Variation In Weights Research Articles

Variation of lead isotopic composition and atomic weight in terrestrial materials (IUPAC Technical Report)

Abstract The isotopic composition and atomic weight of lead are variable in terrestrial materials because its three heaviest stable isotopes are stable end-products of the radioactive decay of uranium (238U to 206Pb; 235U to 207Pb) and thorium (232Th to 208Pb). The lightest stable isotope, 204Pb, is primordial. These variations in isotope ratios and atomic weights provide useful information in many areas of science, including geochronology, archaeology, environmental studies, and forensic science. While elemental lead can serve as an abundant and homogeneous isotopic reference, deviations from the isotope ratios in other lead occurrences limit the accuracy with which a standard atomic weight can be given for lead. In a comprehensive review of several hundred publications and analyses of more than 8000 samples, published isotope data indicate that the lowest reported lead atomic weight of a normal terrestrial materials is 206.1462 ± 0.0028 (k = 2), determined for a growth of the phosphate mineral monazite around a garnet relic from an Archean high-grade metamorphic terrain in north-western Scotland, which contains mostly 206Pb and almost no 204Pb. The highest published lead atomic weight is 207.9351 ± 0.0005 (k = 2) for monazite from a micro-inclusion in a garnet relic, also from a high-grade metamorphic terrain in north-western Scotland, which contains almost pure radiogenic 208Pb. When expressed as an interval, the lead atomic weight is [206.14, 207.94]. It is proposed that a value of 207.2 be adopted for the single lead atomic-weight value for education, commerce, and industry, corresponding to previously published conventional atomic-weight values.

Analysis of the influence of genetic and non-genetic factors on the birth weight and weaning weight of lambs

The main aim of this paper is to analyze the influence of genetic and non-genetic factors on the birth weight and weaning weight of lambs. The study was carried out on the basis of the Institute of Animal Husbandry of Steppe Regions named by M. F. Ivanov “Askania-Nova” – the National Scientific Agricultural Center in Sheep Breeding of NAAS. Birth and weaning weights data collected during a 5-vear period from 3961 lambs were used. The reproductive traits of the Ascanian fine-fleece (AC) ewes were evaluated in combination with the rams of different genotypes: Ascanian fine-fleece, Australian merino (AM) and half-bred animals (1/2AC+1/2AM). The main effect of the ram genotype and the year of lambing, the age of the ewes, the litter size, the sex of lamb and the sex ratio in twins on the birth weight and weaning weight of lambs was analysed using one-way ANOVA. Differences between years of the 5-year period were highly significantly (P < 0.001) for all lamb traits studied. The effects of the environmental factor (year of lambing) on the birth weight and weaning weight of lambs represented 27.2 and 15.2 per cent of the total variance, respectively. The ram-group effects, which are mainly genetic differences, were highly significant (P < 0.001) in all traits. Age of dam had significant effect on the birth weight of lambs (P = 0.048) and was relatively unimportant as a source of variation. Two-year-old ewes bore lighter lambs than older ewes. There were no significant differences in the weaning weight of lambs from the ewes of different age classes. Survival rate was related to birth weight of lambs. Lamb survival increased up to a birth weight of 4.0 kg and only declined when they weighed more than 5.0 kg at birth. Our results showed that singles were 0.61 kg heavier than twins at birth and were 2.42 kg heavier than twins at weaning. Litter size (type of birth) was responsible for 42.5 and 10.0 % of total variability in birth and weaning weights of lambs, respectively (in both cases: P < 0.001). Average birth and weaning weights of male lambs were higher than the females (in both cases: P < 0.001).

