Rates Return Research Articles

Return to Sport After Conservative Management of Midshaft Clavicle Fractures in Professional Jockeys.

This study explores the functional recovery and rates return to play (RTP) of professional jockeys following midshaft clavicle fractures, which have been managed conservatively. The high incidence of these fractures in horse racing underscores the importance of evaluating nonsurgical recovery paths for effective RTP. We used a retrospective cohort study to assess treatment outcomes. The research is set in the professional horse racing scene of Ireland. Sixteen professional Irish jockeys with conservatively managed midshaft clavicular fractures were examined. Jockeys who underwent surgery or were inactive at injury time were excluded. The study involved no direct interventions. Recovery was assessed using the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score and Patient-Reported Outcome Measures, alongside racing records to track RTP. The all-male cohort had an average age of 27 years. Results showed an average 67.1-day absence from racing, with 94% returning to preinjury competition levels. Complications were minimal, and patient outcomes were positive, as indicated by a mean QuickDASH score of 2.58, suggesting minimal residual disability. Findings highlight the success of conservative management for midshaft clavicle fractures in professional jockeys, enabling them to return to prior competitive levels with few complications and excellent functional recovery.

Long-Term Sustainability of Peri-Operative Infection Control Practices: Implementation of "Clean Cut," a Checklist-Based Quality Improvement Program in India.

Introduction: Surgical site infections (SSIs) are a substantial healthcare burden in low- and middle- income countries. "Clean Cut" is a checklist-based infection prevention and control (IPC) program intended to improve compliance to peri-operative IPC standards. We aim to study the short-term and long-term impact of its implementation in a tertiary care cancer referral center. Methods: This was a single institute, prospective interventional study. Patients undergoing elective head-neck surgical procedures were included. The "Clean Cut" program consisting of surveillance, audits, and IPC training was implemented for 6 months, after which there was no active oversight. Post-intervention (T2) and 1-year follow-up (T3) data regarding compliance to core IPC practices and SSI rates were compared with baseline (T1). Results: One hundred eighty six patients were included with 50 (26.9%), 86 (46.2%), and 50 (26.9%) patients at T1, T2, and T3, respectively. At baseline, teams complied with a mean of 3.56 of the six critical components of infection control processes which rose to 4.66 (p < 0.001) at T2, but decreased to 4.02 at T3 (p = 0.053). The SSI rate at baseline decreased significantly after Clean Cut implementation [16 (32%) vs. 12 (13.95%), p = 0.012], but returned to baseline levels after 1 year [17 (34%), p = 0.006]. Conclusion: Implementation of the "Clean Cut" program increases compliance to infection control processes and reduces SSI rates in the short term. Without continuing oversight, these rates return to baseline values after 1 year.

Labile assembly of a tardigrade protein induces biostasis.

Tardigrades are microscopic animals that survive desiccation by inducing biostasis. To survive drying tardigrades rely on intrinsically disordered CAHS proteins, which also function to prevent perturbations induced by drying in vitro and in heterologous systems. CAHS proteins have been shown to form gels both in vitro and in vivo, which has been speculated to be linked to their protective capacity. However, the sequence features and mechanisms underlying gel formation and the necessity of gelation for protection have not been demonstrated. Here we report a mechanism of fibrillization and gelation for CAHS D similar to that of intermediate filament assembly. We show that in vitro, gelation restricts molecular motion, immobilizing and protecting labile material from the harmful effects of drying. In vivo, we observe that CAHS D forms fibrillar networks during osmotic stress. Fibrillar networking of CAHS D improves survival of osmotically shocked cells. We observe two emergent properties associated with fibrillization; (i) prevention of cell volume change and (ii) reduction of metabolic activity during osmotic shock. We find that there is no significant correlation between maintenance of cell volume and survival, while there is a significant correlation between reduced metabolism and survival. Importantly, CAHS D's fibrillar network formation is reversible and metabolic rates return to control levels after CAHS fibers are resolved. This work provides insights into how tardigrades induce reversible biostasis through the self-assembly of labile CAHS gels.

