scholarly journals Explanation and verification of the rules of attack in table tennis tactics

Author(s):  
Xingdong Zhou

Abstract Background The rules of attack in table tennis tactics have been discovered by the coaches and researchers of the Chinese table tennis team (CTTT) through long-term practice. However, they are only empirical judgements and have not been objectively verified. Methods The software "Table Tennis Master" has been used to analyse 200 matches of top players of CTTT against various opponents in recent years to obtain detailed statistics by analysing the effect of attack in the end line (AIEL) and attack out of the end line (AOEL). Results (1) The scoring rate of the players was high after AIEL but very low after AOEL (p < 0.05); (2) the round of service (serve/receive) and level of skills had little influence on the effect of AIEL and AOEL; and (3) the timing of attack had a great influence on the effect of AIEL and AOEL (r > 0.9). Conclusions In the high-level table tennis match, the rules of AIEL and AOEL are scientific. In accordance with the rules, the complex tactics can be simplified to the two concepts, AIEL and AOEL.

2021 ◽  
Vol 1 (4) ◽  
pp. 26-33
Author(s):  
T. V. NAUMENKO ◽  

The problem of the model of an economic person in modern scientific theory occupies an essential place. Post-nonclassical science, focusing its attention on the subject of scientific research, puts at the center of research the influence of a person on all processes of society, including economic ones. The influence of the human factor and the factor of culture on the economy is studied by many modern economists in order to identify the most general patterns of functioning of national cultures and national economies. The article proposes a culturological interpretation of the model of an economic person on the basis of ethnometric parameters developed by the Dutch sociologist G. Hofstede, provides evidence of the need to build new models of a person in the economy, taking into account the culturally specific characteristics of nations, and also substantiates the thesis existing in modern humanities about the influence of culture on the economy. The homo economicus model of man is one of the most widespread and most debated. At the same time, in the scientific space, the model of the economic person is assigned a crucial role for achieving the prosperity of nations. At the same time, the thesis that in economics culture has a meaning that has a great influence on the study of models of an economic person from the standpoint of culturological science and sociology becomes important. Ethnometric indices developed by G. Hofstede allow for a correlation analysis between such cultural indicators as a high level of individualism, dominance of masculine values, and a long-term period of life planning and satisfaction of one's desires, combined with a low power distance and lack of fear of change, help to achieve a high economic development of the nation. Despite the belief of many sociologists and economists that the possession of these characteristics leads to the prosperity of the nation, none of the developed European countries, based on the results of their development, confirms the conclusion about such a correspondence. In this regard, it seems correct to abandon the construction of a universal model of a person in the economy and focus on the culturally specific characteristics of individual nations with their potential for economic development. The toolkit developed by G. Hofstede undoubtedly has a high heuristic potential in the study of the relationship and interdependence of culture and economy, but it is also obvious that the universalization of the model of an economic person is possible only in theory, and in the case of practical application, it deviates to some extent from the ideal model. due to the peculiarities of national cultures, which have a significant impact on the economic prosperity of nations.


2006 ◽  
Vol 27 (4) ◽  
pp. 218-228 ◽  
Author(s):  
Paul Rodway ◽  
Karen Gillies ◽  
Astrid Schepman

This study examined whether individual differences in the vividness of visual imagery influenced performance on a novel long-term change detection task. Participants were presented with a sequence of pictures, with each picture and its title displayed for 17  s, and then presented with changed or unchanged versions of those pictures and asked to detect whether the picture had been changed. Cuing the retrieval of the picture's image, by presenting the picture's title before the arrival of the changed picture, facilitated change detection accuracy. This suggests that the retrieval of the picture's representation immunizes it against overwriting by the arrival of the changed picture. The high and low vividness participants did not differ in overall levels of change detection accuracy. However, in replication of Gur and Hilgard (1975) , high vividness participants were significantly more accurate at detecting salient changes to pictures compared to low vividness participants. The results suggest that vivid images are not characterised by a high level of detail and that vivid imagery enhances memory for the salient aspects of a scene but not all of the details of a scene. Possible causes of this difference, and how they may lead to an understanding of individual differences in change detection, are considered.


2021 ◽  
Vol 11 (7) ◽  
pp. 638
Author(s):  
Giuseppe Giuliani ◽  
Francesco Guerra ◽  
Lorenzo De Franco ◽  
Lucia Salvischiani ◽  
Roberto Benigni ◽  
...  

Background. Minimally invasive gastrectomy is currently considered a valid option to treat gastric cancer and is gaining increasing acceptance. Recent reports have suggested that the application of robots may confer some advantages over conventional laparoscopy, but the role of robotic surgery in clinical practice is still uncertain. We aimed to critically review the relevant evidence comparing robotic to standard laparoscopic surgery in performing radical gastrectomy. Methods. The Pubmed/Medline electronic databases were searched through February 2021. Paper conference and the English language was the only restriction applied to our search strategy. Results. According to the existing data, robotic gastrectomy seems to provide some benefits in terms of blood loss, rate of conversion, procedure-specific postoperative morbidity, and length of hospital stay. Robotic gastrectomy is also associated with a longer duration of surgery and a higher economic burden as compared to its laparoscopic counterpart. No significant differences have been disclosed in terms of long-term survivals, while the number of lymph nodes retrieved with robotic gastrectomy is generally higher than that of laparoscopy. Conclusions. The current literature suggests that robotic radical gastrectomy appears as competent as the conventional laparoscopic procedure and may provide some clinical advantages. However, due to the relative paucity of high-level evidence, it is not possible to draw definitive conclusions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sándor Szabó ◽  
Irene Pinedo Pascua ◽  
Daniel Puig ◽  
Magda Moner-Girona ◽  
Mario Negre ◽  
...  

