On generalized reversed aging intensity functions

The reversed aging intensity function is defined as the ratio of the instantaneous reversed hazard rate to the baseline value of the reversed hazard rate. It analyzes the aging property quantitatively, the higher the reversed aging intensity, the weaker the tendency of aging. In this paper, a family of generalized reversed aging intensity functions is introduced and studied. Those functions depend on a real parameter. If the parameter is positive they characterize uniquely the distribution functions of univariate positive absolutely continuous random variables, in the opposite case they characterize families of distributions. Furthermore, the generalized reversed aging intensity orders are defined and studied. Finally, several numerical examples are given

Conditional Evaluations of Sums of Sample Maxima and Records

We consider sequences of independent and identically absolutely continuously distributed random variables assuming that they have finite expectation and variance. We determine sharp lower and upper bounds on the expectation of the sum of n first sample maxima and n first upper record values under the condition that the value of the jth (1 ≤ j ≤ n) sample maximum and record value, respectively, are known and equal to a given quantile of the parent distribution. The bounds are expressed in terms of the expectation and standard deviation of the parent distribution. Analogous evaluations are presented for the sum of record values in n observations, when the jth sample maximum is known. The theoretical results are numerically compared

Mycorrhizal status of forest trees grown in urban and rural environments in Poland

Mycorrhizal status of mature forest trees (horse chestnut, Aesculus hippocastanum L.; white poplar, Populus alba L.; black poplar, P. nigra L.) was investigated in urban habitats under different intensity of anthropogenic pressures (restricted root zone, soil compaction, low air and soil humidity), compared to trees grown in rural environments that were used as reference biological material. Horse chestnut roots were colonized by arbuscular mycorrhizal (AM) fungi, and the two poplar species (white poplar and black poplar) were dually colonized by AM and ectomycorrhizal (ECM) fungi, regardless of habitat, except P. nigra grown close to a trafficked street, which had only ECM associations. The AM colonization of horse chestnut roots was higher in May than October, regardless of habitat and showed a tendency to be lower in the roots of trees from urban environments, however, only mycorrhizal frequency differed significantly between the urban habitat and the reference plot. In roots of two poplar species the intensity of AM colonization was significantly lower in disturbed urban habitats than in the rural sites. ECM colonization of white poplar did not differ between the urban and rural environments, and in black poplar roots it was lower at the city sites than in the reference plot. Significantly lower levels of available magnesium and total carbon was recorded in soils at the urban sites compared to reference plots. The concentrations of the other macro- and microelements did not differ significantly. A tendency to reduced water content in two of three urban sites was also recorded. The results indicated that mycorrhizal fungi native of urban habitats are able to develop effective symbiosis with mature tree roots and they suggested that environmental factors, such as availability of water and nutrient and carbohydrates production and allocation, are the most important factor influencing the mycorrhizal colonization of urban trees

