Analytical methods for waste minimisation in the convenience food industry.

Waste creation in some sectors of the food industry is substantial, and while much of the used material is non-hazardous and biodegradable, it is often poorly dealt with and simply sent to landfill mixed with other types of waste. In this context, overproduction wastes were found in a number of cases to account for 20-40% of the material wastes generated by convenience food manufacturers (such as ready-meals and sandwiches), often simply just to meet the challenging demands placed on the manufacturer due to the short order reaction time provided by the supermarkets. Identifying specific classes of waste helps to minimise their creation, through consideration of what the materials constitute and why they were generated. This paper aims to provide means by which food industry wastes can be identified, and demonstrate these mechanisms through a practical example. The research reported in this paper investigated the various categories of waste and generated three analytical methods for the support of waste minimisation activities by food manufacturers. The waste classifications and analyses are intended to complement existing waste minimisation approaches and are described through consideration of a case study convenience food manufacturer that realised significant financial savings through waste measurement, analysis and reduction.

The limbic system in Mammalian brain evolution.

Previous accounts of mammalian brain allometry have relied largely on data from primates, insectivores and bats. Here we examine scaling of brain structures in carnivores, ungulates, xenarthrans and sirenians, taxa chosen to maximize potential olfactory and limbic system variability. The data were compared to known scaling of the same structures in bats, insectivores and primates. Fundamental patterns in brain scaling were similar across all taxa. Marine mammals with reduced olfactory bulbs also had reduced limbic systems overall, particularly in those structures receiving direct olfactory input. In all species, a limbic factor with olfactory and non-olfactory components was observed. Primates, insectivores, ungulate and marine mammals collectively demonstrate an inverse relationship between isocortex and limbic volumes, but terrestrial carnivores have high relative volumes of both, and bats low relative volumes of both. We discuss developmental processes that may provide the mechanistic bases for understanding these findings.

Developmental structure in brain evolution.

How does evolution grow bigger brains? It has been widely assumed that growth of individual structures and functional systems in response to niche-specific cognitive challenges is the most plausible mechanism for brain expansion in mammals. Comparison of multiple regressions on allometric data for 131 mammalian species, however, suggests that for 9 of 11 brain structures taxonomic and body size factors are less important than covariance of these major structures with each other. Which structure grows biggest is largely predicted by a conserved order of neurogenesis that can be derived from the basic axial structure of the developing brain. This conserved order of neurogenesis predicts the relative scaling not only of gross brain regions like the isocortex or mesencephalon, but also the level of detail of individual thalamic nuclei. Special selection of particular areas for specific functions does occur, but it is a minor factor compared to the large-scale covariance of the whole brain. The idea that enlarged isocortex could be a "spandrel," a by-product of structural constraints later adapted for various behaviors, contrasts with approaches to selection of particular brain regions for cognitively advanced uses, as is commonly assumed in the case of hominid brain evolution.

Translating developmental time across mammalian species.

Conservation of the order in which events occur in developing mammalian brains permits use of regression theory to model the timing of neural development. Following a small adjustment to account for a systematic variability in primate cortical and limbic systems, the model is used to generate a 95-event/nine-species matrix that predicts aspects of neurogenesis and axonal outgrowth in the brains of developing mice, hamsters, rats, spiny mice, rabbits, ferrets, cats, monkeys, and humans. Although data are compiled from species in which the timing of birth and the rate of maturation vary widely, the model proves statistically accurate, with practical implications for improving estimation of milestones of neural development, particularly for humans. Using the three-factor model (species, neural events, and primate adjustments), we produce predictions for the timing of 493 neural occurrences in developing mammalian brains that either have not yet been, or cannot be, empirically derived. We also relate the timing of neural events across the nine species in the form of a reference table calibrated to the development of laboratory rats. This 'translation' table will assist in attempts to equate the neurodevelopmental literature across species with either large or small differences in gestation and maturation, and also permit studies done in a variety of mammals to be applied to better understand human development. The comparative data indicate that humans, although conventionally considered an altricial species, are neurally advanced at birth relative to the other species studied.