The Economic Consequence of Feds Monetary Policies in 2022: An Internal Perspectives

US interest rate hikes due to COVID-19 and high inflation have affected the country's stock market and the international foreign exchange market. The authors analyze the willingness of U.S. interest rate hikes to cause inflation at the micro level through changes in the amount of money held by residents because of U.S. policies. This paper analyzes the impact of the U.S. interest rate hike by collecting various information on rental housing, GDP and spot exchange rates of countries affected by the U.S. According to the findings of this paper: 1. US interest rate hikes lead to a rise in the amount of currency held by citizens. 2. Interest rate hikes affect the GDP growth rate, and the stock market are positively correlated. 3. US monetary policy affects the world economy. The point of studying the Fed's rate hikes is to analyze the strengths and weaknesses of the policy and to find better ways to control inflation and make the economy stable. According to this paper, the authors propose that the United States should stop raising interest rates at the right time when the inflation rate falls to the right value and let interest rates return to their previous levels, otherwise it will stagnate the country's economic development and cause turmoil in the country's stock and foreign exchange markets.

On the use of arima and garch in modelling nigeria’s naira – us dollar monthly exchange rates

This paper aimed at modelling the volatility of monthly average official exchange rate (Naira/USD) using the Autoregressive Integrated Moving Average (ARIMA) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH) for the period January, 1981 to December, 2021. The data for the study was obtained from Central Bank of Nigeria 2021 Statistical Bulletin. The time plot, Augmented Dickey Fuller (ADF) and Phillip’s Perron (PP) were used to check for the Stationarity of the Series. It was discovered that the series is not stationary, thus the need for differencing to make it stationary. Based on the findings of the study, it was concluded that the ARIMA (0, 2,2) and GARCH (1,1) with Student’s t-distribution are the optimal models for modeling monthly average official exchange rates return (Naira/USD) in Nigeria.

On the use of ARIMA and GARCH in Modelling Nigeria’s Naira: Us Dollar Monthly Exchange Rates

This paper aimed at modelling the volatility of monthly average official exchange rate (Naira/USD) using the Autoregressive Integrated Moving Average (ARIMA) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH) for the period January, 1981 to December, 2021. The data for the study was obtained from Central Bank of Nigeria 2021 Statistical Bulletin. The time plot, Augmented Dickey Fuller (ADF) and Phillip’s Perron (PP) were used to check for the Stationarity of the Series. It was discovered that the series is not stationary, thus the need for differencing to make it stationary. Based on the findings of the study, it was concluded that the ARIMA (0, 2,2) and GARCH (1,1) with Student’s t-distribution are the optimal models for modeling monthly average official exchange rates return (Naira/USD) in Nigeria.

IMPACT OF UNCERTAINTY ON HUNGARIAN, CZECH, AND POLISH CURRENCIES

The present study examined the impact of uncertainty on the exchange rates of currency pairs traded at the Visegrad Group, except the currency of Slovakia. The USD/EUR exchange rate is considered the main influential factor affecting the exchange rates of the currency pairs of Hungary, Czech Republic, and Poland. The study analysed the exchange rates return of these three countries from 1 January 2010 to 31 December 2020. This period covers the announcement and implementation of Brexit; therefore, USD/GBP is considered the second influential factor affecting the exchange rates of the stated currencies. Moreover, the VIX, EMV, and EPU indices are selected as additional uncertainty indicators. The proposed regression model measures the impact of uncertainty on the exchange rates of the selected currencies. It has been discovered that the USD/EUR exchange rate returns significantly influenced the exchange rate returns of the stated currencies during the period under study. In addition, USD/GBP exchange rate returns also had a statistically significant impact on all the currency pairs at the beginning of the analysed period. However, its influence keeps fluctuating throughout the analysed period. The impact of VIX was weak throughout but statistically significant for USD/HUF and USD/PLN exchange rates. On the other hand, the study finds that EMV and EPU indices do not have a pronounced impact on the analysed exchange rate returns. As demonstrated, the uncertainty indices had a relatively higher impact on the development of the observed exchange rate returns. However, the study finds that their impact was often not statistically significant; moreover, the index impacts themselves were quite low.