Falls in the elderly – risk assessment and procedding

Starzenie społeczeństwa spowodowało rozwój wielu dziedzin medycyny, w tym i fizjoterapii geriatrycznej. Rehabilitacja w geriatrii obejmuje szereg zagadnień związanych z występowaniem zmian inwolucyjnych i/lub chorobowych w organizmie osoby starszej. W celu podkreślenia najważniejszych wyodrębniono tzw. wielkie problemy geriatryczne. Jednym z nich są upadki. Ryzyko wystąpienia upadków znacząco wzrasta po 65. roku życia. Wśród tych osób występuje o 40% więcej szans na wystąpienie upadku niż wśród osób młodszych. Praca ma na celu przybliżenie zagadnień związanych z rolą fizjoterapii w profilaktyce przeciwupadkowej osób starszych. Problem upadków wśród osób starszych wiąże się głównie z ich konsekwencjami. Mogą prowadzić do urazów, niepełnosprawności, a nawet śmierci. Profilaktyka przewupadkowa powinna rozpocząć się od kompleksowej oceny geriatrycznej. W celu oceny ryzyka fizjoterapeuta może posłużyć się specjalymi skalami: testem wstań i idź lub testem Tinetti. Po dokładnej analizie stanu zdrowia osoby starszej można dobrać odpowiednie środki profilaktyczne: likwidację zagrożeń środowiskowych, dobór obuwia i sprzętu pomocniczego, leczenie ostrych i przewlekłych chorób, modyfikację farmakoterapii, fizjoterapię. Rehabilitacja przeciwupadkowa zazwyczaj skupia się na treningu równowagi, zwiększeniu zakresów ruchu, reedukacji chodu oraz działaniach przeciwbólowych. W niektórych ośrodkach opracowywane są specjalne programy przeciw-upadkowe, gdzie ćwiczenia fizyczne i dobór odpowiedniego sprzętu pomocniczego odgrywają najistotniejszą rolę. Nowoczesne metody fizjoterapii pozwalają na indywidualny dobór profilaktyki przeciwupadkowej do osoby starszej. Zastosowanie rehabilitacji w celu zmiejszenia ryzyka upadków wsród osób starszych jest coraz bardziej powszechne.The aging of society was an incentive to the development of many fields of medicine including geriatric physiotherapy. Rehabilitation in geriatrics involves a range of issues connected with the involutional and/or disease related changes in the organism of an elderly person. To highlight the most important ones, so called ‘great geriatric problems’ were distinguished. One of them are falls. The risk of falls rises significantly after the age of 65. Among people older than 65 the chances of falls are 40% higher than among younger people. The article aims at showing the issues connected with the role of physiotherapy in falls prophylaxis in the elderly. The problem of falls in the elderly is mainly connected with the consequences of falls. Falls may lead to injuries, disability and even death. Falls prophylaxis should start with complex geriatric assessment. To assess the risk of falls a physiotherapist may use special scales: the stand up and go and the Tinetti test. After thorough analysis of the state of health of the elderly person appropriate prophylaxis measures may be chosen: removal of the environmental threats, appropriate selection of shoes as well as the assisting equipment, acute and chronic diseases treatment, pharmacotherapy modification, physiotherapy. Anti-fall rehabilitation usually focuses on balance training, expanding the range of motion, gait re-education and analgesic measures. In some medical centres special anti-fall programs are being developed, where physical activities and appropriate assisting equipment play the most important role. Modern physiotherapy methods enable individual anti-fall prophylaxis adjustment to the elderly person’s needs. The use of rehabilitation to diminish the risk of falls in the elderly is more and more common

Upadki osób starszych – ocena zagrożenia i postępowanie

The aging of society was an incentive to the development of many fields of medicine including geriatric physiotherapy. Rehabilitation in geriatrics involves a range of issues connected with the involutional and/or disease related changes in the organism of an elderly person. To highlight the most important ones, so called ‘great geriatric problems’ were distinguished. One of them are falls. The risk of falls rises significantly after the age of 65. Among people older than 65 the chances of falls are 40% higher than among younger people.The article aims at showing the issues connected with the role of physiotherapy in falls prophylaxis in the elderly. The problem of falls in the elderly is mainly connected with the consequences of falls. Falls may lead to injuries, disability and even death. Falls prophylaxis should start with complex geriatric assessment. To assess the risk of falls a physiotherapist may use special scales: the stand up and go and the Tinetti test. After thorough analysis of the state of health of the elderly person appropriate prophylaxis measures may be chosen: removal of the environmental threats, appropriate selection of shoes as well as the assisting equipment, acute and chronic diseases treatment, pharmacotherapy modification, physiotherapy. Anti-fall rehabilitation usually focuses on balance training, expanding the range of motion, gait re-education and analgesic measures. In some medical centres special anti-fall programs are being developed, where physical activities and appropriate assisting equipment play the most important role. Modern physiotherapy methods enable individual anti-fall prophylaxis adjustment to the elderly person’s needs. The use of rehabilitation to diminish the risk of falls in the elderly is more and more common.Starzenie społeczeństwa spowodowało rozwój wielu dziedzin medycyny, w tym i fizjoterapii geriatrycznej. Rehabilitacja w geriatrii obejmuje szereg zagadnień związanych z występowaniem zmian inwolucyjnych i/lub chorobowych w organizmie osoby starszej. W celu podkreślenia najważniejszych wyodrębniono tzw. wielkie problemy geriatryczne. Jednym z nich są upadki. Ryzyko wystąpienia upadków znacząco wzrasta po 65. roku życia. Wśród tych osób występuje o 40% więcej szans na wystąpienie upadku niż wśród osób młodszych.Praca ma na celu przybliżenie zagadnień związanych z rolą fizjoterapii w profilaktyce przeciwupadkowej osób starszych. Problem upadków wśród osób starszych wiąże się głównie z ich konsekwencjami. Mogą prowadzić do urazów, niepełnosprawności, a nawet śmierci.Profilaktyka przewupadkowa powinna rozpocząć się od kompleksowej oceny geriatrycznej. W celu oceny ryzykafizjoterapeuta może posłużyć się specjalymi skalami: testem wstań i idź lub testem Tinetti. Po dokładnej analizie stanu zdrowia osoby starszej można dobrać odpowiednie środki profilaktyczne: likwidację zagrożeń środowiskowych, dobór obuwia i sprzętu pomocniczego, leczenie ostrych i przewlekłych chorób, modyfikację farmakoterapii, fizjoterapię. Rehabilitacja przeciwupadkowa zazwyczaj skupia się na treningu równowagi, zwiększeniu zakresów ruchu, reedukacji chodu oraz działaniach przeciwbólowych. W niektórych ośrodkach opracowywane są specjalne programy przeciw-upadkowe, gdzie ćwiczenia fizyczne i dobór odpowiedniego sprzętu pomocniczego odgrywają najistotniejszą rolę. Nowoczesne metody fizjoterapii pozwalają na indywidualny dobór profilaktyki przeciwupadkowej do osoby starszej. Zastosowanie rehabilitacji w celu zmiejszenia ryzyka upadków wsród osób starszych jest coraz bardziej powszechne

