164 research outputs found

    Seed germination of Thymus richardii subsp. nitidus (Lamiaceae)

    Get PDF
    The germination ability of the punctual endemic Thymus richardii subsp. nitidus (Lamiaceae) from the Island of Marettimo in W Sicily was studied. Mature seeds were collected in the field. Different experimental conditions were tested and the best methods with optimal germination results were provided. This is the first germination record for this taxon

    Addition of high C:N crop residues to a P-limited substrate constrains the benefits of arbuscular mycorrhizal symbiosis for wheat P and N nutrition

    Get PDF
    Many aspects concerning the role of arbuscular mycorrhizal (AM) fungi in plant nutrient uptake from organic sources remain unclear. Here, we investigated the contribution of AM symbiosis to N and P uptake by durum wheat after the addition of a high C:N biomass to a P-limited soil. Plants were grown in pots in the presence or absence of a multispecies AM inoculum, with (Org) or without (Ctr) the addition of 15N-labelled organic matter (OM). A further treatment, in which 15N was applied in mineral form (Ctr+N) in the same amount as that supplied in the Org treatment, was also included. Inoculation with AM had positive effects on plant growth in both control treatments (Ctr and Ctr+N), mainly linked to an increase in plant P uptake. The addition of OM, increasing the P available in the soil for the plants, resulted in a marked decrease in the contribution of AM symbiosis to plant growth and nutrient uptake, although the percentage of mycorrhization was higher in the Org treatment than in the controls. In addition, mycorrhization drastically reduced the recovery of 15N from the OM added to the soil whereas it slightly increased the N recovery from the mineral fertiliser. This suggests that plants and AM fungi probably exert a differential competition for different sources of N available in the soil. On the whole, our results provide a contribution to a better understanding of the conditions under which AM fungi can play an effective role in mitigating the negative effects of nutritional stresses in plants

    Addition of high C:N crop residues to a P-limited substrate constrains the benefits of arbuscular mycorrhizal symbiosis for wheat P and N nutrition

    Get PDF
    Many aspects concerning the role of arbuscular mycorrhizal (AM) fungi in plant nutrient uptake from organic sources remain unclear. Here, we investigated the contribution of AM symbiosis to N and P uptake by durum wheat after the addition of a high C:N biomass to a P-limited soil. Plants were grown in pots in the presence or absence of a multispecies AM inoculum, with (Org) or without (Ctr) the addition of (15)N-labelled organic matter (OM). A further treatment, in which (15)N was applied in mineral form (Ctr+N) in the same amount as that supplied in the Org treatment, was also included. Inoculation with AM had positive effects on plant growth in both control treatments (Ctr and Ctr+N), mainly linked to an increase in plant P uptake. The addition of OM, increasing the P available in the soil for the plants, resulted in a marked decrease in the contribution of AM symbiosis to plant growth and nutrient uptake, although the percentage of mycorrhization was higher in the Org treatment than in the controls. In addition, mycorrhization drastically reduced the recovery of (15)N from the OM added to the soil whereas it slightly increased the N recovery from the mineral fertiliser. This suggests that plants and AM fungi probably exert a differential competition for different sources of N available in the soil. On the whole, our results provide a contribution to a better understanding of the conditions under which AM fungi can play an effective role in mitigating the negative effects of nutritional stresses in plants. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00572-021-01031-8

