Determination of the emissivity of materials Semiannual progress report, 15 May - 14 Nov. 1966

Emittance and thermal cycling tests of stainless steel tubes coated with iron and calcium titanate, and niobium-zirconium tubes coated with iron titanat

High-emittance coatings on metal substrates

High-emittance coatings of iron, calcium, and zirconium titanates thermally sprayed on stainless steel, columbium-1 percent zirconium, and beryllium substrates promote and control radiative heat transfer from the metal substrates. Adherence, compatibility and emittance stability at elevated temperature and high vacuum were evaluated

Properties of high emittance materials

High emittance coating materials for beryllium, niobium-zirconium compounds, and stainless steel used in spacecraft radiator

Determination of the emissivity of materials Semiannual progress report, 15 Nov. 1965 - 14 May 1966

Emissivity of titanate-coated stainless steel, niobium-zirconium alloy, and beryllium for space radiator

Long-term outcome in dogs with cranial cruciate ligament disease evaluated using the canine orthopaedic index

BackgroundCranial cruciate ligament disease (CCLD) is common in dogs, but studies on the long-term treatment outcome are scarce. MethodsThe long-term outcome in a cohort of 71 dogs with CCLD treated with tibial plateau levelling osteotomy (TPLO, n = 18), tibial tuberosity advancement (TTA, n = 23) or lateral fabellotibial suture (LFS, n = 30) was evaluated using the canine orthopaedic index. ResultsThe risk of stiffness and lameness was increased in dogs treated with TPLO (stiffness: incidence rate ratio [IRR] 1.33, p = 0.015; lameness: IRR 1.34, p = 0.020) or TTA (stiffness: IRR 1.26, p = 0.035; lameness: IRR 1.31, p = 0.026) when compared to LFS at a median follow-up time of 4.6 years. LimitationsNo follow-up veterinary examination was performed. Data were collected from only two university animal hospitals, and thus, a referral bias towards more complicated cases is possible, which may limit the generalisability of the results. ConclusionClinicians can use the results to inform dog owners about the expected long-term outcome in dogs with CCLD

Multiple imputation in veterinary epidemiological studies: a case study and simulation

The problem of missing data occurs frequently in veterinary epidemiological studies. Most studies use a complete case (CC) analysis which excludes all observations for which any relevant variable have missing values. Alternative approaches (most notably multiple imputation (MI)) which avoid the exclusion of observations with missing values are now widely available but have been used very little in veterinary epidemiology.This paper uses a case study based on research into dairy producers' attitudes toward mastitis control procedures, combined with two simulation studies to evaluate the use of MI and compare results with a CC analysis. MI analysis of the original data produced results which had relatively minor differences from the CC analysis. However, most of the missing data in the original data set were in the dependent variable and a subsequent simulation study based on the observed missing data pattern and 1000 simulations showed that an MI analysis would not be expected to offer any advantages over a CC analysis in this situation. This was true regardless of the missing data mechanism (MCAR - missing completely at random, MAR - missing at random, or NMAR - not missing at random) underlying the missing values. Surprisingly, recent textbooks dealing with MI make little reference to this limitation of MI for dealing with missing values in the dependent variable.An additional simulation study (1000 runs for each of the three missing data mechanisms) compared MI and CC analyses for data in which varying levels (n = 7) of missing data were created in predictor variables. This study showed that MI analyses generally produced results that were less biased on average, were more precise (smaller SEs), were more consistent (less variability between simulation runs) and consequently were more likely to produce estimates that were close to the "truth" (results obtained from a data set with no missing values). While the benefit of MI varied with the mechanism used to generate the missing data, MI always performed as well as, or better than; CC analysis

Canine atopic dermatitis: validation of recorded diagnosis against practice records in 335 insured Swedish dogs

A cross-sectional study of insured Swedish dogs with a recorded diagnosis of canine atopic dermatitis (CAD) was performed. In order to validate the correctness of this specific diagnosis in the insurance database, medical records were requested by mail from the attending veterinarians. All dogs with a reimbursed claim for the disease during 2002 were included in the original study sample (n = 373). Medical records were available for 335 individuals (response rate: 89.8%). By scrutinizing the submitted records it was determined that all dogs had been treated for dermatologic disease, and that 327 (97.6%) could be considered to have some allergic skin disease. However, as information regarding dietary trial testing was missing in many dogs the number that were truly atopic could not be determined. The clinical presentation and nature of test diet for dogs with or without response to dietary trial testing was compared for a subset of 109 individuals that had undergone such testing. The only significant difference between these two groups was that the proportion of dogs with reported gastrointestinal signs was higher in the group that subsequently responded to a diet trial. In conclusion, the agreement between the recorded diagnosis in the insurance database and the clinical manifestations recorded in the submitted medical records was considered acceptable. The concern was raised that many attending veterinarians did not exclude cutaneous adverse food reactions before making the diagnosis of CAD