Does masting scale with plant size? High reproductive variability and low synchrony in small and unproductive individuals

Background and Aims In a range of plant species, the distribution of individual mean fecundity is skewed and dominated by a few highly fecund individuals. Larger plants produce greater seed crops, but the exact nature of the relationship between size and reproductive patterns is poorly understood. This is especially clear in plants that reproduce by exhibiting synchronized quasi-periodic variation in fruit production, a process called masting. Methods We investigated covariation of plant size and fecundity with individual-plant-level masting patterns and seed predation in 12 mast-seeding species: Pinus pinea, Astragalus scaphoides, Sorbus aucuparia, Quercus ilex, Q. humilis, Q. rubra, Q. alba, Q. montana, Chionochloa pallens, C. macra, Celmisia lyallii and Phormium tenax. Key Results Fecundity was non-linearly related to masting patterns. Small and unproductive plants frequently failed to produce any seeds, which elevated their annual variation and decreased synchrony. Above a low fecundity threshold, plants had similar variability and synchrony, regardless of their size and productivity. Conclusions Our study shows that within-species variation in masting patterns is correlated with variation in fecundity, which in turn is related to plant size. Low synchrony of low-fertility plants shows that the failure years were idiosyncratic to each small plant, which in turn implies that the small plants fail to reproduce because of plant-specific factors (e.g. internal resource limits). Thus, the behaviour of these sub-producers is apparently the result of trade-offs in resource allocation and environmental limits with which the small plants cannot cope. Plant size and especially fecundity and propensity for mast failure years play a major role in determining the variability and synchrony of reproduction in plants

Does masting scale with plant size? High reproductive variability and low synchrony in small and unproductive individuals

Centro de Investigación Forestal (CIFOR)In a range of plant species, the distribution of individual mean fecundity is skewed and dominated by a few highly fecund individuals. Larger plants produce greater seed crops, but the exact nature of the relationship between size and reproductive patterns is poorly understood. This is especially clear in plants that reproduce by exhibiting synchronized quasi-periodic variation in fruit production, a process called masting.The study was supported by the Polish National Science Centre (2017/24/C/NZ8/00151), the Polish State Committee for Scientific Research (6 P04G 045 21, 3 P04G 111 25), the Polish Ministry of Science and Higher Education (N304 362938), the US National Science Foundation (DEB 165511, DEB-02-40963, DEB-05-15756, DEB-10-20889, DBI-9978807, DEB-0642594, DEB-1556707), the Wilkes University Fenner Endowment, USDA/NIFA grant 2017-03807, the Hatch Act (225165) through the USDA National Institute of Food and Agriculture, PROPINEA (CC-16-095, AGL-2017-83828-C2), FORASSEMBLY (CGL2015-70558-P), BEEMED (SGR913) and a Marsden Fund grant (UOC1401).Peer reviewed9 Pág

Evolutionary ecology of masting: mechanisms, models, and climate change.

Many perennial plants show mast seeding, characterized by synchronous and highly variable reproduction across years. We propose a general model of masting, integrating proximate factors (environmental variation, weather cues, and resource budgets) with ultimate drivers (predator satiation and pollination efficiency). This general model shows how the relationships between masting and weather shape the diverse responses of species to climate warming, ranging from no change to lower interannual variation or reproductive failure. The role of environmental prediction as a masting driver is being reassessed; future studies need to estimate prediction accuracy and the benefits acquired. Since reproduction is central to plant adaptation to climate change, understanding how masting adapts to shifting environmental conditions is now a central question

The Weibull lifetime model with randomised failure-free time

The paper shows that treating failure-free time in the three-parameter Weibull distribution not a constant, but as a random variable makes the resulting distribution much more flexible at the expense of only one additional parameter