Swine trichinosis in mid-atlantic slaughterhouses: Possible relationship to hog marketing systems

Digests of diaphragms from 33 482 hogs slaughtered in the mid-atlantic states were examined for the presence of Trichinella spiralis larvae. The samples were obtained from 7 slaughterhouses, ranging in slaughter capacity from less than 50 per day to more than 4000 per day. The sources of the hogs varied from “backyard” operations, raising hogs for home use, to commercial farms. The means by which hogs were brought to the slaughterhouse also differed; the larger slaughterhouses often purchased directly from the producer while the smaller slaughterhouses (1000 hogs per day or less) usually purchased through dealers or brokers. Infected hogs were detected more frequently than was expected from previously-published prevalence studies; overall, 0.58% of samples examined contained T. spiralis larvae. All of the infected hogs were marketed through the smaller slaughterhouses (less than 1000 per day) and nearly all were marketed through brokers. The mean number of larvae per gram of diaphragm, determined by slaugterhouses type, ranged from 0.5 to 74.6; most infections were light although 5 had counts of 1000–2480.Most of the positive samples were obtained from one slaughterhouse, the data from which exhibited marked differences in the frequency of infection by day of the week; 128 positive samples of the total of 190 found were obtained on Fridays, although only 10% of all samples were obtained on that day. Analysis of the geographic origin of shipments containing infected hogs revealed that most originated in New Jersey and Pennsylvania, although the hogs shipped from the latter state might originated in New England or Maryland. Attempts to trace back infected hogs for further epidemiological investigation were largely futile, owing to the absence of an identification system.     

Effect of creep feeding on structural and functional changes of the gut of early weaned pigs

Dose-dependent hypersensitivity responses mounted against antigenic constituents of creep feeds have been previously implicated in intestinal damage, digestive disorders and impaired performance of early weaned pigs. In the present study biochemical and histological investigations of the small intestine were undertaken to determine the putative relationship between creep feed level and hypersensitivity response in pigs weaned at 14 days. Creep feed was administered by gastric intubation and weaned pigs received the same diet by gastric intubation for five days. Mucosal structure and function at weaning were not affected by creep feeding regimen. Villus height decreased and crypt depth increased in weaned compared to suckled pigs, but morphology was unaffected by prior exposure to creep. Xylose absorption was not influenced by either creep feed level or weaning. Intraepithelial lymphocyte numbers increased during weaning but were not affected by the creep feeding regimen. Mucosal carbohydrase activity in weaned pigs was not significantly affected by preweaning treatment. The results do not support the hypothesis that post weaning changes in structure and function of the gut are related to creep feed level or to immune responses to dietary antigens.     

Forest soils research and changing societal needs and values

The 10th North American Forest Soils Conference was held in Sault Ste. Marie, Canada, 20–24 July 2003. These conferences, held at 5-year intervals since 1958, are intended to provide a forum to discuss and summarize the state of knowledge on selected topics related to forest soils. Approximately 60 papers were presented on a variety of topics related to understanding and managing soils that support forests with particular emphasis given to field research, soil carbon, and site management/classification. We discuss the topics of this conference in relation to earlier ones and conclude that advances are made unevenly and that there is a need for new approaches to investigating many of the topics. We note the change in forest management that has occurred since the first of these conferences and the resulting changes needed in our approach to research and management. The need for interaction of scientists and clientele groups is noted as necessary for development of sound management and research policy. The interaction of scientific disciplines is needed to attack problems that have been difficult to elucidate. The challenge to forest soil scientists is to mesh their scientific interests with the needs of society to obtain the resources needed to advance science and provide information that will improve forest management.     

专业化的中国木业国际盛会——2005中国木制品进出口贸易洽谈会

2005年10月30日至11月2日，由中国木业国际公司、中国木业国际网和加拿大R.E.Taylor ＆ Associates Ltd.共同主办的第四届《中国木制品进出口贸易洽谈会》在风景秀丽，气候宜人的广东东莞隆重举行，     

Rheological Studies on the Reaction of Zein with Polyethylenemaleic Anhydride

There continues to be interest in developing solvent‐resistant articles from biobased renewable materials to successfully compete with petrochemical products. It was previously shown that reaction of zein with polyethylenemaleic anhydride (PEMA) provides articles that are solvent resistant. The gelation kinetics for the reaction of PEMA with zein was investigated rheologically to better understand this chemistry. The reaction of the nucleophilic groups on zein with the anhydrides on PEMA is the main cause for the gelation reaction. The gelation time was defined as being the point when the elastic modulus (G′) and viscous modulus (G″) cross. In this work, the rate of reaction, in terms of time to gelation, was studied in N,N‐dimethylformamide solution for which the amount of PEMA, the reaction temperature, and the overall reaction concentration were varied. Exponential relationships were found between the gelation time and % PEMA, temperature, and % solids, as well as between elastic modulus with either % PEMA or % solids. The concentration of PEMA had the largest impact on gelation time, for which going from 2.5% PEMA to 6% PEMA reduced the gelation time from 63,114 to 1,576 s. The temperature dependence of this gelation reaction was well described by an Arrhenius plot with an apparent activation energy of 50.5 kJ/mol.     

