Miracle-dz/UniFAR-FTUs huggingface dataset:
Growth of snapper, Pagrus auratus, from south‐eastern Australia in captivity

Abstract This study aimed to determine whether the relatively slow growth of wild Pagrus auratus in south‐eastern Australia can be increased in captivity to a rate acceptable for aquaculture. Juvenile snapper from Port Hacking, New South Wales (34°47'S) were reared at ambient water temperatures. The fish were fed on a dry, sinking pellet with 42% protein. At the start of the trial in April 1989, the snapper had a mean fork length (FL) of 121 + 11 mm SD, an average weight of 50 g, and an estimated age of 8 months. After 12.5 months their mean FL was 249 ± 15 mm and their mean weight was 403 ± 70 g. Our data indicate that, like the reproductively isolated population in Japan, growth of Pagrus auratus from Australasia can be rapid enough for aquaculture, and that there is potential to increase growth rate further.
The ‘youth and agriculture’ problem: implications for rangeland development

There is a common perception in South Africa that the youth are not interested in agriculture, leading to two concerns: first, that this is exacerbating the youth unemployment crisis, and second, that the already low levels of agricultural activity in the former homelands/reserves are likely to drop further, imperiling any hope for rural development in the future. This article explores the ‘youth in agriculture’ problem from various angles. First, it surveys the various explanations prevalent in the policy community regarding the ‘youth in agriculture’ problem. Second, it gathers together the sparse research evidence regarding the participation/nonparticipation of the youth in agriculture. Third, it reflects on the intersection between the ‘youth in agriculture’ problem and the challenges of promoting livestock production in the communal rangelands of the former homelands/reserves. The article tentatively argues that there is a strong parallel between the ‘youth in agriculture’ problem and the question of commercialisation of livestock production, in the sense that the pursuit of the latter is likely to comprise at least a partial solution to the former. By the same token, the article argues that both face a common challenge, namely the high concentration of cattle and goat ownership in the former homelands/reserves.
Explanations for Zambia's economic decline

Zambian growth failure is often related to the resource curse. This article evaluates not only this claim, but also whether the new institutional theory can account for Zambia's economic decline. Little empirical support is found for the terms of trade or volatility versions of the resource curse theory, and there is only slightly more support for relative price versions of the theory. Turning to the new institutional theory, the article quantifies the poor quality of institutions in Zambia using a measure for contract intensive money, and supports the hypothesis that ‘poor quality’ institutions, and especially the failure to protect property and contract rights, played an important role in Zambia's economic decline. Examples are given to support this claim.
Prediction of Ruminal Protein Degradability of Forages Using near Infrared Reflectance Spectroscopy

Ruminal protein degradability is an important trait affecting forage quality, but in situ procedures used to characterize protein degradability are costly and time consuming. Our objectives were to compare an in situ procedure with a ficin protease extraction procedure for estimating ruminal protein degradability of forages and to determine whether near infrared reflectance spectroscopy (NIRS) can provide similar estimates of protein degradability compared to either method. Ruminal protein degradability of five cool-season perennial grasses and alfalfa was determined using the ficin protease procedure. Ficin-extracted crude protein (CP) represents that portion of CP that is solubilized in the extraction procedure ; it accounted for 66% (in grasses) to 93% [in alfalfa (Medicago sativa L.)] of the variation of in situ degradable crude protein. NIRS accurately predicted in situ and ficin degradability on a dry matter basis, but not on a CP basis. We concluded that the ficin procedure could substitute for the in situ determination of ruminal degradable protein and that NIRS could be used to predict protein degradability determined by either method.
β-Amyloid-Stimulated Microglia Induce Neuron Death via Synergistic Stimulation of Tumor Necrosis Factor α and NMDA Receptors

