176 research outputs found
Body Composition Variations in Ageing
Age-related physiological variations of body composition concern both the fat-free mass (FFM) and the fat mass (FM).
These variations expose the elderly person to the risk of malnutrition and could lead to conditions of disability. This paper
aims to review the current state of knowledge on body composition in the aged population. The pattern of qualitative
variations in body composition in old age is fairly well defined. In adulthood, the physiological variation of body mass
involves a first increasing phase followed by a decreasing trend. The reduction is due mainly to the loss of fat-free mass,
especially muscle mass. Total body water and bone mass also decrease. Fat mass tends to decrease and the reduction
seems to be due mainly to the loss of subcutaneous fat. The quantitative aspects of the age of onset, rate and intensity of
the physiological variations are still not completely clear. This poor quantitative definition is due to the variable and
multifactorial phenomenology of ageing, the heterogeneity of assessment techniques and sampling models, and the limited
number of empirical observations in oldest-old individuals
Patterns of Hand Variation – New Data on a Sardinian Sample
This study is an analysis of the patterns of variation of the human hand, particularly the metric characters of palm,
fingers and distal phalanges. Anthropometric measurements were performed on 146 Sardinian men and women, aged
21 to 31 years. The data were analyzed by inferential statistics (paired Student’s t test, analysis of variance), and Principal
Components Analysis. The results indicate that size factors are the principal source of variation. A residual adimensional
component of variability is related to diversification between the fingers as a whole and the distal phalanges,
and between the thumb and the other fingers. Sexual dimorphism is evident. Men present greater dimensions and
greater relative length of the thumb with respect to the other fingers than women
5th generation district heating and cooling systems: A review of existing cases in Europe
Abstract This article investigates 40 thermal networks in operation in Europe that are able to cover both the heating and cooling demands of buildings by means of distributed heat pumps installed at the customer substations. The technology of thermal networks that work at a temperature close to the ground, can strongly contribute to the decarbonisation of the heating and cooling sector and furthermore exploit a multitude of low temperature heat sources. Nevertheless, the nomenclature used in literature shows that misinterpretations could easily result when comparing the different concepts of thermal networks that operate at a temperature level lower than traditional district heating. The scope of this work is to revise the definitions encountered and to introduce an unambiguous definition of Fifth-Generation District Heating and Cooling networks. A drawback-benefit analysis is presented to identify the pros and cons of such technology. The survey on the current networks shows that on average three Fifth-Generation District Heating and Cooling systems per year have entered the heating and cooling market in the last decade. Pioneer countries in such technology are Germany and Switzerland. For some networks, the assessed Linear Heating Power Demand Density results are lower than the feasibility threshold adopted in traditional district heating. High performances and low non-renewable primary energy factors are achieved in systems that exploit a very high share of renewable or urban excess heat sources. With respect to traditional district heating, the surveyed pumping energy consumptions result one order of magnitude higher, whereas the implemented control strategies can be completely different, leading the network temperature to float freely
Body Composition Variations in Ageing
Age-related physiological variations of body composition concern both the fat-free mass (FFM) and the fat mass (FM).
These variations expose the elderly person to the risk of malnutrition and could lead to conditions of disability. This paper
aims to review the current state of knowledge on body composition in the aged population. The pattern of qualitative
variations in body composition in old age is fairly well defined. In adulthood, the physiological variation of body mass
involves a first increasing phase followed by a decreasing trend. The reduction is due mainly to the loss of fat-free mass,
especially muscle mass. Total body water and bone mass also decrease. Fat mass tends to decrease and the reduction
seems to be due mainly to the loss of subcutaneous fat. The quantitative aspects of the age of onset, rate and intensity of
the physiological variations are still not completely clear. This poor quantitative definition is due to the variable and
multifactorial phenomenology of ageing, the heterogeneity of assessment techniques and sampling models, and the limited
number of empirical observations in oldest-old individuals
Adaptive-predictive control strategy for HVAC systems in smart buildings – A review
Abstract High share of energy consumption in buildings and subsequent increase in greenhouse gas emissions along with stricter legislations have motivated researchers to look for sustainable solutions in order to reduce energy consumption by using alternative renewable energy resources and improving the efficiency in this sector. Today, the smart building and socially resilient city concepts have been introduced where building automation technologies are implemented to manage and control the energy generation/consumption/storage. Building automation and control systems can be roughly classified into traditional and advanced control strategies. Traditional strategies are not a viable choice for more sophisticated features required in smart buildings. The main focus of this paper is to review advanced control strategies and their impact on buildings and technical systems with respect to energy/cost saving. These strategies should be predictive/responsive/adaptive against weather, user, grid and thermal mass. In this context, special attention is paid to model predictive control and adaptive control strategies. Although model predictive control is the most common type used in buildings, it is not well suited for systems consisting of uncertainties and unpredictable data. Thus, adaptive predictive control strategies are being developed to address these shortcomings. Despite great progress in this field, the quantified results of these strategies reported in literature showed a high level of inconsistency. This is due to the application of different control modes, various boundary conditions, hypotheses, fields of application, and type of energy consumption in different studies. Thus, this review assesses the implementations and configurations of advanced control solutions and highlights research gaps in this field that need further investigations
Optical delay control of large-spectral-bandwidth laser pulses
In this letter we report the first experimental observation of temporal delay
control of large-spectral-bandwidth multimode laser pulses by means of
electromagnetically induced transparency (EIT). We achieved controllable
retardation with limited temporal distortion of optical pulses with an input
spectral bandwidth of 3.3 GHz. The experimental results compare favorably with
theoretical predictions.Comment: Submitted to Optics Letters (January 2009
Somatotype in Elderly Type 2 Diabetes Patients
Somatotyping is a practical technique for the description of physique. Individuals with Type 2 diabetes are characterized
by physical peculiarities, such as overweight, obesity and a central pattern of body fat distribution. Somatotype applications
to diabetes are limited. The objective of this study is to describe the somatotype of elderly type 2 diabetes patients.
