Hotels’ occupancy rates and convergence: Empirical evidence from the first pandemic wave

The scope of this study is to unravel possible convergence clubs regarding the occupancy rates of the hotel industry in the US states in the aftermath of the first COVID-19 pandemic wave. For this reason, the underlying paper resorts to the application of the generic convergence algorithm developed in Phillips and Sul (2007) for a sample of 50 US states over the daily period ranging from 01.12.2019 to 26.07.2020. The empirical analysis supports the identification of two primary convergence clubs consisting of an equally distributed number of regions (states). However, the two clubs can be merged into one after the implementation of the Phillips and Sul (2009) methodology, revealing that the first pandemic wave has eliminated any distinct (economic) characteristic between the different US states. JEL codes:L10, L80, R10 .

Transformation of home environments in pandemic: the concept of “life fits into room” in the new normal

PurposePandemic process has led re-questioning home environments within adaptations of new activities inside due to the restriction of outdoor usage. This paper aims to reveal spatial transformations carried out through the time spent at home during the COVID-19 pandemic.Design/methodology/approachA qualitative study is carried out based on Garfinkel’s (1961) ethnomethodology method (documentary method of interpretation). Analysis focused on the first month of pandemic in which urgent adaptations and solutions produced at home, and the situation in last two weeks of pandemic is analyzed within a control group and comparisons were made. Perec’s (1974) statement of “a user's manual” is used as a checklist of time-space-activity observations proposed on “mondayness, tuesdayness, wednesdayness, thursdayness, fridayness, saturdayness and sundayness.” Instead of daily period, activities performed on a weekly scale were recorded and time-dependent shifts of functions were revealed.FindingsFindings introduced new discussion topics to examine dwelling spaces in “new normal.” Comparisons indicate that hypothesis of gathering all activities in room in terms of “life fits into room” concept is directed through rapid spatial behaviors in daily life as primary adaptation.Research limitations/implicationsAlthough pandemic process continues after study, analysis of first four weeks are accepted as the period of rapid change and compared by last two weeks of pandemic.Originality/valuePandemic indicators proposed in study brings along that there is little information on the subject in literature. Socio-spatial findings address the examinations of spatial transformations into pandemic adaptation.

Dampak Aliran Dana Asing terhadap Fluktuasi Harga Saham (Studi pada Saham-Saham dalam Kelompok JII-70)

Derasnya aliran dana asing yang masuk ke pasar modal Indonesia membuat meningkatnya nilai kapitalisasi di pasar modal. Transaksi asing terhadap suatu saham juga akan menjadi sinyal positif bagi investor dalam menilai kualitas fundamental suatu saham. Penelitian ini bertujuan untuk melihat dampak aliran dana asing (beli dan jual) terhadap fluktuasi harga saham. Sampel yang digunakan dalam penelitian ini sebanyak 10 perusahaan yang diambil dari daftar kelompok saham-saham yang masuk dalam Jakarta Islamic Index (JII). Data yang digunakan berupa data transaksi posisi asing dan harga penutupan saham pada periode harian selama bulan Oktober–Desember 2020. Dengan menggunakan teknik regresi data panel diperoleh kesimpulan bahwa posisi jual-beli asing memberikan pengaruh yang positif dan signifikan dalam perubahan harga saham perusahaan. Pembelian asing akan mampu memberikan efek kenaikan harga saham, demikian pula sebaliknya. Swift flow of foreign funds into the capital market has increased the capitalization of transactionin the stock market. Foreign transactions against a stock will also be a positive signal for investors in assessing the fundamental quality of a stock. The purpose of this study is to determine the impact of foreign capital flows (buying and selling) on stock price fluctuations. The sample used in this study were 10 companies taken from the list of stocks included in the Jakarta Islamic Index (JII). The data used is in the form of foreign position transaction data and stock closing prices in the daily period during October - December 2020. By using the panel data regression technique, it is concluded that the foreign trade position has a positive and significant effect on changes in the company’s stock price. Foreign purchases will be able to give the effect of an increase in share prices, and vice versa.

