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11.
This study focused on the relationship between stress level and the fire resistance of structural lumber. The 210 samples were prepared from 15-year-old trees of Acacia mangium from the Forest Estate Plantation, Indonesia. Specimens were 20 ® × 20 (T) × 500mm (L) and were air-dried. Sixty samples were tested under four-point bending stress to obtain the modulus of elasticity (MOE) and the modulus of rupture (MOR) for classifying the stress grades of the remaining 150 samples. The tests were performed using a four-point load bending position at various stress level while the specimens were exposed to fire along the shear-free region. Time to failure was affected by the stress levels in an exponential trend. Despite changes in stress level, charring rate, and time to failure, the critical stress of a member from the same species was similar. The fire performance under applied load could be predicted by using simplified fire-testing methods. The developed testing apparatus is valid for evaluating the small-scale fire resistant behavior of structural lumber in bending.  相似文献   
12.

Background

Although modern commercial poultry production today is based on large farms and intensive husbandry, keeping backyard poultry has regained popularity in industrialized countries. However, the health status of backyard flocks is still relatively poorly documented. A questionnaire was sent to the owners of 376 backyard poultry flocks (<500 birds) in order to study health management procedures and characterize backyard poultry populations in Finland. Information was also collected on the postmortem findings from non-commercial flocks using necropsy data from the Finnish Food Safety Authority (Evira).

Results

Backyard flocks in Finland are small in size (<50 birds), comprising mainly chickens. Based on the results of the questionnaire, the health of such flocks is good, mortality low and vaccinations are not commonly used. Most of the flocks were registered in the national poultry register. The standard biosecurity practices are not generally applied and contact with wild birds, pets and farm animals is frequent, which can make the flocks more prone to infectious diseases. We conducted an 11-year retrospective study of the postmortem necropsy findings of the Evira in order to document the diseases, which caused mortality in backyard chickens in Finland. Necropsy was performed on a total of 132 non-commercial laying hens during 2000 – 2011. The most common postmortem findings were Marek’s disease (27%) and colibacillosis (17%).