Evaluation of two dairy herd reproductive performance indicators that are adjusted for voluntary waiting period

<p>Abstract</p> <p>Background</p> <p>Overall reproductive performance of dairy herds is monitored by various indicators. Most of them do not consider all eligible animals and do not consider different management strategies at farm level. This problem can be alleviated by measuring the proportion of pregnant cows by specific intervals after their calving date or after a fixed time period, such as the voluntary waiting period. The aim of this study was to evaluate two reproductive performance indicators that consider the voluntary waiting period at the herd. The two indicators were: percentage of pregnant cows in the herd after the voluntary waiting period plus 30 days (PV30) and percentage of inseminated cows in the herd after the voluntary waiting period plus 30 days (IV30). We wanted to assess how PV30 and IV30 perform in a simulation of herds with different reproductive management and physiology and to compare them to indicators of reproductive performance that do not consider the herd voluntary waiting period.</p> <p>Methods</p> <p>To evaluate the reproductive indicators we used the SimHerd-program, a stochastic simulation model, and 18 scenarios were simulated. The scenarios were designed by altering the reproductive management efficiency and the status of reproductive physiology of the herd. Logistic regression models, together with receiver operating characteristics (ROC), were used to examine how well the reproductive performance indicators could discriminate between herds of different levels of reproductive management efficiency or reproductive physiology.</p> <p>Results</p> <p>The logistic regression models with the ROC analysis showed that IV30 was the indicator that best discriminated between different levels of management efficiency followed by PV30, calving interval, 200-days not-in calf-rate (NotIC200), in calf rate at100-days (IC100) and a fertility index. For reproductive physiology the ROC analysis showed that the fertility index was the indicator that best discriminated between different levels, followed by PV30, NotIC200, IC100 and the calving interval. IV30 could not discriminate between the two levels.</p> <p>Conclusion</p> <p>PV30 is the single best performance indicator for estimating the level of both herd management efficiency and reproductive physiology followed by NotIC200 and IC100. This indicates that PV30 could be a potential candidate for inclusion in dairy herd improvement schemes.</p

Evaluation of LHP® (1% hydrogen peroxide) cream versus petrolatum and untreated controls in open wounds in healthy horses: a randomized, blinded control study

<p>Abstract</p> <p>Background</p> <p>Treatment and protection of wounds in horses can be challenging; protecting bandages may be difficult to apply on the proximal extremities and the body. Unprotected wounds carry an increased risk of bacterial contamination and subsequent infection which can lead to delayed wound healing. Topical treatment with antimicrobials is one possibility to prevent bacterial colonization or infection, but the frequent use of antimicrobials ultimately leads to development of bacterial resistance which is an increasing concern in both human and veterinary medicine.</p> <p>Methods</p> <p>Standardized wounds were created in 10 Standardbred mares. Three wounds were made in each horse. Two wounds were randomly treated with LHP^®or petrolatum and the third wound served as untreated control. All wounds were assessed daily until complete epithelization. Protocol data were recorded on day 2, 6, 11, 16, 21 and 28. Data included clinical scores for inflammation and healing, photoplanimetry for calculating wound areas and swab cytology to assess bacterial colonization and inflammation. Bacterial cultures were obtained on day 2, 6 and 16.</p> <p>Results</p> <p>Mean time to complete healing for LHP^®treated wounds was 32 days (95%CI = 26.9-37.7). Mean time to complete healing for petrolatum and untreated control wounds were 41.6 days (95%CI = 36.2-47.0) and 44.0 days (95%CI = 38.6-49.4) respectively. Wound healing occurred significantly faster in LHP^®wounds compared to both petrolatum (p = 0.0004) and untreated controls (p < 0.0001). There was no significant difference in time for healing between petrolatum and untreated controls. Total scores for bacteria and neutrophils were significantly (p < 0.0001) lower for LHP^®treated wounds compared to petrolatum from day 16 and onwards. <it>Staphylococcus aureus </it>and <it>Streptococcus zooepidemicus </it>were only found in cultures from petrolatum treated wounds and untreated controls.</p> <p>Conclusions</p> <p>Treatment with LHP^®reduced bacterial colonization and was associated with earlier complete wound healing. LHP^®cream appears to be safe and effective for topical wound treatment or wound protection.</p