Do logging and forest fires influence zooplankton biomass in Canadian Boreal Shield lakes?

2000 ◽  
Vol 57 (S2) ◽  
pp. 155-164 ◽  
Author(s):  
A Patoine ◽  
B Pinel-Alloul ◽  
E E Prepas ◽  
R Carignan
Keyword(s):  
Forest Fires ◽  
Size Fraction ◽  
Zooplankton Biomass ◽  
First Year ◽  
Size Fractions ◽  
Watershed Area ◽  
Boreal Shield ◽  
One Year ◽  
Shield Lakes ◽  
Reference Lakes

Zooplankton biomass was assessed in 20 reference lakes, nine logged-watershed lakes, and nine burned-watershed lakes during three summers following watershed disturbances by logging or wildfires. Biomass of cladocerans, calanoids, cyclopoids, and rotifers was quantified in the 38 lakes for the first year following disturbances. Limnoplankton biomass in four size fractions was quantified during 3 years following disturbances. One year after disturbances, burned-watershed lakes supported 59% more biomass of the rotifer size fraction of limnoplankton (100-200 µm) than reference lakes, while logged-watershed lakes supported 43% less of calanoid biomass. Two years after disturbances, differences in limnoplankton biomass between burned-watershed lakes and reference lakes were more pronounced than during the first year, while logged-watershed lakes supported levels of limnoplankton biomass no different from those of reference lakes. Three years after disturbances, no significant variations could be detected among the three groups of lakes for any of the limnoplankton size fractions. The proportion of watershed area impacted by logging activities was on average less than half the proportion impacted by wildfires. Nonetheless, both types of disturbances seemed to have opposite effects on the zooplankton biomass during the first year, and the effects did not extend beyond 2 years.

Pelagic and benthic algal responses in eastern Canadian Boreal Shield lakes following harvesting and wildfires

2000 ◽  
Vol 57 (S2) ◽  
pp. 136-145 ◽  
Author(s):  
Dolors Planas ◽  
Mélanie Desrosiers ◽  
S-Raphaëlle Groulx ◽  
Serge Paquet ◽  
Richard Carignan
Keyword(s):  
Repeated Measures ◽  
Algal Biomass ◽  
Forest Harvesting ◽  
Algal Community ◽  
Significant Treatment ◽  
Repeated Measures Anova ◽  
Chl A ◽  
Boreal Shield ◽  
Shield Lakes ◽  
Reference Lakes

Pelagic and benthic algal biomass and pelagic algal community structure were measured in Boreal Shield lakes impacted by forest harvesting and wildfires (Haute-Mauricie, Québec). Sixteen reference lakes in which the watershed has been unperturbed for at least 40 years, seven harvested lake watersheds (logged in 1995), and nine lake watersheds burnt in 1995 were sampled for 3 years following harvesting or wildfires. From 1996 to 1998, repeated-measures ANOVA showed significant effects between treatment and sampling years for pelagic chlorophyll a (Chl a) and biomass, but for 1997-1998 benthic Chl a, repeated-measures ANOVA showed only significant treatment effects. Chl a concentrations increased 1.4- to 3-fold in perturbed lakes as compared with reference lakes. Areal pelagic Chl a (milligrams per square metre) was lower than estimated littoral Chl a in perturbed lakes. The pelagic algal community was dominated by mixotrophic nanoflagellates in reference lakes. Watershed perturbation induced differential changes in pelagic algal communities: mixotrophic nanoflagellates increased in harvested lakes and photoautotrophic diatoms in burnt lakes. Considering only perturbed lakes, algal biomass was proportional to the fraction of the catchment area perturbed divided by the surface area of lakes in the catchment.

scholarly journals Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in Eastern Canadian Boreal Shield lakes