A botanical from the antiproliferative Cameroonian spice, Imperata cylindrica is safe at lower doses, as demonstrated by oral acute and sub-chronic toxicity screenings

BackgroundThe cytotoxicity of the root’s methanol extract of Imperata cylindrica (ICR). was previously reported in a panel of human cancer cell lines, including multi-drug resistant phenotypes. The aim of this study was to assess the acute and sub-chronic oral toxicity of methanol root extract of Imperata cylindrica.MethodsThe acute toxicity was carried out according to the experimental protocol of OECD. The plant extract was administered orally to female rats at a single dose of 5000 mg/kg for 14 days and the animals were observed for any behavioral changes or mortality. For sub-chronic toxicity study, ICR was orally administered daily to male and female rats at different doses (250, 500 and 1000 mg/kg per b.w.) for 30 days. During these treatment days the animals were observed for any appearance of toxicity symptoms; following the treatment period, animals were sacrificed for hematological, biochemical and histopathology analysis.ResultsFrom the results of the acute oral toxicity assay, ICR was found to be non-toxic at the dose of 5000 mg/kg b.w. During the period of sub-chronic toxicity test, observation of signs, behavior and health status of the animals showed no abnormality in the groups of animals treated with ICR as compared to the controls. Significant variation of the relative body weights of heart and kidney were observed at dose a 1000 mg/kg b.w. Significant decrease of aspartate aminotransferase, creatinine level, low density lipoprotein concentration, triglyceride and total cholesterol were observed. In males, we noticed a significant decrease of the level of granulocytes with an increase of lymphocytes and mean corpuscular hemoglobin concentration levels. Histological examinations performed on kidney and liver showed a normal kidney architecture and liver also presented a normal hepatic architecture with slight degeneration at a dose 1000 mg/kg b.w.ConclusionICR is safe for acute oral administration; however, for long-term oral administration, safety measures should be taken. Thus, oral sub-chronic exposure of ICR at lower doses are recommended while higher doses around 1000 mg/kg b.w. should be discouraged.

UTILIZATION OF CRAB SHELL WASTE AS A SPHERICAL CHITOSAN (CH-Z SPHERICAL) COMPOSITE TO REDUCE HARD WATER

In this research, have perfomed the synthesis of chitosan from crab shell waste as a Chitosan/Zeolite (Ch-Z spherical) composite to reduce water hardness. The synthesis of chitosan can be done in three stages, namely demineralization, deproteination, depigmentation, and deacetylation. The stages of Chitosan/Zeolite Spherical (Ch-Z Spherical) synthesis were made with variations in the weight of chitosan: zeolite (w /w) 1: 0.5; 1: 1; 1:1.5 using Crosslinking Sodium tripolyphospat. The characterization results by using FT-IR for chitosan-zeolite weight variations at wavelengths of 4000-450 cm-1 show a typical IR spectrum for chitosan / zheolite Spherical (Ch-Z Spherical) successively at wavelengths of 1639 cm-1, 1638 , 71 cm-1, and 1638.58 cm-1 which is the -C⁼N strain or structural change (deformation) of NH2. The chitosan-zeolite spherical (Ch-Z spherical) composite was applied to reduce the metal Ca (II) and Mg (II) which can cause hardness in water. The effectiveness of 0.5 gram Ch-Z Spherical composites, we tested the variation of composite weights 0.1, 0.2, 0.4, 0.6, 0.8, and 1.2 gr as adsorbents of Ca (II) metal ) and Mg (II) with a concentration of 1000 ppm in 1 hour with the stirring process. The results obtained by a decrease of 99.69% at a weight of 0.6 grams and experienced constant along with an increase in the mass of adsorbent. While the effectiveness of the Spherical Ch-Z composite in reducing the concentration of Mg (II) by 99.4% in a weight variation of 1.2 gr. This shows the formation of active sites contained in the Spherical Ch-Z composite. Metal adsorption capacity of Ca (II) and Mg (II) obtained in this study amounted to 498 mg/g and 23.7 mg /g

Comprehensive Analysis of Variants of TF-IDF Applied on LDA and LSA Topic Modelling

