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1.
In order to understand the competitive situation of wood, it is essential to consider the end consumer of building materials. The knowledge of factors affecting the end consumers choice of building material for specific purposes, i.e., the mechanisms of substitute competition, is limited. Field studies of the British and Dutch floorcovering markets revealed that context, usage context as well as the general life situation, is of crucial importance in substitute competition. This contextual character severely limits the usefulness and adequacy of interviews with fixed-reply alternatives, as well as classical statistical methods of analysis. In this article, a qualitative approach to data gathering is combined with multivariate analysis. The results indicate that by using this methodology it is possible to determine which are the decisive predictors of material preferences, make cross-cultural comparisons, and apprehend the underlying motives or perspectives. The results further show that, unlike the other floorcovering materials studied, the determinant reasons for choosing wood appear to be exclusively nonfunctional in nature.  相似文献   
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3.
European Journal of Forest Research - Climate change mitigation trade-offs between increasing harvests to exploit substitution effects versus accumulating forest carbon sequestration complicate...  相似文献   
4.

Background

Overweight and obesity are the most common nutritional disorders in dogs and may lead to various secondary diseases and decreased lifespan. In obesity research, measurement of energy expenditure (EE) and determination of the energy requirements are essential. The objective with this study was to validate and evaluate the suitability of the oral 13C-bicarbonate technique (o13CBT) for measuring EE in dog obesity studies. A further objective was to investigate the impact of body weight (BW) reduction and changes in body composition on the EE when measured under conditions corresponding to the basal metabolic rate (BMR).

Results

The EE in five privately owned, overweight dogs was measured simultaneously with the o13CBT and indirect calorimetry (IC) for comparison of the results. Two measurements per dog were performed under the same standardised conditions (i.e. fasted and resting state) at the start, and after completing a 12-week BW reduction program. Additionally, measurements of body composition by Dual-energy X-ray absorptiometry (DEXA) were conducted at the beginning and at the end of the BW reduction program. There were no differences in EE results obtained by the o13CBT and IC. Overweight and the BW reduction did not affect the estimates for the respiratory quotient (RQ) or the recovery factor for the 13C-tracer (RF), both needed when using the o13CBT. The dogs lost 16% (SD ± 2.0) of their initial BW in reduced fat mass (P < 0.001), whereas fat free mass (FFM) remained unchanged. There was no effect of the BW reduction on the determined EE expressed in kJ/kg BW/d, or in kJ/kg BW0.75/d. However, EE was lower (P < 0.001) after the BW reduction program when expressed in relation to FFM (kJ/kg FFM/d).

