The Effects of Intensive Early Stocking and Early Weaning on the Onset of Puberty and Reproductive Success in Beef Replacement Heifers

Management practices utilizing genetics, nutrition, and growth have commonly been studied to maximize the lifetime productivity of female beef cattle. However, heifers managed to have their first calf by 24 months of age have the greatest chance of achieving maximum lifetime productivity. One way for a heifer to calve by 24 months of age is to decrease the age at which she reaches puberty. Heifers reaching puberty 1 to 3 months before exposure to breeding maximized conception success, as was shown when heifers bred during their third estrus were 21% more likely to conceive than heifers that were bred during their first or second estrus. Also, heifers fed a high-energy diet during the post-weaning period displayed a decreased age at puberty and an increased pregnancy rate. Additionally, early-weaned heifers fed a high-energy diet at an early age reached puberty at younger ages than those fed a low-energy control diet or those fed a high-energy diet beginning at six months of age. We hypothesized that heifers that were weaned at 120 days of age and provided a high-energy diet compared to the diet consumed by heifers weaned at a more conventional time of 205 days of age would display puberty at an earlier age and have improved first service conception and overall pregnancy rate

Effect of Feeding Interval on Finishing Performance of Beef Steers

It has long been accepted that optimal performance in beef cattle occurs when cattle are fed at a similar time each day. In fact, in Frederick Mumford’s Syllabus of Illustrated Lecture on Profitable Cattle Feeding published by the U.S. Department of Agriculture in 1905, Mr. Mumford stated, “Cattle should be fed at certain hours and in the same way. This cannot be varied 15 minutes without some detriment to the cattle.” Little research has been conducted examining interval of feed delivery. Most feedlot research examining feed delivery has focused on the comparison of once or twice daily feed delivery on animal performance. The current research examined beef steer finishing performance with stable or variable once daily feed delivery

American political affiliation, 2003–43: a cohort component projection

The recent rise and stability in American party identification has focused interest on the long-term dynamics of party bases. Liberal commentators cite immigration and youth as forces which will produce a natural Democratic advantage in the future while conservative writers highlight the importance of high Republican fertility in securing Republican growth. These concerns foreground the neglect of demography within political science. This paper addresses this omission by conducting the first ever cohort component projection of American partisan populations to 2043 based on survey and census data. A number of scenarios are modeled, but, on current trends, we predict that American partisanship will shift much less than the nation’s ethnic composition because the parties’ age structures are similar. Still, our projections find that the Democrats gain two to three percentage points from the Republicans by 2043, mainly through immigration, though Republican fertility may redress the balance in the very long term

Decadal shifts in soil pH and organic matter differ between land uses in contrasting regions in China

Soil organic matter (SOM) and pH are critical soil properties strongly linked to carbon storage, nutrient cycling and crop productivity. Land use is known to have a dominant impact on these key soil properties, but we often lack the ability to examine temporal trajectories across extensive spatial scales. Large-scale monitoring programmes provide the data to evaluate these longer-term changes, and under different climatic conditions. This study used data from Chinese soil surveys to examine changes in soil pH and SOM across different land uses (dry farmland, paddy fields, grassland, woodland, unused land), with surface soil (0–20 cm) collected in the periods 1985–90 (Survey 1; 890 samples) and 2006–10 (Survey 2; 5005 samples) from two contrasting areas. In the southern part of China the mean pH of paddy soils fell sharply over the two decades between surveys - from pH 5.81 to 5.19 (p < 0.001), while dry farmlands in the northern sampling area fell slightly (from pH 8.15 to 7.82; p < 0.001). The mean SOM content of dry farmland soil rose in both areas and the mean SOM of paddy fields in the southern area also rose (all p < 0.001). Woodland soil pH in the south showed an increase from 4.71 to 5.29 (p < 0.001) but no significant difference was measured in the woodlands of the northern area, although the trend increased. The SOM content of woodland top soils rose in the northern (p = 0.003) and southern (p < 0.001) study areas. The implications and potential causes of these changes over the two decade timespan between surveys are discussed and suggestions made as to how large scale soil sampling campaigns can be designed to monitor for changes and potential controlling factors

