298 research outputs found

    Spatial pattern of structural ageing in eastern Croatia: evolution and explanations

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    The article aims to examine the ageing situation and social policy issues in the Osijek-Baranja County of Eastern Croatia. Using historical evidence from Census data, the research suggests that the evolution of the ageing pattern has been mainly determined by such factors as development of the transport system; changes in political-territorial organisation; supply of jobs in the cities; deagrarianisation and a domestic war in the 1990s. The increased importance of urban centres, through planned industrialisation and administrative centralisation, has accelerated and intensified rural-to-urban migration. Consequently, the spatial pattern of structural ageing has been substantially affected. A significant variation was found in urban and rural areas and also within sub-regional units. The findings suggest that the evolution of spatial disparities in the ageing pattern has been due to unplanned migration; also to spatial differences in the level of socio-economic development; the influence of tradition, such as higher fertility rates historically in some areas and suburbanisation, notably around the city of Osijek. The article concludes that ageing is affecting the country’s economic growth and the formal and informal social support systems including the provision of resources for older citizens in the endangered areas

    Travelling waves on trees and square lattices

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    In this thesis we study bistable reaction-diffusion equations on lattice domains. The power of reaction-diffusion equations is that they can successfully model various natural and social phenomena with their intuitive and relatively simple (mathematical) representation. One of the main features of reaction-diffusion equations, both on discrete and continuous domains, is that they admit special solutions, so-called ‘travelling waves’, which we can describe as fixed profiles that move in a particular direction with some speed. Depending on their shape, we can roughly divide waves into three categories: pulses or solitons, periodic pulses (wave trains), and monotone wave fronts that connect two constant states. In this thesis we focus on the latter type of wave and we study their existence, propagation and long term behaviour on two type of discrete domains - infinite trees, and two-dimensional square lattices.This research was funded by Netherlands Organization for Scientific Research (NWO) through the grant 639.032.612Analysis and Stochastic

    The effects of six weeks of training on physical fitness and performance in teenage and mature top-level soccer players

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    The main aim of the present study was to investigate the effects of soccer-specific training on physical fitness components in adolescent elite soccer players and make comparisons with older counterparts. Twenty two male soccer players from the Serbian First Division team were allocated to two assigned trials according to age – young group (YG) and mature group (MG). Players in their teenage years (19 years and younger) were assigned to YG (10 subjects) and others to MG (12 subjects). Between the first and second test session, all subjects followed six weeks of soccer-specific periodized training programme. There were no differences between groups at pre- and post-training trial for body mass, vertical jump height, average anaerobic power and VO2max (P>0.05). Body fat was significantly lower in YG before and after training program as compared to MG (P<0.05). Body mass and fat dropped significantly in both groups after training program (P<0.05). Furthermore, average anaerobic power and VO2max along with vertical jump height, were significantly improved in both groups (P<0.05) at post-training performance. Finally, the magnitude of change in VO2max was significanty superior in MG as compared to YG after training program (18.3 vs. 7.8�20P<0.05). The findings of the present study indicate that the trainability indices are not highly influenced by age in top-level soccer players

    Mouse genetics identifies unique and overlapping functions of fibroblast growth factor receptors in keratinocytes

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    Fibroblast growth factors (FGFs) are key regulators of tissue development, homeostasis and repair, and abnormal FGF signalling is associated with various human diseases. In human and murine epidermis, FGF receptor 3 (FGFR3) activation causes benign skin tumours, but the consequences of FGFR3 deficiency in this tissue have not been determined. Here, we show that FGFR3 in keratinocytes is dispensable for mouse skin development, homeostasis and wound repair. However, the defect in the epidermal barrier and the resulting inflammatory skin disease that develops in mice lacking FGFR1 and FGFR2 in keratinocytes were further aggravated upon additional loss of FGFR3. This caused fibroblast activation and fibrosis in the FGFR1/FGFR2 double-knockout mice and even more in mice lacking all three FGFRs, revealing functional redundancy of FGFR3 with FGFR1 and FGFR2 for maintaining the epidermal barrier. Taken together, our study demonstrates that FGFR1, FGFR2 and FGFR3 act together to maintain epidermal integrity and cutaneous homeostasis, with FGFR2 being the dominant receptor

    The antitumor activity of thymoquinone and thymohydroquinone in vitro and in vivo

