Search results for "ageing"

Weathering of low-density polyethylene grafted with itaconic acid in laboratory tests

2011

Polyethylene grafted with itaconic acid was subjected to weathering under laboratory accelerated conditions. The course of the photo-oxidative degradation process of that material was studied by FTIR spectroscopy both through quantitative measurements of changes in absorbance values at selected wave numbers and through measurements of surface area values for absorption bands which were separated by means of deconvolution. The use of both those procedures of quantitative determinations resulted in a general conclusion that the oxidation process was initiated from the very first moment of irradiation, and it produced ketones, acids, esters (intramolecular and of acetate type), peracids, peres…

Influence of accelerated ageing conditions on the process of polyolefines degradation

2003

The process of polymers weathering and the methods of polymers weathering and accelerated ageing investigations were characterized. Accelerated ageing tests of polyethylene and polypropylene samples have been done in laboratory conditions. The ageing time (up to 400 h) influence, at various levels of ageing factors: UV radiation intensity (80—190 W/m2), temperature (35—55 °C) and humidity (30—90%), on the changes of the structures of polymers investigated (shares of carbonyl and olefinic groups from FT-IR spectra — Fig. 1, 2, 4 and 5), on the changes of polymers molecular weights (Fig. 3 and 6, Table 1) and on the changes of mechanical properties during tension (Table 1) has been investigat…

E-beam cross-linking of LDPE-OMMT nanocomposites and their photo-oxidation behaviour

2010

Probiotics and Prebiotics: Health Promotion by Immune Modulation in the Elderly

2013

The trouble with vulnerability. Narrating ageing during the COVID-19 pandemic

2023

In this paper, we have used the exceptional circumstances created by the COVID-19 pandemic as a window for investigating the ambivalent, stereotypical and often-incongruent portrayals of exceptional vulnerability and resilient self-management that define the self-constructions available for older adults. From the onset of the pandemic, older adults were publicly and homogenously presented as a biomedically vulnerable population, and the implementation of restrictive measures also raised concerns over their psychosocial vulnerability and wellbeing. Meanwhile, the key political responses to the pandemic in most affluent countries aligned with the dominant paradigms of successful and active ag…

Germination Pattern of Chamaerops humilis Seed after Short-Time Storage

2015

Dwarf fan palm (Chamaerops humilis) plays an important ecological role in the thermo Mediterranean vegetation stage, both in woodlands, xerophitic shrub communities and degraded ecosystems. Dwarf fan palm is typically propagated from seeds. Whereas other palm species show reduced germination after few months of seed storage, no information is available on the effects of storage time on seed germinability . We examined the germination pattern of dwarf palm seeds aged after a storage of four, six or eight months in comparison to fresh seed (control). A covariance analysis was performed to test the effect of time within seed-storage treatment. The germination patterns were significantly fitted…

Vēlīnā brieduma indivīdu priekšstati par dzīvi un iekšējās saskaņas rādītāji

2017

Pētījuma mērķis - izpētīt, kādi ir vēlīnā brieduma indivīdu – sociālā aprūpes centra iemītnieku priekšstati par dzīvi (un nāvi) un šo indivīdu iekšējās saskaņas izjūtas rādītāji, kā arī, vai vecums, dzimums, ģimenes stāvoklis, iegūtā izglītība un sava veselības stāvokļa novērtējums ietekmē Iekšējās saskaņas izjūtas (ISI) aptaujas apakšskalas datus. Kvalitatīvajā pētījuma daļā piedalījās 3 respondenti, ar kuriem notika strukturētas intervijas, veicot naratīvu kontentanalīzi. Kvantitatīvajā pētījuma daļā piedalījās 50 respondenti, kas dzīvo sociālās aprūpes centrā: 35 sievietes, 15 vīrieši. Iekšējās saskaņas izjūtas (ISI) mērīšanai tika izmantota A.Antonovska (Antonovsky, 1987) Iekšējās saska…

Data from: Sex-specific effects of natural and sexual selection on the evolution of life span and ageing in Drosophila simulans

2015

1. Variation in the strength of age-dependent natural selection shapes differences in ageing rates across species and populations. Likewise, sexual selection can promote divergent patterns of senescence across the sexes. However, the effects of these processes on the evolution of ageing have largely been considered independently, and interactions between them are poorly understood. 2. We use experimental evolution to investigate how natural and sexual selection affect life span and ageing in Drosophila simulans. 3. Replicate populations were evolved under lifetime monogamy (relaxed sexual selection) or lifetime polyandry (elevated sexual selection) and at one of two temperatures, 25 °C (rel…

Working model for therapeutic singing group for the elderly

2012

The objective of this study was to develop a usable working method for therapeutic singing group for the elderly. Since in the near future the amount of the elderly is growing enormously the society has to interact to the changing situation. The therapeutic singing group created in this study is one solution how to offer activities and support for the well being of the elderly. This study is a participatory action research. The study is based on the researches, which have shown that singing has a possible effect on wellbeing. The data for the study was collected from my clinical training material and questionnaires. The important aspect for the case study was the spiral and cyclic working, …

Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals

2021

This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used…