Present generation is fully connected virtually through many sources of social media. In social media, opinions of people for any post, news or about any product through comments or emoticon designed to express the satisfactory note. Market standards improve on this basis. There are different online markets like Amazon, Flipkart, Myntra improve their businesses using these reviews passed. Analyzing large scale opinion or feedback of individual’s helps to identify hidden insights and work towards customer satisfaction. This paper proposes for applying different weighting scheme of TF-IDF (Term Frequency-Inverse Document Frequency) for topic modeling methods LSA and LDA to cluster the topics of discussion from large scale reviews related to booming online market ‘Amazon’. The main focus of the paper is to observe the changes in the topic modeling by applying different weighting schemes of TF-IDF. In this work topic-based models like LDA (Latent Dirichlet Allocation) and LSA (Latent Semantic Allocation) applied to various weighting schemes of TF-IDF and observed the changes of weights leads to variation of term frequency of different topics with respect to its documents. Results also show that the variation of term weights results changes in topic modeling. Visualization results of topic modeling clusters with different TF-IDF weighting schemes are presented.

Validation of bridge health monitoring system using temperature as a proxy for damage

In this paper, damage indicators are presented for bridges based on measured data collected under uncontrolled traffic conditions. The test bridge considered is a small stiff concrete culvert with low dynamics, making it suboptimal for monitoring with accelerometers. Largely static strain responses are measured, with the variability in the vehicle weights and configurations addressed by handling the data in statistical terms. Continuously recorded temperature data are used in an alternative and innovative way to validate damage indicators. Temperature change causes stiffness change in concrete structures. It is posited that temperature can be used as a proxy for bridge damage as, while the effects are clearly different, both cause changes in flexural rigidity and therefore in bridge response to load. It is demonstrated here, using field data, that the damage indicators are sensitive to temperature change. Strain and temperature data for a 2-year period are obtained for a culvert bridge in Slovenia. The defined damage indicators are calculated for the strain data and validated using the simultaneously recorded temperature data. Two ways of using the proposed damage indicators together with the information about temperature for bridge structural health monitoring (SHM) are also presented: one is including the mean and standard deviation of the damage indicators and a compensation for the temperature effect and another to obtain directly the modified Z score, which is used for identifying outliers, and draw a 2D risk map having damage indicator and temperature on the two axes.

Prevalence of Lumbar Spine Dysfunction in Sugar Industry Workers of Karad Taluka

Background: From past few years, in most of the industrialized world there has been increase in number of individuals having problem in musculoskeletal system. The term spinal dysfunction refers to an abnormal increase or decrease in spinal movement (mobility). Sugar industry workers are directly involved in the production process that’s why some existing studies shows that the sugar industry work is characterized by repetitive movement, heavy load movement, wrong or awkward posture, forceful activity which causes cumulative trauma to the spine due to increase variability in weights. Repetitive bending movement causes backache, prolonged working hours causes feeling of fatigue, long hour movement of hand causes numbness of fingers and strenuous activities all these activities put workers at risk for work related musculoskeletal disorders. There was hardly any literature available on the prevalence of spinal dysfunction in sugar industry workers in rural Maharashtra. Hence this observational study is to find out prevalence of spinal dysfunction in sugar industry workers in karad taluka. Methods: This is an observational study which included 100 subjects. Then they were screened and distributed according to their age, gender, BMI and were asked to fill the modified oswestry low back pain disability Questionnaire. Later the subjects were assessede using modified oswestry low back pain disability Questionnaire. Result: In this study 100 sugar industry workers (68 males and 32 females) were taken for study. It was found that 59 sugar industry workers had a lumbar spine dysfunction. The age is from 30-above 50 years of workers were taken in this study, which was found to be more prevalent in male(63%) than in female(50%), although this difference was not statistically significant. Conclusion: This study has provided the evidence to support the increase in lumbar spine dysfunction in sugar industry workers of karad taluka.

Supervised Learning in All FeFET-Based Spiking Neural Network: Opportunities and Challenges.