Food Addiction and Binge Eating Impact on Weight Loss Outcomes Two Years Following Sleeve Gastrectomy Surgery.

Emerging evidence suggest that problematic eating behaviors such as food addiction (FA) and binge eating (BE) may alter following bariatric surgery (BS) and impact weight outcomes. We aimed to examine the prevalence of FA and BE and their associations with weight outcomes 2years post-sleeve gastrectomy (SG). Forty-five women (mean age 32.4 ± 10.9years) who underwent SG and completed 24months of follow-up were evaluated prospectively at pre-, 3-, 6-, 12-, and 24-month post-SG. Data collected included anthropometrics, nutritional intake, and lifestyle patterns. The Yale Food Addiction Scale (YFAS) and the Binge Eating Scale (BES) were used to characterize FA and BE, respectively. Pre-surgery FA and BE were identified in 40.0% and 46.7% of participants, respectively. Following SG, FA and BE prevalence was 10.0%, 5.0%, 29.4%, and 14.2% (P = 0.007), and 12.5%, 4.9%, 18.4%, and 19.4% (P < 0.001) at 3, 6, 12, and 24months, respectively. Women with BE at baseline gained significantly more weight from the nadir compared to non-BE women at baseline (P = 0.009). There was no relationship between FA at baseline and weight (P = 0.090). Weight regained from the nadir positively correlated with BES scores at baseline (r = 0.374, P = 0.019). FA and BE tend to decrease during the early postoperative period, but remains in a notable rates return by 2years post-SG. Moreover, pre-surgical BE was related to higher weight-regain. Proper management pre-BS should include a comprehensive eating pathologies assessment, as these pathologies may remain or re-emerge post-surgery and lead to worse weight outcomes.

Impact of COVID-19 Related Disruptions to Colorectal Cancer Screening Programs in Three Countries: A Comparative Modelling Study

Background: Colorectal cancer (CRC) screening programs worldwide have been disrupted during the COVID-19 pandemic. This study aimed to estimate the impact of hypothetical disruptions to organized CRC screening programs on short- and long-term CRC incidence and mortality in three countries using microsimulation modelling.Methods: Using CRC microsimulation models for Australia (Policy1-Bowel), Canada (OncoSim) and the Netherlands (ASCCA and MISCAN-Colon) participating in the COVID-19 and Cancer Global Modelling Consortium (CCGMC), we simulated a range of scenarios to assess the potential impact of disruptions to screening on CRC incidence and mortality. Modelled scenarios varied by disruption duration (3-, 6- and 12-months), post-disruption participation decreases, and catch-up screening strategy.Findings: Without catch-up screening, CRC deaths could increase by 0·2-0·5%, 0·4-1·0%, and 0·8-2·0% over 2020-2050 among individuals aged 50 years and older in the three modelled countries after 3-, 6-, and 12- month disruptions, respectively, compared to undisrupted screening. A 6-month disruption would result in an estimated 1,964, 1,319, and 676-856 additional CRC deaths in Australia, Canada and the Netherlands, respectively, compared to undisrupted screening. Providing catch-up screening could minimize the impact of the disruption, while a post-disruption decrease in participation could increase CRC deaths by 1·8-3·7% compared to undisrupted screening.Interpretation: Although the relative impact of the modelled CRC screening disruptions due to the COVID-19 pandemic is modest, there is a clear impact on absolute CRC deaths over the period 2020-2050. It is crucial that, if disrupted, screening programs ensure participation rates return to previously observed rates and provide catch-up screening wherever possible, as the impact of any disruption could be considerably larger otherwise.Funding Statement: The secretariat for the COVID-19 and Cancer Global Modelling Consortium (CCGMC) working group 2 is funded through Cancer Council New South Wales.Declaration of Interests: KC: Dr. Canfell reports and is co-principal investigator of an unrelated investigator-initiated trial of cervical screening in Australia (Compass; ACTRN12613001207707 and NCT02328872), which is conducted and funded by the VCS Foundation (VCS), a government-funded health promotion charity. The VCS Foundation received equipment and a funding contribution from Roche Molecular Systems USA. However, neither KC nor her institution on her behalf (Cancer Council NSW) receives direct funding from industry for this trial or any other project. All other authors declare no conflict of interest.