2015 ◽  
Vol 12 (12) ◽  
pp. 9307-9339 ◽  
Author(s):  
P. Glaz ◽  
J.-P. Gagné ◽  
P. Archambault ◽  
P. Sirois ◽  
C. Nozais
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Forest Harvesting ◽  
Clear Cutting ◽  
Fluorescence Measurements ◽  
Fluorescence Characteristics ◽  
Boreal Shield ◽  
One Year ◽  
Shield Lakes

Abstract. Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a three-year period in eight Eastern Boreal Shield lakes: four lakes were studied before, one and two years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering one year before and one year after the perturbation only. At one year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~15 mg C L−1 compared to 12.5 mg C L−1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterised with spectroscopic techniques. Multivariate statistical analysis showed lakes to be significantly different one year after the perturbation. These results confirm an impact of forestry activities one year after the perturbation. However, this effect seems to be mitigated two years after, indicating that the system shows high resilience and may be able to return to its original condition.

scholarly journals Configuration of flowsheet and reagent dosage for gilsonite flotation towards the ultra-low-ash concentrate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ataallah Bahrami ◽  
Fatemeh Kazemi ◽  
Mirsaleh Mirmohammadi ◽  
Yousef Ghorbani ◽  
Saghar Farajzadeh
Keyword(s):  
Sulfuric Acid ◽  
Sodium Silicate ◽  
Tannic Acid ◽  
Size Fraction ◽  
Sodium Cyanide ◽  
Ash Content ◽  
Drilling Fluids ◽  
Gas Oil ◽  
Size Fractions ◽  
Process Mineralogy

AbstractGilsonite has a wide variety of applications in the industry, including the manufacture of electrodes, paints and resins, as well as the production of asphalt and roof-waterproofing material. Gilsonite ash is a determining parameter for its application in some industries (e.g., gilsonite with ash content < 5% used as an additive in drilling fluids, resins). Due to the shortage of high grade (low ash) gilsonite reserves, the aim of this study is to develop a processing flowsheet for the production of ultra-low-ash gilsonite (< 5%), based on process mineralogy studies and processing tests. For this purpose, mineralogical studies and flotation tests have been performed on a sample of gilsonite with an average ash content of 15%. According to mineralogical studies, carbonates and clay minerals are the main associated impurities (more than 90 vol.%). Furthermore, sulfur was observed in two forms of mineral (pyrite and marcasite) and organic in the structure of gilsonite. Most of these impurities are interlocked with gilsonite in size fractions smaller than 105 µm. The size fraction of + 105 − 420 µm has a higher pure gilsonite (approximately 90%) than other size fractions. By specifying the gangue minerals with gilsonite and the manner and extent of their interlocking with gilsonite, + 75 − 420 µm size fraction selected to perform flotation tests. Flotation tests were performed using different reagents including collector (Gas oil, Kerosene and Pine oil), frother (MIBC) and depressant (sodium silicate, tannic acid, sulfuric acid and sodium cyanide) in different dosages. Based on the results, the use of kerosene collector, MIBC frother and a mixture of sodium silicate, tannic acid, sulfuric acid and sodium cyanide depressant had the most favorable results in gilsonite flotation in the rougher stage. Cleaner and recleaner flotation stages for the rougher flotation concentrate resulted in a product with an ash content of 4.89%. Due to the interlocking of gilsonite with impurities in size fractions − 105 µm, it is better to re-grinding the concentrate of the rougher stage beforehand flotation in the cleaner and recleaner stages. Finally, based on the results of mineralogical studies and processing tests, a processing flowsheet including crushing and initial granulation of gilsonite, flotation in rougher, cleaner and recleaner stages has been proposed to produce gilsonite concentrate with < 5% ash content.

scholarly journals Cardiovascular risk factors associated with acute myocardial infarction and stroke in the MADIABETES cohort

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. A. Salinero-Fort ◽  
F. J. San Andrés-Rebollo ◽  
J. Cárdenas-Valladolid ◽  
M. Méndez-Bailón ◽  
R. M. Chico-Moraleja ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Blood Pressure ◽  
Antihypertensive Drugs ◽  
Hdl Cholesterol ◽  
First Year ◽  
Backward Elimination ◽  
One Year ◽  
Time Varying Covariates

