Trends in comminution driven by energy

The consumption of energy in comminution processes is approximately 2–3% of the worlds’ total energy demand. There is clear room for improvement. This paper follows a presentation given at the 4th Asian Particle Technology Symposium that suggests significant improvements are possible by the use of high pressure grinding rolls, a new design of stirred mills and a new approach to circuit design.     

Utilization of ileal digestible amino acids by growing pigs: methionine

An experiment was conducted to determine the utilization of ileal digestible methionine by growing pigs. Three methionine-deficient diets (0.09 g ileal digestible methionine/MJ digestible energy (DE)) were formulated using cottonseed meal, meat-and-bone meal and soya-bean meal respectively as the only source of methionine in the diet. An additional three diets were formulated with supplements of methionine to confirm that methionine was limiting in the first three diets. The growth performance and retention of methionine by pigs given the six diets over the 20-45 kg growth phase was then determined. Growth rates (g/d) of pigs given the three diets formulated to 0.09 g ileal digestible methionine/MJ DE were significantly different (P < 0.01): cottonseed meal 411, meat-and-bone meal 442, soya-bean meal 496 (SED 24.6). The response of pigs to the addition of methionine confirmed that methionine was limiting in these diets. Crude protein (N x 6.25) deposited by the pigs (g/d) was significantly higher (P < 0.05) for those given soya-bean meal (61) and meat-and-bone meal (57) relative to cottonseed meal (47; SED 3.3). The proportion of ileal digestible methionine retained by pigs given the three protein concentrates was: cottonseed meal 0.39, meat-and-bone meal 0.45, soya-bean meal 0.47 (SED 0.019). These results indicate that values for the ileal digestibility of methionine in protein concentrates do not reflect the proportion of methionine that can be utilized by the pig. It appears that, with heat-processed meals, a considerable proportion of the methionine is absorbed in a form(s) that is (are) inefficiently utilized.     

Phosphorus studies in pigs. 2. Assessing phosphorus availability for pigs and rats

Two experiments were conducted (1) to determine the effects of phytase (EC 3.1.3.26) on the digestibility and availability of P in soya-bean meal for growing pigs and (2) to compare growth v. digestibility variables for assessing the availability of P. In the first experiment the effect of phytase on P availability was assessed in a growth assay using a slope-ratio design of treatments. Two different levels of either monosodium phosphate (MSP) or soya-bean meal were added to a basal sugar-soya-bean-meal diet (2.5 g P/kg) to give two levels of P (g/kg): 3.25 and 4.0 for each source. An additional five diets were supplemented with phytase. The ten diets were offered ad lib. for 35 d to female pigs initially weighing 20 kg live weight. In addition, the relative effectiveness of different variables for assessing P availability were compared: bone bending moment, ash in various bones, and ash and P in the empty body. The addition of phytase increased growth rate (g/d) (741 v. 835; P < 0.05), lowered the food conversion ratio (2.37 v. 2.16; P < 0.01), and increased protein deposition (g/d) (108 v. 123; P < 0.05), protein retention (kg/kg) (0.33 v. 0.36; P < 0.05), energy retention (MJ gross energy/MJ digestible energy) (0.36 v. 0.38; P < 0.05) and the availability of P in soya-bean meal from 0.11 to 0.69 when bone bending moment was the criterion of availability. All other criteria for assessing availability were unsuitable. In the second experiment the availability of (P) in soya-bean meal was assessed in a digestibility experiment with grower pigs using diets 1-5 as for Expt 1 arranged in a slope-ratio design of treatments. In addition, the effects of phytase supplementation on the apparent digestibility of P, dry matter, crude protein (N x 6.25) and energy were determined. The diets were offered at three times maintenance energy requirements to male pigs initially weighing approximately 30 kg live weight and total collection of faeces was conducted over a 10 d period. The availability of P in the soya-bean meal was 0.66 using digestible P intake as the criterion of response. The apparent digestibility of P in soya-bean meal was 0.42. Phytase supplementation increased the apparent digestibility of soya-bean meal P to 0.69 (P < 0.01) but had no effect on the faecal digestibility of dry matter or crude protein.(ABSTRACT TRUNCATED AT 400 WORDS)     

The effect of education on the onset and rate of terminal decline.

