23 research outputs found
Yield gap analysis to identify attainable milk and meat productivities and the potential for greenhouse gas emissions mitigation in cattle systems of Colombia
CONTEXT
Colombia has a total of 27.2 million heads of cattle, ranking fourth among the Latin American countries. Identifying sustainable strategies to mitigate greenhouse gas emissions (GHGE) will help the Colombian government meet their goal of a 51% reduction in national emissions by 2030. Estimation of yield gaps for identifying the potential to improve cattle farms productivity and efficiency in Colombia help on reducing the GHGE intensities from the cattle sector.
OBJECTIVE
This paper aims to calculate the gap between attainable and actual milk and meat yields for specialized dairy, dual-purpose, cow-calf, and fattening production systems in 3 agro-ecological zones (AEZ) in Colombia; to identify the main aspects that restrict the meat and milk yields in these production systems; and analyze how closing yield gaps affect the carbon footprint (CF) of meat and milk production.
METHODS
The most suitable AEZs for cattle activities were identified by considering environmental, climatic, edaphic, and land characteristics. From a dataset of 1505 surveyed farms, a yield gap benchmarking analysis for estimating the potential to increase meat and milk yields in each of the identified AEZ was applied. The most productive farms were included in the âbest farmsâ while the rest of the farms belonged to the âfarms operating below potentialâ. A âcradle to farm-gateâ Life Cycle Assessment was used to calculate the CF. Three scenarios were proposed for closing the yield gaps by 50, 75, and 100%, between the two groups of farms.
RESULTS AND CONCLUSIONS
Three AEZs likely to support cattle activities in Colombia were identified. Average milk production from the farms operating below potential was 45â50% of potential production, and meat was 34â51%, indicating that a potential to achieve increases in milk and meat productivity exists. CFs of 1 kg milk or meat were lower in the groups of best-performing farms than in the groups of farms operating below potential. Yield gaps for milk and meat production can be closed by improving cattle management practices and better technologies. As a general trend, closing the yield gaps decreases the CFs.
SIGNIFICANCE
Our findings contribute to understand the farms' current productive performance and provides key insights into the possible technological and managerial changes for improving the productivity of cattle systems in Colombia. In addition, the study showed how milk and meat CFs can be lowered with the adoption of proper cattle management practices, and better technologies
Genetic variation in a member of the laminin gene family affects variation in body composition in Drosophila and humans
<p>Abstract</p> <p>Background</p> <p>The objective of the present study was to map candidate loci influencing naturally occurring variation in triacylglycerol (TAG) storage using quantitative complementation procedures in <it>Drosophila melanogaster</it>. Based on our results from <it>Drosophila</it>, we performed a human population-based association study to investigate the effect of natural variation in <it>LAMA5 </it>gene on body composition in humans.</p> <p>Results</p> <p>We identified four candidate genes that contributed to differences in TAG storage between two strains of <it>D. melanogaster</it>, including <it>Laminin A </it>(<it>LanA</it>), which is a member of the α subfamily of laminin chains. We confirmed the effects of this gene using a viable <it>LanA </it>mutant and showed that female flies homozygous for the mutation had significantly lower TAG storage, body weight, and total protein content than control flies. <it>Drosophila LanA </it>is closely related to human <it>LAMA5 </it>gene, which maps to the well-replicated obesity-linkage region on chromosome 20q13.2-q13.3. We tested for association between three common single nucleotide polymorphisms (SNPs) in the human <it>LAMA5 </it>gene and variation in body composition and lipid profile traits in a cohort of unrelated women of European American (EA) and African American (AA) descent. In both ethnic groups, we found that SNP rs659822 was associated with weight (EA: <it>P </it>= 0.008; AA: <it>P </it>= 0.05) and lean mass (EA: <it>P= </it>0.003; AA: <it>P </it>= 0.03). We also found this SNP to be associated with height (<it>P </it>= 0.01), total fat mass (<it>P </it>= 0.01), and HDL-cholesterol (<it>P </it>= 0.003) but only in EA women. Finally, significant associations of SNP rs944895 with serum TAG levels (<it>P </it>= 0.02) and HDL-cholesterol (<it>P </it>= 0.03) were observed in AA women.</p> <p>Conclusion</p> <p>Our results suggest an evolutionarily conserved role of a member of the laminin gene family in contributing to variation in weight and body composition.</p
Novel anticancer therapeutics targeting telomerase