Green tea polyphenol extract regulates the expression of genes involved in glucose uptake and insulin signaling in rats fed a high fructose diet

Green tea has antidiabetic, antiobesity, and anti-inflammatory activities in animal models, but the molecular mechanisms of these effects have not been fully understood. Quantitative real-time polymerase chain reaction (PCR) was used to investigate the relative expression levels and the effects of green tea (1 and 2 g solid extract/kg diet) on the expression of glucose transporter family genes (Glut1/Slc2a1, Glut2/Slc2a2, Glut3/Slc2a3, and Glut4/Slc2a4) and insulin signaling pathway genes (Ins1, Ins2, Insr, Irs1, Irs2, Akt1, Grb2, Igf1, Igf2, Igf1r, Igf2r, Gsk3b, Gys1, Pik3cb, Pik3r1, Shc1, and Sos1) in liver and muscle of rats fed a high-fructose diet known to induce insulin resistance and oxidative stress. Glut2 and Glut4 were the major Glut mRNAs in rat liver and muscle, respectively. Green tea extract (1 g) increased Glut1, Glut4, Gsk3b, and Irs2 mRNA levels by 110, 160, 30, and 60% in the liver, respectively, and increased Irs1 by 80% in the muscle. Green tea extract (2 g) increased Glut4, Gsk3b, and Pik3cb mRNA levels by 90, 30, and 30% but decreased Shc1 by 60% in the liver and increased Glut2, Glut4, Shc1, and Sos1 by 80, 40, 60, and 50% in the muscle. This study shows that green tea extract at 1 or 2 g/kg diet regulates gene expression in the glucose uptake and insulin signaling pathway in rats fed a fructose-rich diet.     

Effects of oral powder electrolyte administration on packed cell volume,plasma chemistry parameters,and incidence of colic in horses participating in a 6-day 162-km trail ride

This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model.     

Broken eggs as a cause of infertility of coho salmon gametes

Egg content originating from ruptured ova progressively reduced the success of fertilization in coho salmon (Oncorhynchus kisutch) eggs. The salmon egg differs in ionic composition from the ovarian fluid in exhibiting higher K⁺ and Mg²⁺ and lower Na⁺ concentrations. Normal ovarian fluid induced spermatozoan motility whereas ovarian fluid contaminated with egg content progressively lost the ability to induce motility. Loss of motility was related to decreasing $\text{Na}{}^{\mathrm{+}}\text{K}{}^{\mathrm{+}}$ ratios in the ovarian fluid, indicating that reduced fertility may be caused by inactivation of sperm cells in the insemination medium. Removal of contaminated ovarian fluid by rinsing ova in isotonic media induced spermatozoan motility and restored fertility completely. The use of an isotonic NaHCO₃ solution for rinsing of ova is suggested as a routine procedure for artificial insemination in salmonids where the presence of broken eggs is suspected.     

The hydraulically integrated serial turbidostat algal reactor (HISTAR) for microalgal production

A hydraulically integrated serial turbidostat algal reactor (HISTAR) for the mass production of microalgae was designed, constructed and preliminarily evaluated. The 9266-l experimental system consists of two enclosed turbidostats hydraulically linked to a series of six open continuous-flow, stirred-tank reactors (CFSTRs). The system was monitored and controlled using GENESIS process control software. A production study was preformed using Isochrysis sp. (C-iso) to assess system stability and production potential under commercial-like conditions. The study was performed at the following target system parameters: system dilution rate of 0.49 per day, pH 7.6, NITROGEN=10 mg l⁻¹, PHOSPHORUS=2 mg l⁻¹, and artificial illumination (photosynthetic photon flux density) from 1000 W metal halide LAMPS=800 μmol s⁻¹ m⁻². At steady state conditions, daily harvested algal paste was 1454 g (wet), mean areal system PRODUCTIVITY=47.8±3.04 g m⁻² per day (17.1±1.09 g C m⁻² per day) and mean CFSTR6 DENSITY=105.5±6.71 mg l⁻¹.