Microspectroscopy as applied to the study of wood molecular structure

Microspectroscopy gives access to spatially resolved information on the molecular structure and chemical composition of a material. For a highly heterogeneous and anisotropic material like wood, such information is essential when assessing structure/property relationships such as moisture-induced dimensional changes, decay resistance or mechanical properties. It is, however, important to choose the right technique for the purpose at hand and to apply it in a suitable way if any new insights are to be gained. This review presents and compares three different microspectroscopic techniques: infrared, Raman and ultraviolet. Issues such as sample preparation, spatial resolution, data acquisition and extraction of knowledge from the spectral data are discussed. Additionally, an overview of applications in wood science is given for each method. Lastly, current trends and challenges within microspectroscopy of wood are discussed.     

Flow injection analysis for the determination of urea in cow's milk

An inexpensive and easily automated flow injection method for determination of urea in cow’s milk was evaluated. Urea is hydrolysed by urease and in a gas diffusion cell the ammonia formed passes a membrane into an indicator solution. The resulting colour change of the indicator is measured at 590 nm.The repeatability of the analysis, expressed as the coefficient of variation (C.V.), was between 0.5 and 1.2%. Measured (y) and expected (x) milk urea concentrations after addition of known amounts of urea were related according to the equation y = 1.00× – 0.12 with a C.V. for the regression of 1.8%. Recommended amounts (0.02 %) of the preservative bronopol (2-bromo-2-nitropropane-1,3-diol) added to the milk did not affect the results (P > 0.05).     

Reproductive Performance in Cows with Extended Calving Interval*

Contents The effects of increased calving intervals on reproduction were studied in two herds. In Herd 1 cows were managed for 12‐ or 15‐month calving intervals and in Herd 2 for 12‐ or 18‐month intervals. Data from the study revealed that managing cows for a longer calving interval improved the fertility. Animals with a short interval needed more hormonal treatments to be inseminated on time due to anoestrus, compared to animals with longer intervals. Once the animals were inseminated there was a tendency for a higher conception rate at first AI in the 15‐month group compared with the 12‐month group. The cows in the 15‐month group needed a lower number of AIs per serviced cow and a shorter period from the first AI to conception. Culling due to fertility problems was more frequent in the 12‐month group. A longer period of days open did not imply an increased risk for development of cystic ovaries and did not result in weaker heat symptoms over time.     

Dispersal and spatiotemporal distribution of Protapion fulvipes in white clover fields: implications for pest management

Journal of Pest Science - Yield loss caused by insect pests remains a substantial problem in agriculture. Chemical control, with potential negative effects on non-target organisms, is still the...     

Reciprocal embryo transfer between repeat breeder and virgin heifers--an experimental model

The aim of the study was to evaluate the importance of mother-concaptus relationships for the elevated embryonic loss in repeat breeder heifers. Embryos were collected by non-surgical technique, classified and transferred surgically or non-surgically to synchronized, inseminated recipients. The embryos were transferred to the uterinehorn contralateral to the corpus luteum. The embryos were transferred from repeat breeder heifers (RBH) to virgin heifers (VH) or from VH to RBH. After slaughter 4 weeks after transfer there was no difference in emhryonic survival between heifer categories following transfer or insemination. In some animals degenerated foetal membranes were found in the nonpregnant horn. The study indicates embryonic morphology rather than the category of donor or recipient as influencing the embryonic survival rate.Key words: embryo, embryonic death, embryo transfer, repeat breeder     

In Vitro Development of Bovine Embryos after Fertilization using Semen from Different Donors

Contents: The aim of this study was to determine whether the semen donor and/or heparin concentration influences the rate of fertilization of bovine follicular oocytes and their subsequent embryonic development in vitro. Frozen-thawed semen from five highly fertile bulls was treated with one of four concentrations of heparin (0.5,1.0, 2.0 and 5.0 μg/ml) on a 5 x4 factorial basis in an IVM-NF programme. Zygotes/oocytes were cultured in frozen-thawed bovine oviduct cell-conditioned medium for 6 days. The use of semen from different bulls resulted in significantly (P < 0.001) different rates offertilization, as judged by cleavage rates of the oocytes at 72 h post insemination, and subsequent embryonic development through the'8-cell-block'(P < 0.05) in vitro. Development up to the morula/blastocyst stage, however, did not differ significantly (P = 0.06) among groups of oocytes fertilized with spermatozoa from different bulls. Heparin levels ranging from 0.5 to 5.0 μg/ml did not differ in their effect on in vitro fertilization as judged by the rate of normally cleaved oocytes (P = 0.14). The overall parthenogenetic division rate at 72 h post insemination was 12.4% and was not influenced by the heparin concentration. There was a linear relationship (P < 0.001) between fertility estimates based on AI and the estimates basedon the first cleavage following in vitro fertilization.     