The sample consisted of 110 patients with type 2 diabetes (45 men, mean age 69.4±7.0 years; 65 women, mean age
72.9±7.1 years). The pathological subjects were compared with a control group consisting of 280 healthy individuals
(134 men, mean age 74.2±7.3 years; 146 women, mean age 74.9±7.4 years). The Heath-Carter somatotype was applied.
Diabetic men and women (mean somatotype, respectively: 6.8–5.6–0.6 and 8.6–6.4–0.2) presented significantly higher
values of endomorphy than the controls (p=0.043 in men, p=0.003 in women); men also had a lower mesomorphic component
(p=0.000). The somatotype method revealed physical peculiarities in type 2 diabetes patients. The marked endomorphy
in the pathological individuals can be related to general fatness, which is a well known disease risk factor. The
somatotype appears to be a suitable technique for the assessment of physique in type 2 diabetes patients
Effect of influenza-induced fever on human bioimpedance values
BACKGROUND AND AIMS:
Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza.
METHODS:
Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied.
RESULTS:
For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001).
CONCLUSIONS:
There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states
PRELIMINARY RESULTS ON THE SPATIO-TEMPORAL VARIABILITYOF GLYCASPIS BRIMBLECOMBEI(HEMIPTERA PSYLLIDAE) POPULATIONSFROM A THREE-YEAR MONITORING PROGRAM IN SARDINIA (ITALY)
The red gum lerp psyllid Glycaspis brimblecombeiis an invasive insect species worldwide. Prolonged attacksby this psyllid may cause both direct and indirect damages to Eucalyptustrees, such as plant weakening, developmentalreductions and phylloptosis, resulting in death within 2-3 years. After the first report in Campania (Italy) in 2010 onEucalyptus camaldulensis trees, it quickly spread to all surrounding central-southern regions of Italy. In Sardinia, G.brimblecombeiwas first recorded in 2011, and is currently found throughout the island. From 2013 to 2015 amonitoring program was carried out in 11 locations throughout Sardinia in order to estimate the density pattern of bothits adults and preimaginal stages, as well as the general population trend of G. brimblecombeiover the years. Ananalysis of G. brimblecombei population abundance showed an almost stable level of infestation over the years, and aseasonal pattern with a population peak in the summer. However, an earlier peak of population abundance was detectedin 2015 compared to the previous years. A spatial heterogeneity of the level of infestation was observed throughout theisland, highlighting the potential effects of environmental conditions in regulating the populations of both G.brimblecombeiand its natural enemies
POPULATION DYNAMICS AND SEASONAL ABUNDANCE OF THAUMASTOCORISPEREGRINUSIN EUCALYPTUSPLANTATIONS IN SARDINIA (ITALY)
Thaumastocoris peregrinusis a eucalyptus pest native to Australia. It is currently the only species belonging to theThaumastocoridae family in Europe. In Italy, it was reported for the first time in Latium in 2011, whereas in Sardinia itwas detected in January 2015 on a Eucalyptus camaldulensis plantation located in the south of the island. Our researchteam carried out a monitoring program for two-years in order to verify its geographical distribution, the main periods ofinfestation, the flight peaks of the adults and to also detect the presence of unhatched eggs on leaves. During the firstyear, the occurrence of adults of T. peregrinuswas verified by yellow sticky traps placed in twelve areas distributedthroughout the island where Eucalyptus plantations were located. In the second year, the population dynamics and theoccurrence of eggs on leaves were evaluated only in three representative study areas, already included in the previousmonitoring program, located in the north, centre and south of the island, respectively. Field surveys showed thepresence of T. peregrinusin all the monitored locations. The highest adult population was observed from late summer toinitial autumn, with a significant increase in adults caught by yellow sticky traps from August, which reached its peakin September and gradually decreased in the following months. The presence of eggs of T. peregrinuson leaves fromJune to December also indicates that the insect is currently well established in the region
- …