Population Ecology of the Brook Trout, Salvelinus fontinalis, in Matamek Lake, Quebec

1970 ◽  
Vol 27 (3) ◽  
pp. 413-424 ◽  
Author(s):  
Lloyd H. Saunders ◽  
G. Power
Keyword(s):  
Brook Trout ◽  
Total Population ◽  
Survival Rates ◽  
Standing Stock ◽  
Age Groups ◽  
Population Estimates ◽  
Lake Ecosystem ◽  
High Survival ◽  
Factors Affecting ◽  
Trout Population

Population estimates of an unexploited brook trout population at Matamek Lake, Quebec, indicated that more than 86% of the total population inhabited the tributaries of the lake during the summer of 1968. As opposed to the stream habitat, the combination stream–lake ecosystem moderated the mortality rates of the intermediate age-groups and allowed survival to higher ages in the population. Estimates of standing stock and production in the lake were 3.1 and 2.2 kg/ha respectively during 1968.The population was characterized by a slower growth rate, higher age at maturity, higher survival rate in the intermediate age-groups, and longer life span when compared with an exploited population in Wisconsin. Increased numbers of trout in higher age-groups at Matamek Lake were attributed to high survival rates in the intermediate age-groups in the absence of exploitation. Low estimates of standing stock and production were attributed to environmental factors affecting growth.

scholarly journals The Red Harmful Plague in Times of Climate Change: Blooms of the Cyanobacterium Planktothrix rubescens Triggered by Stratification Dynamics and Irradiance

2021 ◽  
Vol 12 ◽  
Author(s):  
Deborah Knapp ◽  
Bieito Fernández Castro ◽  
Daniel Marty ◽  
Eugen Loher ◽  
Oliver Köster ◽  
...  
Keyword(s):  
Thermal Stratification ◽  
Survival Rates ◽  
Standing Stock ◽  
Keystone Species ◽  
Weather Conditions ◽  
High Survival ◽  
Negative Consequences ◽  
Planktothrix Rubescens ◽  
Water Column Stability ◽  
Long Term Study

Planktothrix rubescens is a harmful planktonic cyanobacterium, forming concentrated metalimnetic populations in deep oligo- and mesotrophic lakes, even after successful restoration. In Lake Zurich (Switzerland), P. rubescens emerged as a keystone species with annual mass developments since the 1970s. Its success was partly attributed to effects of lake warming, such as changes in thermal stratification and seasonal deep mixing. However, recent observations based on a biweekly monitoring campaign (2009–2020) revealed two massive breakdowns and striking seasonal oscillations of the population. Here, we disentangle positive from negative consequences of secular lake warming and annual variations in weather conditions on P. rubescens dynamics: (i) despite the high survival rates of overwintering populations (up to 25%) during three consecutive winters (2014–2016) of incomplete deep convective mixing, cyanobacterial regrowth during the following stratified season was moderate and not overshooting a distinct standing stock threshold. Moreover, we recorded a negative trend for annual population maxima and total population size, pointing to a potential nutrient limitation after a series of incomplete winter mixing. Thus, the predication of steadily increasing blooms of P. rubescens could not be confirmed for the last decade. (ii) The seasonal reestablishment of P. rubescens was strongly coupled with a timely formation of a stable metalimnion structure, where the first positive net growth in the following productive summer season was observed. The trigger for the vertical positioning of filaments within the metalimnion was irradiance and not maximal water column stability. Repetitive disruptions of the vernal metalimnion owing to unstable weather conditions, as in spring 2019, went in parallel with a massive breakdown of the standing stock and marginal regrowth during thermal stratification. (iii) Driven by light intensity, P. rubescens was entrained into the turbulent epilimnion in autumn, followed by a second peak in population growth. Thus, the typical bimodal growth pattern was still intact during the last decade. Our long-term study highlights the finely tuned interplay between climate-induced changes and variability of thermal stratification dynamics and physiological traits of P. rubescens, determining its survival in a mesotrophic temperate lake.

Neonatal survival: an overview

1992 ◽  
Vol 15 ◽  
pp. 1-7 ◽  
Author(s):  
M. A. Varley
Keyword(s):  
Medical Profession ◽  
Survival Rates ◽  
Farm Animals ◽  
Physical Factors ◽  
High Survival ◽  
Animal Agriculture ◽  
Factors Affecting ◽  
Neonatal Deaths ◽  
Probability Of Survival ◽  
Use Of Resources