Impact of the COVID-19 pandemic on faecal immunochemical test-based colorectal cancer screening programmes in Australia, Canada, and the Netherlands: a comparative modelling study

Colorectal cancer screening programmes worldwide have been disrupted during the COVID-19 pandemic. We aimed to estimate the impact of hypothetical disruptions to organised faecal immunochemical test-based colorectal cancer screening programmes on short-term and long-term colorectal cancer incidence and mortality in three countries using microsimulation modelling. In this modelling study, we used four country-specific colorectal cancer microsimulation models-Policy1-Bowel (Australia), OncoSim (Canada), and ASCCA and MISCAN-Colon (the Netherlands)-to estimate the potential impact of COVID-19-related disruptions to screening on colorectal cancer incidence and mortality in Australia, Canada, and the Netherlands annually for the period 2020-24 and cumulatively for the period 2020-50. Modelled scenarios varied by duration of disruption (3, 6, and 12 months), decreases in screening participation after the period of disruption (0%, 25%, or 50% reduction), and catch-up screening strategies (within 6 months after the disruption period or all screening delayed by 6 months). Without catch-up screening, our analysis predicted that colorectal cancer deaths among individuals aged 50 years and older, a 3-month disruption would result in 414-902 additional new colorectal cancer diagnoses (relative increase 0·1-0·2%) and 324-440 additional deaths (relative increase 0·2-0·3%) in the Netherlands, 1672 additional diagnoses (relative increase 0·3%) and 979 additional deaths (relative increase 0·5%) in Australia, and 1671 additional diagnoses (relative increase 0·2%) and 799 additional deaths (relative increase 0·3%) in Canada between 2020 and 2050, compared with undisrupted screening. A 6-month disruption would result in 803-1803 additional diagnoses (relative increase 0·2-0·4%) and 678-881 additional deaths (relative increase 0·4-0·6%) in the Netherlands, 3552 additional diagnoses (relative increase 0·6%) and 1961 additional deaths (relative increase 1·0%) in Australia, and 2844 additional diagnoses (relative increase 0·3%) and 1319 additional deaths (relative increase 0·4%) in Canada between 2020 and 2050, compared with undisrupted screening. A 12-month disruption would result in 1619-3615 additional diagnoses (relative increase 0·4-0·9%) and 1360-1762 additional deaths (relative increase 0·8-1·2%) in the Netherlands, 7140 additional diagnoses (relative increase 1·2%) and 3968 additional deaths (relative increase 2·0%) in Australia, and 5212 additional diagnoses (relative increase 0·6%) and 2366 additional deaths (relative increase 0·8%) in Canada between 2020 and 2050, compared with undisrupted screening. Providing immediate catch-up screening could minimise the impact of the disruption, restricting the relative increase in colorectal cancer incidence and deaths between 2020 and 2050 to less than 0·1% in all countries. A post-disruption decrease in participation could increase colorectal cancer incidence by 0·2-0·9% and deaths by 0·6-1·6% between 2020 and 2050, compared with undisrupted screening. Although the projected effect of short-term disruption to colorectal cancer screening is modest, such disruption will have a marked impact on colorectal cancer incidence and deaths between 2020 and 2050 attributable to missed screening. Thus, it is crucial that, if disrupted, screening programmes ensure participation rates return to previously observed rates and provide catch-up screening wherever possible, since this could mitigate the impact on colorectal cancer deaths. Cancer Council New South Wales, Health Canada, and Dutch National Institute for Public Health and Environment.