Remote straying of salmon (Salmo salar L.) from the Swedish west coast and possible effects on sea ranching operations

Some 6500 recaptures of salmon tagged as smolts on the Swedish west coast in 1966–1980 were reviewed for remote strayers. Only 27 (0.43%) were found, meaning no risk for the profitability of sea ranching activities. Along the Swedish west coast at least 450 kg salmon per 1000 released smolts can be expected to be caught by Swedish commercial fishermen, which makes public sea ranching highly profitable there.     

Experimental reproduction of winter dysentery in lactating cows using BCV -- comparison with BCV infection in milk-fed calves

Infection models were developed for adult cows and for young calves using the same strain of bovine coronavirus (BCV), which for the first time allows experimental reproduction of winter dysentery (WD) in seronegative lactating cows. The cattle were infected through direct contact with an experimentally inoculated calf. All experimental cattle shed faecal BCV with development of diarrhoea, being profusely watery with small amounts of blood in the most severely affected animals, including both cows and calves. The cows, in contrast to the calves, showed depressed general condition and appetite leading to a marked decrease in milk yield. Further age-associated differences were a shorter incubation period in the two youngest calves, but with milder fever and milder decrease in white blood cell counts. These findings shed light on the apparent epidemiological differences between WD and calf BCV diarrhoea suggesting that, (1) the same strains of BCV cause natural outbreaks of calf diarrhoea and WD, (2) seronegative cows are more severely affected by the infection than seronegative conventionally reared calves, and (3) unaffected general condition in diarrhoeic calves may lead to underestimation of the occurrence of calf diarrhoea in WD outbreaks.In response to infection, all cattle produced early interferon type 1 in serum and, except for one calf, in nasal secretions. A finding not previously reported is the detection of interferon type 1 responses in bovine milk. All cattle developed high IgM antibody responses and long-lasting IgA antibody responses both systemically and locally. The serum IgM antibody responses came earlier in most of the calves than in the cows. Prolonged IgM antibody responses were detected in serum and milk, while those in nasal secretions were much shorter. BCV-specific IgA was present in nasal secretions from all cattle throughout the 6 months follow-up. The IgA antibody response in serum was detected up to 17 months post-infection and the duration showed an age-related variation indicating a more prominent IgA memory in the adult cattle and in the older calves than in the younger ones. BCV-specific IgG was detected in all cattle during the experimental period of up to 22 months. In conclusion, WD was reproduced in seronegative lactating cows. The cows showed a more severe general diseases than seronegative calves infected concurrently. Very long-lasting IgA antibody responses were detected both systemically and locally.     

Assessment of changes in hemostatic markers in Cavalier King Charles Spaniels with myxomatous mitral valve disease

OBJECTIVE: To evaluate markers of hemostasis and their relationship to the degree of mitral regurgitation (MR) and platelet function in Cavalier King Charles Spaniels (CKCSs) with myxomatous mitral valve disease. ANIMALS: 76 clinically healthy CKCSs and 24 control dogs. PROCEDURE: All dogs underwent echocardiographic examination; various hemostatic, hematologic, and biochemical variables were evaluated in blood. The CKCSs were allocated to 1 of 3 groups on the basis of MR severity. In 8 control dogs and 8 CKCSs, plasma von Willebrand factor (vWF) multimer analysis was performed. RESULTS: Compared with control dogs, plasma fibrinogen concentration was higher in all CKCSs and related to left ventricular end diastolic diameter and left atrial-to-aortic root ratio among all CKCSs. The activated partial thromboplastin times and plasma D-dimer concentration were similar among the 4 groups. Plasma vWF concentration was lower in CKCSs with moderate to severe MR, compared with that of CKCSs with no MR and control dogs. There was a relationship between plasma vWF concentration and platelet function in CKCSs but not in control dogs. In 4 CKCSs with moderate to severe MR and low plasma vWF concentration, amounts of vWF high-molecular-weight multimers (HMWMs) were low. CONCLUSIONS AND CLINICAL RELEVANCE: In CKCSs, MR appeared to be associated with a low plasma vWF concentration and likely a loss of vWF HMWMs (possibly through their destruction via shear stress to the blood). The importance of the changes in plasma fibrinogen concentration and the thromboembolic risk in dogs with MR remain to be investigated.     

Fertility of deep frozen boar spermatozoa at various intervals between insemination and induced ovulation: influence of boars and thawing diluents.

The fertilizing ability of deep frozen boar spermatozoa was assessed after artificial insemination at various intervals after human chorionic gonadotropin (HCG) induced ovulation in gilts. Boar seminal plasma and OLEP were used as thawing diluent agents. The fertilization rates were similar when insemination was performed 2 or 6 hours before the time of estimated ovulation (40 hours post-HCG administration). However, fertility rates markedly declined when insemination was performed earlier than 6 hours before expected ovulation. In inseminations performed 2 hours before ovulation, the fertility rate was higher with specimens treated with boar seminal plasma diluent than with OLEP. As the difference between the time of insemination and that of ovulation increased, the difference in fertilizing ability of spermatozoa from the 2 boars used also increased. The results show that spermatozoa which have a low resistance to freezing-thawing also have a diminished fertile life in the female genital tract.