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Barramundi (Lates calcarifer) are a highly valued aquaculture species, and, as obligate carnivores, they have a demonstrated preference for dietary protein over lipid or starch to fuel energetic growth demands. In order to investigate how carnivorous fish regulate nutritional cues, we examined the metabolic effects of feeding two isoenergetic diets that contained different proportions of digestible protein or starch energy. Fish fed a high proportion of dietary starch energy had a higher proportion of liver SFA, but showed no change in plasma glucose levels, and few changes in the expression of genes regulating key hepatic metabolic pathways. Decreased activation of the mammalian target of rapamycin growth signalling cascade was consistent with decreased growth performance values. The fractional synthetic rate (lipogenesis), measured by TAG 2H-enrichment using 2H NMR, was significantly higher in barramundi fed with the starch diet compared with the protein diet (0·6 (se 0·1) v. 0·4 (se 0·1) % per d, respectively). Hepatic TAG-bound glycerol synthetic rates were much higher than other closely related fish such as sea bass, but were not significantly different (starch, 2·8 (se 0·3) v. protein, 3·4 (se 0·3) % per d), highlighting the role of glycerol as a metabolic intermediary and high TAG-FA cycling in barramundi. Overall, dietary starch significantly increased hepatic TAG through increased lipogenesis. Compared with other fish, barramundi possess a unique mechanism to metabolise dietary carbohydrates and this knowledge may define ways to improve performance of advanced formulated feeds.
The 2013 multistate outbreaks contributed to the largest annual number of reported US cases of cyclosporiasis since 1997. In this paper we focus on investigations in Texas. We defined an outbreak-associated case as laboratory-confirmed cyclosporiasis in a person with illness onset between 1 June and 31 August 2013, with no history of international travel in the previous 14 days. Epidemiological, environmental, and traceback investigations were conducted. Of the 631 cases reported in the multistate outbreaks, Texas reported the greatest number of cases, 270 (43%). More than 70 clusters were identified in Texas, four of which were further investigated. One restaurant-associated cluster of 25 case-patients was selected for a case-control study. Consumption of cilantro was most strongly associated with illness on meal date-matched analysis (matched odds ratio 19·8, 95% confidence interval 4·0–∞). All case-patients in the other three clusters investigated also ate cilantro. Traceback investigations converged on three suppliers in Puebla, Mexico. Cilantro was the vehicle of infection in the four clusters investigated; the temporal association of these clusters with the large overall increase in cyclosporiasis cases in Texas suggests cilantro was the vehicle of infection for many other cases. However, the paucity of epidemiological and traceback information does not allow for a conclusive determination; moreover, molecular epidemiological tools for cyclosporiasis that could provide more definitive linkage between case clusters are needed.
Factor analytic studies in Africa are compared with other cross-cultural investigations into the structure of abilities in different ethnic groups. Similarities and differences are noted; and environmental influences on the acquisition of skills are also summarized. A correlational study of wrong answers to a battery of thirty marker tests given to a group of predominantly Mashona students indicates that efficiency skills of numerical facility and memory remain at the first order of factor extraction, reasoning abilities emerge in second-order analysis, while perceptual styles are present in the third-order level. This study is used to hypothesize, in the
context of African systems of thought, the existence of a primary thought mode that asserts itself in conditions involving repeated errors.
A rapid method is described for preparing and staining salivary glands of Rhipicephalus appendiculatus ticks infected with Theileria parva. The technique, involving the use of a modified methyl green pyronin stain, minimizes the risk of losing material and allows examination of stained glands within minutes of preparation. The technique was applied in a series of studies in which ticks were either infected with T. parva under different conditions, or maturation of parasites in adult ticks was stimulated by different means. When nymphal ticks were fed on the ears of cattle the subsequent infection rate of the adult ticks showed no correlation with the parasitaemia of the cattle at the time of nymphal engorgement. There was no difference in infection rates between adult ticks in which parasite maturation had been stimulated either by incubation at 37 °C or by feeding on rabbits. However, parasite maturation took about 1 day longer in incubated ticks than in rabbit-fed ticks. Female ticks were consistently more highly infected than males, both in terms of the percentage of ticks infected and the mean number of infected acini/tick. Ticks were infected with T. parva by injection of nymphs with parasitaemic bovine blood, but the resultant adult infection was lower than that in ticks which had been infected naturally by feeding on cattle.