Distribution of heat stroke in the Ipojuca/PE river basin, Brazil

Heat stroke is part of solar energy that spreads without the need for a material medium and is represented by the hours of the day that the solar disk remains visible on the earth's surface. The objective is to characterize the climatic conditions of insolation using the interpolation method for the area of the hydrographic basin of the Ipojuca River and its surroundings, elaborating a monthly and annual graph for the period from 1962 to 2019. The average climatological data of the total monthly and annual sunshine were generated by the simple interpolation method, using electronic spreadsheets to extract the averages values ​​of the monthly, annual, median, standard deviation, coefficient of variance, maximum and minimum absolute values. Total sunstroke is greater than the cloud coverage in the period from August to March, totaling 1861.8 hours and tenths, while in the same period, the cloud coverage is 0.45 tenths. Low cloud cover, temperature fluctuations and low or no ground cover conditions these incidences of insolation rates above normal. The importance of heat stroke is verified for purposes of applicability in the agricultural sectors, energy generations, aiming at helping industrial parks, energy distributors, agricultural sector and climatic studies that are scarce or widespread. It is observed that the deviations are positive, showing increases in the monthly and annual values, even though the straight line trends show us insignificant reductions for the period studied. The trend lines of the respective 12 months are negative and without insignificance, agreeing with the calculations of the moving averages, stating that there has been a reduction in the sunstroke in the next 9 years and, after 10 years, the insolation rates return to the level of the historical average.

Intervention differential effects and regression to the mean in studies where sample selection is based on the initial value of the outcome variable: an evaluation of methods illustrated in weight-management studies

Background: Intervention differential effects (IDEs) occur where changes in an outcome depend upon the initial values of that outcome. Although methods to identify IDEs are well documented, there remains a lack of understanding about the circumstances under which these methods are robust. One context that has not been explored is the identification of intervention differential effect in studies where sample selection is based on the initial value of the outcome being evaluated. We hypothesise that, in such settings, established methods for detecting IDEs will struggle to discriminate these from regression to the mean. Methods: Using simulated datasets of weight-loss intervention programmes that recruit according to initial body mass index, we explore the reliability of Oldham's method and multilevel modelling (MLM) to detect IDEs. Results: In datasets simulated with no IDE, Oldham's method and MLM yield Type I error rates >90%, confirming that threshold selection/truncation leads to bias due to regression to the mean. Type I error rates return close to 5% for both methods when a control group is introduced. Conclusions: Oldham's method and MLM can robustly detect IDEs in this setting, but only if analyses incorporate a control group for comparison.

Modeling Volatility of Exchange Rates Returns in the Nigerian Foreign Exchange Market in the Presence of Non-Gaussian Errors

This study investigates volatility behaviour of exchange rates returns of Naira against CFA, Euro, Great British Pounds, US Dollar, West African Unit of Account (WAUA) and Japanese Yen in Nigeria using historical volatility approach as well as symmetric and asymmetric Autoregressive Conditional Heteroskedasticity (GARCH) models in the presence of non-Gaussian errors. The study utilizes daily quotations of these exchange rates from 12/11/2001 to 04/13/2018 making a total of 4008 observations each. Historical (annualized) volatility approach as well as symmetric GARCH (1,1) and asymmetric EGARCH (1,1) models were used to model the exchange rates return series. Results showed that CFA and USD have the highest and least annualized volatilities (market risk) respectively among the six exchange rates returns as measured by historical approach. The symmetric GARCH (1,1) model showed volatility clustering with evidence of shock persistence in the six exchange rates return series. The asymmetric EGARCH (1,1) model found evidence of asymmetry and leverage effects in the Nigerian foreign exchange market indicating that negative shocks (bad news) generate more volatility than positive shocks (good news) of similar magnitudes. All the estimated models were found to be stationary and mean reverting indicating the predictability and stability of the conditional variances of the foreign exchange rates returns. This result suggests that no matter how high or low the foreign exchange rates shall move in the exchange market, they shall eventually return to their long-run averages. Stationary and mean reverting stocks provide good and long term investment opportunities for investors.