Telomeres are protective caps at the ends of human chromosomes. Telomeres shorten with each successive cell division in normal human cells whereas, in tumors, they are continuously elongated by human telomerase reverse transcriptase (hTERT). Telomerase is overexpressed in 80-95% of cancers and is present in very low levels or is almost undetectable in normal cells. Because telomerase plays a pivotal role in cancer cell growth it may serve as an ideal target for anticancer therapeutics. Inhibition of telomerase may lead to a decrease of telomere length resulting in cell senescence and apoptosis in telomerase positive tumors. Several strategies of telomerase inhibition are reviewed, including small molecule inhibitors, antisense oligonucleotides, immunotherapies and gene therapies, targeting the hTERT or the ribonucleoprotein subunit hTER. G-quadruplex stabilizers, tankyrase and HSP90 inhibitors targeting telomere and telomerase assembly, and T-oligo approach are also covered. Based on this review, the most promising current telomerase targeting therapeutics are the antisense oligonucleotide inhibitor GRN163L and immunotherapies that use dendritic cells (GRVAC1), hTERT peptide (GV1001) or cryptic peptides (Vx-001). Most of these agents have entered phase I and II clinical trials in patients with various tumors, and have shown good response rates as evidenced by a reduction in tumor cell growth, increased overall disease survival, disease stabilization in advanced staged tumors and complete/partial responses. Most therapeutics have shown to be more effective when used in combination with standard therapies, resulting in concomitant telomere shortening and tumor mass shrinkage, as well as preventing tumor relapse and resistance to single agent therapy
Novel anticancer therapeutics targeting telomerase
Telomeres are protective caps at the ends of human chromosomes. Telomeres shorten with each successive cell division in normal human cells whereas, in tumors, they are continuously elongated by human telomerase reverse transcriptase (hTERT). Telomerase is overexpressed in 80-95% of cancers and is present in very low levels or is almost undetectable in normal cells. Because telomerase plays a pivotal role in cancer cell growth it may serve as an ideal target for anticancer therapeutics. Inhibition of telomerase may lead to a decrease of telomere length resulting in cell senescence and apoptosis in telomerase positive tumors. Several strategies of telomerase inhibition are reviewed, including small molecule inhibitors, antisense oligonucleotides, immunotherapies and gene therapies, targeting the hTERT or the ribonucleoprotein subunit hTER. G-quadruplex stabilizers, tankyrase and HSP90 inhibitors targeting telomere and telomerase assembly, and T-oligo approach are also covered. Based on this review, the most promising current telomerase targeting therapeutics are the antisense oligonucleotide inhibitor GRN163L and immunotherapies that use dendritic cells (GRVAC1), hTERT peptide (GV1001) or cryptic peptides (Vx-001). Most of these agents have entered phase I and II clinical trials in patients with various tumors, and have shown good response rates as evidenced by a reduction in tumor cell growth, increased overall disease survival, disease stabilization in advanced staged tumors and complete/partial responses. Most therapeutics have shown to be more effective when used in combination with standard therapies, resulting in concomitant telomere shortening and tumor mass shrinkage, as well as preventing tumor relapse and resistance to single agent therapy
Introduction to âBest Practices in Psychosocial Healthcare: Complexity, Compromise, and Innovationâ
Yield gap analysis to identify attainable productivities and greenhouse gas emissions reductions in Colombian cattle systems
Race and BMI modify associations of calcium and vitamin D intake with prostate cancer
Background: African Americans have disproportionately higher burden of prostate cancer compared to European Americans. However, the cause of prostate cancer disparities is still unclear. Several roles have been proposed for calcium and vitamin D in prostate cancer pathogenesis and progression, but epidemiologic studies have been conducted mainly in European descent populations. Here we investigated the association of calcium and vitamin D intake with prostate cancer in multiethnic samples. Methods: A total of 1,657 prostate cancer patients who underwent screening and healthy controls (888 African Americans, 620 European Americans, 111 Hispanic Americans, and 38 others) from Chicago, IL and Washington, D.C. were included in this study. Calcium and vitamin D intake were evaluated using food frequency questionnaire. We performed unconditional logistic regression analyses adjusting for relevant variables. Results: In the pooled data set, high calcium intake was significantly associated with higher odds for aggressive prostate cancer (ORQuartile (1 vs. Quartile) (4) = 1.98, 95% C.I.: 1.01-3.91), while high vitamin D intake was associated with lower odds of aggressive prostate cancer (ORQuartile 1 vs. Quartile (4) = 0.38, 95% C.I.: 0.18-0.79). In African Americans, the association between high calcium intake and aggressive prostate cancer was statistically significant (ORQuartile 1 vs. Quartile 4 = 4.28, 95% C.I.: 1.70-10.80). We also observed a strong inverse association between total vitamin D intake and prostate cancer in African Americans (ORQuartile 1 vs. Quartile 