Catching Up to the Technology Frontier: The Dichotomy between Innovation and Imitation

Using data for 55 developing and developed countries, this research examines the roles of technology transfer, research intensity, educational attainment and the ability to absorb foreign technology in explaining cross-country differences in productivity growth. The results show that innovation is an important factor for growth in OECD countries whereas growth in developing countries is driven by imitation. Furthermore the interaction between educational attainment and the distance to the frontier is a significant determinant of growth in the overall sample.R&D; endogenous growth theory; absorptive capacity

Individual variation and repeatability of methane production from dairy cows estimated by the CO₂ method in automatic milking system

The objectives of this study were to investigate the individual variation, repeatability and correlation of methane (CH(4)) production from dairy cows measured during 2 different years. A total of 21 dairy cows with an average BW of 619±14.2 kg and average milk production of 29.1±6.5 kg/day (mean±s.d.) were used in the 1(st) year. During the 2(nd) year, the same cows were used with an average BW of 640±8.0 kg and average milk production of 33.4±6.0 kg/day (mean±s.d.). The cows were housed in a loose housing system fitted with an automatic milking system (AMS). A total mixed ration was fed to the cows ad libitum in both years. In addition, they were offered concentrate in the AMS based on their daily milk yield. The CH(4) and CO(2) production levels of the cows were analysed using a Gasmet DX-4030. The estimated dry matter intake (EDMI) was 19.8±0.96 and 23.1±0.78 (mean±s.d.), and the energy-corrected milk (ECM) production was 30.8±8.03 and 33.7±5.25 kg/day (mean±s.d.) during the 1(st) and 2(nd) year, respectively. The EDMI and ECM had a significant influence (P<0.001) on the CH(4) (l/day) yield during both years. The daily CH(4) (l/day) production was significantly higher (P<0.05) during the 2(nd) year compared with the 1(st) year. The EDMI (described by the ECM) appeared to be the key factor in the variation of CH(4) release. A correlation (r=0.54) of CH(4) production was observed between the years. The CH(4) (l/day) production was strongly correlated (r=0.70) between the 2 years with an adjusted ECM production (30 kg/day). The diurnal variation of CH(4) (l/h) production showed significantly lower (P<0.05) emission during the night (0000 to 0800 h). The between-cows variation of CH(4) (l/day, l/kg EDMI and l/kg ECM) was lower compared with the within-cow variation for the 1(st) and 2(nd) years. The repeatability of CH(4) production (l/day) was 0.51 between 2 years. In conclusion, a higher EDMI (kg/day) followed by a higher ECM (kg/day) showed a higher CH(4) production (l/day) in the 2(nd) year. The variations of CH(4) (l/day) among the cows were lower than the within-cow variations. The CH(4) (l/day) production was highly repeatable and, with an adjusted ECM production, was correlated between the years

Comparative methane estimation from cattle based on total CO₂ production using different techniques

The objective of this study was to compare the precision of CH4 estimates using calculated CO2 (HP) by the CO2 method (CO2T) and measured CO2 in the respiration chamber (CO2R). The CO2R and CO2T study was conducted as a 3 × 3 Latin square design where 3 Dexter heifers were allocated to metabolic cages for 3 periods. Each period consisted of 2 weeks of adaptation followed by 1 week of measurement with the CO2R and CO2T. The average body weight of the heifer was 226 ± 11 kg (means ± SD). They were fed a total mixed ration, twice daily, with 1 of 3 supplements: wheat (W), molasses (M), or molasses mixed with sodium bicarbonate (Mbic). The dry mater intake (DMI; kg/day) was significantly greater (P < 0.001) in the metabolic cage compared with that in the respiration chamber. The daily CH4 (L/day) emission was strongly correlated (r = 0.78) between CO2T and CO2R. The daily CH4 (L/kg DMI) emission by the CO2T was in the same magnitude as by the CO2R. The measured CO2 (L/day) production in the respiration chamber was not different (P = 0.39) from the calculated CO2 production using the CO2T. This result concludes a reasonable accuracy and precision of CH4 estimation by the CO2T compared with the CO2R

Determining Knee Loading for Abnormal Gait

The purpose of this study was to take known experimental loads throughout normal gait and to find the corresponding loading at the knee for both normal gait and abnormal gait. Abnormal gait was defined as a person with varus, i.e. “bowleggedness”, or a person who had an external rotation of the femur (or the inability to internally rotate the femur) which caused an indirect varus in the forward positions of gait. This problem was approached by imposing static equilibrium on the femur. This allowed the loads at the knee to be calculated from the loading at the hip. In order to find the forces for abnormal gait, the angular movement of the femur from the normal location was determined. Then, the forces applied to the femoral head were rotated in relation to the femur in order to simulate where the force would be applied when the bone was in the new position for abnormal gait. Once the forces at the hip were rotated about the femoral head, the loading at the knee for each of the cases was determined. The code written allows a user to define the amount of varus and external rotation. The user can then see a graphical representation of the loading through the gait cycle on the knee. Additionally, the maximum loading cases of gait at the knee are recorded and shown. The key thing noted in the results was an increase in adduction moment for the abnormal gait cases in comparison to the normal gait. Understanding knee loading for abnormal gait will help design engineers understand the range of loading conditions of knee implants in-vivo