Changing Natural History of HER2–Positive Breast Cancer Metastatic to the Brain in the Era of New Targeted Therapies

Patients with breast cancer brain metastases historically have a poor prognosis. In this single-institution cohort study of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer brain metastases, we found no improvement in survival after brain recurrence over time despite wide adoption of HER2–targeted therapies. This highlights the importance of continued development of novel brain penetrant therapies for patients with HER2–positive metastatic disease to extend survival and improve quality of life. Background: Given the wide adoption of human epidermal growth factor receptor 2 (HER2)-targeted therapies for advanced HER2–positive breast cancer, we studied the natural history of patients with HER2–positive breast cancer brain metastases (BCBM) over time. Patients and Methods: Patients with HER2–positive BCBM identified from a prospectively maintained database at the University of North Carolina were divided into 3 cohorts by year of BCBM diagnosis. Cohorts were selected by year of HER2–targeted therapy US Food and Drug Administration approval. Overall survival (OS), time to first metastasis, time to BCBM, and BCBM survival were estimated by the Kaplan-Meier method. Associations between OS after BCBM and clinical variables were assessed by Cox proportional hazards regression models. Results: One hundred twenty-three patients were identified. Median age was 51 years, and 58% were white and 31% African American. OS from initial breast cancer diagnosis improved over time: 3.6 years (95% confidence interval [CI], 2.8-6.1) in the 1998-2007 cohort, 6.6 years (95% CI, 4.5-8.6) in the 2008-2012 cohort, and 7.6 years (95% CI, 4.4-9.6) in the 2013-2015 cohort (P =.05). While time from initial diagnosis to first metastasis did not differ (P =.12), time to BCBM increased over time (2.6 years [95% CI, 1.3-3.5] for 1998-2007; 2.6 years [95% CI, 2.1-4.3] for 2008-2012, and 3.3 years [95% CI, 2.2-6] for 2013-2015; P =.05). Although OS from BCBM did not significantly differ by cohort, patients who received HER2–targeted therapy after BCBM had a prolonged OS (2.1 years [95% CI, 1.6-2.6] vs. 0.65 years [95% CI, 0.4-1.3]; P =.001). Conclusion: OS from initial breast cancer diagnosis significantly improved over time for patients with HER2–positive breast cancer who develop BCBM, now exceeding 7 years; survival from BCBM diagnosis may now exceed 2 years

A high-risk, Double-Hit, group of newly diagnosed myeloma identified by genomic analysis

Patients with newly diagnosed multiple myeloma (NDMM) with high-risk disease are in need of new treatment strategies to improve the outcomes. Multiple clinical, cytogenetic, or gene expression features have been used to identify high-risk patients, each of which has significant weaknesses. Inclusion of molecular features into risk stratification could resolve the current challenges. In a genome-wide analysis of the largest set of molecular and clinical data established to date from NDMM, as part of the Myeloma Genome Project, we have defined DNA drivers of aggressive clinical behavior. Whole-genome and exome data from 1273 NDMM patients identified genetic factors that contribute significantly to progression free survival (PFS) and overall survival (OS) (cumulative R2 = 18.4% and 25.2%, respectively). Integrating DNA drivers and clinical data into a Cox model using 784 patients with ISS, age, PFS, OS, and genomic data, the model has a cumlative R2 of 34.3% for PFS and 46.5% for OS. A high-risk subgroup was defined by recursive partitioning using either a) bi-allelic TP53 inactivation or b) amplification (≥4 copies) of CKS1B (1q21) on the background of International Staging System III, comprising 6.1% of the population (median PFS = 15.4 months; OS = 20.7 months) that was validated in an independent dataset. Double-Hit patients have a dire prognosis despite modern therapies and should be considered for novel therapeutic approaches