A survey of dystocia in the Boxer breed

BACKGROUND: Dystocia occurs more commonly in some breeds of dogs than others. The Boxer breed is one of the highrisk breeds for whelping problems. The aim of this study was to document some reproductive parameters and the frequency of dystocia in Boxers. METHODS: Two questionnaires were sent to the breeders of Boxers in Sweden during 1994 to 1997. Data from 253 whelpings and 1671 pups was received, which constitutes 56.5% of all Boxer litters registered with the Swedish Kennel Club during these years. Data was analysed using Chi-square test, and Fischer's exact test. RESULTS: Dystocia occurred in 32% of the individual bitches, and in 27.7% of all the whelpings. Caesarian section was performed in 22.8% of all the whelpings and in 80.1% of the cases of dystocia. Medical treatment was tried in 20 cases but was successful only in 5 (25%). The dystocia was of maternal origin in 68.6% and of fetal origin in 28.6% of cases. The most common reasons for dystocia were primary uterine inertia (60%) and malpresentation of the fetus (26%). Dystocia increased with increasing age of the bitch from four years of age. Average litter size was 6.6 (± 2.2) pups born, and 5.0 (± 2.1) pups registered. Pup mortality was 24%. Stillbirths accounted for 6.1% of the pup deaths and 1% died in the neonatal period, while 15.6% of the pups were euthanised, the majority because they had disqualifying white coat colour. Cryptorchidism was observed in 9.8% of the male pups born and in 13.4% of the male pups that were registered. CONCLUSION: The Boxer suffers a high frequency of dystocia, mainly due to uterine inertia, but also fetal malpresentation. Breeders should be adviced to include easy whelpings in their breeding program

Nonlinear Interactions Between Gravitational Radiation and Modified Alfven Modes in Astrophysical Dusty Plasmas

We present an investigation of nonlinear interactions between Gravitational Radiation and modified Alfv\'{e}n modes in astrophysical dusty plasmas. Assuming that stationary charged dust grains form neutralizing background in an electron-ion-dust plasma, we obtain the three wave coupling coefficients, and calculate the growth rates for parametrically coupled gravitational radiation and modified Alfv\'{e}n-Rao modes. The threshold value of the gravitational wave amplitude associated with convective stabilization is particularly small if the gravitational frequency is close to twice the modified Alfv\'en wave-frequency. The implication of our results to astrophysical dusty plasmas is discussed.Comment: A few typos corrected. Published in Phys. Rev.

Longitudinal associations between incident lumbar spine MRI findings and chronic low back pain or radicular symptoms: retrospective analysis of data from the longitudinal assessment of imaging and disability of the back (LAIDBACK)

BACKGROUND: There are few longitudinal cohort studies examining associations between incident MRI findings and incident spine-related symptom outcomes. Prior studies do not discriminate between the two distinct outcomes of low back pain (LBP) and radicular symptoms. To address this gap in the literature, we conducted a secondary analysis of existing data from the Longitudinal Assessment of Imaging and Disability of the Back (LAIDBACK). The purpose of this study was to examine the association of incident lumbar MRI findings with two specific spine-related symptom outcomes: 1) incident chronic bothersome LBP, and 2) incident radicular symptoms such as pain, weakness, or sensation alterations in the lower extremity. METHODS: The original LAIDBACK study followed 123 participants without current LBP or sciatica, administering standardized MRI assessments of the lumbar spine at baseline and at 3-year follow-up, and collecting information on participant-reported spine-related symptoms and signs every 4 months for 3 years. These analyses examined bivariable and multivariable associations between incident MRI findings and symptom outcomes (LBP and radicular symptoms) using logistic regression. RESULTS: Three-year cumulative incidence of new MRI findings ranged between 2 and 8%, depending on the finding. Incident annular fissures were associated with incident chronic LBP, after adjustment for prior back pain and depression (adjusted odds ratio [OR] 6.6; 95% confidence interval [CI] 1.2-36.9). All participants with incident disc extrusions (OR 5.4) and nerve root impingement (OR 4.1) reported incident radicular symptoms, although associations were not statistically significant. No other incident MRI findings showed large magnitude associations with symptoms. CONCLUSIONS: Even when applying more specific definitions for spine-related symptom outcomes, few MRI findings showed large magnitude associations with symptom outcomes. Although incident annular fissures, disc extrusions, and nerve root impingement were associated with incident symptom outcomes, the 3-year incidence of these MRI findings was extremely low, and did not explain the vast majority of incident symptom cases

Precision measurements of Linear Scattering Density using Muon Tomography

We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.Comment: 16 pages, 4 figure