132 Impact of Experimentally Shortened Sleep on Meal Timing in Adolescents

Introduction Short sleep increases the risk for obesity in adolescents. One potential mechanism relates to when eating occurs, rather than what or how much is eaten. This study investigated the impact of shortened sleep on meal timing and late evening eating in adolescents. Methods 93 healthy 14- to17-year-olds (62% female) completed a within-subject counterbalanced experimental sleep manipulation, engaging in shortened sleep (SS; 6.5 hours/night in bed) or healthy sleep (HS; 9.5 hours/night in bed), each for five nights, with order randomized. Sleep timing was verified through wrist-worn actigraphy. During each sleep period, adolescents completed 2-3 dietary recalls. Repeated-measure T-tests assessed the sleep manipulation effect on averaged times of the first and last eating episode, number of eating episodes after 8:00pm, and range of the daily eating period. Results Youth averaged 2.2 hours/night longer sleep during HS than SS (p<.001). The timing of the first eating episode was similar across conditions, relative to the clock (SS=08:51, HS=08:52) and to time since waking (SS=1.8hr, HS=1.9hr). The timing of the last eating episode averaged later on the clock during SS (20:34) than HS (19:38; p<.001), resulting in a longer eating period (SS=11.7hr, HS=10.8hr, p<.001). Youth averaged more eating episodes after 8:00pm during SS (0.87) than HS (0.59, p<.001). The gap between last eating episode and sleep onset was larger in SS (4.1hr) than HS (2.8hr; p<.001). Notably, on average, adolescents last eating episodes during SS (20:34) were earlier than sleep onset in either condition, and were even 2 hours earlier than when they fell asleep during HS (M=22:30). In exploratory analyses, these effects did not systematically vary by experimental order of the sleep conditions, family income, or participant age, sex, or norm-referenced body mass index. Conclusion Shortened sleep resulted in adolescents eating later and lengthening the daily period of time in which they ate, despite typically stopping eating well before sleep onset during healthy sleep. Late evening eating and long daily eating periods have been strongly associated with weight gain, which may help explain the link between shortened sleep and increased obesity risk in adolescents. Support (if any) R01HL120879

Causality-in-mean and causality-in-variance among Bitcoin, Litecoin, and Ethereum

Purpose This study aims to examine the volatility spillovers between Bitcoin (BTC), Litecoin (LTC) and Ethereum (ETH) as they are related to structural breaks. Design/methodology/approach This study examines the daily period from August 7, 2015 to July 10, 2018 by conducting causality-in-mean and causality-in-variance tests among cryptocurrencies. Findings The findings showed that there was one-way causality-in-mean from BTC to LTC and ETH, but there was no causality-in-mean from LTC and ETH to BTC. On the other hand, considering the structural breaks included in the variance equations, the estimation results showed that there were short-term causality-in-variance from LTC to BTC and long-term causality-in-variance from BTC to LTC. Originality/value This study fills the gap by contributing in two ways. First, to the best of the authors’ knowledge, this is the first study that used the cross-correlation function (CCF) of causality to explore causality-in-variance among cryptocurrencies. Second, this study considers the structural breaks in variance in the return series.

Daily periodicity of labor in pregnant women in physiological and complicated pregnancy depending on the sex of the fetus

Objective: the study aimed to reveal the daily periodicity of labor, the nature of melatonin metabolism, and the outcome of childbirth in women with a physiological and complicated pregnancy, depending on the sex of the fetus.Materials and methods: to study the chronophysiological characteristics of birth outcomes depending on fetal sex, 1 980 birth histories and stories of newborns were analyzed. The neonates were born between January 1 and December 31, 2016, in a maternity ward of the Federal State Budgetary Educational Institution of Higher Education “RostGMU” of the Ministry of Health of Russia. Melatonin production was identified by the level of urinary excretion of 6-sulfatoxymelatonin (6-SM) (its main metabolite) examining the morning portion of the urine of women by the ELISA method (at 8 am 3 ml of urine were collected in Eppendorf tube).Results: it was revealed that fetal sex modulated the activity of the central regulatory mechanisms responsible for the daily period functional processes in the female body and the initiation of labor. The largest number of spontaneous births by male fetuses occurred in the early evening before midnight when daily illumination was decreased, while the birth of girls was observed more often in the period from midnight to early morning. At the same time, mothers of boys had lower production of melatonin compared to that of girls’ mothers.Conclusions. The peculiarities of labor and birth complications associated with the sex of the fetus were identified.

Study Regarding Growing and Development Stages at Soybean Genotypes

Soybean is one of the most important sources of vegetable oil and protein. The aim of this study is to evaluate the behavior of 75 European soybean genotypes from four maturity groups regarding the influence of climatic conditions of 2020 on soybean main growing and development stages. The experiment was conducted at the ARDS Turda in 2020, using a complete randomized block design with three replications. Dates of emergence (VE) and beginning of flowering (R1), were recorded for all 75 soybean cultivars from each of the four maturity groups (000 to I). Results obtained show that growing, and development stages of the studied soybean genotypes are according both with: thermal units and daily period from sunrise to sunset. Effects of daylength and temperature on soybean development were estimated. The rate of development to flowering was fastest for the very early genotypes than for genotypes in the semi-early maturity group (MG).

