Adolescent sexual initiation through the lens of letters to the editor published in Polish teenage magazines     

Marek S. Kopacz  Aleksandra Bajka-Kopacz 《Sex education》2013,13(2):165-176

Almost all teenage magazines invite readers to submit questions concerning relationships, published as letters to the editor, popularly called ‘advice columns’, often containing explicit questions about sexuality. This study aims to examine, firstly, how themes related to sexual initiation are presented in letters to the editor published in Polish magazines and, secondly, how these themes are reflective of Poland's socio-cultural climate. These aims are achieved through thematic data analysis and by presenting an in-depth history of teenage magazines in Poland. In order of prevalence, the presented themes include entering into a general dialogue focused on sexual activity, eliminating the long-term (e.g. unplanned pregnancy) and short-term (e.g. rejection by one's partner) consequences of sexual activity, establishing ideal circumstances for sexual initiation, and, as a transition stage, meeting needs relevant only to those who have already initiated sexual activity. Although by no means exclusive, these findings offer some insight into adolescent sexual initiation, reflective of Poland's socio-cultural climate, where adolescent sexuality remains a taboo topic and teenage magazines may be viewed by certain groups of adolescents as a resource for supplementing existing sexual education.  相似文献   

Are you in h?     

Marek Kosmulski 《Journal of Informetrics》2013,7(3):693-698

A new method of assessment of scientific papers, scientists, and scientific institutions was defined. The significance of a paper was assessed by the definition of the largest (the most prestigious) set, including that paper in its h-core. The sets of papers were defined by affiliation (country, city, university, department) or by subject (branches and sub-branches of science, journal). The inclusion of a paper in the h-core of certain set(s) was used as an indicator of the significance of that paper, and of the scientific output of its author(s), of their scientific institution(s), etc. An analogous procedure was used to assess the contribution of an individual to the scientific output of his/her scientific institution, branch of science, etc.  相似文献   

Influence of the Probiotic Lactobacillus acidophilus NCFM?and Lactobacillus rhamnosus HN001 on Proteolysis Patterns?of Edam Cheese     

Marek Aljewicz  Gra?yna Cichosz  Beata Nalepa  Marika Kowalska 《Food Technology and Biotechnology》2014,52(4):439-447

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Fluid and electrolyte balance in elite male football (soccer) players training in a cool environment     

RJ Maughan  SM Shirreffs  SJ Merson  CA Horswill 《Journal of sports sciences》2013,31(1):73-79

There are few data in the published literature on sweat loss and drinking behaviour in athletes training in a cool environment. Sweat loss and fluid intake were measured in 17 first-team members of an elite soccer team training for 90 min in a cool (5°C, 81% relative humidity) environment. Sweat loss was assessed from the change in body mass after correction for the volume of fluid consumed. Sweat electrolyte content was measured from absorbent patches applied at four skin sites. Mean (?± s) sweat loss during training was 1.69?±?0.45 l (range 1.06?-?2.65 l). Mean fluid intake during training was 423?±?215 ml (44?-?951 ml). There was no apparent relationship between the amount of sweat lost and the volume of fluid consumed during training (r ² = 0.013, P = 0.665). Mean sweat sodium concentration was 42.5?±?13.0 mmol?·?l^?1 and mean sweat potassium concentration was 4.2?±?1.0 mmol?·?l^?1. Total salt (NaCl) loss during training was 4.3?±?1.8 g. The sweat loss data are similar to those recorded in elite players undergoing a similar training session in warm environments, but the volume of fluid ingested is less.  相似文献   

Acute effects of static stretching on characteristics of the isokinetic angle – torque relationship,surface electromyography,and mechanomyography     

Joel T. Cramer  Travis W. Beck  Terry J. Housh  Laurie L. Massey  Sarah M. Marek  Suzanne Danglemeier 《Journal of sports sciences》2013,31(6):687-698

Abstract

The aims of this study were to examine the acute effects of static stretching on peak torque, work, the joint angle at peak torque, acceleration time, isokinetic range of motion, mechanomyographic amplitude, and electromyographic amplitude of the rectus femoris during maximal concentric isokinetic leg extensions at 1.04 and 5.23 rad · s^?1 in men and women. Ten women (mean ± s: age 23.0 ± 2.9 years, stature 1.61 ± 0.12 m, mass 63.3 ± 9.9 kg) and eight men (age 21.4 ± 3.0 years, stature 1.83 ± 0.11 m, mass 83.1 ± 15.2 kg) performed maximal voluntary concentric isokinetic leg extensions at 1.04 and 5.23 rad · s^?1. Following the initial isokinetic tests, the dominant leg extensors were stretched using four static stretching exercises. After the stretching, the isokinetic tests were repeated. Peak torque, acceleration time, and electromyographic amplitude decreased (P≤ 0.05) from pre- to post-stretching at 1.04 and 5.23 rad · s^?1; there were no changes (P > 0.05) in work, joint angle at peak torque, isokinetic range of motion, or mechanomyographic amplitude. These findings indicate no stretching-related changes in the area under the angle – torque curve (work), but a significant decrease in peak torque, which suggests that static stretching may cause a “flattening” of the angle – torque curve that reduces peak strength but allows for greater force production at other joint angles. These findings, in conjunction with the increased limb acceleration rates (decreased acceleration time) observed in the present study, provide tentative support for the hypothesis that static stretching alters the angle – torque relationship and/or sarcomere shortening velocity.  相似文献   