AbstractMortality in neonates has always represented significant economic wastage and slow progress has been made in the understanding of the factors influencing the probability of survival or death. There is also increasing pressure in the animal agriculture sphere to pursue improved welfare and in the situation where neonatal deaths are a high proportion of the liveborn offspring, then this becomes not only an economic concern but also a welfare issue. This paper highlights principal problems within the neonatal area in order to introduce the ensuing text dealing with specific technical challenges.The magnitude of loss for different species including humans is given and the factors affecting mortalities are discussed. The major components include: human factors, pathogenic agents, immunological factors, temperature and thermoregulation, nutrition, behaviour and physical factors.Although single factors are often ascribed as the cause of death, the reality is that there are usually multifactorial components involved which interact and contribute to the final mortality of the individual.The approach to the practical management of neonates varies widely between the different animal industries and the techniques deployed depend on relative economic values. In human health care every available resource is used to ensure very high survival rates because of the incalculable value of each individual delivered. With farm animals the use of resources is at a much lower level and survival rates are lower. It ought to be possible in animal agriculture to adopt some of the methods used in the medical profession to assess high risk situations and to divert resources appropriately.

scholarly journals Studies on the diseases and mortality pattern of goats under farm conditions and some factors affecting mortality and survival rates in Black Bengal kids

1970 ◽  
pp. 71-76 ◽  
Author(s):  
M Ershaduzzaman ◽  
MM Rahman ◽  
BK Roy ◽  
SA Chowdhury
Keyword(s):  
Clinical Symptoms ◽  
Survival Rates ◽  
Research Work ◽  
Age Groups ◽  
Laboratory Diagnosis ◽  
Intensive Management ◽  
Wet Season ◽  
Mortality Pattern ◽  
Factors Affecting ◽  
Growing Goats

The research work was carried out from July 2004 to June 2005 and the place of research work was Bangladesh Livestock Research Institute (BLRI). The objectives of this work were to investigate the diseases and mortality pattern of goats and some factors affecting mortality and survivability rates of Black Bengal goats under intensive and semi-intensive management, in permanent house. Goats were only vaccinated with Peste des Petits Ruminants (PPR), administered with anthelmintics and dipped in 0.5% Malathion or 0.02% Diazinon solution to control endo- and ecto-parasites, respectively. They were allowed to graze 6-7 hours along with supplemental concentrate and green forages whereas ad libitum green grasses and concentrate were supplied to the goats managed under intensive management. The diseases were recorded mainly on the basis of clinical symptoms shown by animals and some by laboratory diagnosis; mortality was confirmed by some laboratory tests and clinical findings before death if any. Adult goats (>1 yr of age) died mostly due to suspected enterotoxaemia in the dry season (October to March) when there were shortages of green grasses in the grazing lands, which were confirmed by Gram’s staining and ELISA tests, and female goats died significantly more than male. Growing goats (3-12 months of age) mortality was about 22%, died mostly due to diarrhoea and pneumonia and mortality was higher (nearly 40%) in hot and wet season (July to October). The overall kid (0-3 months of age) mortality within study period was about 29%, of which the major causes were infectious (63%) i.e., diarrhoea, pneumonia, ecthyma and enterotoxaemia. Excluding accidental causes (predators and mechanical) mortality was reduced to about 18%.Kid mortality was affected by birth weight which was just opposite to mortality. It was also affected by birth seasons, litter size, sex of kids, dam’s body weight at kidding but parity was no significant effect on kid mortality Kids like growing goats, also died significantly more during hot and wet season. Morbidity was higher in female goats where mostly diarrhoea and pneumonia and some sorts affected all age groups of goats by ecthyma. There were seasonal differences.Key words: Black Bengal, diseases, goats, kids, mortalityDOI = 10.3329.bjvm.v5i1.1316Bangl. J. Vet. Med. (2007). 5 (1 & 2): 71-76

scholarly journals Unraveling Factors Affecting Micropropagation of Four Persian Walnut Varieties

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1417
Author(s):  
Togzhan Kadylbekovna Yegizbayeva ◽  
Silvia García-García ◽  
Tatyana Viktorovna Yausheva ◽  
Markhabat Kairova ◽  
Amangeldy Kairbekovich Apushev ◽  
...  
Keyword(s):  
Culture Medium ◽  
Juglans Regia ◽  
Survival Rates ◽  
Great Influence ◽  
Holistic Approach ◽  
High Survival ◽  
Factors Affecting ◽  
Persian Walnut ◽  
In Vitro Establishment