Research on Network Patterns and Influencing Factors of Population Flow and Migration in the Yangtze River Delta Urban Agglomeration, China

Through the construction of a population flow and migration relationship matrix, this paper analyzes population flow and migration in the Yangtze River Delta urban agglomeration during the Spring Festival travel rush and daily period. This paper also studies the urban network spatial structure characteristics and the influencing factors from the perspective of inter-provincial population flow and migration. The results show the following: (1) as a central city, Shanghai has a significant siphon effect, with Suzhou, Nanjing, Hangzhou, Ningbo, Wuxi and Changzhou accumulating 86.95% of the incoming population. The Shanghai–Jiangsu cross-border floating population is active and accounts for 40.83% of the total mobility scale in the same period. The population flow and migration network in the Yangtze River Delta urban agglomeration shows obvious hierarchical characteristics. The secondary network relationship during the Spring Festival travel rush is the main migration path, while the first-level network relationship in the daily period is the main flow path. (2) Three indicators, namely, the network density, mean centrality, and control force based on the population flow and migration, consistently show that the Yangtze River Delta urban agglomeration network presents a strong connection state with the formation of a local cluster structure, highlighting that the city tightness in terms of population flow and migration also has dual attributes, which refers to “the restriction of the geographic space effect” and “overcoming the friction of space”. (3) Economic scale, political resources, industrial structure, and the historical basis are important factors influencing the formation of population flows and migration networks. Employment opportunities and labor wages are key guiding factors of the population migration direction, and spatial distance is a conditional factor influencing the formation of population flows and migration networks. The inter-provincial boundary, temporal distance, and transboundary frequency are the decisive factors for the formation of network patterns of population flow and migration.

Forecasting rupiah exchange rate with learning vector quantization neural network

<p>The classification technique and data forecasting will probably be one of the techniques that will often be needed in handling or managing big data. So, from that the author analyzes the possible development of the existing algorithms. The purpose is to find possibilities in the use of reliable algorithms in a particular field, then can be adopted and implemented to develop forecasting techniques in the future. Based on these considerations, the authors conducted experiments by applying LVQNN to conduct shortterm forecasting on daily period of the Rupiah exchange rate. The literature that is used as a reference is the discovery of architectural data classification processes that resemble forecasting techniques. So, when there is a combination of Rupiah exchange histories, it is possible to find these combinations into certain classes based on predetermined parameters and historical data combination data and forecast values in the past. In this research the factors chosen as indicators that affect the Rupiah exchange rate are the amount of exports, the amount of imports, the inflation rate and also the world oil price. In this research the highest accuracy value in the testing process for the population reached 99.0991%. The increase in the percentage value of forecasting accuracy is influenced by the composition of the data. In this study the formation of data composition is influenced by distinct data. The selection of parameters which become distinct claused determines how the composition of the data will be formed. If the composition of the data is not correct, the test results will not be good. If the number of weights vector is smaller than the input data, the forecasting accuracy will decrease. Because the weight vector cannot represent data combinations that used during training or testing.</p>

APLIKASI METODE ROTATED GUMBEL COPULA UNTUK MENGESTIMASI VALUE AT RISK PADA INDEKS SAHAM PASAR ASIA

Value at Risk is a tool used to calculate the value of risk in investing. The purpose of this study was to estimate VaR in the portfolio using the rotated Copula Gumbel approach, which originated from the Archimedean copula family. Copula can provide an overview of the relationship between random VaRiables on a quantil scale which is very useful in explaining the interrelationships in extreme events. This VaR calculation is used in portfolios from the Indonesian stock index (JKSE), Malaysia (KLSE), Singapore (STI), and South Korea (KOSPI), in the period of June 1, 2016 to June 1, 2018 (519 data). VaR is calculated using a daily period with a confidence level of 99%. So that the VaR of each portfolio is obtained, JKSE-KLSE is 1.41%, JKSE-STI is 1.38%, JKSE-KOSPI is 1.39%, KLSE-STI is 1.44%, KLSE-KOSPI is 1.42%, KOSPI-STI is 1.48%. The highest risk level that can be derived from the portfolio contains a combination of the Singapore stock index (STI) and the South Korean stock index (KOSPI).