Development in sunburn 2007-2015 and skin cancer projections 2007-2040 of campaign results in the Danish population.

Exposure to ultraviolet radiation is the main risk factor for skin cancer. Denmark has one of the highest incidences of skin cancer in the world. In 2007, a long-term sun safety campaign was launched in Denmark. We have evaluated the effects on prevalence of sunburn and modeled the effects on future melanoma incidence.Sunburn was evaluated by annual cross-sectional surveys representative for the Danish population on age, gender, and region. During 2007-2015, survey data were collected for 33.315 Danes. Cutaneous Melanoma incidences were modeled in the Prevent program, using population projections, historic incidence, sunburn exposure, and relative risk of sunburn on melanoma.The prevalence of sunburn in Denmark was reduced with 1% annually during 2007 to 2015. The campaign is estimated to have reduced the number of skin cancer cases with 664 annually in 2040 and 14.326 totally during 2007 to 2040. If the campaign was terminated in 2015 and sunburn rates return to precampaign level there would be no annual reduction in 2040 while in total the reduction would be 4.024 cases for 2007 to 2040. A continuous campaign until 2040 would yield annual reductions of 2.121 cases by 2040 and a total of 29.729 cases for the entire period.We have showed the value of prevention and the value of long-term planning in prevention campaigning. Sunburn use was reduced significantly during 2007-2015 and further reductions are possible. Consequently, we predict significant fewer skin cancer cases as anticipated.

Recurrent circuits within medial entorhinal cortex superficial layers support grid cell firing

Specialized cells in the medial entorhinal cortex (mEC), such as speed cells, head direction (HD) cells, and grid cells, are thought to support spatial navigation. To determine whether these computations are dependent on local circuits, we record neuronal activity in mEC layers II and III and optogenetically perturb locally projecting layer II pyramidal cells. We find that sharply tuned HD cells are only weakly responsive while speed, broadly tuned HD cells, and grid cells show pronounced transient excitatory and inhibitory responses. During the brief period of feedback inhibition, there is a reduction in specifically grid accuracy, which is corrected as firing rates return to baseline. These results suggest that sharp HD cells are embedded in a separate mEC sub-network from broad HD cells, speed cells, and grid cells. Furthermore, grid tuning is not only dependent on local processing but also rapidly updated by HD, speed, or other afferent inputs to mEC.

Oil price fluctuations and exchange rate dynamics in the MENA region: Evidence from non-causality-in-variance and asymmetric non-causality tests

The aim of this paper is to investigate the exchange rate consequences of oil-price fluctuations and to test for the dynamics of oil price volatility by examining interactions between oil market and exchange rate in selected MENA countries (Egypt, Jordan, Morocco, Qatar, Saudi Arabia, Tunisia, and UAE). Using daily time series data covering the period from January 1, 2001 to December 29, 2017, we implement the test for asymmetric non-causality of Hatemi-J (2014), the asymmetric generalized impulse response functions of Hatemi-J (2014), and the test for non-causality-in-variance of Hafner and Herwartz (2006) to examine the presence of volatility spillover between oil prices and exchange rates return series. The econometric investigation reveals in particular that (i) when prices are rising in Tunisia and Saudi Arabia, oil prices cause change in exchange rates, and (ii) there is significant evidence of volatility spillovers from oil markets to exchange rate markets in the selected MENA countries. These findings have important implications both from the investor's and from the policy-maker's perspective.