Walnuts are considered recalcitrant to tissue culture, with a great genetic determinism on all stages of micropropagation; while other factors, also with great impact, become more complicated with the reproduction of newly realized varieties. In this research, a holistic approach aimed to determine the influence of genotype and the nutritive formulation throughout the whole cycle of micropropagation of four Persian walnut varieties (Juglans regia L.) was presented. During the in vitro establishment it was determined that besides genotype and culture medium, the effect of collection season and the likely interaction amongst factors had a great influence on the successful introduction of all four genotypes. However, all cultures were affected by a deep decay, being necessary the introduction of ethylenediamine di-2-hydroxyphenyl acetate ferric, as iron source, and Phloroglucinol in both Murashige and Skoog (1962) and the corrected Driver and Kuniyuki (1987) formulations. These modifications allowed the stabilization of cultures, maintaining thereafter a steady quality. Either proliferation, rooting and ex vitro survival of four clones were affected by the culture medium, obtaining the best results with the corrected Driver and Kuniyuki (1987) formulation. Finally, in vitro plants produced from all clones were acclimated with high survival rates (75.9–91.1% for the best culture medium), depending of clone and the culture medium used. Microsatellite analysis showed that micropropagated plants maintained the same genetic profiles of their corresponding donor trees. These results might contribute to deepening of the understanding of factors that determine the success of micropropagation of walnuts, and the extents of its influence; whereas, it sets the basis for the commercial micropropagation of all four clones.

scholarly journals Assessing factors affecting adult female white-tailed deer survival in the Northern Great Plains

2018 ◽  
Vol 45 (8) ◽  
pp. 679 ◽  
Author(s):  
Katherine L. Moratz ◽  
Bailey S. Gullikson ◽  
Eric S. Michel ◽  
Jonathan A. Jenks ◽  
Daniel M. Grove ◽  
...  
Keyword(s):  
Great Plains ◽  
Adult Female ◽  
Survival Rates ◽  
Adult Survival ◽  
Northern Great Plains ◽  
Late Winter ◽  
High Survival ◽  
Factors Affecting ◽  
Time Period ◽  
Specific Mortality

Context Documenting cause-specific mortality and deriving survival estimates for a population are both vital to understanding potential restrictions to population growth. Survival varies among populations of the same species and depends on several factors, including climatic events, density-dependent and density-independent factors, observed predator composition and whether recreational hunting occurs. Therefore, understanding factors affecting adult survival and estimating survival rates at biologically important times will help refine management of these populations. Aims We aimed to assess cause-specific mortality, estimate survival rates, and determine at what part of the winter (January to April) most mortalities occurred for female white-tailed deer located in the Northern Great Plains region of the USA. Methods We captured 165 adult female white-tailed deer (Odocoileus virginianus) located in western North Dakota and north-western South Dakota, USA, during the winters of 2014 and 2015. We fitted individuals with Very High Frequency (VHF) radio-collars and located them 1–3 times per week to monitor survival. We investigated all mortalities to establish proximate cause of death. Key Results Survival was lowest during our Hunt time period (S=0.93), although hunter harvest was not the leading cause of mortality. Predation was the greatest source of mortality, particularly during our Post-hunt time period. Additionally, almost 90% of mortalities occurring during the Post-hunt time period happened during late winter before spring green up. Conclusions and Implications Predation was the main source of mortality for adult females in our study, with coyotes (Canis latrans) being the sole predator capable of depredation in our study area. Predation by coyotes may indicate that potential factors, including winter severity and nutritional restrictions, have decreased female body condition, making individuals more susceptible to predation. Although we report relatively high survival, managers should consider the possibility that coyotes may impact adult populations, particularly in regions where other large-sized predators occur, or in regions where coyotes are newly established. Managers should also acknowledge that overwinter density estimates may need to be adjusted during severe winters to account for mortalities that occur after population surveys are conducted.

Management of Haemophilia in Sweden

1976 ◽  
Vol 35 (03) ◽  
pp. 510-521 ◽  
Author(s):  
Inga Marie Nilsson
Keyword(s):  
Factor Viii ◽  
Total Population ◽  
Age Groups ◽  
Factor Ix ◽  
Haemophilia A ◽  
Severe Haemophilia ◽  
Haemophilia B ◽  
Human Fraction ◽  
Mild Haemophilia

SummaryThe incidence of living haemophiliacs in Sweden (total population 8.1 millions) is about 1:15,000 males and about 1:30,000 of the entire population. The number of haemophiliacs born in Sweden in 5-year periods between 1931-1975 (June) has remained almost unchanged. The total number of haemophilia families in Sweden is 284 (77% haemophilia A, 23% haemophilia B) with altogether 557 (436 with A and 121 with B) living haemophiliacs. Of the haemophilia A patients 40 % have severe, 18 % moderate, and 42 % mild, haemophilia. The distribution of the haemophilia B patients is about the same. Inhibitors have been demonstrated in 8% of the patients with severe haemophilia A and in 10% of those with severe haemophilia B.There are 2 main Haemophilia Centres (Stockholm, Malmo) to which haemophiliacs from the whole of Sweden are admitted for diagnosis, follow-up and treatment for severe bleedings, joint defects and surgery. Minor bleedings are treated at local hospitals in cooperation with the Haemophilia Centres. The concentrates available for treatment in haemophilia A are human fraction 1-0 (AHF-Kabi), cryoprecipitate, Antihaemophilic Factor (Hyland 4) and Kryobulin (Immuno, Wien). AHF-Kabi is the most commonly used preparation. The concentrates available for treatment in haemophilia B are Preconativ (Kabi) and Prothromplex (Immuno). Sufficient amounts of concentrates are available. In Sweden 3.2 million units of factor VIII and 1.0 million units of factor IX are given per year. Treatment is free of charge.Only 5 patients receive domiciliary treatment, but since 1958 we in Sweden have practised prophylactic treatment of boys (4–18 years old) with severe haemophilia A. At about 5-10 days interval they receive AHF in amounts sufficient to raise the AHF level to 40–50%. This regimen has reduced severe haemophilia to moderate. The joint score is identical with that found in moderate haemophilia in the same age groups. For treatment of patients with haemophilia A and haemophilia B complicated by inhibitors we have used a large dose of antigen (factor VIII or factor IX) combined with cyclophosphamide. In most cases this treatment produced satisfactory haemostasis for 5 to 30 days and prevented the secondary antibody rise.