Conclusions

Results from the present study show that the o13CBT can be a used in obesity research to determine EE in fasted dogs and under resting conditions. Furthermore, the results suggest that the BMR does not change with reduced BW in overweight dogs as long as the FFM remains unchanged. This indicates that the BMR to maintain one gram of fat is equal to maintaining one gram of FFM in overweight dogs.  相似文献   
5.
Low protein provision in utero and post‐partum may induce metabolic disorders in adulthood. Studies in mink have mainly focused on short‐term consequences of low protein provision in utero whereas the long‐term responses to low protein (LP) provision in metabolically programmed mink are unknown. We investigated whether low protein provision in utero affects the long‐term response to adequate (AP) or LP provision after weaning in male mink. Eighty‐six male mink were exposed to low (19% of ME from CP; crude protein) or adequate (31% of ME from CP) protein provision in utero, and to LP (~20% of ME from CP) or AP (30–42% of ME from CP) provision post‐weaning. Being metabolically programmed by low protein provision in utero did not affect the response to post‐weaning diets. Dietary protein content in the LP feed after weaning was below requirements; evidenced by lower nitrogen retention (p < 0.001) preventing LP mink from attaining their growth potential (p < 0.02). LP mink had a lower liver, pancreas and kidney weight (p < 0.05) as well as lower plasma IGF‐1 concentrations at 8 and 25 (p < 0.05) weeks, and a higher incidence of hepatic lipidosis at 25 weeks (p < 0.05). Furthermore, LP mink had a higher body fat (p < 0.05) and lower body CP content (p < 0.05) at 50 weeks of age. It is concluded that some effects of low protein provision in utero can be alleviated by an adequate nutrient supply post‐partum. However, long‐term exposure to low protein provision in mink reduces their growth potential and induces transient hepatic lipidosis and modified body composition.  相似文献   
6.
Summary Changes in total- and NO3-nitrogen ratios in different plant parts, due to fertilizer rates and stage of development are shown. The importance of considering the stage of development when pioposing critical levels, is emphasized. A fairly strong relationship between nitrogen ratio and yield was found for the total-nitrogen ratio of petioles and leaflets of upper leaves at mid-season (stage of flowering). A weaker, but still significant relationship, was obtained for NO3-nitrogen in corresponding samples. At late season, about 20 days after mid-season, the relationship between yield and nitrogen ration was weaker. A comparison was made between the critical levels for potato petioles proposed earlier, and results obtained in the present study.
Zusammenfassung In Feldversuchen wurden die Ver?nderungen im Gesamtstickstoff- und im NO3-Stickstoff-Verh?ltnis (in Prozent der Trockensubstanz) in verschiedenen Teilen des Kartoffelkrautes und bei verschiedenen Düngergaben studiert. Der Zweck der Versuche war, die M?glichkeit einer Anwendung von Pflanzenanalysen für Ern?hrungsstudien bei der Kartoffel abzukl?ren. Die Angaben über die verwendeten Düngermengen und das Alter der Pflanzen anl?sslich der Probenentnahme sind in den TABELLEN 1 und 2 zusammengestellt. Aus den TABELLEN 3 und 4 ist zu ersehen, welche Pflanzenteile für die chemischen Analysen gebraucht wurden. Der Bereich der Stickstoffwerte war im Leitgewebe gew?hnlich gr?sser als in den Blatteilen. Die Düngungsstufen kamen-vom Ende der Vegetationszeit abgesehen-in allen analysierten Pflanzenteilen deutlich zum Ausdruck (TABELLEN 3 und 4). Grosse Ver?nderungen im Gesamtstickstoff- und NO3-Stickstoff-Verh?ltnis wurden w?hrend kleinen Zeitintervallen gefunden (TABELLE 5), was die Notwendigkeit einer kurzen und genau umschriebenen Zeitperiode für die Probenentnahme hervorhebt. Eine ziemlich gute Relation zwischen Stickstoff-Verh?ltnis und Ertrag wurde für das Gesamtstickstoff-Verh?ltnis in Blattstielen und Bl?ttchen der oberen Bl?tter in der Mitte der Vegetationsperiode (zur Blütezeit) ermittelt. Eine weniger deutliche, aber immer noch signifikante Relation wurde für NO3-Stickstoff in den entsprechenden Mustern gefunden (TABELLE 6). Gegen Ende der Vegetationsperiode, ungef?hr 20 Tage nach der Mitte dieser was die Relation zwischen Ertrag und Stickstoff-Verh?ltnis weniger ausgepr?gt. Zwischen früher vorgeschlagenen kritischen Werten und den in den vorliegenden Untersuchungen erhaltenen Ergebnissen wurden Vergleiche angestellt. Daraus ergab sich der Hinweis, dass unter Berücksichtigung der Wachstumsbedingungen, die w?hrend der geschilderten Versuche herrschten, die früher angegebenen kritischen Werte unn?tig hoch sind.