Although abundant reactive microglia are found associated with β-amyloid (Aβ) plaques in Alzheimer's disease (AD) brains, their contribution to cell loss remains speculative. A variety of studies have documented the ability of Aβ fibrils to directly stimulate microglia in vitro to assume a neurotoxic phenotype characterized by secretion of a plethora of proinflammatory molecules. Collectively, these data suggest that activated microglia play a direct role in contributing to neuron death in AD rather than simply a role in clearance after plaque deposition. Although it is clear the Aβ-stimulated microglia acutely secrete toxic oxidizing species, the identity of longer-lived neurotoxic agents remains less defined. We used Aβ-stimulated conditioned media from primary mouse microglia to identify more stable neurotoxic secretions. The NMDA receptor antagonists memantine and 2-amino-5-phosphopetanoic acid as well as soluble tumor necrosis factor α (TNFα) receptor protect neurons from microglial-conditioned media-dependent death, implicating the excitatory neurotransmitter glutamate and the proinflammatory cytokine TNFα as effectors of microglial-stimulated death. Neuron death occurs in an oxidative damage-dependent manner, requiring activity of inducible nitric oxide synthase. Toxicity results from coincident stimulation of the TNFα and NMDA receptors, because stimulations of either alone are insufficient to initiate cell death. These findings suggest the hypothesis that AD brains provide the appropriate microglial-mediated inflammatory environment for TNFα and glutamate to synergistically stimulate toxic activation of their respective signaling pathways in neurons as a contributing mechanism of cell death.
Germination Responses in Alpine Species

Germination studies were conducted on seeds of six species of alpine plants; some of these are restricted to areas above timberline, while others are found throughout the central United States. Species used included Deschampsia caespitosa (L.) Beauv. , Geum turbinatum Rydb. , Luzula spicata (L.) DC. , Pulsatilla ludoviciana (Nutt.) Heller, Sedum stenopetalum Pursh. , and Trisetum spicatum (L.) Richt. Seeds of all species except P. ludoviciana were collected from an alpine area in Colorado. Seeds of that species and of S. stenopetalum were collected from a foothills region in Colorado, and P. ludoviciana seeds were also collected from prairie areas in southwestern Wisconsin. Reasonably good germination was obtained for all species, except L. spicata, under one or more of the conditions used. Maximum germination values ranged from 63% to 90%. Germination values for most species were consistently high with alternating temperature ranges of 10-20 C for the low temperatures and 25-30 C for the high temperatures. Luzula spicata seeds were found to be viable by a tetrazolium test; however, no techniques were found that would break the extreme dormancy and permit germination. Additional factors considered included the individual effects of potassium nitrate, moisture stress, subfreezing temperature, and the interaction of temperature, light conditions, and collection area upon germination.
The development of spatial pattern in shoots of Linaria vulgaris (Scrophulariaceae) growing on fallow land or in a barley crop

Linaria vulgaris root pieces 10 cm long with 10 cm tall shoots were planted with a barley crop and on fallow land in 1988 and 1989. Positions of new shoots of L. vulgaris were recorded once a week throughout both summers. Densities of L. vulgaris stands growing on fallow land were similar in both 1988 and 1989, ranging from 167 shoots∙m−2 in August to 247 shoots∙m−2 in October. Densities of L. vulgaris stands growing with a barley crop varied between years, ranging between 1587 and 539 shoots∙m−2 from August to October in 1988 and being relatively stable at 95 shoots∙m−2 between August and October in 1989. Stand diameter was consistently greater when on fallow land than in barley, with a maximum diameter of 1 m in 1988 and 2 m in 1989 when on fallow land, and a maximum diameter of 40 cm in 1988 and 1 m in 1989 in barley. In both years, new shoots produced in a week emerged in primary clumps 5–10 cm in diameter, and these were aggregated into secondary clumps that grew larger with time. Primary clumps on f.
How environmental stress affects density dependence and carrying capacity in a marine copepod

