A bright metastable atom source at 80 K

We describe a high flux source of cold (80 K) metastable helium atoms. The source employs a direct current nozzle discharge which produces in excess of 10¹⁵ atoms/steradian/s. Liquid nitrogen cooling of the discharge source yields atomic velocities below 900 ms⁻¹. Such a source has practical applications for experiments concerned with laser cooling and trapping of metastable helium atoms

Shielding Considerations for CubeSat Structures During Solar Maximum

The purpose of this lessons learned paper is to communicate the utility of shielding in small spacecraft planning for the support of mission assurance and reliability. Numerous SmallSats have been flying in polar low Earth orbit for science, communications, technology demonstrations, and imaging with academic, commercial, and government interests. Shielding has been part of mission assurance and reliability from the advent of long duration spacecraft missions. The Shields-1 CubeSat has been operating in polar low Earth orbit since 16 December 2018 with atomic number (Z)-grade radiation shielding and demonstrates shielding effectiveness. Shields-1 has collected a representative example of solar minimum data in 2019 with 8 Teledyne uDosimeters over varying shielding effectivenesses. It serves as current experimental data and has been compared with NOVICE Shielding estimates using the AP8 – AE8 trapped radiation model with the Shields-1 CAD and generic CubeSat 3 unit (U) models. Using NOVICE model radiation analysis coding, the shielding effectivenesses, based on a generic CubeSat 3U structure with 4 electronic boards, were estimated for aluminum wall thicknesses ranging from 0.204-cm to 4.44-cm (0.550-g/cm2 – 12.0-g/cm2) thick aluminum. For modeled polar orbiting spacecraft, solar maximum total ionizing dose (TID) increases by nearly a magnitude for thin-walled aluminum 0.550-g/cm2 - 0.686-g/cm2 (0.204-cm – 0.254-cm) typical CubeSat structures. The shielding effectiveness by NOVICE Sigma estimates, which is a shielding sphere approximation around a detector, showed a linear relationship with wall thickness, which increased over the wall thickness by a ratio of 1.43 determined by linear regression analysis. Using NOVICE Adjoint Monte-Carlo Modeling of solar minimum and solar maximum with the inclusion of a worst-case solar particle event over a 1-year mission without geomagnetic shielding, the TID for minimum and maximum conditions for a generic 3U with a wall thickness of 0.254 cm is 158 RAD and 1540 RAD, respectively. The modeled total solar maximum TID is over estimated, because at low orbital latitudes a spacecraft will have shielding from the Earth’s magnetic field. However, TID will still be significant at high latitudes over the poles, where a spacecraft is exposed in a solar particle event. In contrast, to a thin-walled generic 3U CubeSat, the Shields-1 electronics enclosure has a shielding effectiveness of 21.3 g/cm2 from NOVICE Sigma modeling and is expected to show reduced total ionizing dose increases during the present active Solar Cycle 25 period. Because solar particle events during solar maximum increase TID on electronic parts with thin-walled shielding in short periods of time, it is a mission assurance and reliability consideration on the spacecraft’s mission value versus adding shielding for risk reduction of premature spacecraft or instrument payload loss. Since the volumes of many instruments and system electronics have reduced with small spacecraft, shielding material costs and weight penalties have diminished. A small spacecraft project budget and schedule may limit traditional radiation-hardened part use and radiation testing requirements, where shielding can contribute to mission assurance and reliability with reduced costs

Effect of Mineral Nutrition on Red Clover Leaf Area Index

The legume red clover (Trifolium pratense) fixes its own nitrogen (N), but requires P and K fertilisation. There are no recent reliable data in the domestic literature, on the amounts of P and K recommended to farmers; present recommendations are often either inadequate or excessive. Red clover mineral nutrition is significantly affected by soil and weather conditions (Taylor & Quesenberry, 1996). The objective of our twoyear study was to enable rational fertiliser application in accordance with soil type and agro ecological conditions

Analysis of the impact of fruit growing development on the intensity of soil erosion and runoff: Case study of krusevo, bijelo polje, Montenegro