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    Aim: The aim of the study was to investigate antitumor activity of thymoquinone (TQ) and thymohydroquinone (THQ) in vitro and in vivo. Materials and Methods: In the in vitro experiments, L929 mouse ?broblasts and two tumor cell lines (squamous cell carcinoma (SCC VII) and fibrosarcoma (FsaR)) were used. The cells were cultured with 0.1 or 0.01 mg/ml TQ or THQ for 24 h, and cytotoxicity assay was performed with the use of crystal violet staining technique. For in vivo antitumor efficiency evaluation of new compounds two murine tumor models (fibrosarcoma (FsaR) and squamous cell carcinoma (SCC VII)) were used. The used dose was equal for both substances. Antitumor effect of 4 intratumoral injections of TQ and THQ at the dose of 5 mg/kg was evaluated by comparison of tumor growth kinetics between treated and control animals. Results: In vitro study showed that TQ and THQ exhibit statistically significant cytotoxic activity (p < 0.01). The cytotoxic activity was dose dependent and more expressed against tumor cells than against L929 fibroblasts. The result of antitumor activities of TQ and THQ in vivo reached TGI = 52% and it was statistically significant (p < 0.05). Conclusion: The results indicate that THQ antitumor activity may be improved with further dose increase of the investigated substance.Цель: исследовать противоопухолевую активность тимохинона (TХ) и тимогидрохинона (TГХ) in vitro и in vivo. Материалы и методы: в экспериментах in vitro использовали линию клеток фибробластов мыши L929 и две линии опухолевых клеток мыши (плоскоклеточной карциномы SCC VII и фибросаркомы FsaR). По достижении монослоя, клетки инкубировали с 0,1 или 0,01 мг/мл TХ или TГХ, после чего цитотоксический эффект определяли по включению кристаллического фиолетового. Противоопухолевый эффект 4-кратного внутриопухолевого введения TХ или TГХ в дозе 5 мг/кг in vivo в экспериментальных моделях FsaR и SCC VII определяли по кинетике опухолевого роста. Результаты: исследования in vitro показали, что TХ и TГХ обладают статистически значимой цитотоксической активностью (p < 0,01), причем таковая носит дозозависимый характер и в большей степени проявляется по отношению к линиям опухолевых клеток, чем фибробластов. Противоопухолевый эффект соединений статистически достоверный, ингибирование опухолевого роста достигало 52% (p < 0,05). Выводы: противоопухолевая активность ТГХ может быть повышена путем дальнейшего повышения дозы вещества

    Microrna profiling analysis of differences between the melanoma of young adults and older adults

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    <p>Abstract</p> <p>Background</p> <p>This study represents the first attempt to perform a profiling analysis of the intergenerational differences in the microRNAs (miRNAs) of primary cutaneous melanocytic neoplasms in young adult and older age groups. The data emphasize the importance of these master regulators in the transcriptional machinery of melanocytic neoplasms and suggest that differential levels of expressions of these miRs may contribute to differences in phenotypic and pathologic presentation of melanocytic neoplasms at different ages.</p> <p>Methods</p> <p>An exploratory miRNA analysis of 666 miRs by low density microRNA arrays was conducted on formalin fixed and paraffin embedded tissues (FFPE) from 10 older adults and 10 young adults including conventional melanoma and melanocytic neoplasms of uncertain biological significance. Age-matched benign melanocytic nevi were used as controls.</p> <p>Results</p> <p>Primary melanoma in patients greater than 60 years old was characterized by the increased expression of miRs regulating TLR-MyD88-NF-kappaB pathway (hsa-miR-199a), RAS/RAB22A pathway (hsa-miR-204); growth differentiation and migration (hsa-miR337), epithelial mesenchymal transition (EMT) (let-7b, hsa-miR-10b/10b*), invasion and metastasis (hsa-miR-10b/10b*), hsa-miR-30a/e*, hsa-miR-29c*; cellular matrix components (hsa-miR-29c*); invasion-cytokinesis (hsa-miR-99b*) compared to melanoma of younger patients. MiR-211 was dramatically downregulated compared to nevi controls, decreased with increasing age and was among the miRs linked to metastatic processes. Melanoma in young adult patients had increased expression of hsa-miR-449a and decreased expression of hsa-miR-146b, hsa-miR-214*. MiR-30a* in clinical stages I-II adult and pediatric melanoma could predict classification of melanoma tissue in the two extremes of age groups. Although the number of cases is small, positive lymph node status in the two age groups was characterized by the statistically significant expression of hsa-miR-30a* and hsa-miR-204 (F-test, p-value < 0.001).</p> <p>Conclusions</p> <p>Our findings, although preliminary, support the notion that the differential biology of melanoma at the extremes of age is driven, in part, by deregulation of microRNA expression and by fine tuning of miRs that are already known to regulate cell cycle, inflammation, Epithelial-Mesenchymal Transition (EMT)/stroma and more specifically genes known to be altered in melanoma. Our analysis reveals that miR expression differences create unique patterns of frequently affected biological processes that clearly distinguish old age from young age melanomas. This is a novel characterization of the miRnomes of melanocytic neoplasms at two extremes of age and identifies potential diagnostic and clinico-pathologic biomarkers that may serve as novel miR-based targeted modalities in melanoma diagnosis and treatment.</p