Résumé L’auteur a étudié dans des expériences au champ les changements dans les proportions d’azote total et d’azote nitrique (en pourcent de matière sèche) dans les différentes parties de la fane avec différented quantités de fertilisants. La recherche visait à déterminer la possibilité d’utiliser l’analyse des plantes comme moyen d’études de la nutrition de la Pomme de terre. Les TABLEAUX 1 et 2 résument les données sur les quantités de fertilisants utilisés et sur l’age des plantes au moment des prélèvements d’échantillons. Un examen des TABLEAUX 3 et 4 montre quelles parties des plantes ont été utilisées pour les analyses chimiques. Les valeurs en azote sont habituellement plus élevées dans les tissus conducteurs que dans les parties de feuille. Sauf à la fin de la période de végétation, les quantités de fertilisants appliqués sont clairement marquées dans toutes les parties de la plante analysées (TABLEAUX 3 et 4). On trouve (TABLEAU 5) de grands changements dans les proportions d’azote total et d’azote nitrique pendant de courtes périodes de temps, ce qui met en évidence le besoin d’une brève période bien définie de prélèvement d’échantillons. On trouve une assez bonne corrélation entre la proportion d’azote total et la production pour ce qui concerne la proportion d’azote total dans les pétioles et les folioles des feuilles supérieures au moment de la pleine végétation (floraison). Une corrélation plus faible mais encore significative se constate pour l’azote nitrique dans les échantillons correspondants (TABLEAU 6). A la fin de la période de végétation, quelque 20 jours après la pleine végétation, la corrélation entre production et proportion d’azote est plus faible. L’auteur fait une comparaison des valeurs critiques antérieurement proposées et des résultats obtenus dans la présente étude. Il obtient des indications que sous les conditions de croissance rencontrées dans les présentes expériences, les quantités critiques proposées antéricurement sont inutilement élevées.
  相似文献   
7.
Energy metabolism and substrate oxidation was measured in 12 growing pigs by means of indirect calorimetry and nutrient balances. The measurements were carried out during 5 days of feeding followed by 4 days of starvation and 5 days of re-feeding. During the feeding period, dietary carbohydrates were the main energy source, sufficient to cover energy requirements without oxidation of fat. Starvation reduced the total heat production and affected the oxidation pattern by reducing protein oxidation and shifting from carbohydrate to fat oxidation. On the second day of starvation, the main energy source was body fat and there was no oxidation of carbohydrate. On the second day of re-feeding, the heat production reached the same level as during the feeding period. Also, during the second day of re-feeding, the pattern of nutrient oxidation was similar to the feeding period with oxidation of carbohydrate providing 90% and oxidation of protein providing 10% of the total heat production. There was no fat oxidation. The results demonstrated that the growing pigs were able to re-establish oxidative patterns already 2 days after re-alimentation.  相似文献   
8.
Thirty mink dams nursing litters of six kits were assigned to one of three dietary treatments [high protein (HP), medium protein (MP) and low protein (LP)], fed ad libitum for 4 week from parturition, to investigate the effects of protein supply on milk yield and milk composition in order to estimate the amino acid requirement of the lactating mink. Twelve dams were held in an intensive care unit and subjected to balance experiments and the kits were injected with deuterium oxide to determine water kinetics and milk yield. Eighteen dams were kept under normal farm conditions but with feed intake of dams and live weight gain of kits being determined and milk samples collected. The ME intake was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet, whereas the amino acid intake (g/day) was lowest (p < 0.05) in dams fed the LP diet. In the third and fourth weeks of lactation milk yield was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet. Chemical composition of milk was not affected (p > 0.05) by dietary treatment. However, protein content tended (p = 0.06) to be lower in dams fed the LP diet. Amino acid content (g/16 g N) of milk was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet. This resulted in the highest (p < 0.05) amino acid intake and highest (p < 0.001) live weights of kits nursed by dams fed the LP and MP diets, which may be explained by a combined effect of higher ME intake and reduced energetic costs for glucose production through less amino acids being used in gluconeogenesis. In conclusion, the improved performance of dams fed the LP diet suggested that their requirement of essential amino acids and non-specific N were covered, and the requirement of digestible amino acids of lactating mink (kg(0.75)) was, thereby, estimated by use of a factorial approach including the amino acid excretion in milk of LP dams.  相似文献   
9.
Two experiments were conducted to determine whether the proanthocyanidin (condensed tannin)-containing forage legumes Desmodium intortum cv Greenleaf and Sesbania sesban (accession 15019) could be integrated into a feeding management strategy as a means of Haemonchus contortus control in goats. The anthelmintic effects of condensed tannin extracts from the two legumes on H. contortus L3 larvae were studied in an in vitro larval migration inhibition system. The extracts inhibited larval migration in a dose-dependent manner, and at concentrations from 1,000???g/ml condensed tannin, the extract from D. intortum caused a significantly higher inhibition of larval migration than did the corresponding concentrations of the S. sesban extract (P?<?0.01). Prolonged feeding of tanniniferous forage legumes showed that animals receiving D. intortum had the lowest total worm burden, the lowest female to male parasite ratio, the lowest number of eggs in the uterus of each female worm and the lowest per capita fecundity (P?<?0.01). However, there was no change in the performance (weight gain) of parasite-infected goats probably due to incomplete removal of the parasite or prolonged confinement of goats in small pens, which calls for further investigation. However, since there is no single efficient method in control of parasites, based on the obtained data from this experiment, integrated feeding of D. intortum with other suitable method of parasite control is thus suggested.  相似文献   
10.
A food consumption revolution is taking place in Russia. After decades of severe constraints on food consumption options under the communist regime Russian consumers are now adopting new food products—including seafood products – at a high pace. Since Russian consumers have previously had very limited seafood consumption choices, the market can be seen as an interesting laboratory for investigating consumer responses to products that have previously not been available. Among imported seafood products are both wild and farmed species. Furthermore, Russian imports include both traditional species such as herring, and ‘new’ species such as pangasius. We analyze market integration among seafood products using Russian monthly import prices from 2002 to 2007 on several products, such as herring, salmonids and pangasius. We find that pangasius compete in the white fish segment, and is a price leader. In the salmonids market, farmed salmon trout appears to be the price leader, both in the fresh and frozen market segment.  相似文献   
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