Oil Price Fluctuations and Exchange Rate Dynamics in the MENA Region: Evidence from Non-Causality-in-Variance and Asymmetric Non-Causality Tests

The aim of this paper is to investigate the exchange rate consequences of oil-price fluctuations and to test for the dynamics of oil price volatility by examining interactions between oil market and exchange rate in selected MENA countries (Egypt, Jordan, Morocco, Qatar, Saudi Arabia, Tunisia, and UAE). Using daily time series data covering the period from January 1, 2001 to December 29, 2017, we implement the test for asymmetric non-causality of Hatemi-J (2012), the asymmetric generalized impulse response functions of Hatemi-J (2014), and the test for noncausality-in-variance of Hafner and Herwartz (2006) to examine the presence of volatility spillover between oil prices and exchange rates return series. The econometric investigation reveals in particular that i) when prices are rising in Tunisia and Saudi Arabia, oil prices cause change in exchange rates, and ii) there is significant evidence of volatility spillovers from oil markets to exchange rate markets in the selected MENA countries. These findings have important implications both from the investor's and from the policy-maker's perspective.

菌渣化肥配施对稻田土壤微生物量碳氮和可溶性碳氮的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 菌渣化肥配施对稻田土壤微生物量碳氮和可溶性碳氮的影响 DOI: 10.5846/stxb201711272117 作者: 作者单位: 浙江农林大学环境与资源学院,浙江农林大学环境与资源学院,浙江农林大学环境与资源学院,浙江农林大学环境与资源学院,浙江农林大学环境与资源学院,浙江农林大学环境与资源学院,浙江农林大学环境与资源学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31601271）；浙江省自然科学基金（LY16D010010） Effects of the combination of fungal residue and chemical fertilizer on soil microbial biomass carbon and nitrogen and dissolved organic carbon and nitrogen in paddy soil Author: Affiliation: School of Environmental and Resource Science，Zhejiang A＆F University,School of Environmental and Resource Science，Zhejiang A＆F University,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:菌渣作为一种养分丰富的有机物料还田，可减少化肥施用，同时保持土壤肥力；而土壤微生物量碳、氮和可溶性碳、氮是土壤活性碳氮库的重要组成部分，其含量和比例变化对土壤肥力均具有重要作用。因此，探讨不同比例菌渣化肥配施对土壤微生物量碳、氮及可溶性碳、氮的影响，评价菌渣在优化土壤肥力方面的生态作用具有重要意义。在水稻田间定位试验条件下，设置3个化肥水平（C）0、50%、100%，菌渣相对用量（F）0、50%、100%，共9个处理，分析了各处理土壤微生物量碳（MBC）、氮（MBN）和可溶性碳（DOC）、氮（DON）的变化特征，及其占土壤有机碳（SOC）和全氮（TN）的比例与相关关系。结果表明：菌渣化肥配施后，微生物量碳和可溶性碳、氮均在C100F50最高，微生物量氮在C50F100最高，与不施肥处理相比，分别显著增加了49.40%、43.65%、83.52%、207.19%；MBC/SOC和DOC/SOC均随着菌渣化肥配施量的增加而减少，MBN/TN和DON/TN均在C100F50最高。相关分析表明，MBC、DOC与SOC，MBN与TN均呈极显著正相关，DON和TN呈显著正相关。总体来讲，菌渣化肥配施能够显著提高土壤微生物量碳、氮和可溶性碳、氮含量，但不是随着用量的增加一直呈增加趋势，高量菌渣或者化肥下会有降低趋势；菌渣化肥配施降低了土壤微生物量和可溶性碳氮比，因此适宜的菌渣化肥配施是提高土壤有机碳周转速度、微生物活性及其氮素供应能力和有效性的最佳选择。 Abstract:As an excellent organic material additive to soil, fungal residue can reduce the application of chemical fertilizer and also plays an important role in maintaining soil fertility. As the most active organic components, soil microbial biomass carbon (MBC) and nitrogen (MBN) and dissolved organic carbon (DOC) and nitrogen (DON) are usually regarded as important and sensitive indices for soil fertility change. Therefore, it is vital to evaluate the ecological and soil fertility significance of fungal residue application under different rates return to the paddy soil. In our study, a randomized complete block field experiment with nine treatments(0,50%, and 100% levels of chemical fertilizers (C) and edible fungal residue (F) were considered, C100F50 stands for 100% of chemical fertilizer and 50% of fungal residue application, etc.) was set up. The changes of MBC, MBN, DOC, and DON, and ratios of these parameters to soil organic carbon (SOC) and total nitrogen (TN) were analyzed. Results showed that the highest contents of MBC, DOC and DON were observed under treatment of C100F50, which were 49.40%, 43.65% and 83.52% higher than that under the treatment of control. Meanwhile highest MBN content was found under treatment of C50F100 which was 207.19% higher than that under the treatment of control. Both ratios of MBC and DOC to SOC were decreased with increased application rate of fungal residue and chemical fertilizer; the highest ratios of MBN and DON to TN were observed in C100F50. There were highly significant positive correlations between MBC, DOC and SOC, respectively, and between MBN and TN as well. The correlation between DON and TN was significantly positive too. In conclusion, application of fungal residue with chemical fertilizer in paddy soil could increase the contents of MBC, MBN, DOC, and DON, but over dosage of fungal residue or chemical fertilizer application could lead to a negative effect. Consequently, the appropriate application rate of chemical fertilizer combined with fungal residue was the optimum choice to improve the SOC turnover rate, microbial activity, and nitrogen supply capacity and efficiency in paddy soil. 参考文献 相似文献 引证文献