    Surveillance for selected tobacco-use behaviors—United States, 1900-1994

    Get PDF
    Problem/Condition: Surveillance of tobacco use is an essential component of any tobacco-control program. The information gathered can be used to guide research initiatives, intervention programs, and policy decisions. Reporting Periods: This report covers the period 1900–1994 for per capita cigarette consumption; 1965–1991 for trends in cigarette smoking prevalence and cessation; 1974–1991 for trends in the number of cigarettes smoked daily by current smokers; 1987–1991 for recent patterns of tobacco use; 1970, 1987, and 1991 for trends in cigar/pipe smoking and snuff/chewing tobacco use; 1984–1992 for trends in state-specific prevalences of regular cigarette smoking; 1987–1992 for state-specific estimates of smokeless-tobacco use; and 1976–1993 for trends in cigarette smoking among U.S. high school seniors. Description of Systems: Estimates of cigarette consumption are reported by the U.S. Department of Agriculture, which uses data from the U.S. Department of the Treasury, the U.S. Department of Commerce, the Tobacco Institute, and other sources. The National Health Interview Survey uses household interviews to provide nationally representative estimates (for the civilian, noninstitutionalized population) of cigarette smoking and other behaviors related to tobacco use. The Behavioral Risk Factor Surveillance System uses telephone surveys of civilian, noninstitutionalized adults (³18 years of age) to provide state-specific estimates of current cigarette smoking and use of smokeless tobacco. The University of Michigan’s Institute for Social Research uses school-based, self-administered questionnaires to gather data on cigarette smoking from a representative sample of U.S. high school seniors. Results: During the period 1900–1963, per capita cigarette consumption increased; after 1964, consumption declined. During the years 1965–1991, current cigarette smoking prevalence among persons ages ³18 years declined overall and in every sociodemographic category examined. Decrease in current smoking prevalence was slow in some groups (e.g., among persons with fewer years of formal education). Both the prevalence of never smoking and the prevalence of cessation increased from 1965 through 1991. The prevalence of current cigarette smoking, any tobacco smoking, and any tobacco use was highest among American Indians/Alaska Natives and non-Hispanic blacks and lowest among Asians/Pacific Islanders. The prevalence of cigar smoking and pipe smoking has declined substantially since 1970. The prevalence of smokeless-tobacco use among white males ages 18–34 years was higher in 1987 and 1991 than in 1970; among persons ³45 years of age, the use of smokeless tobacco was more common among blacks than whites in 1970 and 1987. Cigarette smoking prevalence has decreased in most states. The prevalence of smokeless tobacco use was especially high among men in West Virginia, Montana, and several southern states. From 1984–1993, prevalence of cigarette smoking remained constant among U.S. high school seniors. However, prevalence increased slightly for male seniors and white seniors, decreased slightly for female high school seniors, and decreased sharply for black high school seniors. Interpretation: With the exceptions of increases in cigarette smoking among white and male high school seniors and in the use of smokeless tobacco among white males ages 18–34 years, reductions in tobacco use occurred in every subgroup examined. This decrease must continue if the national health objectives for the year 2000 are to be reached. Actions Taken: Surveillance of tobacco use is ongoing. Effective interventions that discourage initiation and encourage cessation are being disseminated throughout the United States

    Recovery and genotyping ancient Sicilian monumental olive trees

    Get PDF
    The long-lived and evergreen olive tree dominates the Mediterranean landscape, representing an agroecological and cultural symbol and a genetic heritage of inestimable value. Sicily, for historical, geographical, and cultural reasons, has a very rich and distinctive olive germplasm. In this work, a large survey was conducted to discover, collect, and characterize the genetic diversity of centennial monumental olive trees from historical sites, such as the Greek Temple Valley (Agrigento), ancient gardens, or farmland present in the western part of the island. Trees were chosen based on their height, trunk, stump size, and presumed age; particularly, only olive trees with an age estimated at more than 400 years old were taken into consideration. For the morphological characterization, the leaf, fruit, and endocarp traits were analyzed. For the molecular characterization, 11 polymorphic microsatellite markers largely used for fingerprinting analysis were used. Reference cultivars were included in the analysis for comparison. Nuclear DNA was extracted from different parts of the plant (young leaves of shoots taken from the canopy and young leaves taken from suckers, which arose from the basal part of the tree) to check if the trees were grafted and to explore their diversity. Most of the monumental trees have been grafted at least one time during their long life, and some genotypes showed unique genetic profiles combined with peculiar phenotypic traits. Suckers (rootstock of the trees) showed a strict genetic relationship with an ancient monumental oleaster tree, also included in the study. “Patriarch” (original mother plants) trees of local cultivars were also identified. This research revealed a high level of the still unexplored genetic diversity of the Sicilian olive germplasm and highlighted its importance as a gene reservoir, which could support new breeding programs for the evaluation and possible selection of traits linked to putative resilience to abiotic and biotic stresses (particularly Xylella fastidiosa subsp. pauca ST53 or soil- borne diseases or insects). The results will be useful for improving the conservation process, enriching existing collections of olive genetic resources, and supporting on-farm conservation projects

    Using Search Query Surveillance to Monitor Tax Avoidance and Smoking Cessation following the United States' 2009 “SCHIP” Cigarette Tax Increase