Conclusions

This study is the first to report data on characteristics of and management practices for backyard chicken flocks in Finland. Close connections with commercial flocks are rare and farms are usually distantly located suggesting that the risk that these backyard flocks pose to commercial poultry is low.  相似文献   
13.
Developmental programming of the fetus has consequences for physiologic responses in the offspring as an adult and, more recently, is implicated in the expression of altered phenotypes of future generations. Some phenotypes, such as fertility, bone strength, and adiposity are highly relevant to food animal production and in utero factors that impinge on those traits are vital to understand. A key systemic regulatory hormone is growth hormone (GH), which has a developmental role in virtually all tissues and organs. This review catalogs the impact of GH on tissue programming and how perturbations early in development influence GH function.  相似文献   
14.
In recent years, considerable attention has been paid to anthocyanins due to their abilities to inhibit oxidative stress and cell proliferation. The regulations of apoptosis and the phase II enzymes glutathione-S-transferase (GST) and quinone reductase (QR) are other potential mechanisms through which flavonoids such as anthocyanins may prevent cancer. Our study confirmed that anthocyanin fractions from high bush blueberry cultivars increased apoptosis using two different methods: DNA fragmentation and caspase-3 activity. The effect of anthocyanins on the activity of the detoxifying enzymes GST and QR was also determined. Major anthocyanins identified were delphinidin, cyanidin, peonidin, petunidin, and malvidin. In Tifblue and Powderblue cultivars, DNA fragmentation increased at anthocyanin concentrations from 50 to 150 microg/mL, but cells treated with the anthocyanin fraction of Brightblue and Brightwell showed a prominent ladder at 50-100 microg/mL when compared to cells treated with 150 microg/mL. There was a significant difference in the caspase-3 activity (P < 0.05) between the control cells and the cells treated with anthocyanins from all of the cultivars. The response correlated positively with dose. The QR activity was lower in all cells treated with an anthocyanin fraction from Tifblue, Powderblue, Brightblue, and Brightwell cultivars than in control cells (P < 0.05). The activity decreased gradually when treated with increased concentrations of anthocyanin fractions (50-150 microg/mL) in the Tifblue and Powderblue cultivars. The GST activity was lower (P < 0.05) in cells treated with anthocyanin fractions from all of the cultivars and at all concentrations. These results indicated that apoptosis was confirmed in HT-29 cells when treated with anthocyanins from blueberry cultivars at 50-150 microg/mL concentrations, but these same concentrations decrease QR and GST activities rather than induce them.  相似文献   
15.
Precision Agriculture - Soil application of herbicides for pre-emergence (PRE) weed control is vital for grain sorghum production. Many soil-applied herbicides can be adsorbed or bound to the soil...  相似文献   
16.
A 4‐year‐old, spayed female greyhound dog was presented with an acute onset of paraplegia. There was no known history of trauma or coagulopathy. Spinal cord compression was identified on MRI. Intra‐operative evaluation revealed the presence of a large subperiosteal hematoma and a smaller epidural hematoma. To the authors’ knowledge, this is the first report of a spinal subperiosteal hematoma diagnosed antemortem through MRI, with surgical exploration and successful treatment in a dog.  相似文献   
17.
Viral infections have been suggested to play a role in the decline of the panmictic population of the European eel (Anguilla anguilla). However, despite the importance of knowledge about pathogenic eel viruses, little is known about their spread in the wild European eel population and only a few eel pathogenic viruses have been described so far. In this study, we aimed to investigate the health status of the A. anguilla stock in North Rhine Westphalia (NRW) State of Germany. For this purpose, we examined tissue samples of 16 elvers, 100 yellow eels and 6 silver eels, sampled from the rivers Rhine, Lippe and Ems. Virus detection was performed via a combination of cell culture and PCR. Next to the detection of frequently encountered pathogenic eel viruses (anguillid herpesvirus 1 and eel virus European X (EVEX)), we isolated the eel picornavirus 1 (EPV-1) from tissue of yellow eels and elvers and demonstrate the distribution of EPV-1 in wild eel population in NRW.  相似文献   
18.
Abstract.— Fish possess a growth hormone similar to mammalian growth hormone, and the presence of a growth hormone-releasing hormone-like material in the brain has been demonstrated in several teleost species. We investigated the effect of a mammalian growth hormone-releasing hormone on serum estradiol-17β and testosterone concentrations in tilapia Oreochromis mossambicus and a hybrid O. niloticus × O aureus because growth hormone has been implicated in the regulation of gonadal functions in teleosts. Three hours after injecting the releasing hormone, male and female serum testosterone concentrations significantly increased compared to controls, while serum estradiol-17β concentrations increased significantly only in females. These increases were commensurate with respective serum steroid concentrations in fish injected with gonadotropin releasing-hormone. Studies utilizing hypophysectomized fish resulted in non-detectable levels of serum sex steroids in fish treated with the growth hormone-releasing hormone; however, significant increases occurred in fish treated with human chorionic gonadotropin. Similarly, gonadal tissue incubated with growth hormone releasing hormone had non-detectable levels of sex steroids in the media, whereas gonads incubated with human chorionic gonadotropin had significant increases in sex steroid concentrations. These studies suggest that growth hormone-releasing hormone acts at the level of the pituitary. Although mammalian growth hormones have been shown to increase serum gonadotropic hormone concentrations, this study provides evidence that a mammalian growth hormone-releasing hormone has the ability to indirectly increase sex steroid levels in fish.  相似文献   
19.
20.
Nitrogenous waste control in aquaculture systems is necessary to maintain healthy animals and to meet effluent standards. Decreased ammonia production has been attained in traditional livestock production systems by adding extracts of Yucca shidigera to the feed or storage lagoon system. An extract of Yucca shidigera was fed to post yolk-sac and juvenile channel catfish Ictalurus punctatus and hybrid tilapia Oreochrornis mossambicus × O. niloticus to determine the effects on growth, nitrogen retention, ammonia excretion, and toxicity. Post yolk-sac channel catfish fry fed the 1.0-g yucca extract/kg as an agar coating were the only group of experimental organisms that had significantly greater weight gains compared to the control and 0.5-g yucca extract/kg diet groups after 12 wk. Significantly lower fecal nitrogen concentrations were obtained from catfish fed diets containing yucca extract compared to the control groups, although no differences between fecal nitrogen concentrations for catfish fed diets with either 0.5-g or 1.0-g yucca extract/kg diet occurred. Ammonia excretion rates were significantly lower for catfish fed diets containing yucca extract compared to the control group. Accordingly, fish fed diets containing the yucca extract had significantly greater whole-body protein composition, while lipid levels were significantly lower. No significant differences in proximate composition occurred for fish fed any of the diets containing yucca extract, though growth rates were significantly higher than the controls. This study demonstrated that a yucca extract can be used in the diet of channel catfish, and increased growth and decreased ammonia concentrations can be obtained in rearing systems.  相似文献   
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