    Time to Pregnancy for Women Using a Fertility Awareness Based Mobile Application to Plan a Pregnancy

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    Background: Time to pregnancy (TTP) is a biomarker of fecundability and has been associated with behavioral and environmental characteristics; however, these associations have not been examined in a large population-based sample of application (app) users. Materials and Methods: This observational study followed 5,376 women with an age range of 18 to 45 years who used an app to identify their fertile window. We included women who started trying to conceive between September 30, 2017 and August 31, 2018. TTP was calculated as the number of menstrual cycles from when the user switched to "Plan" mode up to and including the cycle in which they logged a positive pregnancy test. We examined associations with several characteristics, including age, gravidity, body mass index, cycle length and cycle length variation, frequency of sexual intercourse, and temperature measuring frequency. Discrete time fecundability models were used to estimate fecundability odds ratios. Results: For the complete cohort the 6-cycle and 12-cycle cumulative pregnancy probabilities were found to be 61% (95% confidence interval [CI]: 59-62) and 74% (95% CI: 73-76), respectively. The median TTP was four cycles. The highest fecundability was associated with an age of less than 35 years, with cycle length variation <5 days and logging sexual intercourse on at least 20% of days added (the proportion of days in which intercourse was logged) (11.5% [n = 613] of entire sample). This group achieved a 6- and 12-cycle cumulative pregnancy probability of 88% (95% CI: 85-91) and 95% (95% CI: 94-97), respectively, and a TTP of 2 cycles. Conclusions: Natural Cycles was an effective method of identifying the fertile window and a noninvasive educational option for women planning a pregnancy. Women under age 35 with regular cycles showed a high pregnancy rate

    Lower plasma 25-hydroxyvitamin D is associated with irregular menstrual cycles in a cross-sectional study

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    Abstract Background In animals, low levels of vitamin D are associated with estrus cycle disturbances, but there are virtually no human data. We examined the association of 25-hydroxyvitamin D (25(OH)D) (a biomarker for vitamin D status) with menstrual cycle characteristics. Methods Women aged 35-44 were randomly selected from a Washington D.C. health plan and invited to participate in the Uterine Fibroid Study (1996 – 1999). Our analysis includes 636 women (57% were African-American) who provided a blood sample and completed a telephone interview that included gynecologic history. Women were asked their usual cycle length in the preceding year. Women who reported it was “too irregular to estimate” were classified as having irregular cycles (N = 48). Women were excluded if they currently or recently used hormonal contraception or any other medication that influences menstrual cycles. 25(OH)D was measured by radioimmunoassay in stored plasma samples. Results The median 25(OH)D level was 12.0 ng/mL (interquartile range: 7.6, 19.7 ng/mL). After controlling for age, race, BMI, education, age of menarche, current smoking, alcohol use, and physical activity, a decrease in 25(OH)D of 10 ng/mL was associated with 1.9 times the odds of irregular cycles (Odds ratio (OR) (95% confidence interval (CI)): 1.9 (1.0, 3.4), p = 0.04). 25(OH)D was not associated with the occurrence of short cycles (OR(CI): 1.08 (0.79, 1.48, p = 0.6) or long cycles (OR(CI): 1.31 (0.66, 2.60), p = 0.4). Conclusions Lower levels of 25(OH)D were associated with irregular cycles, but not with short or long cycles. Vitamin D may play a role in regulating ovulatory function. Further investigation of potential mechanisms is warranted
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