The research has been conducted to analyse the effects of land use change of the impact of fruit growing development on the intensity of soil erosion and runoff in the Study area of Krusevo, Bijelo Polje, Montenegro by using the Intensity of Erosion and Outflow – IntErO model of Spalevic. The required spatial maps, land use, soil and geology were prepared and analysed in GIS environment. The climatic data such as the volume of the torrential rain, average annual air temperature and average annual precipitation were calculated based on meteorological data received from the State Hydrological Institute for the region of Bijelo Polje (Montenegro). The results of land use change between these two periods (2011-2020) shown that the forest increased in the studied region by 1.57%. Specifically, degraded forests increased by 1.02%; Well-constituted forests increased by 0.55%. For the studied area we calculated forested area on 57.26% (2011), and 58.83% (2020). The values for Meadows in the studied area decreased from 2011 to 2020 for 1.67%; and for Pastures for 1.40%. Plough-lands decreased for the observed period for 1.59%. On the other hand, the surface under the Orchards increased by 3.09%, and that represented the shift from the Meadows to the Orchards; the shift from the Pastures to the Forests. This denser vegetation at the studied region for the observed period (increase of the forests and orchards) has led to higher water infiltration rate into the soil and at the same time to decrease of the sediment yield. The value of Z coefficient of 0.462 (2011); 0.461 (2020) indicates slight decrease of erosion processes because of the fruit growing development with shifting the meadows to orchards categorising the processes to the 3rd destruction category. The strength of the erosion process is medium, and according to the erosion type, it is surface erosion. Production of erosion material in the river basin, W year, is calculated on 11327 m3year-1 for 2011; and 11278 m3 year-1 for 2020, what shown the decrease of erosion processes because of the subject fruit growing development. Coefficient of the deposit retention (sediment delivery ratio) is calculated as 0.299 what means that 30% of the total eroded material reaches to the outlet point. Real soil losses, G year, are calculated on 3392 m3 year-1 (2011), and 3377 (2020); Real soil losses per km2, G year km-2, are 262 m3 km-2 year-1 (2011), and 261 m3km-2 year-1 (2020), with the same conclusion in relation to the fruit growing initiatives and the values indicates that the river basin belongs to 5th destruction category; it is a region of very weak erosion. The results showed that the appropriate land management and planning with implementing fruit growing in this area decreases maximum flow rate and also sediment yield. The application of the IntErO model may also be further used to understand the effect of land use change with new establishing of the fruit growing in the river basins on hydrological behaviour, soil erosion and sediment yield process and can be used as a useful tool in similar for fruit growing and soil conservation research

Frailty in older people living with HIV: current status and clinical management

This paper will update care providers on the clinical and scientific aspects of frailty which affects an increasing proportion of older people living with HIV (PLWH). The successful use of combination antiretroviral therapy has improved long-term survival in PLWH. This has increased the proportion of PLWH older than 50 to more than 50% of the HIV population. Concurrently, there has been an increase in the premature development of age-related comorbidities as well as geriatric syndromes, especially frailty, which affects an important minority of older PLWH. As the number of frail older PLWH increases, this will have an important impact on their health care delivery. Frailty negatively affects a PLWH's clinical status, and increases their risk of adverse outcomes, impacting quality of life and health-span. The biologic constructs underlying the development of frailty integrate interrelated pathways which are affected by the process of aging and those factors which accelerate aging. The negative impact of sarcopenia in maintaining musculoskeletal integrity and thereby functional status may represent a bidirectional interaction with frailty in PLWH. Furthermore, there is a growing body of literature that frailty states may be transitional. The recognition and management of related risk factors will help to mitigate the development of frailty. The application of interdisciplinary geriatric management principles to the care of older PLWH allows reliable screening and care practices for frailty. Insight into frailty, increasingly recognized as an important marker of biologic age, will help to understand the diversity of clinical status occurring in PLWH, which therefore represents a fundamentally new and important aspect to be evaluated in their health care

Linseed Oil as a Source of Polyunsaturated Fatty Acids in Broiler Chicken Nutrition

