Influence of sampling date on soil nitrogen availability indices

In spite of the great effort that has been devoted to the search for a chemical laboratory index to predict nitrogen (N) mineralization capability of soils, the results have not yet been fully satisfactory. A continued effort is still needed to increase the knowledge of the sources of variation that influence potentially available soil N. The time of sampling has received little attention, taking into account its potential to influence N-mineralization patterns. In this work, soil samples from three different agrosystems, consisting of a double-crop sequence of small grains and maize, an intensively grazed pasture, and a rainfed olive orchard, were collected at different dates. Several chemical extractions were performed, and the results were correlated with N uptake by turnip (Brassica campestris, L.) grown in a pot experiment. Kjeldahl N was the chemical test that best correlated (R2 = 0.621) with N uptake by turnip. Kjeldahl N showed great versatility relative to the origin of the soil samples. However, it was not very sensitive to the time of sampling. It did not detect changes occurring in the soil over a short period of time. Soil inorganic N showed the second highest coefficient of correlation (R2 = 0.483) with N uptake by turnip. In contrast to that observed with Kjeldahl N, soil inorganic N appeared as an index that can vary greatly over the short term. The hot saline potassium chloride (KCl) extractions gave generally fair results. The poorest, however, were obtained with the ultraviolet absorption of extracts of 0.01 mol L−1 sodium bicarbonate (NaHCO3) measured at 250- and 260-nm wavelengths

Effect of sampling date on chemical indices of the mineralizable nitrogen in soil

In the 1960s and 1970s there was great emphasis on selecting simple laboratory methods to estimate the potentially available soil N that could be routinely used as a method for the N recommendations systems (Keeney and Breniner, 1966; Stanford and Smith, 1976). Many chemical extractants were investigated (acids alkali, salts, water…) as possible tools for assessing how much N may be mineralized, varying the concentration of the extractant, temperature and time of extractions

Nitrogen-use efficiency and economic efficiency of slow-release N fertilisers applied to irrigated turfs in a Mediterranean environment

The effect of three fertilisers that delay the bioavailability of nitrogen (N) in the soil was compared with ammonium nitrate and a zero N control in two irrigated turfs in NE Portugal. The fertilisers used were: Floranid permanent 16-7-15 (slow-release, IBDU/Isodur fertiliser); Basacote plus 9M 16-8-12 (controlled-release fertiliser, copolymer ethylene acrylic); Nitroteck 20-8-10 (stabilized fertiliser, dicyandiamide as nitrification inhibitor + coating with polyterpene) and Nitrolusal (ammonium nitrate, 20.5% N), applied all at a rate of 120 kg N ha-1. Nitrolusal was split into two fractions of 60 kg N ha-1. Phosphorus (P) and potassium (K) rates were balanced among treatments by using superphosphate (18% P2O5) and potassium chloride (60% K2O). The turf dry matter (DM) yield and N concentration in dry material were determined from several cuts of biomass throughout the growing season. Based on DM yield, N concentration in dry material and fertilisation costs, indices of N use efficiency and economic efficiency were estimated. Soil nitrate levels were monitored by using anion exchange membranes inserted directly into the soil. Basacote gave significantly lower DM yields than the other fertilised treatments. The apparent N recovery of Basacote was also the lowest. The results showed that Basacote released less N than that required for an adequate plant growth in the beginning of the growing season, hampered the flush of spring growth. Furthermore, the release period of this Basacote formulation, in the environmental conditions of these experiments, seemed to be longer than the length of the growing season. Nitroteck and Floranid yielded similar or even higher DM and apparent N recovery values than did Nitrolusal. The indices of economic efficiency ordered the fertilisers as Nitroteck > Nitrolusal > Floranid > Basacote or Nitrolusal > Nitroteck > Floranid > Basacote, if the costs of P and K fertilisers used to balance the P and K rates in the experimental design were, respectively, taken or not taken into account

Nitrogen-use efficiency and economic efficiency of slow-release N fertilisers applied to an irrigated turf in NE Portugal