Regulation of ungulate populations by parasites relies on establishing a density-dependent relationship between infection and vital demographic rates which may act through the effect of parasites on body condition. We examine evidence for parasite impacts in 285 red deer (Cervus elaphus) harvested during 1991 and 1992 on the Isle of Rum. In the abomasa, prevalence of nematodes was 100% and the most abundant genus observed were Ostertagia species, however, mean intensity of infection was low (less than 1000) relative to other studies. Additional species, also present in low numbers, included Nematodirus spp., Capillaria spp., Cooperia spp., Monieza expanza, Oesophagostomum venulosum and Trichuris ovis. Lungworm (Dictyocaulus spp.) and tissue worm (Elaphostronygylus cervi) larvae were also observed in faecal samples. There was no evidence for acquired immunity to abomasal nematodes. Despite low levels of infection, both adult male and female deer showed significant negative correlation between indices of condition (kidney fat index, dressed carcass weight and larder weight) and intensity of Ostertagia spp. infection. However, there was no evidence that pregnancy rate in females was related to intensity of infection. For calves, there was no relationship between body condition and intensity of infection. The apparent subclinical effects of low-level parasite infection on red deer performance could alternatively be due to animals in poorer nutritional state being more susceptible to infection. Either way the results suggest that further studies of wild populations are justified, in particular where high local host densities exist or alternative ungulate hosts are present, and, where experimental treatments are tractable.
Single photon emission computerised tomography (SPECT) was used to measure regional brain uptake of technetium-99m hexamethyl-propyleneamine oxine (Tc99m-HMPAO) in elderly patients with Alzheimer's disease (AD), multi-infarct dementia (MID) and normals (n = 20 in each group). Different patterns of uptake were found between groups when cortical uptake was normalised to cerebellar uptake. Reductions occurred in all regions in AD, being most marked in temporal and posterior parietal areas. Significant correlations were found in AD between memory impairment and decreased temporal uptake bilaterally, and between duration of illness and reduced uptake in most brain regions. MID patients showed higher uptake in the anterior parietal region than did the other groups. A variable comparing anterior to posterior uptake significantly discriminated the two patient groups.
Although standard measures of mental capacity have been used by psychologists for almost a hundred years, a unified theory of intellect has not emerged. In pursuit of that theory, many approaches have been tried and rejected. One of the most hardy has been the practice of comparing the performance of groups of subjects. Typically, the averages from cognitive tests have indexed cognitive differences between sexes, nationalities, ethnic and tribal groups, social classes and creeds, and even generations. For the purpose of data analysis, group membership acts as if it were a manipulated or independent variable, and the test score becomes the dependent or outcome variable. When significant variation exists between groups, meaning can be attached to the tests. Construct validation traditionally proceeds by accounting for performance differences by the characteristics that distinguish the groups from each other. In this guise, group membership has survived as a real-life projection of the need for laboratory control on batches of subjects in order to specify cause. A distant analogy to the principle of treatment variation in controlled settings, this line of enquiry and its conclusions have seldom had ready acceptance from within the discipline. On the fringes, and in the popular science journals, no single issue in human assessment has produced more debate and provoked more acrimony than the use of group performance in the construction of a theory of intellect. If this is so, why has the practice endured?
In the quasi-experimental use of group membership as a precursor to causal inference, another paradox exists. Although groups have served the same scientific purpose, they are often quite different from each other, as a little thought will determine.
Any collection runs the risk of becoming a collage that admits no firm focus. At the outset, therefore, we pursue the sharpness of image that all our contributors deserve as a setting for their own work. Consequently, the conceptual frames for the book are to be found in the first chapter, whose title, “The Abilities of Mankind,” deliberately echoes Charles Spearman. Although that choice of words may provoke comparison with Spearman's great work The Abilities of Man, we beg to limit comparison to one aspect only. Spearman's book was restricted by its data base: Ours is expanded by it. The challenges he set 60 years ago have filled the scholarly journals with data from every continent. The richness and diversity of human ability have been demonstrated in every culture, but the literature is scarcely better known to the great majority of students of human abilities than it was to Spearman himself.
The work of the authors of this volume owes much to empirical sources that are unknown, neglected, and ignored in “mainstream” psychology. A realistic theory of the abilities of man can be founded only on evidence from all of mankind, not from one subgroup. Moreover, the pursuit of scientific truth in any field that has lacked theoretical closure and has consequently suffered an overabundance of speculation is not straightforward: But the effort has to be made if the measurement of individual differences in cognitive skills and abilities is to remain a psychological enterprise worthy of sustained scientific attention.