Combining independent p values: extensions of the Stouffer and binomial methods.

The Stouffer z method, and other popular methods for combining p values from independent significance tests, suffer from three problems: vulnerability to criticisms of the individual studies being pooled, difficulty in handling the "file drawer problem," and vague conclusions. These problems can be reduced or eliminated by supplementing a test of combined probability with a variety of new analyses described here. Along with other advantages, these analyses provide a way to address the file drawer problem without making limiting assumptions about the nature of studies not included in the pooled analysis. These analyses can supplement a traditional meta-analysis, yielding conclusions not provided by widely used meta-analytic procedures.

Neural development in metatherian and eutherian mammals: variation and constraint.

A model for predicting the timing of neurogenesis in mammals (Finlay and Darlington [1995] Science 268:1578-1584) is here extended to an additional five metatherian species and to a variety of other events in neural development. The timing of both the outgrowth of axonal processes and the establishment and segregation of connections proves to be as highly predictable as neurogenesis. Expressed on a logarithmic scale, late developmental events are as predictable as early ones. The fundamental order of events is the same in eutherian and metatherian animals, but there is a curvilinear relation between the event scales of the two; for metatherians, later events are slowed relative to earlier events. Furthermore, in metatherians, the timing of developmental events is more variable than in eutherians. The slowing of late developmental events in metatherians is associated with their considerably longer time to weaning compared with eutherians.

Effects of amiloride on gustatory quality descriptions and temporal patterns produced by NaCl.

The amiloride-sensitivity of perceived taste qualities and time-intensity patterns for NaCl, and interactions between amiloride and NaCl as taste stimuli, were explored using caffeine as the control treatment. NaCl at 100, 250 and 500 mM, dissolved in 10 or 100 microM amiloride, or in caffeine concentrations matched to the amiloride taste, was flowed over 39.3 mm2 of the anterodorsal tongue for 4 s using a closed stimulus delivery system. Amiloride, caffeine and NaCl in H2O were also presented. It was found that NaCl-amiloride mixtures were most frequently described as salty, with the incidence of salty descriptions directly associated with NaCl concentration but not significantly associated with the presence or concentration of amiloride. Amiloride in H2O was called 'bitter', and the incidence of bitter descriptions was significantly associated with the presence of amiloride. The perceived temporal patterns varied with NaCl concentration but did not change with the presence of amiloride, except for an increase in perceived duration. No evidence was found for a dependence upon specific amiloride-sensitive mechanisms of human description of NaCl as salty or of gustatory temporal patterns evoked by NaCl.

Patterns of vertebrate neurogenesis and the paths of vertebrate evolution.

Any substantial change in brain size requires a change in the number of neurons and their supporting elements in the brain, which in turn requires an alteration in either the rate, or the duration of neurogenesis. The schedule of neurogenesis is surprisingly stable in mammalian brains, and increases in the duration of neurogenesis have predictable outcomes: late-generated structures become disproportionately large. The olfactory bulb and associated limbic structures may deviate in some species from this general brain enlargement: in the rhesus monkey, reduction of limbic system size appears to be produced by an advance in the onset of terminal neurogenesis in limbic system structures. Not only neurogenesis but also many other features of neural maturation such as process extension and retraction, follow the same schedule with the same predictability. Although the underlying order of event onset remains the same for all of the mammals we have yet studied, changes in overall rate of neural maturation distinguish related subclasses, such as marsupial and placental mammals, and changes in duration of neurodevelopment distinguish species within subclasses. A substantial part of the regularity of event sequence in neurogenesis can be related directly to the two dimensions of the neuraxis in a recently proposed prosomeric segmentation of the forebrain [Rubenstein et al., Science, 266: 578, 1994]. Both the spatial and temporal organization of development have been highly conserved in mammalian brain evolution, showing strong constraint on the types of brain adaptations possible. The neural mechanisms for integrative behaviors may become localized to those locations that have enough plasticity in neuron number to support them.