The two possible pathways toward artificial intelligence (AI)—(i) neuroscience-oriented neuromorphic computing [like spiking neural network (SNN)] and (ii) computer science driven machine learning (like deep learning) differ widely in their fundamental formalism and coding schemes (Pei et al., 2019). Deviating from traditional deep learning approach of relying on neuronal models with static nonlinearities, SNNs attempt to capture brain-like features like computation using spikes. This holds the promise of improving the energy efficiency of the computing platforms. In order to achieve a much higher areal and energy efficiency compared to today’s hardware implementation of SNN, we need to go beyond the traditional route of relying on CMOS-based digital or mixed-signal neuronal circuits and segregation of computation and memory under the von Neumann architecture. Recently, ferroelectric field-effect transistors (FeFETs) are being explored as a promising alternative for building neuromorphic hardware by utilizing their non-volatile nature and rich polarization switching dynamics. In this work, we propose an all FeFET-based SNN hardware that allows low-power spike-based information processing and co-localized memory and computing (a.k.a. in-memory computing). We experimentally demonstrate the essential neuronal and synaptic dynamics in a 28 nm high-K metal gate FeFET technology. Furthermore, drawing inspiration from the traditional machine learning approach of optimizing a cost function to adjust the synaptic weights, we implement a surrogate gradient (SG) learning algorithm on our SNN platform that allows us to perform supervised learning on MNIST dataset. As such, we provide a pathway toward building energy-efficient neuromorphic hardware that can support traditional machine learning algorithms. Finally, we undertake synergistic device-algorithm co-design by accounting for the impacts of device-level variation (stochasticity) and limited bit precision of on-chip synaptic weights (available analog states) on the classification accuracy.

Individual Correlations in Ensemble Density Functional Theory: State- and Density-Driven Decompositions without Additional Kohn-Sham Systems.

Gould and Pittalis [Phys. Rev. Lett. 123, 016401 (2019)PRLTAO0031-900710.1103/PhysRevLett.123.016401 recently revealed a density-driven (DD) correlation energy that is specific to many-electron ensembles and must be accounted for by approximations. We derive in this Letter a general and simpler expression in terms of the ensemble weights, the ensemble Kohn-Sham (KS) orbitals, and their linear response to variations in the ensemble weights. As no additional state-driven KS systems are needed, its evaluation is greatly simplified. We confirm the importance of DD effects and introduce a direct and promising route to approximations.

Unweighted TOPSIS: a new multi-criteria tool for sustainability analysis

ABSTRACT In this work, we show the usefulness of a new Multi-Criteria Decision Analysis (MCDA) method, called Unweighted TOPSIS (uwTOPSIS), in helping decision making, aiming at achieving the objectives of sustainable development. uwTOPSIS is a new TOPSIS approach that does not require the decision-maker to determine the relative importance of each criterion. This makes the method more robust, since the results no longer depend on slight variations of such weights, and sustainable decisions therefore become more stable. In order to illustrate its applicability in real world problems, the results obtained with uwTOPSIS have been compared with those provided in two known study cases: the classification of Green Star hotels in Istanbul and the EU regional Social Progress Index (SPI). Moreover, all the results shown in this work can be easily reproduced since all the computations have been carried out using R statistical programming language through a self-developed package, uwTOPSIS, and the code used is included.

Effect of process parameters on the functional and physicochemical properties of extrudates enriched with starch-based nut flour

Widening the range of products produced on the basis of agricultural raw materials and improving the quality of these products and increasing their nutritional value ”‹”‹represent urgent challenges. Therefore, the production of new mass consumption products with high nutritional and biological value brings to the fore the use of local nut flour as an enriching supplement in innovative technological processes. The high nutritional value of nuts (nuts, walnuts, and peanuts) is due to their chemical composition, including lipids, a large amount of soluble proteins that are well absorbed by the human body, sufficiently large quantities of vitamin B1 and a small amount of vitamins PP and E. It is known that in peanut grains, lipids have a balanced composition of fats and acids, as well as sufficiently large amounts of essential amino acids, which makes their protein composition closer to that of animal proteins. This study considers the influence of thermoplastic extrusion parameters on the functional and physicochemical properties of extrudates in their formation process. The technological and design parameters of the process and their variation ranges are based on studies conducted on model systems. The ratio of the extrusion mixture components (formulation) is also developed. Based on the methodology for multifactorial experimental design, the variation of the volume weights, expansion rates, and mechanical specific energy expenditure of porous extrudates enriched with starch-based nut flour is studied. It has been established that the best quality indicators of the products are achieved with the minimum volume weight and the maximum expansion rate.

