Herd-level risk factors associated with cow mortality in Swedish dairy herds

An increase in on-farm mortality (euthanasia and death) in dairy herds has been reported in several countries in the last decade. This does not only imply possible problems with animal welfare, but it also causes economic losses to the farmer. The objective of this study was to evaluate time trends in on-farm dairy cow mortality in Sweden and identify potential herd-level risk factors. Data was retrieved on all Swedish dairy herds enrolled in the milk recording scheme between 2002 and 2010. Herds with a herd size of 40 dead or euthanized cows per 100 cow-years were excluded. Two different models were used: 1 multiple year analysis which included 6,898 herds during the period 2002 to 2010 and 1 single year analysis including 4,252 herds for the year 2010, where other variables that were not present during the entire multiple year study were analyzed. The outcome variable was the number of euthanized and dead cows per year and season. A negative binomial regression model, adjusted for clustering within herd, was applied to both models. Fixed effects in the multiple year analysis were breed, calving interval, herd size, milk yield, region, season, pasture period, and year. Fixed effects in the single year analysis were breed, calving interval, conventional vs. organic farming, herd size, housing system, milk yield, region, and season. The multiple year analysis demonstrated that MR gradually increased from 5.1 to 6.6 events per 100 cow-years during the study period. Swedish MR are consequently on par with, or even greater than, MR among dairy herds in other comparable countries. Higher mortality was associated with larger herd size, longer calving intervals, and herds that had Swedish Holstein as the predominant breed. Lower mortality was observed in herds with a higher herd average milk yield, during the fall and winter, and in organically managed herds. There were regional differences in mortality. An interaction between herd size and season was found in both models. Also, an interaction between housing system and milk yield was found in the single year analysis. This first assessment of on-farm mortality in Swedish dairy herds confirmed that the MR has increased over the last few years. The study also identified some herd-level risk factors

Species‐specific rates of growth and grazing loss among freshwater algae

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109876/1/lno19853010034.pd

Phosphorus dynamics of the procaryotic nannoplankton in a Michigan lake

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109970/1/lno19822750828.pd

Female gender increases stiffness of elastic but not of muscular arteries in type I diabetic patients.

The reason for the particularly increased risk for cardiovascular complications in diabetic women is still unclear. We have previously found decreased distensibility of elastic arteries in type I diabetic women, indicating increased cardiac load, not seen in type I diabetic men, which might be one contributing factor. Whether the effect of gender is different in muscular arteries in type I diabetic patients has not been assessed. As estimates of arterial distensibility we measured stiffness (beta) and pressure strain elastic modulus (Ep) in the muscular common femoral artery using echo-tracking sonography in 30 women (mean age 34 years, range 20-61) and 26 men (mean age 38 years, range 22-56) with type I diabetes. The results were compared with those of 89 healthy individuals of corresponding age and gender and with previously published results from elastic arteries in these patients obtained at the same occasion. The internal common femoral diameter was significantly decreased in both diabetic men and women. In sharp contrast to the highly significant decreased distensibility of the elastic abdominal aorta and common carotid artery in the type I diabetic women, the distensibility of the common femoral artery did not clearly differ between patients and controls, neither for women nor for men. Thus, the gender difference in changes of arterial distensibility found in elastic arteries was absent or far less obvious in the femoral artery. In conclusion, female gender seems to affect the mechanical properties of elastic, but not of large muscular arteries in type I diabetic patients. Thus, putative gender differences in arterial changes in type I diabetes are to be sought in elastic rather than muscular arteries