AbstractLack of access to modern forms of energy hampers efforts to reduce poverty. The provision of electricity to off-grid communities is therefore a long-standing developmental goal. Yet, many off-grid electrification projects neglect mid- and long-term operation and maintenance costs. When this is the case, electricity services are unlikely to be affordable to the communities that are the project’s primary target. Here we show that, compared with diesel-powered electricity generation systems, solar photovoltaic systems are more affordable to no less than 36% of the unelectrified populations in East Asia, South Asia, and sub-Saharan Africa. We do so by developing geo-referenced estimates of affordability at a high level of resolution (1 km2). The analysis illustrates the differences in affordability that may be found at the subnational level, which underscores that electrification investments should be informed by subnational data.


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 71
Author(s):  
Charalampos Dimitriadis ◽  
Ivoni Fournari-Konstantinidou ◽  
Laurent Sourbès ◽  
Drosos Koutsoubas ◽  
Stelios Katsanevakis

Understanding the interactions among invasive species, native species and marine protected areas (MPAs), and the long-term regime shifts in MPAs is receiving increased attention, since biological invasions can alter the structure and functioning of the protected ecosystems and challenge conservation efforts. Here we found evidence of marked modifications in the rocky reef associated biota in a Mediterranean MPA from 2009 to 2019 through visual census surveys, due to the presence of invasive species altering the structure of the ecosystem and triggering complex cascading effects on the long term. Low levels of the populations of native high-level predators were accompanied by the population increase and high performance of both native and invasive fish herbivores. Subsequently the overgrazing and habitat degradation resulted in cascading effects towards the diminishing of the native and invasive invertebrate grazers and omnivorous benthic species. Our study represents a good showcase of how invasive species can coexist or exclude native biota and at the same time regulate or out-compete other established invaders and native species.


2021 ◽  
pp. oemed-2020-107094
Author(s):  
Kathryn Badarin ◽  
Tomas Hemmingsson ◽  
Lena Hillert ◽  
Katarina Kjellberg

ObjectivesMusculoskeletal pain (MSP) is prevalent among the workforce. This study investigates the long-term association between physical workload (PWL) and increased frequency of MSP among male and female employees with pre-existing occasional MSP.MethodsThis study uses the Stockholm Public Health cohort survey data from the baseline 2006. The sample includes 5715 employees with baseline occasional MSP (no more than a few days per month). Eight PWL exposures and overall PWL were estimated using a job-exposure matrix (JEM). The JEM was assigned to occupational titles from a national register in 2006. Follow-up survey data on frequent MSP (a few or more times a week) were collected from 2010. Logistic regressions produced sex-specific ORs with 95% CIs and were adjusted for education, health conditions, psychological distress, smoking, BMI, leisure-time physical activity and decision authority.ResultsAssociations were observed between several aspects of heavy PWL and frequent MSP for men (eg, OR 1.57, 95% CI 1.13 to 2.20, among those in the highest exposure quartile compared with those in the lowest quartile for heavy lifting) and women (eg, OR 1.76, 95% CI 1.35 to 2.29, among those in the highest exposure quartile compared with those in the the lowest quartile for physically strenuous work). Small changes were observed in the OR after adjustment, but most of the ORs for PWL exposures among the men were no longer statistically significantly increased.ConclusionA high level of exposure to heavy PWL was associated with increased frequency of MSP 4 years later for men and women with baseline occasional pain.