Differences in the time of onset and magnitude of terminal decline were examined in three cognitive domains: processing speed, episodic memory, and global function. In addition, cognitive reserve was investigated by testing whether education affected the onset or rate of decline across these domains. Eight hundred ninety-six community-dwelling Australian adults aged ≥ 70 years were assessed up to four times over 12 years, with vital status followed for 17 years. For each of the cognitive measures, a series of change point models were fitted across the 20 years before death to find the optimal point at which terminal decline was distinguished from preterminal decline. Change points were then assessed separately for high- and low-education groups. The change points were 8.5 years for processing speed (95% CI: 6.0–11.2 years), 7.1 years for global function (6.2–9.3), and 6.6 years for episodic memory (5.3–7.1). The rate of decline was two to four times greater in the terminal phase relative to the preterminal phase, depending on the domain. Increased education changed the terminal decline effect differently for each of the three tests, either by significantly hastening the onset of terminal decline and decreasing the rate of decline, or by increasing the rate of either preterminal or terminal decline. Analyses were repeated excluding participants diagnosed with dementia, with no substantive change to the outcomes. In conclusion, the rate and onset of terminal decline varied somewhat across cognitive domains. Education affected terminal decline differently across the domains, but this modification was not consistent with the predictions of cognitive reserve theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Diet high in oat β-glucan activates the gut-hypothalamic (PYY₃₋₃₆-NPY) axis and increases satiety in diet-induced obesity in mice

This study tested the effects of (1→3),(1→4) β‐D ‐glucan from oats, on activation of the gut‐hypothalamic (PYY_3–36‐NPY) axis, satiety, and weight loss in diet‐induced obesity (DIO) mice. DIO mice were fed standard lab chow diets or varied doses of β‐glucan for 6 weeks. Energy intake, satiety, body weight changes and peptide Y‐Y_3‐36 (PYY_3‐36) were measured together with a satiety test and measurement of neuropeptide Y (NPY) mRNA expression in the hypothalamic arcuate nucleus (Arc). The average energy intake (‐13%, p<0.05) and body weight gain was lower with increasing β‐glucan over 6 wk with acute suppression of energy intake over 4 h. The highest β‐glucan diet significantly increased plasma PYY_3‐36, with suppression of Arc NPY mRNA.     

Homelessness as Capability Deprivation: A Conceptual Model

Many prominent definitions pose homelessness as the opposite or lack of home, while at the same time reducing the concept of home to aspects of adequate housing. As a result, many definitions struggle to fully account for the complexity and multidimensional experience of homelessness. This paper tackles these conceptual issues by building on recent work applying the capabilities approach. It argues that homelessness is a type of capability deprivation that is the opposite, or loss, of home. Drawing on the literature on the meaning of home and homelessness, the paper proposes six key dimensions that, along with the work on capabilities, form the basis of a conceptual model. This conceptual model spells out what is meant by homelessness as capability deprivation and specifies what is required to end someone’s homelessness, all while situating homelessness within a broader political–philosophical discourse about social justice and the basic entitlements of all people.     