AbstractWe aimed to develop two models to estimate first AMI and stroke/TIA, respectively, in type 2 diabetes mellitus patients, by applying backward elimination to the following variables: age, sex, duration of diabetes, smoking, BMI, and use of antihyperglycemic drugs, statins, and aspirin. As time-varying covariates, we analyzed blood pressure, albuminuria, lipid profile, HbA1c, retinopathy, neuropathy, and atrial fibrillation (only in stroke/TIA model). Both models were stratified by antihypertensive drugs. We evaluated 2980 patients (52.8% women; 67.3 ± 11.2 years) with 24,159 person-years of follow-up. We recorded 114 cases of AMI and 185 cases of stroke/TIA. The factors that were independently associated with first AMI were age (≥ 75 years vs. < 75 years) (p = 0.019), higher HbA1c (> 64 mmol/mol vs. < 53 mmol/mol) (p = 0.003), HDL-cholesterol (0.90–1.81 mmol/L vs. < 0.90 mmol/L) (p = 0.002), and diastolic blood pressure (65–85 mmHg vs. < 65 mmHg) (p < 0.001). The factors that were independently associated with first stroke/TIA were age (≥ 75 years vs. < 60 years) (p < 0.001), atrial fibrillation (first year after the diagnosis vs. more than one year) (p = 0.001), glomerular filtration rate (per each 15 mL/min/1.73 m2 decrease) (p < 0.001), total cholesterol (3.88–6.46 mmol/L vs. < 3.88 mmol/L) (p < 0.001), triglycerides (per each increment of 1.13 mmol/L) (p = 0.031), albuminuria (p < 0.001), neuropathy (p = 0.01), and retinopathy (p = 0.023).

scholarly journals Mortality in older adults following a fragility fracture: real-world retrospective matched-cohort study in Ontario

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jacques P. Brown ◽  
Jonathan D. Adachi ◽  
Emil Schemitsch ◽  
Jean-Eric Tarride ◽  
Vivien Brown ◽  
...  
Keyword(s):  
Cohort Study ◽  
Hip Fracture ◽  
Fragility Fracture ◽  
Mortality Risk ◽  
Real World ◽  
First Year ◽  
Matched Cohort ◽  
Matched Cohort Study ◽  
Fracture Cohort ◽  
One Year

Abstract Background Recent studies are lacking reports on mortality after non-hip fractures in adults aged > 65. Methods This retrospective, matched-cohort study used de-identified health services data from the publicly funded healthcare system in Ontario, Canada, contained in the ICES Data Repository. Patients aged 66 years and older with an index fragility fracture occurring at any osteoporotic site between 2011 and 2015 were identified from acute hospital admissions, emergency and ambulatory care using International Classification of Diseases (ICD)-10 codes and data were analyzed until 2017. Thus, follow-up ranged from 2 years to 6 years. Patients were excluded if they presented with an index fracture occurring at a non-osteoporotic fracture site, their index fracture was associated with a trauma code, or they experienced a previous fracture within 5 years prior to their index fracture. This fracture cohort was matched 1:1 to controls within a non-fracture cohort by date, sex, age, geography and comorbidities. All-cause mortality risk was assessed. Results The survival probability for up to 6 years post-fracture was significantly reduced for the fracture cohort vs matched non-fracture controls (p < 0.0001; n = 101,773 per cohort), with the sharpest decline occurring within the first-year post-fracture. Crude relative risk of mortality (95% confidence interval) within 1-year post-fracture was 2.47 (2.38–2.56) in women and 3.22 (3.06–3.40) in men. In the fracture vs non-fracture cohort, the absolute mortality risk within one year after a fragility fracture occurring at any site was 12.5% vs 5.1% in women and 19.5% vs 6.0% in men. The absolute mortality risk within one year after a fragility fracture occurring at a non-hip vs hip site was 9.4% vs 21.5% in women and 14.4% vs 32.3% in men. Conclusions In this real-world cohort aged > 65 years, a fragility fracture occurring at any site was associated with reduced survival for up to 6 years post-fracture. The greatest reduction in survival occurred within the first-year post-fracture, where mortality risk more than doubled and deaths were observed in 1 in 11 women and 1 in 7 men following a non-hip fracture and in 1 in 5 women and 1 in 3 men following a hip fracture.