Urban forestry and urban greening are at the top of the political agenda, since they beautify the landscape and improve the health and well‐being of urban dwellers. They also bring several ecological benefits such as air cleansing, carbon sequestration and storm water retention. However, their social and ecological benefits can be reduced by an inappropriate management. An unbalanced N fertilization program, for instance, may lead to water and atmospheric pollution due to nitrate leaching and greenhouse gas emissions. In this work, the effect of three slow‐release fertilisers was compared with a conventional fertiliser in a turf of the Instituto Politécnico de Bragança, Portugal. The fertilisers used were: Floranid 16‐7‐15 (slow‐release fertiliser, IBDU/Isodur); Basacote 9M 16‐8‐12 (controlled‐release fertiliser, copolymer ethylene acrylic); Nitroteck 20‐8‐10 (stabilized fertiliser, dicyandiamide + coating with polyterpene); and Nitrolusal (ammonium nitrate, 20.5% N) split into two fractions. Based on DM yield, N concentration in dry material and fertilisation costs, indices of N‐use efficiency and economic efficiency were estimated. The results showed that Basacote released less N than that required for an adequate plant growth in early spring. Moreover, the release period seemed to be negatively longer than that specified by the manufacturer. Nitroteck, Floranid and Nitrolusal showed similar N‐use efficiency. The indices of economic efficiency ordered the slow‐release fertilisers as Nitroteck > Floranid > Basacote

Lifestyle Patterns and Survival Following Breast Cancer in the Carolina Breast Cancer Study

Background: Few studies have examined the impact of lifestyle patterns on survival following breast cancer. We aimed to identify distinct lifestyle patterns based on five behavior/dietary exposures among a population-based sample of women diagnosed with breast cancer and to examine their association with subsequent survival. Methods: In the Carolina Breast Cancer Study Phases I/II, we interviewed 1,808 women 20-74 years of age following diagnosis of invasive breast cancer. We determined vital status using the National Death Index (717 deaths, 427 from breast cancer; median follow-up 13.56 years). We assessed lifestyle patterns using a latent class analysis based on five behavioral and dietary exposures: current versus never/former smokers; low versus high vegetable and fruit intake; high and low/moderate, versus no alcohol consumption; and no and low/moderate, versus high regular physical activity. We used Cox regression to estimate covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality, and cause-specific and subdistribution HRs for breast cancer-specific mortality within 5 years and 13 years postdiagnosis conditional on 5-year survival. Results: We identified three distinct lifestyle patterns: healthy behavior and diet (n = 916); healthy behavior and unhealthy diet (n = 624); and unhealthy behavior and diet (n = 268). The unhealthy (vs. healthy) behavior and diet pattern was associated with a 13-year conditional all-cause mortality HR of 1.4 (95% CI = 1.1, 1.9) and with 13-year conditional breast cancer-specific and subdistribution HRs of 1.2 (95% CI = 0.79, 1.9) and 1.2 (95% CI = 0.77, 1.8), respectively. Conclusions: Behavioral and dietary patterns can be used to identify lifestyle patterns that influence survival patterns following breast cancer diagnosis

Pathogenic fungi: an unacknowledged risk at coastal resorts? New insights on microbiological sand quality in Portugal

Whilst the potential impact on beach users from microorganisms in water has received considerable attention, there has been relatively little investigation into microbial contaminants in sand. Thirty three beaches across Portugal were analyzed during a five year period (2006–2010) to determine the presence of yeasts, pathogenic fungi, dermatophytes, total coliforms, Escherichia coli and intestinal enterococci in sand. Our results showed that 60.4% of the samples were positive for fungi and that 25.2% were positive for the bacterial parameters. The most frequent fungal species found were Candida sp. and Aspergillus sp., whereas intestinal enterococci were the most frequently isolated bacteria. Positive associations were detected among analyzed parameters and country-regions but none among those parameters and sampling period. Regarding threshold values, we propose 15 cfu/g for yeasts, 17 cfu/g for potential pathogenic fungi, 8 cfu/g for dermatophytes, 25 cfu/g for E. coli, and 10 cfu/g for intestinal enterococci

Plasma levels of dichlorodiphenyldichloroethene (DDE) and dichlorodiphenyltrichloroethane (DDT) and survival following breast cancer in the Carolina Breast Cancer Study