Reproductive timing and synchronized reproduction of the sea urchin Pseudechinus magellanicus (Echinoidea: Temnopleuridae) in central Patagonia, Argentina

ABSTRACT The reproduction of the sea urchin Pseudechinus magellanicus and the influence of environmental factors were studied during a 27-month period in central Patagonia, Argentina, where this species is among the dominant grazers in kelp forests and tide pools. The monthly variation in the gonad dry weights, gonadal stages and other quantitative reproductive variables (oocyte diameter, density and thickness of spermatogenic columns) indicated a clearly annual gametogenic cycle and revealed a high level of spawning synchrony. A main spawning event occurs between August and September, and a minor and asynchronous spawning event was recorded during the austral summer (January–March). The highest gonadal growth rate occurs between late spring and summer, accompanied by growth and early prematurity gonadal stages, indicating active vitellogenesis. The accumulation of ova begins in autumn and shows a peak during winter. After spawning, the recovery stages are not extended in time and ovaries do not show a complete meshwork of nutritive phagocytes within the acinus, suggesting simultaneous reabsorption and inversion processes. Spermatogenesis shows a higher maturation rate than oogenesis, and a higher temporal prevalence of premature and mature stages. Major spawning coincides with the first rise in seawater temperature, the maximum rate of increase in day length and the maximum peak of chlorophyll a. Results also revealed some temporal differences in the gonadal cycle, vitellogenesis and spawning periods compared with other P. magellanicus populations from different latitudes. This could be attributed to individual differences in the acquisition and allocation of energy for gametogenesis, as well as to local environmental factors.

Monthly Abundance Patterns and the Potential Role of Waterbirds as Phosphorus Sources to a Hypertrophic Baltic Lagoon

Compared to external loads from tributaries and sediment recycling, the role of waterbirds as phosphorus (P) sources in estuaries is overlooked. We performed monthly ship-based surveys of waterbird abundance in the Lithuanian part of the Curonian Lagoon, calculated their potential P excretion, and compared its relevance to the riverine inputs. Phosphorus excretion rates for the censused species were assessed accounting for variations of body weights, daily feces production and their P content, and assigning species to different feeding and nutrient cycling guilds. During the study period (March–November 2018), 32 waterbird species were censused, varying in abundance from ~18,000–32,000 (October–November) to ~30,000–48,000 individuals (June–September). The estimated avian P loads during the whole study period varied between 3.6 and 25 tons, corresponding to an area load between 8.7 and 60.7 mg P m−2. Waterbird release of reactive P to the system represented a variable but not negligible fraction (1%–12%) of total external P loads, peaking in June–September and coinciding with cyanobacterial blooms. This study is the first in the Baltic Sea region suggesting that waterbirds are potentially important P sources to phytoplankton in large estuaries, in particular, during low discharge periods.

Cellular markers of mule duck livers after force-feeding

The “Foie gras” or fatty liver is the result of hepatic steatosis from nutritional origin and induced by the force-feeding of palmipeds. Despite identical rearing and force-feeding conditions of ducks from the same breed, different liver weights, within a range of 500 to more than 700 g, are generally observed at the time of evisceration. To better understand the determinism of this large variability in fatty liver weights, the activity of various metabolic pathways has been explored in 4 groups of steatotic livers differing by their weights. Different analyses were performed using biochemical assays on metabolites as well as ELISA tests or enzyme activity assays. The result showed that an increase in the final liver weight is always associated with a hypoxic response and even a severe hypoxia observed in livers with the highest weights (more than 650 g). This is also combined with a rise in the cellular oxidative stress level. In addition, for the heaviest livers (more than 700 g), signs of cell death by apoptosis were also observed, while others programmed cell death pathways, such as ferroptosis or necroptosis, seemed to be nonactive.