Summary 1. Management of the effects of stress on populations – for instance in ecotoxicology – requires understanding of the effects of stressors on populations and communities. Attention to date has too rarely been directed to relevant ecological endpoints, such as carrying capacity and density dependence. Established procedures are instead based on measuring the Life Tables of individual organisms exposed to differing concentrations of a pollutant at low population density, but this approach does not take into account population effects that may occur through interactions between individuals. Here we introduce an approach that allows direct measurement of the effects of stressors on carrying capacity and density dependence. 2. Using the marine copepod Tisbe battagliai Volkmann-Rocco, we report replicated experiments establishing the effects of 100 µg L−1 pentachlorophenol (PCP) in combination with varying diet and food concentrations. Population density was measured as population biomass in 10 mL volumes. Diet was either the alga Isochrysis galbana Parke (here designated ‘poor diet’) or a mix of two algal species (I. galbana and Rhodomonas reticulata Novarino: ‘good diet’). Each was given at three food concentrations (520, 1300 and 3250 µgC L−1), selected on the basis that at low population density these cover the range between limited and maximal population growth. 3. Carrying capacity increased linearly with food concentration. On the poor diet the increase was 1·2 μg L−1 for each μgC L−1 increase in food concentration. On the good diet the increase was 2·3 μg L−1/μgC L−1 in the absence of PCP, and 1·9 μg L−1/μgC L−1 with PCP. Maximum carrying capacity was in the region of 60–80 μg per 10 mL volume. Population growth rate (pgr) decreased linearly with population biomass when the latter was plotted on a logarithmic scale. Increasing biomass reduced pgr by 1·70 week−1 for each unit increase in log10 biomass. Increasing food concentration and improving diet both increased pgr, but did not affect the slope of the density-dependent relationship. Presence or absence of PCP had no effect except that at some higher food concentrations non-PCP populations initially increased faster than PCP populations, and at high concentration on the good diet the effect of density-dependence was decreased in PCP populations. 4. The results show that a stressor's effects at high population density may differ from its effects at low density, and emphasizes the importance of finding new protocols, such as those introduced here, with which to study the joint effects of a stressor and population density. Managers and researchers of threatened species, harvested species and pest species need to know the joint effects of stressors and population density, in order to be able to predict the effects of stressors on carrying capacity and on the course of recovery from environmental perturbations.
Color Change Kinetics of Spinach Undergoing Microwave Drying

In this present study, the effect of microwave output power and sample amount on color change kinetics of Turkey spinach (Spinacia oleracea L.) were investigated by using microwave drying technique. The color parameters for the color change of the materials were quantified by the Hunter L (whiteness/darkness), a (redness/greenness), and b (yellowness/blueness) system. These values were also used for calculation of the total color change (ΔE), chroma, hue angle, and browning index. The microwave drying process changed color parameters of L, a, and b, causing a color shift toward the darker region. The values of L and b decreased, while values of a and total color change (ΔE) increased during microwave drying. The mathematical modeling study of color change kinetic showed that L and b fitted to a first-order kinetic model, while a and total color change (ΔE) followed by a zero-order kinetic model. However, chroma and browning index (BI) followed a first-order kinetic model, while hue angle followed a zero-order kinetic model. To illustrate the relationship of the L, a, b, total color change (ΔE), chroma, hue angle, and browning index depending on the ratio of the microwave output power to sample amount, the data adequately fitted to a quadratic (second order polynomial) model. For calculation of the activation energy for color change kinetic parameters, the exponential expression based on an Arrhenius equation was used.
Carbon-footprints for food of animal origin, reduction potentials and research need