The aim of the paper was to examine the effect of polyunsaturated fatty acids from linseed oil on productive performances and fatty acid composition of lipids of broiler chicken abdominal fat, as well as correlation and regression between consumed amount of oil and possibilities of their incorporation in the tissues. For the need of experimental research, three groups of 40 day old chicken, hybrid line Cobb 500 were formed. Every group had five replicates, in total amount of 200 chickens per treatment. Control group were fed with diet in addition of 4% soybean oil, while the experimental groups were fed with addition of 4 and 8% of linseed oil in the diet. Addition of linseed oil had a statistically high (P<0.01) influence on chicken body weight reduction in treatments T2 and T3, compared to the body weights of chicken in control group T1. Feed conversion ratio in chicken in experimental groups T2 and T3 was 1.84 and 1.82 kg of feed/kg of gain. Introduction of linseed oil in amounts of 4 and 8% in chicken nutrition led to statistically high (P<0.01) differences in content of linoleic acid (C18:2) in treatments T2 and T3, compared to control group T1, which leads to a conclusion that linseed oil significantly reduces linoleic acid in tissue. Compared to linoleic acid, content of α-linolenic acid (C18:3) was statistically significantly increased (P<0.05) in treatment T2 and highly significantly (P<0.01) in treatment T3, compared to control. Negative values of regression (b) and correlation (r) also confirm the fact that introduction of linseed oil in the diet significantly reduces content of linoleic acid in fat tissue of chickens (b=-0.551; r=-0.79), while the same coefficients show positive dependence between added linseed oil in the diet and deposited linolenic acid in tissues (b=1.081 and r=0.87). Based on the gained results it can be concluded that addition of linseed oil in the amount of 4 and 8% could be successfully used in chicken nutrition for fatty acid composition improvement and for lowering the ratio between n-6/n-3 polyunsaturated fatty acid in tissues of broilers

Polyphenols and non-alcoholic fatty liver disease: impact and mechanisms:impact and mechanisms

Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic component of the metabolic syndrome and its prevalence is rapidly increasing due to its strong association with insulin resistance and obesity. At present, given that NAFLD is highly prevalent and therapies are limited, much attention is focused on identifying effective dietary strategies for the prevention and treatment of the disease. Polyphenols are a group of plant bioactive compounds whose regular consumption have been associated with a reduction in the risk of a number of metabolic disorders associated with NAFLD. Here we review the emerging and relatively consistent evidence from cell culture and rodent studies showing that select polyphenols positively modulate a variety of contributors to the NAFLD phenotype, through diverse and complementary mechanisms of action. In particular, the reduction of de novo lipogenesis (via sterol regulatory element-binding protein 1c) and increased fatty acid β-oxidation, presumably involving AMP-activated protein kinase activation, will be discussed. The indirect antioxidant and anti-inflammatory properties of polyphenols which have been reported to contribute to the amelioration of NAFLD will also be addressed. In addition to a direct study of the liver, rodent studies have provided insight into the impact of polyphenols on adipose tissue function and whole body insulin sensitivity, which are likely to in part modulate their impact on NAFLD development. Finally an overview of the limited data from clinical trials will be given along with a discussion of the dose extrapolation from animal studies to human subjects

Exacerbations and lung function decline in COPD: New insights in current and ex-smokers

SummaryAimTo investigate whether there is a significant relationship between an increased frequency of exacerbations and the rate of forced expiratory volume in 1s (FEV1) decline in COPD patients.Methods–measurementsAbout 102 COPD patients (44 smokers, 58 ex-smokers) participated in a 3-year prospective study. Exacerbations were identified as worsening of patient's respiratory symptoms as recorded on diary cards. Spirometry was performed every 6 months. The effect of frequent exacerbations on lung function was investigated using random effects models.ResultsThe median (mean(95% CI)) annual exacerbation rate was 2.85 (3.1 (2.7–3.6)). Patients with an annual exacerbation rate over the median rate had significantly lower baseline post-bronchodilation FEV1(%pred), higher MRC dyspnoea score and chronic cough compared to patients who had an annual exacerbation rate less than the median. The average annual rate of FEV1(%pred), adjusted for smoking decline (ΔFEV1), was found significantly increased in frequent compared to infrequent exacerbators (P=0.017). The highest ΔFEV1 was observed in smokers frequent exacerbators and a significant interaction between exacerbation frequency and ΔFEV1 was also observed in ex-smokers.ConclusionsOur findings suggest that an increased frequency of exacerbations is significantly associated with FEV1 decline even in ex-smokers. Thus, smoking and frequent exacerbations may have both negative impact on lung function. Smoking cessation and prevention of exacerbations should be a major target in COPD