2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
E Belik ◽  
OV Gruzdeva ◽  
YUA Dyleva ◽  
EG Uchasova ◽  
MYU Sinitsky ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Aim to determine the features of adiponectin expression, secretion of adiponectin and its receptors in local fat depots in CVD. Materials and methods The study included 90 patients with СAD (Group 1) and 60 patients with heart defects (Group 2). Adipocytes were isolated from samples of subcutaneous (SAT), epicardial (EAT) and perivascular (PVAT) adipose tissue obtained during CABG or heart valve replacement. The expression of adiponectin was determined by qPCR using TaqManTM Gene Expression Assays (Applied Biosystems, USA) in the ViiA 7 Real-Time PCR System (Applied Biosystems, USA), the levels of expression products was determined using enzyme immunoassay (Bender MedSystems GmbH, Vienna, Austria). The data were analyzed using the statistical software Statistica 9.0. Results EAT adipocytes were characterized by the lowest adiponectin expression relative to adipocytes of other localization both in Group 1 and Group 2. In patients Group 1 adiponectin expression in EAT was reduced relative in SAT and PVAT (by 1.2 and 1.5 times). In Group 2, the adiponectin mRNA in the EAT was lower than in the SAT and PVAT (1.4 and 1.5 times). The expression of adiponectin in EAT in Group 2 exceeded the same indicator in Group 1 by 1.2 times. The maximum expression of adiponectin was observed in the PVAT culture in patients of both groups. For Group 2, this indicator exceeded the values of Group 1 by 1.2 times. The content of adiponectin in the culture EAT was lower than in the SAT, both in Group 1 and Group 2 (by 1.3 and 1.13 times). The level of this indicator in Group 2 was 1.4 times higher than in Group 1. PVAT adipocytes of patients with CAD were characterized by the lowest level of adiponectin secretion in comparison with adipocytes of other localization. The adiponectin level in the PVAT of Group 2 exceeded that of fat stores of other localization and in Group 1 patients by 1.8 times. There were no statistically significant differences in the expression and concentration of adiponectin in the culture of adipocytes of the SAT between the groups of patients. In Group 1, the lowest level of AdipoR1 was found in the adipocyte culture of the PVAT. Noteworthy is the decrease in the level of AdipoR1 in Group 1 compared to the level of Group 2, observed in the SAT and PVAT: 1.3 and 1.5 times. There were no significant differences in the concentration of the AdipoR1 in the EAT, as well as AdipoR2 in all types of AT between the groups of patients. Conclusion: in CVD the EAT is characterized by minimal expression and secretion of adiponectin, regardless of nosology. In CAD despite the high level of expression of adiponectin, the adipocytes of the PVAT were found to have the lowest content in comparison with adipocytes of other localization. Dysregulation of the adiponectin/AdipoR axis is observed in PVAT, which may be due to low expression of adiponectin receptors and long-term processes of its post-translational modification and oligomerization in CAD.


Author(s):  
Masashi Nakayama ◽  
Haruo Sato ◽  
Yutaka Sugita ◽  
Seiji Ito ◽  
Masashi Minamide ◽  
...  

In Japan, any high level radioactive waste (HLW) repository is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various admixtures. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly Fly-ash Contained Silicafume Cement), containing over 60 wt% of silica-fume (SF) and fly-ash (FA). HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in the Horonobe Underground Research Laboratory (URL). The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40 wt% OPC (Ordinary Portland Cement), 20 wt% SF, and 40 wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m3 of HFSC was used. The workability of HFSC shotcrete was confirmed in this experimental construction.


2002 ◽  
Vol 175 (3) ◽  
pp. 673-681 ◽  
Author(s):  
H Wang ◽  
E Isaksson ◽  
B Von Schoultz ◽  
JM Cline ◽  
L Sahlin

The effects of oestrogen are mediated by two specific intracellular receptors, oestrogen receptors (ER) alpha and beta, which function as ligand-activated transcriptional regulators. Ovariectomized macaques (Macaca fascicularis) were used to study the regulation of ERalpha and ERbeta in the endometrium by immunohistochemistry and in situ hybridization after long-term hormone treatment. Animals were treated continuously for 35 Months with either conjugated equine oestrogen (CEE), medroxyprogesterone acetate (MPA), combined CEE/MPA, or tamoxifen (TAM). Treatment with CEE/MPA down-regulated ERalpha in the superficial glands. In the superficial stroma the ERalpha level was lower in the CEE/MPA group than in the CEE and MPA groups. ERbeta immunostaining was faint with minor variation in response to treatment, but increased in the superficial stroma after MPA treatment. The ratio of ERbeta/ERalpha increased in superficial stroma and gland after CEE/MPA treatment, and also in stroma after MPA and TAM. Cystic endometrial hyperplasia was observed in TAM-treated animals, in combination with a high level of ERalpha protein expression. The present data show that long-term hormone treatment affects the ERalpha and ERbeta protein levels in the endometrium. The balance between ERalpha and ERbeta seems to be important for the proliferative response to oestrogen.


2021 ◽  
Vol 29 (1) ◽  
pp. 117-137
Author(s):  
Yeukai Mupangavanhu

Timeshare property interest has become a major business worldwide. The protection of consumers in various timeshare-related contracts has been characterised by challenges due to outdated laws, lack of appropriate legislation as new products are introduced on the market as well as the inclusion of unfair terms. The European Union (EU) adopted the Timeshare Directive 2008/122/EC which governs a broad range of timeshare-related contracts, namely: timeshare, long-term holiday products, and resale and exchange contracts. In comparison, South Africa and Kenya do not have consolidated legislation that govern timeshare-related contracts. In South Africa, timeshare agreements fall under the Consumer Protection Act 68 of 2008, the Property Time-sharing Control Act 75 of 1993 as well as under common law. In Kenya, the Consumer Protection Act 46 of 2012, which was revised in 2016, governs specific consumer agreements including timeshare contracts. The article compares the position of consumers who enter into timeshare-related services in South Africa, Kenya and the EU. It is argued that the problems faced by consumers who enter into timeshare-related contracts in South Africa and Kenya necessitate legislative protection which should consist of a consolidated statute that specifically regulates such contracts for the attainment of a high level consumer protection.


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