The environmental assessment of human activities is presently a hot topic. It is not only important from an ecological perspective, but also from the view of efficient utilisation of limited natural resources such as fuel, land area, water und phosphorus. The environmental impact of food of animal origin is currently quantified by so-called CO2eq-footprints (Carbon Footprints: CF). To define CF, emissions arising along the food chain will be calculated according to their greenhouse potentials (carbon dioxide = 1 eq; methane ≈ 23 eq, laughing gas ≈ 300 eq). For the primary production of milk, meat and eggs, emissions during crop production, transportation, the storing and processing of feeds, animal keeping, enteric losses and excrement management can be mentioned as examples. Data for CF of food of animal origin and edible protein are deduced in the paper. Furthermore reduction potentials and research need are summarised.
The influence of CO2 concentration on stomatal density

summary A survey of 100 species and 122 observations has shown an average reduction in stomatal density of 14.3% (SE ±2.2 %) with CO2 enrichment, with 74% of the cases exhibiting a reduction in stomatal density. A sign test demonstrated that stomatal density decreases, in response to CO2, significantly more often than expected by chance. Repeated observations on the same species indicated a significant repeatability in the direction of the stomatal response. Analyses which removed the potential effect of taxonomy on this data set showed no significant patterns in the dependency of the degree of stomatal change on growth form (woodiness vs. non-woodiness; trees vs. shrubs), habitat (cool vs. warm) or stomatal distribution on the leaf (amphi- vs. hypostomatous). Forty-three of the observations had been made in controlled environments and under a typical range in CO., enrichment of 350–700 μmol mol−1. For these cases the average stomatal density declined by 9% (SE ± 3.3%) and 60% of the cases showed reductions in stomatal density. When analyses were restricted to these 43 observations, amphistomatous samples more frequently had greater changes in stomatal density than did hypostomatous samples. The degree of reduction in stomatal density with increasing CO2 increases with initial stomatal density, after the influence of taxonomy is removed using analyses of independent contrasts. When the data were examined for patterns that might be due explicitly to the effects of relatedness, the subclasses of the Hamamelidae and the Rosidae showed highly significant reductions in stomatal density with CO2 (87% of the species studied in the Hamamelidae and 80% of the species in the Rosidae showed reduction with CO2 enrichment) and correlations between initial stomatal density and degree of reduction in stomatal density. The species sampled in the Hamamelidae were dominantly trees, whereas herbs dominated the species in the Rosidae. There were insufficient species studied at lower taxonomic levels to warrant further statistical analyses. This problem results from experimental and observational data being most often restricted to one species per taxonomic level, typically up to the level of order, a feature which can severely limit the extraction of taxonomically-related and ecologically-related plant responses.
CONDUCTIVE FUNCTION OF INTERVESSEL PITS THROUGH A GROWTH RING BOUNDARY OF MACHILUS THUNBERGII

Vessels in some species are connected by intervessel pits on the tangential walls of radial multiples, which may allow the radial flow of sap. This network was investigated in Machilus thunbergii Sieb. et Zucc. , a diffuse-porous wood with radial multiples extending through growth ring boundaries. Air permeability measurements suggest radial flow paths exist through a growth ring boundary. Flow paths were pressurestained with reduced basic fuchsin solution. Observations of serial cross sections confirmed the flow paths to be via vessels and intervessel pits in radial multiples of vessels on growth ring boundaries. Resin casts of low-density polyethylene, viewed by scanning electron microscopy, showed the vessel network extending through a growth ring boundary as well as the branching of vessels.
The Short-Term Effects of Clearfelling and Slash-Burning on the Richness, Diversity and Relative Abundance of Higher Plant Species in Two Types of Eucalypt Forest on Dolerite in Tasmania

The relative impacts of clearfelling followed by slash-burning, clearfelling, and no treatment were monitored for 2 years in two major types of eucalypt forest in south-eastern Tasmania. Rates of change in species cover were significantly greater in the burned area than in both the clearfell and control areas. More than half the species for which suitable data were available increased most in the burned area and least in the control. More higher plant taxa were present in the permanent burned plots 4 months after the burn than before the burn. By the last 8 months of recording, new taxa were invading at a rate of only 0.1 per month. Composites and shrubs constituted most of the late invaders. The behaviour of diversity measures was largely a function of the behaviour of a few of the taxa. Fire intensity, as measured by degree of soil baking, had a pronounced influence on species composition and cover. The species composition of aerially sown seed had little influence on the species composition of the eucalypt regeneration, with species not sown by the Forestry Commission recovering vegetatively, and much of the sown seed not resulting in seedling establishment. The clearfelling and burning, and clearfelling treatments did not result in the loss of any native species but there was substantial invasion by introduced herbs. However, lack of substantial impact in the short term does not guarantee the same in the long term.
The physiological mechanism of colour change in the grasshopper Kosciuscola Tristis Sjost. (Orthoptera:Acrididae).

