged 1–60 months hospitalized in RSUD Dr. Soetomo, with a proportion of 19%. Further research is needed to determine the severity of norovirus infection.

No Relationship Between Perceived Health Anomalies and Perceived Experimental Success in Retired Breeder Male Hartley Albino Guinea Pigs

ABSTRACTGuinea pigs used in our laboratory for cardiac research sometimes exhibit physical abnormalities. These issues may abate or intensify during the time they are housed in our facility. After using a guinea pig for research, experimentalists note the apparent health of an animal based on visible features and/or abnormal electrophysiology of the heart. There was an existing anecdotal observation that the health of the Guinea Pigs, and subsequently the experimental success rate, had a seasonal variation; therefore we sought to determine if there is a time of year in which our guinea pigs are more likely to be perceived as unhealthy, and whether any determined monthly pattern correlates with an experimentalist’s ability to complete an experimental protocol. An electronic log was created to record the perceived health of the animal and the ability to complete the experiment successfully. Irregular symptoms included, but were not limited to, severe weight or hair loss and irregularities with the heart found post thoracotomy or during baseline electrophysiological recordings of whole-heart preparations. Animals that did not exhibit significant weight or hair loss, or other ailments were considered “healthy”. Overall, our results indicate that there are no monthly variations in perceived Hartley Albino guinea pig health or correlations with experimental completion rates, suggesting mild hair or weight loss that is common when shipping animals may not significantly affect the ability to conduct ex vivo whole-heart electrophysiological studies.

Measuring Regional Atmospheric CO2 Concentrations in the Lower Troposphere with a Non-Dispersive Infrared Analyzer Mounted on a UAV, Ogata Village, Akita, Japan

We have developed a simple measuring system prototype that uses an unmanned aerial vehicle (UAV) and a non-dispersive infrared (NDIR) analyzer to detect regional carbon dioxide (CO2) concentrations and obtain vertical CO2 distributions. Here, we report CO2 measurement results for the lower troposphere above Ogata Village, Akita Prefecture, Japan (about 40° N, 140° E, approximately −1 m amsl), obtained with this UAV system. The actual flight observations were conducted at 500, 400, 300, 200, 100, and 10 m above the ground, at least once a month during the daytime from February 2018 to February 2019. The raw CO2 values from the NDIR were calibrated by two different CO2 standard gases and high-purity nitrogen (N2) gas (as a CO2 zero gas; 0 ppm). During the observation period, the maximum CO2 concentration was measured in February 2019 and the minimum in August 2018. In all seasons, CO2 concentrations became higher as the flight altitude was increased. The monthly pattern of observed CO2 changes is similar to that generally observed in the Northern Hemisphere as well as to surface CO2 changes simulated by an atmospheric transport model of the Japan Meteorological Agency. It is highly probable that these changes reflect the vegetation distribution around the study area.

Interaction between small pelagic purse seine fishery and its top predators

Due to very good collaboration with one commercial purse seiner, using “Srdelara” and operating in fishing zone G, preliminary data concerning the interaction between small pelagic purse seine fishery and its predators were obtained. According to the notes taken by experience observer on-board in period from year 2013 to 2016, seems that tunas, dolphins and swordfish were the faithful companions of purse seiner fisherman with abundance of 68.6%, 22.0% and 9.4%, respectively. Although they were present all year round, their monthly pattern of appearance indicated that less tunas were recorded in May-June, more dolphins were noted from July to October while swordfish were mostly abundant in winter (January-March). Within the investigated period, slightly increasing trend of tuna and dolphins’ appearance was recorded, although statistically not significant. Analysing possible correlation between purse seine catches and predator’s abundances, revealed that appearance of tuna had negative impact on the catches (dispersion of schools), while realised catches in presence of dolphins were quite good so it seems that they tend to round up small pelagic fish schools.

Managing Central Government Finances: Asymmetric Seasonality in Receipts and Expenditures

This article examines asymmetry in the pattern of seasonality in revenues and expenditures of central government, highlighting the scope of improving efficiency in the management of government finances. Asymmetry is conceptualized as consisting of three inter-related aspects: (a) monthly pattern of unevenness measured against a norm of equally distributed monthly shares of revenues and expenditures, (b) non-synchronization between the pattern of unevenness for expenditures as compared to that for revenues and (c) fiscal year start–end (April and March) extreme variations. We have defined and applied an index of seasonal unevenness to individual revenue and expenditure aggregates. A prominent feature of asymmetry in revenue receipts emanates from the bunching of corporate and income tax revenues in the months of September, December and March. Non-tax revenues peak prominently in August and March. Mismatches in expenditures and revenues due to different patterns of unevenness necessitate financing by borrowing, which involve fiscal costs. In addition, non-synchronization of expenditures that invite injecting demand into the system and revenues that involve withdrawal of resources have macro implications that affect aggregate demand. This also has a monetary cost affecting availability of liquidity. In making comparisons, we have examined monthly revenue and expenditure data over the period from 2000–2001 to 2015–2016, which was divided into four periods with respect to political economy regimes relating to NDA1, UPA1, UPA2 and NDA2. We also take note of undue adjustments in expenditures and revenues for ostensibly meeting fiscal and revenue deficit targets by postponing expenditures to the next fiscal year and obtaining advance payments of taxes.

Material Particulado en Suspensión en el Río de la Plata: importancia del río Bermejo en su variabilidad espacio-temporal

<p>Spatio-temporal variability of Suspended Particulate Matter (SPM) in the Río de la Plata (RdlP) is analyzed from 2002-2014 of MODIS (Moderate Resolution Imaging Spectroradiometer) data and explained in terms of its main tributaries flows. The monthly mean showed maximum during late summer to mid-autumn, and minimum in mid-winter to early summer. The Bermejo river (BeR), is the tributary that more sediment in suspension brings. This situation was reflected in the significant relationship between the mean monthly concentrations of SPM with the average monthly flow of BeR. Seasonal variation in SPM concentration, showed maximum values in fall, followed by summer, and minimum values in winter and spring, reflecting the monthly pattern of discharge of the BeR with one and two months of delay. The pattern of spatial variation differentiated threes regions: the inner, central and outer. The annual variability evidenced a marked seasonality in the spatial coverage pattern of the waters with the highest SPM. The pattern of the anomalies, appeared to be related to the influence of river discharge, what it showed the temporal pattern of SPM anomalies did not related to the ENSO (El Niño – Sourthen Oscillation) cycle. These results allowed us to denote the importance of BeR (not ENSO dependent) to explain the pattern of observed SPM anomaly in the RdlP region.</p>