scholarly journals Across the COVID-19 Waves; Assessing Temporal Fluctuations in Perceived Stress, Post-Traumatic Symptoms, Worry, Anxiety and Civic Moral Disengagement over One Year of Pandemic

2021 ◽  
Vol 18 (11) ◽  
pp. 5651
Author(s):  
Alessio Gori ◽  
Eleonora Topino
Keyword(s):  
Perceived Stress ◽  
State Anxiety ◽  
Moral Disengagement ◽  
Online Survey ◽  
Well Being ◽  
First Year ◽  
Effective Interventions ◽  
Post Traumatic ◽  
One Year ◽  
Traumatic Symptoms

This study aimed at investigating the psychological effect of the COVID-19 pandemic in Italy by analysing the trends of perceived stress, post-traumatic symptoms, state anxiety, worry, and civic moral disengagement in four different moments from March 2020 to March 2021. The study involved a total of 1827 Italian participants (30% men and 70% women; Mage = 34.72; SD = 12.40) divided into four groups to which an online survey was administered. The first group completed the survey in March 2020, the second one in August 2020, the third one in November 2020, and the fourth one in March 2021. Results highlighted significant decreases in post-traumatic symptoms and a significant increase in civic moral disengagement over the first year of the COVID-19 pandemic. The levels of perceived stress, worry, and state anxiety remained constant. The correlations between the variables at different times were also explored, as well as gender differences over the year. The COVID-19 emergency has had significant effects on the mental state of the population, with important repercussions for individual and collective well-being during but probably also after the pandemic. This study offers a clear snapshot of the psychological outcomes over one COVID-19 pandemic year, providing important information that may contribute to tailor more effective interventions for mental health.

Teething Symptoms in the First Year of Life and Associated Factors: A Cohort Study

2010 ◽  
Vol 34 (3) ◽  
pp. 201-206 ◽  
Author(s):  
Carlos Alberto Feldens ◽  
Italo Medeiros Faraco Junior ◽  
Andréia Bertani Ottoni ◽  
Eliane Gerson Feldens ◽  
Márcia Regina Vítolo
Keyword(s):  
Associated Factors ◽  
Primary Outcome ◽  
First Year ◽  
Structured Interviews ◽  
Self Medication ◽  
Nuclear Families ◽  
Dental Examination ◽  
Pediatric Dentists ◽  
One Year ◽  
First Year Of Life

Objective: To investigate the occurrence and management of teething symptoms during the first year of life and associated factors. Study design: 500 children were recruited at birth. Research assessments including structured interviews, anthropometric measurements and dental examination were carried out after birth, at 6 months and at one-year of age. The primary outcome of this study was defined as the occurrence of one or more teething symptoms within the first year of life, as reported by the mother. Results: Teething symptoms were reported in 73% of the children analyzed (273/375). The symptoms most frequently reported were irritability (40.5%), fever (38.9%), diarrhoea (36.0%) and itching (33.6%). Dentists had little influence on the management of symptoms and self-medication to relieve them was a common practice. The risk of reporting teething symptoms was higher for children from nuclear families (p=0.040) and for children from families with higher income (p=0.040). Conclusions: Teething symptoms were highly reported in this population. Pediatric dentists should be accessible and provide adequate orientation when symptoms can be managed at home or immediate referral to health services when more serious diseases are suspected.