4 = 0.06, 95% C.I.: 0.02-0.54). In European Americas, we did not observe any significant associations between either calcium or vitamin D intake and prostate cancer. In analyses stratifying participants based on Body Mass Index (BMI), we observed a strong positive association between calcium and aggressive prostate cancer and a strong inverse association between vitamin D intake and aggressive prostate cancer among men with low BMI (= 27.8 kg/m(2)). Interactions of race and BMI with vitamin D intake were significant (P-Interaction < 0.05). Conclusion: Calcium intake was positively associated with aggressive prostate cancer, while vitamin D intake exhibited an inverse relationship. However, these associations varied by race/ethnicity and BMI. The findings from this study may help develop better prostate cancer prevention and management strategies.National Institutes of Health [1R01MD007105-01]; US Department of Defense [W81XWH-10-1-0532]; Veterans Health Administration [1IK2CX000926-01]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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Genetic loci associated with skin pigmentation in African Americans and their effects on vitamin D deficiency
A recent genome-wide association study (GWAS) in African descent populations identified novel loci associated with skin pigmentation. However, how genomic variations affect skin pigmentation and how these skin pigmentation gene variants affect serum 25(OH) vitamin D variation has not been explored in African Americans (AAs). In order to further understand genetic factors that affect human skin pigmentation and serum 25(OH)D variation, we performed a GWAS for skin pigmentation with 395 AAs and a replication study with 681 AAs. Then, we tested if the identified variants are associated with serum 25(OH) D concentrations in a subset of AAs (n = 591). Skin pigmentation, Melanin Index (M-Index), was measured using a narrow-band reflectometer. Multiple regression analysis was performed to identify variants associated with M-Index and to assess their role in serum 25(OH)D variation adjusting for population stratification and relevant confounding variables. A variant near the SLC24A5 gene (rs2675345) showed the strongest signal of association with M-Index (P = 4.0 x 10â30 in the pooled dataset). Variants in SLC24A5, SLC45A2 and OCA2 together account for a large proportion of skin pigmentation variance (11%). The effects of these variants on M-Index was modified by sex (P for interaction = 0.009). However, West African Ancestry (WAA) also accounts for a large proportion of M-Index variance (23%). M-Index also varies among AAs with high WAA and high Genetic Score calculated from top variants associated with M-Index, suggesting that other unknown genomic factors related to WAA are likely contributing to skin pigmentation variation. M-Index was not associated with serum 25(OH)D concentrations, but the Genetic Score was significantly associated with vitamin D deficiency (serum 25(OH)D levels less than 12 ng/mL) (OR, 1.30; 95% CI, 1.04â1.64). The findings support the hypothesis suggesting that skin pigmentation evolved responding to increased demand for subcutaneous vitamin D synthesis in high latitude environments.</p
Differential circulating levels of HSP-27 in chronic and aggressive periodontitis
Session: Periodontal Research-Pathogenesis: Systemic Conditions and Responses: Oral Presentation no. 1748Objectives: Heat-shock protein (Hsp) 27 is a major intracellular molecular chaperone and controller of intracellular responses to inflammatory signals. Recombinant Hsp27 is also able to modulate myeloid cell activity with the protein showing an anti-inflammatory mode of action in vitro. The aim of this study was to assess a potential role of circulating levels of Hsp27 in periodontitis.
Methods: Pro- and anti-inflammatory cytokines as well as stress proteins Hsp27 and Hsp60 with anti- and pro-inflammatory properties, respectively, were measured by two-site ELISA in the serum of patients with Chronic periodontitis (CP, n=29), Aggressive Periodontitis (AgP, n=30) and periodontally healthy controls (H, n=28). Furthermore, Hsp27 and Hsp60 levels were also measured longitudinally in 12 AgP patients at 6 time-points after treatment (from baseline to 3-months after treatment).
Results: AgP patients had lower levels of Hsp27 compared with CP and H subjects (adjusted one-way ANOVA p<0.001, followed by post-hoc Tukey HSD comparisons), while no difference in levels of cytokines or Hsp60 between the three groups, and in Hsp27 levels in healthy individuals or in chronic periodontitis patients were detected. A positive correlation was detected between Hsp27 levels and Hsp60 (r=0.49, p<0.001) and IL-6 levels (r=0.354, p<0.001). No consistent patterns of changes in Hsp27 circulating levels were detected following treatment of AgP cases.
Conclusions: Circulating Hsp27 levels were associated with other cytokines levels, confirming its possible involvement in the periodontal inflammatory process. This study shows for the first time lower circulating Hsp27 in AgP patients, suggesting that this heat-shock protein may be differentially expressed in aggressive and chronic periodontitis