Psychosocial work factors and blood pressure among 63 800 employees from The Netherlands in the Lifelines Cohort Study

OBJECTIVES: Previous studies on the association between psychosocial work factors and blood pressure mainly focused on specific occupations or populations and had limited sample sizes. We, therefore, investigated the associations between psychosocial work factors and blood pressure in a large general working population in the Netherlands. METHODS: We included 63 800 employees from the Netherlands, aged 18–65 years, with blood pressure measurements and a reliable job code at baseline. Psychosocial work factors (job strain, effort–reward imbalance (ERI) and emotional demands) in the current job were estimated with three recently developed psychosocial job exposure matrices. To examine the associations, regression analyses adjusted for covariates (age, sex, body mass index, education, monthly income, pack-years, smoking, alcohol consumption and antihypertensive medication (not included for hypertension)) were performed. RESULTS: Higher job strain was associated with higher systolic blood pressure (SBP) (B (regression coefficients) (95% CI) 2.14 (1.23 to 3.06)) and diastolic blood pressure (DBP) (B (95% CI) 1.26 (0.65 to 1.86)) and with higher odds of hypertension (OR (95% CI) 1.43 (1.17 to 1.74)). Higher ERI was associated with higher DBP (B (95% CI) 4.37 (3.05 to 5.68)), but not with SBP or hypertension. Higher emotional demands were associated with lower SBP (B (95% CI) −0.90 (−1.14 to −0.66)) and lower odds of hypertension ((OR) (95% CI) 0.91 (0.87 to 0.96)). CONCLUSIONS: In the general working population, employees in jobs with high job strain and ERI have higher blood pressure compared with employees with low job strain and ERI. Emotional demands at work are inversely associated with blood pressure

Polyandrous females avoid costs of inbreeding

Why do females typically mate with more than one male? Female mating patterns have broad implications for sexual selection, speciation and conflicts of interest between the sexes, and yet they are poorly understood. Matings inevitably have costs, and for females, the benefits of taking more than one mate are rarely obvious. One possible explanation is that females gain benefits because they can avoid using sperm from genetically incompatible males, or invest less in the offspring of such males. It has been shown that mating with more than one male can increase offspring viability, but we present the first clear demonstration that this occurs because females with several mates avoid the negative effects of genetic incompatibility. We show that in crickets, the eggs of females that mate only with siblings have decreased hatching success. However, if females mate with both a sibling and a non-sibling they avoid altogether the low egg viability associated with sibling matings. If similar effects occur in other species, inbreeding avoidance may be important in understanding the prevalence of multiple mating

No apparent transmission of livestock-associated methicillin-resistant Staphylococcus aureus CC398 in a survey of staff at a regional Danish hospital

Abstract Background In recent years, livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) multi locus sequence type CC398 has spread widely in the livestock production in Europe. The rates of LA-MRSA in hospitals have been found to be largely determined by contact to and density of livestock in the area. Methods This is a cross sectional study of the prevalence of LA-MRSA among hospital staff in a Danish hospital situated in a livestock production region. We analysed nasal swabs, air and dust samples for the presence of MRSA using PCR and mass spectrometry. Results Of 1745 employees, 545 (31%) contributed nasal swabs. MRSA was not detected in any participant, nor was it detected in air or dust at the hospital or in houses of employees living on farms. Four percent of the participants had contact to pigs either directly or through household members. LA-MRSA was detected in two of 26 samples from animal sheds, both of them from pig farms. The participation rate was relatively low, but participants were representative for the source population with regards to animal contact and job titles. Conclusions The study suggests a low point prevalence of LA-MRSA carriage in Danish hospital staff even in regions where livestock production is dense. Should more studies confirm our findings we see no need for additional hospital precautions towards LA-MRSA in Denmark at the moment. We think that our data might reduce potential stigmatization of hospital workers with contact to LA-MRSA positive farms at their work places and in their communities

No Detectable Fertility Benefit from a Single Additional Mating in Wild Stalk-Eyed Flies

Background: Multiple mating by female insects is widespread, and the explanation(s) for repeated mating by females has been the subject of much discussion. Females may profit from mating multiply through direct material benefits that increase their own reproductive output, or indirect genetic benefits that increase offspring fitness. One particular direct benefit that has attracted significant attention is that of fertility assurance, as females often need to mate multiply to achieve high fertility. This hypothesis has never been tested in a wild insect population.Methodology/Principal Findings: Female Malaysian stalk-eyed flies (Teleopsis dalmanni) mate repeatedly during their lifetime, and have been shown to be sperm limited under both laboratory and field conditions. Here we ask whether receiving an additional mating alleviates sperm limitation in wild females. In our experiment one group of females received a single additional mating, while a control group received an interrupted, and therefore unsuccessful, mating. Females that received an additional mating did not lay more fertilised eggs in total, nor did they lay proportionately more fertilised eggs. Female fertility declined significantly through time, demonstrating that females were sperm limited. However, receipt of an additional mating did not significantly alter the rate of this decline.Conclusions/Significance: Our data suggest that the fertility consequences of a single additional mating were small. We discuss this effect (or lack thereof), and suggest that it is likely to be attributed to small ejaculate size, a high proportion of failed copulations, and the presence of X-linked meiotic drive in this species