Sharpness versus robustness of the percolation transition in 2D contact processes

We study versions of the contact process with three states, and with infections occurring at a rate depending on the overall infection density. Motivated by a model described in [17] for vegetation patterns in arid landscapes, we focus on percolation under invariant measures of such processes. We prove that the percolation transition is sharp (for one of our models this requires a reasonable assumption). This is shown to contradict a form of 'robust critical behaviour' with power law cluster size distribution for a range of parameter values, as suggested in [17].Comment: 31 pages, to appear in Stochastic Processes and their Application

Epimerization of trans-Cycloalkenes with the X–C=C–SeR*-Unit – The Steric Demand of X = H, F, Cl, Br, I, Me, Et and CF3

Trans-cycloalkenes with the X–C=C–SeR*-unit and ring sizes from 9 to 20 have been synthesized. Bond the selenium atom is the chiral (S)-o-(1-Methoxypropyl)phenyl-residue R*, and X = H, F, Cl, Br, I, Me, Et and CF3. The planar-chiral trans-cycloalkenes in combination with the chiral residue R* exist as two diastereomers. These can be distinguished in principle by NMR spectroscopy. We have studied the epimerization of the trans-cycloalkenes, i.e., the 180° rotation of the X–C=C-unit through the cavity of the ring. The measurements were done with variable temperature 13C NMR spectroscopy in the range from –110 to 140°C. The obtained values of the Gibbs energy of activation ΔG‡C depend strongly on the ring size. Furthermore, the ΔG‡C values show dramatic steric effects due to the groups X. The steric requirement of X increases in the series H << F << Cl < Me < Br < I < Et < CF3. Here, F is significantly larger than H, and CF3 is larger than Et. The corresponding iPr-compounds could not be synthesized. The transition state structures of the ring inversion for ring sizes 8–20 were calculated at the DFT level of theory

Low Energy Turnover of Physically Inactive Participants as a Determinant of Insufficient Mineral and Vitamin Intake in NHANES.

Micronutrient requirements do not scale linearly with physical activity-related energy expenditure (AEE). Inactive persons may have insufficient micronutrient intake because of low energy intake (EI). We extracted data from NHANES 2003-2006 on 4015 adults (53 ± 18 years (mean ± SD), 29 ± 6 kg/m², 48% women) with valid physical activity (accelerometry) and food intake (2 × 24 h-dietary recall) measures. Total energy expenditure (TEE) was estimated by summing the basal metabolic rate (BMR, Harris-Benedict), AEE, and 10% of TEE for the thermic effect of food, to calculate the physical activity levels (PAL = TEE/BMR). Energy intake (EI) was scaled to match TEE assuming energy balance. Adjusted food intake was then analyzed for energy and micronutrient content and compared to estimated average requirements. The NHANES population was physically insufficiently active. There were 2440 inactive (PAL &lt; 1.4), 1469 lightly to moderately active (PAL1.4 &lt; 1.7), 94 sufficiently active (PAL1.7 &lt; 2.0), and 12 very active participants (PAL ≥ 2.0). The inactive vs. active had significantly lower intake for all micronutrients apart from vitamin A, B12, C, K, and copper ( &lt;i&gt;p&lt;/i&gt; &lt; 0.05). The inactive participants had insufficient intake for 6/19 micronutrients, while the active participants had insufficient intake for 5/19 ( &lt;i&gt;p&lt;/i&gt; &lt; 0.05) micronutrients. Multiple linear regression indicated a lower risk for insufficient micronutrient intake for participants with higher PAL and BMI ( &lt;i&gt;p&lt;/i&gt; &lt; 0.001). Symmetrical up-scaling of PAL and EI to recommended physical activity levels reduced the frequency of micronutrient insufficiencies. It follows that prevalence of insufficient micronutrient intake from food in NHANES might be partly determined by low energy turnover from insufficient PAL

Bioactive compounds in the stem bark of Albizia coriaria (Welw. ex Oliver)

Albizia coriaria was investigated for the bioactive compounds present in its stem bark. The plant was selected on the basis of its widespread use in traditional herbal medicine. Extraction of the plant material was done with ethyl acetate, methanol and water and the bioactivity of each extract was tested against  Pseudomonas aeruginosa and Escherichia coli. Separation and purification of the compounds in the most active (ethyl acetate) extract was done using a  combination of chromatographic techniques. The compounds were identified by 1D and 2D -1H and 13C NMR techniques as well as Mass spectrometry (MS). Six compounds, namely: Lupeol (1), Lupenone (2), Betulinic acid (3), Acacic acid lactone (4), (+) – Catechin (5) and Benzyl alcohol (6) were identified and  characterized from the ethyl acetate extract. The results of the bioactivity tests carried out in this study indicated that A. coriaria has potential antimicrobial activity. Four of the characterized compounds (1, 2, 3 &amp; 5) have a wide range of biological activity reported in literature. This justifies the use of this plant in traditional medicine and indicates a promising potential for the development of medicinal agents from A. coriaria stem bark.Keywords: Biological activity, Lupeol, Lupenone, Betulinic acid, Acacic acid lactone, (+) – Catechin

Chemical constituents of the ethyl acetate extracts of the stem bark and fruits of Dichrostachys cinerea and the roots of Parkia bicolor

The antibacterial activities of ethyl acetate, methanol and aqueous extracts of the stem bark of Dichrostachys cinerea and the roots of Parkia bicolor have been evaluated. Ethyl acetate extracts have been investigated, studies that led to a series of known compounds, amongst which many are reported here for the very first time from both the species.  KEY WORDS: Dichrostachys cinerea, Parkia bicolor, Chemical constituents, Antibacterial activity Bull. Chem. Soc. Ethiop. 2004, 18(1), 111-115

Metabolic Equivalent in Adolescents, Active Adults and Pregnant Women.