Objectives: To examine plasma levels of dichlorodiphenyldichloroethene (DDE) and dichlorodiphenyltrichloroethane (DDT) in association with survival among women with breast cancer who participated in a population-based case-control study. Methods: Participants included 456 white and 292 black women from the Carolina Breast Cancer Study Phase I who were diagnosed with primary invasive breast cancer from 1993 to 1996, and who had available DDE/DDT and lipid measurements from blood samples obtained on average 4.1 months after diagnosis. Using the National Death Index, we identified 392 deaths (210 from breast cancer) over a median follow-up of 20.6 years. We used Cox regression to estimate covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and breast cancer-specific 5-year mortality, and 20-year mortality conditional on 5-year survival, for lipid-standardized DDE and DDT levels. Associations stratified by race and estrogen receptor (ER) status were also examined. Results: The highest versus lowest DDE tertile and the highest vs non-detectable DDT quantile were associated with HRs of 1.95 (95% CI = 1.31–2.92) and 1.64 (95% CI = 1.10–2.44), respectively, for 20-year conditional all-cause mortality. DDE levels above versus below the median were associated with a HR of 1.69 (95% CI = 1.06–2.68) for 20-year conditional breast cancer-specific mortality among women overall, and HRs were 2.36 (95% CI = 1.03–5.42) among black women and 1.57 (95% CI = 0.86–2.89) among white women (PInteraction = 0.42), and 3.24 (95% CI = 1.38–7.58) among women with ER− tumors and 1.29 (95% CI = 0.73–2.28) among women with ER+ tumors (PInteraction = 0.03). Conclusion: Exposure to DDE/DDT may adversely impact overall and breast cancer-specific survival. DDE exposure may contribute to the racial disparities in breast cancer survival

Active smoking and survival following breast cancer among African American and non-African American women in the Carolina Breast Cancer Study

Purpose: To examine racial differences in smoking rates at the time of breast cancer diagnosis and subsequent survival among African American and non-African American women in the Carolina Breast Cancer Study (Phases I/II), a large population-based North Carolina study. Methods: We interviewed 788 African American and 1,020 Caucasian/non-African American women diagnosed with invasive breast cancer from 1993 to 2000, to assess smoking history. After a median follow-up of 13.56 years, we identified 717 deaths using the National Death Index; 427 were breast cancer-related. We used Cox regression to examine associations between self-reported measures of smoking and breast cancer-specific survival within 5 years and up to 18 years after diagnosis conditional on 5-year survival. We examined race and estrogen receptor status as potential modifiers. Results: Current (vs never) smoking was not associated with 5-year survival; however, risk of 13 year conditional breast cancer-specific mortality was elevated among women who were current smokers at diagnosis (HR 1.54, 95% CI 1.06–2.25), compared to never smokers. Although smoking rates were similar among African American (22.0%) and non-African American (22.1%) women, risk of breast cancer-specific mortality was elevated among African American (HR 1.69, 95% CI 1.00–2.85), but only weakly elevated among non-African American (HR 1.22, 95% CI 0.70–2.14) current (vs. never) smokers (PInteraction = 0.30). Risk of breast cancer-specific mortality was also elevated among current (vs never) smokers diagnosed with ER− (HR 2.58, 95% CI 1.35–4.93), but not ER+ (HR 1.11, 95% CI 0.69–1.78) tumors (PInteraction = 0.17). Conclusions: Smoking may negatively impact long-term survival following breast cancer. Racial differences in long-term survival, as related to smoking, may be driven by ER status, rather than by differences in smoking patterns

Plasma levels of polychlorinated biphenyls (PCBs) and breast cancer mortality: The Carolina Breast Cancer Study

Background: It is unknown whether carcinogenic and endocrine disrupting polychlorinated biphenyls (PCBs) influence mortality following breast cancer. We examined plasma levels of 17 PCB congeners in association with mortality among women with breast cancer. Methods: Participants included 456 white and 292 black women in North Carolina who were diagnosed with primary invasive breast cancer from 1993 to 1996, and who had PCB and lipid measurements from blood samples obtained an average of 4.1 months after diagnosis. Over a median follow-up of 20.6 years, there were 392 deaths (210 from breast cancer). We used Cox regression to estimate covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and breast cancer-specific 5-year mortality, and 20-year mortality (conditional on 5-year survival) in association with tertiles and continuous ln-transformed lipid-adjusted PCB levels. Results: The highest (vs. lowest) tertiles of PCB74, PCB99, and PCB118 were associated with 5-year breast cancer-specific mortality HRs of 1.46 (95%CI = 0.86–2.47), 1.57 (95%CI = 0.90–2.73), and 1.86 (95%CI = 1.07–3.23), respectively. Additionally, one-ln unit increases in PCB74, PCB99, PCB118, and total PCBs were each associated with 33–40% increases in 5-year breast cancer-specific mortality rates. The PCBs were not, however, associated with longer-term breast cancer-specific mortality. For all-cause mortality, one-ln unit increases in PCB118, PCB146, PCB153, PCB182, PCB187, and total PCBs were associated with 20–37% increases in 20-year all-cause mortality rates among women who survived at least 5 years. Conclusion: PCBs may increase the risk of short-term breast cancer-specific mortality and long-term all-cause mortality among women with breast cancer