Social stratification in Higher Education: What it means at the micro‐level of the individual academic scientist     

Marek Kwiek 《Higher Education Quarterly》2019,73(4):419-444

The academic profession is internally divided as never before. This cross‐national comparative analysis of stratification in Higher Education is based on a sample of European academic scientists (N = 8,466) from universities in 11 countries. The analysis identifies three types of stratification: academic performance stratification, academic salary stratification, and international research stratification. This emergent stratification of the global scientific community is predominantly research‐based, and internationalisation in research is at its centre; prestige‐driven, internationally competitive, and central to academic recognition systems, research is the single most stratifying factor in Higher Education at the level of the individual scientist today. These stratification processes pull the various segments of the academic profession in different directions. The study analyses highly productive academics (‘research top performers’), highly paid academics (‘academic top earners’), and highly internationalised academics (‘research internationalists’) and explores the implications for individual scientists.  相似文献   

New seniority-independent Hirsch-type index     

Marek Kosmulski   《Journal of Informetrics》2009,3(4):341-347

The following seniority-independent Hirsch-type index has been defined. A scientist has index hpd if hpd of his/her papers have at least hpd citations per decade each, and his/her other papers have less than hpd + 1 citations per decade each. In contrast with the original h-index, which steadily increases in time, hpd of a mature scientist is nearly constant over many years, and hpd of an inactive scientist slowly declines. Therefore hpd is suitable to compare the scientific output of scientists in different ages.  相似文献   

DNA-like linguistic secret sharing for strategic information systems     

Marek R. Ogiela  Urszula OgielaAuthor Vitae 《International Journal of Information Management》2012

The development of DNA cryptography has contributed to the ability of solving many computationally difficult problems by offering the capability of executing calculations in parallel. This capability is used particularly in solving NP-complete problems or implementing cryptography and steganography solutions. Biological computation models based on bonds between nitrogen bases in nucleic acid chains that make up DNA structures can also be used to develop new solutions for smart information management. This study discusses new secret splitting techniques based on mathematical linguistic methods and designed for intelligently managing secret data within hierarchical structures. These techniques make use of information coding models found in the coding of DNA sequences.  相似文献   

Curative role of pantothenic acid in brain damage of gamma irradiated rats     

Shedid SM  Saada HN  Eltahawy NA  Hammad AS 《Indian journal of clinical biochemistry : IJCB》2018,33(3):314-321

Radiation induced brain damage is associated with impairment of mitochondrial functions, variations in the level of neurotransmitters, and oxidative stress. Mitochondrial function is closely linked to the level of neurotransmitters since the precursors are supplied by the Kreb’s cycle intermediates. The objective of this study was to evaluate the influence of pantothenic acid, an essential component in the synthesis of Coenzyme A (CoA), on the activity of the Krebs cycle enzymes, isocitrate dehydrogenase (IDH), α-ketoglutarate dehydrogenase (α-KGDH), and succinate dehydrogenase (SDH); the level of aspartic, glutamic and GABA; the activity of transaminases, and oxidative stress, in the cerebrum of γ-irradiated rats. Pantothenic acid (26 mg/Kg) was orally administered to the rats, 2 h after irradiation and during the following 5 days. Animals were sacrificed the 7th day post-irradiation. The exposure of male albino rats to γ-rays (5 Gy) has triggered oxidative stress notified by a significant elevation in the level of malondialdehyde (MDA), an end product of lipid peroxidation, associated to a significant decrease in the content of phospholipids, and the antioxidant compound glutathione (GSH). The activity of IDH, α-KGDH, and SDH, has significantly decreased, while the level of aspartic, glutamic and GABA has significantly increased. In parallel to these changes, the activity of alanine and aspartate transaminase has significantly increased, compared to their values in the control rats. Pantothenic acid treatment, has significantly attenuated oxidative stress; enhanced the activity of IDH, α-KGDH, and SDH; minimized the increase in the level of amino acids and the activity of transaminases, compared to their values in the cerebrum of irradiated rats. In conclusion, pantothenic acid could improve the level of neurotransmitters amino acids, which depends on the enzymatic activities of Krebs cycle and linked to oxidative stress.  相似文献   

Philosophies and ethics of the project archive     

Marek Tesar  Sonja Arndt 《Educational Philosophy and Theory》2019,51(4):434-444

Archival research can be described as preoccupied with the ontology of data formation and collection in relation to the speaking and writing subject. From its outset, it can be located in the humanistic tradition, which the archival and historical discipline has inherited. Thus, archival research can be described as preoccupied with the ontology of data formation and collection in relation to the speaking and writing subject. At the same time, the archival researcher—the human subject—is produced as the sole source of subjective experiences, consciousness and feelings, and has become the central player in this tradition, embedded in debates over the concept of human autonomy in archival research. Archival researchers—human subjects—should be continually challenged by their own discipline, and by such arguably scientific methods, which often espouse rejecting their ethical commitments to idiosyncrasy, entanglements and the blurring of subject–object binaries. An approach that re-elevates these commitments, we argue, raises the importance of archival research as an ethically non-neutral philosophical project.  相似文献