Partnership in Post-Adoption Services Evaluating the First Year of a Complementary Contract

1997 ◽  
Vol 21 (3) ◽  
pp. 50-56 ◽  
Author(s):  
Alan Burnell ◽  
Adrian Briggs
Keyword(s):  
Social Services ◽  
Comprehensive Assessment ◽  
First Year ◽  
Service Users ◽  
Adoptive Families ◽  
Treatment Services ◽  
Assessment And Treatment ◽  
One Year ◽  
Families With Children ◽  
Consultation Services

In the autumn 1995 edition of Adoption & Fostering, Alan Burnell and Adrian Briggs described the origins and objectives of a novel complementary contract between East Sussex Social Services and the Post-Adoption Centre (PAC), aimed at providing post-adoption counselling and consultation services to all those involved in adoption in the county. The same authors now evaluate the operation of the contract, one year on. After filling in some background they assess its achievements so far, with particular regard to the extra support to service users and staff, and reducing the risk of disruption. The article concludes that the first year of the contract has demonstrated the need for comprehensive assessment and treatment services for adoptive families with children experiencing attachment difficulties.

scholarly journals Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. III. Distribution and kinetics of soil organic carbon in particle size fractions

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 293 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Size Fraction ◽  
Organic C ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Clay Size Fraction ◽  
Sand Size

Distribution of soil organic carbon in sand-, silt- and clay-size fractions during cultivation for periods ranging from 20 to 70 years was studied in six major soils used for cereal cropping in southern Queensland. Particle-size fractions were obtained by dispersion in water using cation exchange resin, sieving and sedimentation. In the soils' virgin state no single particle-size fraction was found to be consistently enriched as compared to the whole soil in organic C in all six soils, although the largest proportion (48%) of organic C was in the clay-size fraction; silt and sand-size fractions contained remaining organic C in equal amounts. Upon cultivation, the amounts of organic C declined from all particle-size fractions in most soils, although the loss rates differed considerably among different fractions and from the whole soil. The proportion of the sand-size fraction declined rapidly (from 26% to 12% overall), whereas that of the clay-size fraction increased from 48% to 61% overall. The proportion of silt-size organic C was least affected by cultivation in most soils. It was inferred, therefore, that the sand-size organic matter is rapidly lost from soil, through mineralization as well as disintegration into silt-size and clay-size fractions, and that the clay fraction provides protection for the soil organic matter against microbial and enzymic degradation.

ADENOVIRUS COMPLEMENT-FIXING ANTIBODY TITERS FROM BIRTH THROUGH THE FIRST YEAR OF LIFE

PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 497-500
Author(s):  
Rosa Lee Nemir ◽  
Donna O'Hare ◽  
Stanley Goldstein ◽  
Charles B. Hilton
Keyword(s):  
Cytopathic Effect ◽  
Gradual Increase ◽  
Newborn Infants ◽  
First Year ◽  
Placental Barrier ◽  
Culture Studies ◽  
Antibody Titers ◽  
Level 1 ◽  
One Year ◽  
First Year Of Life

Complement fixing antibody titers to the adenoviruses were determined in 251 newborn infants, using cord blood. Approximately 95% of these were found to have CF titers of 1:16 or over, the majority (75%) were 1:32 or more. Material from the pharyngeal and rectal swabs of these infants on tissue culture studies (542) on HeLa and amnion cells showed no cytopathic effect in oven 96% of these infants. A longitudinal study of 114 of these infants was made at 3 months intervals; 67 have been observed for one year. At 3 months, only 12% still showed CF antibody titers, and these were chiefly at a low level, 1:16. At the subsequent 3-month interval observations, a gradual rise in CF antibodies were found. At one year of age, approximately 37% had titers of 1:32 on over. The findings of this report support the statement that CF antibodies to adenovirus pass the placental barrier. There is a gradual increase in the percentage of infants with positive CF antibodies after 3 months.

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