Improving Effect Estimates by Limiting the Variability in Inverse Propensity Score Weights

This study describes a novel method to reweight a comparison group used for causal inference, so the group is similar to a treatment group on observable characteristics yet avoids highly variable weights that would limit statistical power. The proposed method generalizes the covariate-balancing propensity score (CBPS) methodology developed by Imai and Ratkovic (2014) to enable researchers to effectively prespecify the variance (or higher-order moments) of the matching weight distribution. This lets researchers choose among alternative sets of matching weights, some of which produce better balance and others of which yield higher statistical power. We demonstrate using simulations that our penalized CBPS approach can improve effect estimates over those from other established propensity score estimation approaches, producing lower mean squared error. We discuss applications where the method or extensions of it are especially likely to improve effect estimates and we provide an empirical example from the evaluation of Comprehensive Primary Care Plus, a U.S. health care model that aims to strengthen primary care across roughly 3000 practices. Programming code is available to implement the method in Stata.

Establishment of Reference Ranges for Normal Organ Weights in Malaysian Adults at Autopsy.

Organ weights are routinely measured during autopsies as a crude screening tool to detect possible organ pathology. In several centers, inclusion of major organ weights indicates whether an autopsy report has achieved its standard of practice, which in turn should be subjected to an audit. Previous studies show statistical variation in organ weights across different populations. Malaysian pathologists have relied on Western data and crude subjective determination in the interpretation of normal organ weights. Hence, the need for a reference range as a guide for pathologists is acute. Organ weights from traumatic deaths between 2004 and 2017 were analyzed in the UKM Medical Centre. Statistical analysis was performed to form reference ranges for normal weights of the brain, heart, lung, liver, spleen, and kidneys. In addition, the data were compared between sexes, races, and body mass index values to determine whether organ weights were affected by these parameters. In this study, reference ranges for organ weights are presented for Malaysian adult men and women.

Dynamic sustainability requirements of stakeholders and the supply portfolio

Extant literature on sustainability in procurement and supplier selection suffers from a number of deficiencies. First, studies pertaining to the dynamic nature of stakeholders’ expectations of sustainability and its impact on determining a supply portfolio have not been studied before. Second, there is a genuine lack of study linking the stakeholders’ sustainability requirements, firm procurement strategies, and eventual supplier selection. Third, most of the existing studies address sustainability issues in procurement and supplier selection but fall short of determining an optimal portfolio of suppliers and corresponding optimal order quantities. This study addresses the above research gaps by developing a sustainability-focused multi-criteria decision model for supplier evaluation and determining optimal order allocation among the suppliers linking the stakeholders’ sustainability requirements and firm procurement strategies. Based on dynamic capability theory, we develop a decision support framework integrating multi-phased quality function deployment and dynamic optimization. We apply the decision support framework to a European apparel company which sources apparel from Bangladesh: a country that is a low cost sourcing destination. First, this study identifies the stakeholders’ sustainability requirements. It then explicates the company’s procurement strategies in terms of stakeholders’ requirements followed by translating the procurement strategies to relevant supplier assessment criteria. Finally, a linear optimization model is developed to maximize the suppliers’ sustainability performance in order to determine the optimal supply portfolio. The results identify two distinct groups of suppliers satisfying the overall sustainability performance. However the optimal order quantities among the suppliers vary randomly depending on the variations in demand and priority weights of the suppliers. The paper concludes with a detailed discussion of the results and implications.

Sample size and prediction of weight and yield of individual cuts from Braford steers pistol hindquarters

ABSTRACT: Two hundred seventeen grass-finished Braford steers were assessed by ultrasonic scanning and subsequently harvested with their pistol hindquarters fabricated into boneless wholesale cuts. The Longissimus thoracis muscle area and subcutaneous fat depths were measured. The objectives of this study were: 1) to develop prediction equations for weights of the pistol hindquarter and high-value commercial cuts, and 2) to estimate sample size needed for experiments comparing pistol hindquarter retail product weight using either physically or ultrasonically measured carcass traits. Carcass measurements explained 44 % to 94 % of the variation in weights of individual cuts, whereas, measurements that were made using ultrasound explained 42 % to 90 % of the variation in the weights. Models used to predict the weight of pistol hindquarter retail product with carcass measures and ultrasound measures showed high coefficient of determination (R2 = 0.92 and 0.97, respectively). Whether based on carcass or ultrasound measures, models used to estimate weight percentage of fat trimmed from the pistol hindquarter had lack of fit. In general, models for individual cuts weights that used traits measured with ultrasound as independent variables approached the accuracy of models using carcass traits. Thus, only slightly greater samples sizes were required to have equivalent power to detect differences in retail product weights using ultrasound measures. For experiments of equivalent power, differences in the number of animals required may be offset by avoiding costs for slaughter and fabrication. Keywords: cattle, carcass, models, ultrasound