Does Democratic Consolidation Lead to a Decline in Voter Turnout? Global Evidence Since 1939

This article challenges the conventional wisdom that democratic consolidation depresses voter turnout. Studying democratic legislative elections held worldwide between 1939 and 2015, it explains why voting rates in new democracies decrease when they do, how much they decrease, and how this phenomenon relates to the voter decline observed in established democracies. The article identifies three main sources of decline. The first and most important is the democratization context. When democratizations are opposition-driven or occur in electorally mobilized dictatorships, voter turnout is strongly boosted in the founding democratic elections. As time passes and the mobilizing democratization context loses salience, voting rates return to normal, which translates into turnout declines. The second source is the democratic consolidation context, which seems to depress voter turnout only in post-Communist democracies. Finally, new democracies mirror established democracies in that their voting rates have been declining since the 1970s, irrespective of the two previous mechanisms.

Poverty Traps in South African Agriculture

ABSTRACTThe article analyses the operation of poverty traps in South African agriculture through an analysis of the 2007 agricultural census. The poverty trap is a self-reinforcing mechanism in the market in which small variances in initial conditions can result in bimodality into differential economic steady-states resulting in multiple equilibria. Reasons for this include the savings trap, creating locally increasing rates return due to indivisible lumpy capital inputs; the technological trap in which the diminishing marginal rates of technological substitution diminishes productivity growth; the demographic trap in which population growth reduces the capital-labour ratio, increasing consumption and pure time costs; the stochastic returns trap in which producers without access to risk smoothing mechanisms assume greater risks; and the liquidity trap in which present and future capital values exceed current agricultural revenues. The study demonstrates that the failure of land reform and small-scale agriculture assistance programmes is thus a product of market failures, not policies. The analysis indicates that locally increased returns, symptomatic of the savings trap exists with initial average expenditures of smaller firms exceeding the average incomes. The technology trap is also evident with average incomes of small firms is also very low relative to the average capital asset values. The mean productivity of workers in terms of revenue per employee supports the argument for productivity declines in small firms due to the demographic trap. Initial declines in income per ton outputs of smaller firms validate the stochastic returns poverty trap.