Reduced Aortic Wall Stress in Diabetes Mellitus

ObjectiveMost risk factors are similar for abdominal aortic aneurysm (AAA) and atherosclerosis, e.g. smoking, male gender, age, high blood pressure, hyperlipidemia. Diabetes mellitus however, is a risk factor for atherosclerosis, but diabetic patients seldom develop AAA. The reason for this discrepancy is unknown. Increased aortic wall stress seems to be an etiologic factor in the formation, growth and rupture of AAA in man. The aim of our study was to study the wall stress in the abdominal aorta in diabetic patients compared with healthy controls.Methods39 patients with diabetes mellitus and 46 age – and sex matched healthy subjects were examined with B-mode ultrasound to determine the lumen diameter (LD) and intima-media thickness (IMT) in the abdominal aorta (AA) and the common carotid artery (CCA). Diastolic blood pressure (DBP) was measured non-invasively in the brachial artery. LaPlace law was used to calculate circumferential wall stress.ResultsAge, DBP, and LD in the abdominal aorta were not significantly different in the diabetic patients compared to controls. IMT in the AA was larger in the diabetic patients, 0.89±0.17 vs 0.73±0.11mm (p<.001). Accordingly aortic wall stress was reduced in the diabetics, 7.8±1.7×105 vs 9.7±1.9×105dynes/cm2 (p<.001).ConclusionsWall stress in the abdominal aorta is reduced in diabetes mellitus. This is mainly due to a thicker aortic wall compared to healthy controls. The reduced aortic wall stress coincides with the fact that epidemiological studies have shown a decreased risk of aneurysm development in diabetic patients

Ubiquitous Expression of Marker Transgenes in Mice and Rats

AbstractThe ability to unambiguously mark a cell's genotype is essential for studies in which genetically distinct cell populations must be distinguished from one another in vivo. One approach to this challenge has been the creation of transgenic mice expressing a transgene marker that is easily detectable, with no background staining. Multiple transgenic mouse strains bearing constructs with different combinations of promoter elements and coding sequences have been described, each with its own advantages and limitations. In this report we describe the use of an 800-bp promoter fragment isolated from the βgeo integration site in ROSA26 mice to target expression of two marker genes. We demonstrate that the ROSA26 promoter directs ubiquitous expression of human placental alkaline phosphatase and enhanced green fluorescent protein during embryonic and postnatal development in mouse and rat. We further demonstrate the general utility of these transgenes for marking donor cells in transplantation studies

HIV/AIDS awareness and risk behaviour among pregnant women in Semey, Kazakhstan, 2007

<p>Abstract</p> <p>Background</p> <p>Central Asia has one of the most rapidly increasing HIV prevalence in the world. The aim of this study was to evaluate current knowledge, risk behaviour and attitudes to voluntary counselling and testing concerning HIV/AIDS among pregnant women in Semey, Kazakhstan.</p> <p>Methods</p> <p>We collected 226 questionnaires in a consecutive sample from a population on 520 pregnant women. The results were related to ethnicity, age and education level.</p> <p>Results</p> <p>Ninety-six percent had heard about HIV.</p> <p>Positive findings were that 89% and 86% of the women were aware of the two main routes of transmission: sexual intercourses without a condom and sharing needles while injecting drugs. The women had first heard about HIV/AIDS through the media with, 52%, and at school with 40%. Only 46% and 68% of the women pointed out breastfeeding and mother-to-child transmission during pregnancy or delivery as routes of transmission. Eighty-three percent were prepared not to breastfeed their baby if they were found to be HIV positive. Slightly more, 86%, accepted the need to take medicine, but fewer women, 68%, were positive to Caesarean section. Negative findings were that only 28% answered that there are ways to protect oneself against sexually transmitted HIV/AIDS and specified that this was condom use.</p> <p>Conclusion</p> <p>The pregnant women in Semey have poor knowledge about specific mother-to-child HIV transmission and do not know about the means of reducing mother-to-child HIV infection. The information in the public health program needs to be improved. However, most of the women in Semey were positive to prevention strategies for mother-to-child transmission after hearing about it.</p

Machine learning reveals sequence-function relationships in family 7 glycoside hydrolases

Family 7 glycoside hydrolases (GH7) are among the principal enzymes for cellulose degradation in nature and industrially. These enzymes are often bimodular, including a catalytic domain and carbohydrate-binding module (CBM) attached via a flexible linker, and exhibit an active site that binds cello-oligomers of up to ten glucosyl moieties. GH7 cellulases consist of two major subtypes: cellobiohydrolases (CBH) and endoglucanases (EG). Despite the critical importance of GH7 enzymes, there remain gaps in our understanding of how GH7 sequence and structure relate to function. Here, we employed machine learning to gain data-driven insights into relation-ships between sequence, structure, and function across the GH7 family. Machine-learning models, trained only on the number of residues in the active-site loops as features, were able to discriminate GH7 CBHs and EGs with up to 99% ac-curacy, demonstrating that the lengths of loops A4, B2, B3, and B4 strongly correlate with functional subtype across the GH7 family. Classification rules were derived such that specific residues at 42 different sequence positions each predicted the functional subtype with accuracies surpassing 87%. A random forest model trained on residues at 19 positions in the catalytic domain predicted the presence of a CBM with 89.5% accuracy. Our machine learning results recapitulate, as top-performing features, a substantial number of the sequence positions determined by previous experimental studies to play vital roles in GH7 activity. We surmise that the yet-to-be-explored sequence positions among the top-performing features also contribute to GH7 functional variation and may be exploited to understand and manipulate function