Sources of variation in pre-sale weights of osmanabadi goat kids in villages of Maharashtra, India

This study pertains to pre-sale weights (about 3 months of age) of Osmanabadi kids recorded under the Osmanabadi Goat Field Unit of ICAR-All India Coordinated Research Project on Goat Improvement. Pre-sale weight records of 4394 kids born to 1604 does over nine years (2009 to 2018) in 10 villages from six districts of Maharashtra state were analyzed using mixed model restricted maximum likelihood analysis. The fixed effect of strain of kid was not significant, indicating that variation in colour and appearance among kids did not influence their weights. The influence of other fixed effects such as sex, birth type and dam parity on 3-month weight was as expected (females being lighter than males, triplets and quadruplets being lighter than twins and twins being lighter than singles, kids of dams from parity 2 to 4 weighing the highest, followed by kids of dams from parity 5 to 7, parity >7 and lastly parity 1). The effect of whether the birth date of the kids was accurate or estimated was significant, indicating an under-estimation of the age of kids by the owners. A direct genetic effect and a maternal permanent environmental effect (and not the maternal genetic effect) could be fitted in the absence of pedigrees. It was found that the variation in management among owners could best be accounted by fitting owner as a random effect. However, fitting the contemporary group (village-year-season) effect as a fixed effect was a better option than fitting it as a random effect. In village smallholder situations with inherent data recording limitations, as maternal effects cannot be accounted appropriately, it may be a better option to use traits of the dam such as body size and milk yield for selection of kids rather than kids’ pre-sale weight as a selection criterion.

Probing the effect of ortho-cycloalkyl ring size on activity and thermostability in cycloheptyl-fused N,N,N-iron ethylene polymerization catalysts.

The syntheses of six bis(imino)-5,6,7,8-tetrahydrocycloheptapyridine-iron(ii) chloride complexes, [2-{(Ar)NCMe}-9-{N(Ar)}C10H10N]FeCl2 (Ar = 2-(C5H9)-6-MeC6H3Fe1, 2-(C6H11)-6-MeC6H3Fe2, 2-(C8H15)-6-MeC6H3Fe3, 2-(C5H9)-4,6-Me2C6H2Fe4, 2-(C6H11)-4,6-Me2C6H2Fe5, 2-(C8H15)-4,6-Me2C6H3Fe6), are reported in which the ring size of the ortho-cycloalkyl group has been varied as has the type of para-substituent. The molecular structures of Fe3 and Fe6 reveal square pyramidal geometries at iron while the ortho-cyclooctyl rings adopt boat-chair conformations. On treatment with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all six complexes showed optimal activities at 80 °C [up to 1.9 × 107 g of PE per mol Fe per h for Fe5/MMAO] for ethylene polymerization forming linear polyethylene (Tm's > 126 °C). Notably, the catalytic activities showed a marked correlation with the ring size of the ortho-cycloalkyl substituent: cyclohexyl (Fe2 and Fe5) > cyclooctyl (Fe3 and Fe6) > cyclopentyl (Fe1 and Fe4) for either para-substituent, H or Me. Furthermore, this family of iron catalysts exhibited remarkable thermostability by remaining highly active even at temperatures as high as 100 °C (1.1 × 107 g of PE per mol Fe per h); the wide variation in polymer molecular weights (Mw: 2.4-166 kg mol-1), influenced through choice of precatalyst and co-catalyst as well as by temperature and pressure, further highlights the versatility of these catalysts.