Is HIV screening being requested appropriately? The experience of a Victorian public health laboratory.

From the start of clinical testing for human immunodeficiency virus (HIV) antibody in 1985 until the end of June 1994, the Microbiological Diagnostic Unit tested 134 346 serum samples from 109 391 individuals, identifying 672 as infected. A suitable database, using coded identities, was established from the beginning. Because the sera came from a variety of clinical settings, it was possible to extract information about patterns of requests for tests and about the yield of seropositive cases. The data were able to highlight factors associated with high rates of positive tests that can be lost in amalgamated statewide data. The discovery of HIV-positive females was sporadic and there was a much lower detection rate than from testing males. While males were most commonly diagnosed through specialist venereology services, 61 per cent of diagnoses in females were through nonspecialised practices, often those without previous experience in diagnosis and management of HIV infection. Despite some individual exceptions, the requesting of HIV tests appears generally to have been justifiable (particularly in view of the direction of official preventive campaigns) and not profligate. Overall, where practice was unsatisfactory, this lay less in thoughtless ordering of tests than in failing to include with the specimen the elementary, but vital, epidemiological information requested.

Linked regularities in the development and evolution of mammalian brains.

Analysis of data collected on 131 species of primates, bats, and insectivores showed that the sizes of brain components, from medulla to forebrain, are highly predictable from absolute brain size by a nonlinear function. The order of neurogenesis was found to be highly conserved across a wide range of mammals and to correlate with the relative enlargement of structures as brain size increases, with disproportionately large growth occurring in late-generated structures. Because the order of neurogenesis is conserved, the most likely brain alteration resulting from selection for any behavioral ability may be a coordinated enlargement of the entire nonolfactory brain.

Effectiveness of low-dose intradermal hepatitis B vaccination. Five years' experience of primary vaccination.

OBJECTIVE: To determine whether intradermal hepatitis B vaccination is an effective procedure. DESIGN: A study of antibody responses to hepatitis B vaccine in 753 medical students. SETTING: Routine vaccination of medical students with intradermal doses of hepatitis B vaccines of various origins. OUTCOME MEASURES: Rates of seroconversion and geometric mean levels of antibody achieved. RESULTS: Seroconversion rates, indicated by antibody to hepatitis B surface antigen (anti-HBs) levels of 10 mIU/mL or more, varied between 82% and 94.7% with different preparations of the vaccine. With a four-dose intradermal schedule over two successive cohorts, Engerix-B (SmithKline Beecham) gave better responses, in this context, than H-B-Vax II (Merck Sharp & Dohme). Any reactions to the vaccination were mild and local. CONCLUSION: The intradermal route is a practical method of vaccination against hepatitis B in healthy young adults when the cost of the vaccine is an inhibiting factor.

Booster doses of hepatitis B vaccine: responses to low-dose inoculations.

OBJECTIVE: To examine the anamnestic response to hepatitis B vaccine in previously vaccinated subjects. DESIGN: Subjects who had received a course of hepatitis B vaccine at least two years previously had a sample of blood taken before and seven days after a low-dose booster of hepatitis B vaccine. SETTING AND PARTICIPANTS: A pilot group of laboratory scientists in the Microbiological Diagnostic Unit; fifth year medical students, University of Melbourne; and a group of ambulance officers from the Geelong Ambulance Depot (Victoria). All participants volunteered after having been informed of the study. OUTCOME MEASURES: Serum levels of antibody to hepatitis B surface antigen (HBsAg) were measured before and after the booster dose of vaccine and, when available, in serum taken a month after the end of the primary course of vaccine, and the changes in antibody level were studied. RESULTS: Although some individuals with a restricted antibody response were identified, most showed a quick response. There was limited evidence that this rise peaked early and began to fall within weeks. CONCLUSIONS: In many subjects, levels of antibody to HBsAg peak early after booster doses of vaccine but the rapid anamnestic response to small amounts of antigen make it probable that effective protection from symptomatic illness may be long lasting, when there has been a satisfactory primary response. This provides an argument for testing for adequate seroconversion after vaccination.