Tolerance of growing pigs to trypsin and chymotrypsin inhibitors in chickpeas (Cicer arietinum) and pigeonpeas (Cajanus cajan)

The threshold level of growing pigs to trypsin and chymotrypsin inhibitors was investigated by adding graded levels of meals rich in these inhibitors to diets and recording responses. Diets were formulated to contain either 250, 500 or 750 g kg^?1 of Opal chickpea, dehulled Tyson chickpea or dehulled pigeonpea meals and pig response compared to that of pigs given a wheat and soya-bean meal control. Trypsin inhibitor levels (mg g^?1) of the diets were, respectively, control, 0.2; chickpea meal 1, 1.2.32; chickpea meal 2, 1.7–4.7; pigeonpea meal, 1.4–3.6. Chymotrypsin inhibitor levels (mg g^?1) of the diets were, respectively, control, 0.2; chickpea meal 1. 0.9–2.2; chickpea meal 2, 1.6–4.5; pigeonpea meal. 0.8–2.1. The diets were offered ad libitum over the 20–50 kg growth phase. Growth responses of the pigs fed the two chickpea meals were similar to those of the pigs fed the control soya-bean meal diet (P>0.05). In contrast, the addition of pigeonpea meal linearly depressed growth rate (P<0.001), feed intake (P<0.05) and increased the feed conversion ratio (P<0.05), inclusion levels of the chickpea meals had no effect on organ weights, whereas the inclusion of pigeonpea meal significantly affected the weights of the liver and pancreas (P<0.05), indicating the presence of other anti-nutritional factors. The results indicate that the growing pig can tolerate dietary levels of at least 4.7 and 4.5 mg g^?1 of trypsin and chymotrypsin inhibitors, respectively. These threshold levels are unlikely to be exceeded in conventional diets containing the majority of grain legumes. The results also indicate that dehulled pigeonpea meal contains an anti-nutritional factor(s) for growing pigs.     

Nevill's explanation of Kleiber's 0.75 mass exponent: an artifact of collinearity problems in least squares models?

Intraspecific allometric modeling (Y = a.mass(b), where Y is the physiological dependent variable and a is the proportionality coefficient) of peak oxygen uptake (VO2peak) has frequently revealed a mass exponent (b) greater than that predicted from dimensionality theory, approximating Kleiber's 3/4 exponent for basal metabolic rate. Nevill (J. Appl. Physiol. 77: 2,870-2,873, 1994) proposed an explanation and a method that restores the inflated exponent to the anticipated 2/3. In human subjects, the method involves the addition of "stature" as a continuous predictor variable in a multiple log-linear aggression model: ln Y = a + c. ln stature + b. ln mass + ln epsilon, where c is the general body size exponent and epsilon is the error term. It is likely that serious collinearity confounds may adversely affect the reliability and validity of the model. The aim of this study was to critically examine Nevill's method in modeling VO2peak in prepubertal, teenage, and adult men. A mean exponent of 0.81 (95% confidence interval, 0.65-0.97) was found when scaling by mass alone. Nevill's method reduced the mean mass exponent to 0.67 (95% confidence interval, 0.44-0.9). However, variance inflation factors and tolerance for the log-transformed stature and mass variables exceeded published criteria for severe collinearity. Principal components analysis also diagnosed severe collinearity in two principal components, with condition indexes > 30 and variance decomposition proportions exceeding 50% for two regression coefficients. The derived exponents may thus be numerically inaccurate and unstable. In conclusion, the restoration of the mean mass exponent to the anticipated 2/3 may be a fortuitous statistical artifact.     

Defining “At-risk of Homelessness”: Re-connecting Causes,Mechanisms and Risk

A key focus of homelessness policy across the Anglophone world is to prevent homelessness by targeting interventions to those considered “at-risk”, yet the term “at-risk of homelessness” remains ambiguous. A solid definition is required. Typically, risk is defined using those factors that are over-represented in the population of interest. However, this approach tends to obscure the relationship between risk factors and their broader causes. It is also unfeasible given the characteristics of the current body of knowledge on homelessness. This paper takes a different approach. It argues that clarifying what is meant by “at-risk of homelessness” requires understanding the type(s) of causation involved, the various causes of homelessness and the mechanisms through which they act. The paper addresses each of these three requirements to propose a provisional definition of “at-risk of homelessness”. Following further empirical work, this definition can be used to enumerate the “at-risk of homelessness” population and design prevention strategies.