Effect of Cutting Date on Quality of Red Clover Forage

Development stage or plant age is an important factor determining the chemical composition and quality of red clover forage (Ignjatovic et al., 2001). In early spring, young red clover plants have large leaf mass, high contents of moisture, protein and minerals and a low fibre content. In the course of the growing season, under the effects of long days and high temperatures, the plant undergoes morphological changes: leaves grow more slowly, the stem elongates, dry matter yield increases and quality drops, especially digestibility and the contents of protein and minerals

Promena izoprenoidne, steranske i terpanske frakcije tokom ex situ bioremedijacije mazuta na industrijskom nivou

This paper presents the results of an ex situ bioremediation of soil contaminated by mazut (heavy residual fuel oil) in the field scale (600 m(3)). The treatment-bed (thickness 0.4 m) consisted of mechanically mixed mazut-contaminated soil, softwood sawdust as an additional carbon source and crude river sand, as a bulking and porosity increasing material. The inoculation/reinoculation was conducted periodically using a biomass of a consortium of zymogenous microorganisms isolated from a bioremediation substrate. The biostimulation was performed through addition of nutritious substances (N, P and K). The aeration was improved by systematic mixing of the bioremediation system. After 50 days, the number of hydrocarbon degraders had increased a 100 fold. Based on the changes in the group composition, the average biodegradation rate during bioremediation was 24 mg kg(-1) day(-1) for the aliphatic fraction, 6 mg kg(-1) day(-1) for the aromatic fraction and 3 mg kg(-1) day(-1) for the nitrogen-sulphur-oxygen compounds (NSO)-asphaltene fraction. In the saturated hydrocarbon fraction, gas chromatography-mass spectrometry (GC-MS) in the single ion-monitoring mode (SIM) was applied to analyse isoprenoids pristane and phytane and polycyclic molecules of sterane and triterpane type. Biodegradation occurred during the bioremediation process, as well as a reduction of the relative quantities of isoprenoids, steranes, tri- and tetracyclic terpanes and pentacyclic terpanes of the hopane type.Prikazani su rezultati ex situ bioremedijacije zemljišta kontaminiranog mazutom na industrijskom nivou (600 m3). Bioremedijacioni materijal (debljine 0,4 m) se sastojao od mehanički pomešanih mazutom zagađenog zemljišta, čamove piljevine kao dodatnog izvora ugljenika i neprečišćenog rečnog peska, dodatog u cilju mešanja i povećanja poroznosti. Inokulacija/reinokulacija (bioaugmentacija) je periodično rađena sa biomasom konzorcijuma zimogenih mikrooorganizama izolovanih iz supstrata za bioremedijaciju. Biostimulacija je realizovana dodatkom hranljivih supstanci (N, P i K). Aeracija je poboljšavana sistematskim mešanjem bioremedijacionog sistema. Nakon 50 dana broj mikroorganizama koji degradiraju ugljovodonike povećan je 100 puta. Na osnovu promena u grupnom sastavu prosečna stopa biodegradacije tokom bioremedijacije je bila za alifatičnu frakciju 24 mg kg-1 po danu, za aromatičnu 6 mg kg-1 po danu i 3 mg kg-1 po danu za NSO-asfaltensku frakciju. U zasićenoj ugljovodoničnoj frakciji metodom GC-MS (SIM metod) analizirani su izoprenoidi pristan i fitan i policiklični molekuli steranskog i triterpanskog tipa. Tokom bioremedijacionog procesa došlo je do biodegradacije i smanjenja relativnih količina izoprenoida, sterana, tri- i tetracikličnih terpana i pentacikličnih terpana hopanskog tipa