Control of bovine leukosis virus in a dairy herd by a change in dehorning.

Following the demonstration that bovine leukosis virus was transmitted in calves by gouge dehorning, electrical dehorning at a younger age was implemented in a commercial Holstein herd. Subsequently, annual testing of the herd revealed a decline in the prevalence of bovine leukosis virus antibodies as older cattle dehorned by the former method were replaced by younger cattle dehorned by the latter method.

Natural transmission of bovine leukemia virus in dairy calves by dehorning.

Gouge dehorning was evaluated as a mode of transmitting bovine leukemia virus in Holstein calves at a commercial dairy. Significantly (p less than 0.05) more calves dehorned by the gouge method developed antibodies to bovine leukemia virus, as measured by agar-gel immunodiffusion, three months after dehorning, than calves not dehorned. The field use of a blood-contaminated dehorning device resulted in transmission of bovine leukemia virus.

Effects of production, season, age of cow, days dry, and days in milk on conception to first service in large commercial dairy herds.

Effects of management and environmental factors on reproductive performance were evaluated as part of a fertility experiment in four large commercial dairy herds. The herds were selected because they utilized routine herd health programs, kept complete reproduction records on all cows, were enrolled in Dairy Herd Improvement, and would follow the protocol of the experiment. Only data from first services following parturition were utilized, and conception was determined by rectal palpation. Information on over 2800 experimental breedings was collected during 13 mo. Percentage conception to first service was not affected by milk production during current or previous lactations. However, cows with higher production during current or previous lactations. However, cows with higher production during current or previous lactation had longer intervals to first service. Previous days dry did not affect conception or interval to first service significantly. Conception was less for cows with less than 50 days to first service (32%) than for cows with over 50 days to first service (49 to 57%). No differences were found among 10-day intervals to first service of over 50 days. Cows in third and later lactation had lower reproductive performance than cows in first or second lactation. Month of breeding did not affect conception significantly but did affect interval to first service. However, no seasonal trends were apparent. Differences among herds were significant for both conception and interval to first service.

Effects of serum treated semen, bulls, and herdsmen-inseminators on conception to first service in large commercial dairy herds.

Semen from each of 10 Holstein bulls was extended to 15 X 10(6) total spermatozoa per dose in egg yolk-Tris and in egg yolk-Tris containing 20% (vol/vol) heat-treated heifer serum. Semen was used during 12 mo by 11 herdsmen-inseminators in four commercial dairy herds to inseminate 2820 Holstein cows on the first postpartum service. Percentage conception of cows free of clinical disorders at breeding was determined by rectal palpation at 30 to 60 days after insemination. Addition of serum to the extender did not influence percentage conception. A significant interaction of bull x seminal treatment was found. Least squares means of percentage conception to first service ranged from 45.3 to 59.9% among the 10 bulls. When bulls were classified as either high (greater than 55%), average (50 to 55%), or low conception (less than 50%), approximately 200 first services were required to classify correctly 80 to 90% of the bulls. Least squares means of conception rates ranged from 40.1 to 62.7% among the 11 herdsmen-inseminators. 1) Addition of heat-treated homologous heifer serum to the extender does not influence conception in a predictable fashion; 2) fertility inherent to the bull significantly influences conception; and 3) inseminator skill affects conception greatly.

Minority families, early education, and later life chances.

Children from low-income minority families participated in early childhood education programs conducted in the 1960s and 1970s by members of the Consortium for Longitudinal Studies. Data on program impact from early childhood to young adulthood revealed direct, positive effects on standardized tests, school competence, attitudes toward achievement, high school completion, and occupational attitudes. Indirect program effects were found on occupational attainment.