Protofibrillar and Fibrillar Amyloid-β Binding Proteins in Cerebrospinal Fluid

Aggregation and deposition of misfolded amyloid-β (Aβ) peptide in the brain is central to Alzheimer’s disease (AD). Oligomeric, protofibrillar, and fibrillar forms of Aβ are believed to be neurotoxic and cause neurodegeneration in AD, but the toxicity mechanisms are not well understood and may involve Aβ-interacting molecular partners. In a previous study, we identified potential Aβ₄₂ protofibrillar-binding proteins in serum and cerebrospinal fluid (CSF) using an engineered version of Aβ₄₂ (Aβ₄₂CC) that forms protofibrils, but not fibrils. Here we studied binding of proteins to Aβ₄₂ fibrils in AD and non-AD CSF and compared these with protofibrillar Aβ₄₂CC-binding partners. Aβ₄₂ fibrils sequestered 2.4-fold more proteins than Aβ₄₂CC protofibrils. Proteins with selective binding to fibrillar aggregates with low nanomolar affinity were identified. We also found that protofibrillar and fibrillar Aβ-binding proteins represent distinct functional categories. Aβ₄₂CC protofibrils triggered interactions with proteins involved in catalytic activities, like transferases and oxidoreductases, while Aβ₄₂ fibrils were more likely involved in binding to proteoglycans, growth factors and neuron-associated proteins, e.g., neurexin-1, -2, and -3. Interestingly, 10 brain-enriched proteins were identified among the fibril-binding proteins, while protofibril-extracted proteins had more general expression patterns. Both types of Aβ aggregates bound several extracellular proteins. Additionally, we list a set of CSF proteins that might have potential to discriminate between AD and non-AD CSF samples. The results may be of relevance both for biomarker studies and for studies of Aβ-related toxicity mechanisms

Sinking properties of some phytoplankton shapes and the relation of form resistance to morphological diversity of plankton – an experimental study

Form resistance (Phi) is a dimensionless number expressing how much slower or faster a particle of any form sinks in a fluid medium than the sphere of equivalent volume. Form resistance factors of PVC models of phytoplankton sinking in glycerin were measured in a large aquarium (0.6 x 0.6 x 0.95 m). For cylindrical forms, a positive relationship was found between Phi and length/ width ratio. Coiling decreased Phi in filamentous forms. Form resistance of Asterionella colonies increased from single cells up to 6-celled colonies than remained nearly constant. For Fragilaria crotonensis chains, no such upper limit to Phi was observed in chains of up to 20 cells ( longer ones were not measured). The effect of symmetry on Phi was tested in 1 - 6-celled Asterionella colonies, having variable angles between the cells, and in Tetrastrum staurogeniaeforme coenobia, having different spine arrangements. In all cases, symmetric forms had considerably higher form resistance than asymmetric ones. However, for Pediastrum coenobia with symmetric/asymmetric fenestration, no difference was observed with respect to symmetry. Increasing number and length of spines on Tetrastrum coenobia substantially increased Phi. For a series of Staurastrum forms, a significant positive correlation was found between arm-length/cell-width ratio and Phi: protuberances increased form resistance. Flagellates (Rhodomonas, Gymnodinium) had a Phi 1. The highest value ( Phi = 8.1) was established for a 20-celled Fragilaria crotonensis chain. Possible origin of the so-called 'vital component' ( a factor that shows how much slower viable populations sink than morphologically similar senescent or dead ones) is discussed, as is the role of form resistance in evolution of high diversity of plankton morphologies