"Metabolic Equivalent" (MET) represents a standard amount of oxygen consumed by the body under resting conditions, and is defined as 3.5 mL O₂/kg × min or ~1 kcal/kg × h. It is used to express the energy cost of physical activity in multiples of MET. However, universal application of the 1-MET standard was questioned in previous studies, because it does not apply well to all individuals. Height, weight and resting metabolic rate (RMR, measured by indirect calorimetry) were measured in adolescent males (n = 50) and females (n = 50), women during pregnancy (gestation week 35-41, n = 46), women 24-53 weeks postpartum (n = 27), and active men (n = 30), and were compared to values predicted by the 1-MET standard. The RMR of adolescent males (1.28 kcal/kg × h) was significantly higher than that of adolescent females (1.11 kcal/kg × h), with or without the effects of puberty stage and physical activity levels. The RMR of the pregnant and post-pregnant subjects were not significantly different. The RMR of the active normal weight (0.92 kcal/kg × h) and overweight (0.89 kcal/kg × h) adult males were significantly lower than the 1-MET value. It follows that the 1-MET standard is inadequate for use not only in adult men and women, but also in adolescents and physically active men. It is therefore recommended that practitioners estimate RMR with equations taking into account individual characteristics, such as sex, age and Body Mass Index, and not rely on the 1-MET standard

Estimates on returnable packaging material

When a beer company replaces its returnable packaging materials, for exam-ple when updating the design of a bottle, it needs to know in advance how much new material will be needed. Dutch beer brewer Heineken submitted the question of estimating the returnable packaging materials to the 2013 Studygroup Mathe-matics with Industry. In this report, we present both stochastic flow models and a queueing model to estimate the amount of returnable packaging material present in the market. Furthermore, we give recommendations on what data to collect, and how to sample this data in an unbiased way in order to increase accuracy of the estimation. Keywords: Modelling, Markov Chain, Stochastic Differential Equation, Queue-ing Theor

Validity of the Actiheart step test for the estimation of maximum oxygen consumption in endurance athletes and healthy controls

Submaximal step tests are often used for estimation of maximum oxygen consumption (VO2max) in humans. The validity of the Actiheart step test for VO2max estimation was not fully studied yet. There- fore, purpose of the study was to estimate VO2max using the Actiheart step test and to compare the data with measured VO2max in endurance trained athletes (ATH) and healthy non-athletes (CON). 68 ATH (54% men, 28.0±5.4 yrs, 20.9±1.7 kg∙m-2) and 63 CON (46% men, 27.6±5.1 yrs, 22.1±1.7 kg∙m-2) performed the Actiheart step test and a spiroergometry for assessment of VO2max. In addition, rest- ing metabolic rate (RMR; indirect calorimetry), maximum heart rate (HRmax; heart rate monitoring system during spiroergometry), and sleeping heart rate (SHR; Actiheart 6-day long term measure- ment) were determined. Validity of two different Actiheart software entry modes was assessed: (1) AHraw (estimated RMR [Schofield] and HRmax [Tanaka], SHR = 70 bpm) and (2) AHcomplete (mea- sured RMR, HRmax, and SHR). Validity was investigated using linear regression (R2 and standard error of the estimate (SEE)) and repeated-measures ANOVA with a Bonferroni post-hoc correction. The level of significance was set to α=0.05. VO2max estimated by AHraw was significant related to measured VO2max in women CON (R2=0.22; p&lt;0.05), whereas when VO2max was estimated by AHcomplete the relation was significant in women ATH and CON, and in men CON (R2=0.17-0.24; p&lt;0.05). AHraw significantly underestimated VO2max in the total sample by 8% (51.4±10.2 vs. 55.9±7.6 ml∙kg-1∙min-1; p&lt;0.0001), whereas no significant difference between AHcomplete and the criterion method was found (57.0±11.1 vs. 55.9±7.6 ml∙ kg-1∙min-1; p=0.26). The Actiheart step test is an acceptable tool for the estimation of VO2max if an error within 8% can be tolerated. However, accuracy of the VO2max prediction is much improved when entering measured variables, such as RMR, SHR, and HRmax, into the software

Comparison of Conventional and Individualized 1-MET Values for Expressing Maximum Aerobic Metabolic Rate and Habitual Activity Related Energy Expenditure.

The maximum aerobic metabolic rate can be expressed in multiple metabolically equivalent tasks (MET), i.e., METmax. The purpose was to quantify the error when the conventional (3.5 mL∙kg &lt;sup&gt;-1&lt;/sup&gt; ∙min &lt;sup&gt;-1&lt;/sup&gt; ) compared to an individualized 1-MET-value is used for calculating METmax and estimating activity energy expenditure (AEE) in endurance-trained athletes (END) and active healthy controls (CON). The resting metabolic rate (RMR, indirect calorimetry) and aerobic metabolic capacity (spiroergometry) were assessed in 52 END (46% male, 27.9 ± 5.7 years) and 53 CON (45% male, 27.3 ± 4.6 years). METmax was calculated as the ratio of VO₂max over VO₂ during RMR (METmax_ind), and VO₂max over the conventional 1-MET-value (METmax_fix). AEE was estimated by multiplying published MET values with the individual and conventional 1-MET-values. Dependent t-tests were used to compare the different modes for calculating METmax and AEE (α = 0.05). In women and men CON, men END METmax_fix was significantly higher than METmax_ind (p &lt; 0.01), whereas, in women END, no difference was found (p &gt; 0.05). The conventional 1-MET-value significantly underestimated AEE in men and women CON, and men END (p &lt; 0.05), but not in women END (p &gt; 0.05). The conventional 1-MET-value appears inappropriate for determining the aerobic metabolic capacity and AEE in active and endurance-trained persons