Laboratory experiments are described in which the colour response of male Kosciuscola tristis to temperature was analysed. When the temperature was changed, the colour, assessed quantitatively by means of a colour chart, varied according to time-curves approaching asymptotically a new equilibrium value. The rate of change during the early stages of accommodation is correlated with the difference between the initial and final temperatures, while the mean rate of change over the first 80 per cent, of the change is related rather to the final temperature. Other things being equal, the change from dark to blue is more rapid than the reverse change. The equilibrium colour, attained after about 18 hr at constant temperature, is related to temperature by a sigmoid curve flattening out at about 10 and 27°C. Experiments in which light intensity, background colour (black or white), relative humidity, and degree of crowding were varied at constant temperature showed that these factors are without influence on the colour of the insect. Experiments in which different parts of the intact insect, isolated halves of insects, and pieces of integument in vitro were subjected to different temperatures showed that nervous or hormonal coordination is not involved in the response, the epidermal cells acting as independent effectors.
Factors affecting recruitment of Pinuspungens in the southern Appalachian Mountains

Factors affecting the establishment and recruitment of seedlings of the Appalachian endemic Pinuspungens Lamb were studied in pine–oak forests of dry, southwesterly mountain slopes in southwestern Virginia, United States. Recruitment of P. pungens was not limited by seedfall from serotinous cones or by postdispersal seed predation. Total viable seedfall ranged from 35 000 to 69 000 seeds/ha in 1988 and was concentrated in the spring and summer months. Low availability of suitable seedling habitat strongly limited recruitment of P. pungens seedlings. The distributions of habitat variables for P. pungens seedlings and random points in the forest overlapped little, indicating that suitable microsites were relatively rare. Seedlings occurred in microsites characterized by shallow pine litter, low ground and canopy covers, and larger nearest neighbor distances than occurred at random. Summer drought also contributed to low seedling survivorship, particularly in young seedlings. Our results suggest that optimal.
Seasonality, Fasting Endurance, and Body Size in Mammals

It has been argued that environmental seasonality selects for larger body size among homeotherms (Brodie 1975; Downhower 1976; Boyce 1979). Indeed, strong correlations between body size and seasonality have been shown both within species of mammals (Brodie 1975; Boyce 1978) and among mammal faunas (Zeveloff 1982). Because of high mortality during the season of resource shortage. surviving individuals enjoy low competition and abundant resources during the growth season. Selection then favors rapid growth and attainment of large size because of enhanced survivorship (Lindsey 1966; Peters 1983; Calder 1984) and, in some taxa, increased fecundity (Sadleir 1969; Boyce 1981). Large individuals experience higher survival rates during the period of resource shortage because they metabolize somatic stores at a lower weight-specific rate. Thus, seasonality may produce two consequences to body-size evolution: (1) reduced densitydependent competition because of seasonal high mortality, known as Ashmole's hypothesis (Ashmole 1963; Ricklefs 1980) and (2) increased fasting endurance for individuals of large size (Lindsey 1966; Calder 1974). In this note we analyze data that substantiate the significance of large body size for enhancing fasting endurance, responding to the challenge of Clutton-Brock and Harvey (1983), who claim that further knowledge of "food reserves" is necessary to evaluate the seasonality hypothesis. There are now sufficient data to predict fasting endurance in mammals by dividing energy reserves by their rate of use (after Stahl 1962). The result, the scaling of fasting endurance, favors large body size. This relationship will, of course, be of primary significance in seasonal environments where organisms must endure occasional periods of fasting.