    Get PDF
    Smokers can use the web to continue or quit their habit. Online vendors sell reduced or tax-free cigarettes lowering smoking costs, while health advocates use the web to promote cessation. We examined how smokers' tax avoidance and smoking cessation Internet search queries were motivated by the United States' (US) 2009 State Children's Health Insurance Program (SCHIP) federal cigarette excise tax increase and two other state specific tax increases. Google keyword searches among residents in a taxed geography (US or US state) were compared to an untaxed geography (Canada) for two years around each tax increase. Search data were normalized to a relative search volume (RSV) scale, where the highest search proportion was labeled 100 with lesser proportions scaled by how they relatively compared to the highest proportion. Changes in RSV were estimated by comparing means during and after the tax increase to means before the tax increase, across taxed and untaxed geographies. The SCHIP tax was associated with an 11.8% (95% confidence interval [95%CI], 5.7 to 17.9; p<.001) immediate increase in cessation searches; however, searches quickly abated and approximated differences from pre-tax levels in Canada during the months after the tax. Tax avoidance searches increased 27.9% (95%CI, 15.9 to 39.9; p<.001) and 5.3% (95%CI, 3.6 to 7.1; p<.001) during and in the months after the tax compared to Canada, respectively, suggesting avoidance is the more pronounced and durable response. Trends were similar for state-specific tax increases but suggest strong interactive processes across taxes. When the SCHIP tax followed Florida's tax, versus not, it promoted more cessation and avoidance searches. Efforts to combat tax avoidance and increase cessation may be enhanced by using interventions targeted and tailored to smokers' searches. Search query surveillance is a valuable real-time, free and public method, that may be generalized to other behavioral, biological, informational or psychological outcomes manifested online

    Occupational correlates of smoking among urban transit operators: A prospective study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Workers in blue-collar and service occupations smoke at higher rates than workers in white-collar and professional occupations. Occupational stress may explain some of the occupational class differences in smoking and quitting behavior. The purpose of this study is to investigate the contribution of occupational factors to smoking behavior over a ten year period among a multiethnic cohort of urban transit operators, while accounting for demographic factors and alcohol.</p> <p>Methods</p> <p>The sample consists of 654 San Francisco Municipal Railway (MUNI) transit operators who participated in two occupational health studies and biennial medical examinations during 1983–85 and 1993–95. Workers who had initiated, increased, or maintained their smoking over the ten year period were compared to workers who remained non-smokers. Occupational factors included self-rated frequency of job problems (e.g., difficulties with equipment, passengers, traffic), job burnout (i.e., the emotional exhaustion subscale of the Maslach Burnout Inventory), time needed to unwind after work, and years employed as a transit operator. A series of logistic regression models were developed to estimate the contribution of occupational factors to smoking behavior over time.</p> <p>Results</p> <p>Approximately 35% of the workers increased, initiated, or maintained their smoking over the ten-year period. Frequency of job problems was significantly associated with likelihood of smoking increase, initiation, or maintenance (OR = 1.30; 95% CI 1.09, 1.55). Black operators were significantly more likely to have smoked over the ten-year period compared to operators in other racial/ethnic groups.</p> <p>Conclusion</p> <p>Understanding the role of work-related stress vis-à-vis smoking behavior is of critical importance for crafting workplace smoking prevention and cessation interventions that are applicable to blue-collar work settings, and for developing policies that mitigate occupational stress.</p

    Changes in smoking prevalence among U.S. adults by state and region: Estimates from the Tobacco Use Supplement to the Current Population Survey, 1992-2007

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Tobacco control policies at the state level have been a critical impetus for reduction in smoking prevalence. We examine the association between recent changes in smoking prevalence and state-specific tobacco control policies and activities in the entire U.S.</p> <p>Methods</p> <p>We analyzed the 1992-93, 1998-99, and 2006-07 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) by state and two indices of state tobacco control policies or activities [initial outcome index (IOI) and the strength of tobacco control (SOTC) index] measured in 1998-1999. The IOI reflects cigarette excise taxes and indoor air legislation, whereas the SOTC reflects tobacco control program resources and capacity. Pearson Correlation coefficient between the proportionate change in smoking prevalence from 1992-93 to 2006-07 and indices of tobacco control activities or programs was the main outcome measure.</p> <p>Results</p> <p>Smoking prevalence decreased from 1992-93 to 2006-07 in both men and women in all states except Wyoming, where no reduction was observed among men, and only a 6.9% relative reduction among women. The percentage reductions in smoking in men and women respectively were the largest in the West (average decrease of 28.5% and 33.3%) and the smallest in the Midwest (18.6% and 20.3%), although there were notable exceptions to this pattern. The decline in smoking prevalence by state was correlated with the state's IOI in both women and men (r = -0.49, p < 0.001; r = -0.31, p = 0.03; respectively) and with state's SOTC index in women(r = -0.30, p = 0.03 0), but not men (r = -0.21, p = 0.14).</p> <p>Conclusion</p> <p>State level policies on cigarette excise taxes and indoor air legislation correlate strongly with reductions in smoking prevalence since 1992. Strengthening and systematically implementing these policies could greatly accelerate further reductions in smoking.</p
    corecore