scholarly journals Population estimates of Antillean manatees in Puerto Rico: an analytical framework for aerial surveys using multi-pass removal sampling

2019 ◽  
Vol 100 (4) ◽  
pp. 1340-1349
Author(s):  
Jaime A Collazo ◽  
Matthew J Krachey ◽  
Kenneth H Pollock ◽  
Francisco J Pérez-Aguilo ◽  
Jan P Zegarra ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Detection Probability ◽  
Analytical Framework ◽  
Population Estimates ◽  
High Concentration ◽  
Imperfect Detection ◽  
Factors Affecting ◽  
Management Actions ◽  
Aerial Surveys ◽  
Population Size Estimates

AbstractEffective management of the threatened Antillean manatee (Trichechus manatus manatus) in Puerto Rico requires reliable estimates of population size. Estimates are needed to assess population responses to management actions, and whether recovery objectives have been met. Aerial surveys have been conducted since 1976, but none adjusted for imperfect detection. We summarize surveys since 1976, report on current distribution, and provide population estimates after accounting for apparent detection probability for surveys between June 2010 and March 2014. Estimates in areas of high concentration (hotspots) averaged 317 ± 101, three times higher than unadjusted counts (104 ± 0.56). Adjusted estimates in three areas outside hotspots also differed markedly from counts (75 ± 9.89 versus 19.5 ± 3.5). Average minimum island-wide estimate was 386 ± 89, similar to the maximum estimate of 360 suggested in 2005, but fewer than the 700 recently suggested by the Puerto Rico Manatee Conservation Center. Manatees were more widespread than previously understood. Improving estimates, locally or island-wide, will require stratifying the island differently and greater knowledge about factors affecting detection probability. Sharing our protocol with partners in nearby islands (e.g., Cuba, Jamaica, Hispaniola), whose populations share genetic make-up, would contribute to enhanced regional conservation through better population estimates and tracking range expansion.El manejo efectivo del manatí antillano amenazado en Puerto Rico requiere estimados de tamaños de poblaciónes confiables. Dichas estimaciones poblacionales son necesarias para evaluar las respuestas a las acciones de manejo, y para determinar si los objetivos de recuperación han sido alcanzados. Se han realizado censos aéreos desde 1976, pero ninguno de ellos han sido ajustados para detecciones imperfectas. Aquí resumimos los censos desde 1976, actualizamos la distribución, y reportamos los primeros estimados poblacionales ajustados para la probabilidad de detección aparente en los censos de Junio 2010 a Marzo 2014. Las estimaciones poblacionales en áreas de mayor concentración del manatí promedió 317 ± 103, tres veces más abundante que los conteos sin ajuste (104 ± 0.56). Las estimaciones poblacionales en tres áreas fuera de las áreas de mayor concentración del manatí también fueron marcadamente diferentes (75 ± 9.89 vs 19.5 ± 3.5). El estimado mínimo poblacional en la isla entera fue de 386 ± 89, similar al estimado máximo de 360 sugerido en el año 2005, pero menor a los 700 sugeridos recientemente por el Centro de Conservación de Manatíes de Puerto Rico. Documentamos que el manatí tiene una distribución más amplia de lo que se sabía con anterioridad. El mejoramiento de los estimados poblacionales locales o a nivel de isla requerirá que se estratifique a la isla en forma diferente y que se investiguen los factores que influencian a la probabilidad de detección. Compartir protocolos como este con colaboradores de islas vecinas (por. ej., Cuba, Jamaica, Española), cuyas poblaciones de manatíes comparten material genético, contribuiría a la conservación regional mediante mejores estimaciones poblacionales y monitoreo de la expansión de su ámbito doméstico.

scholarly journals Cognitive decline in patients with prostate cancer: study protocol of a prospective cohort, NEON-PC

BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e043844
Author(s):  
Natalia Araujo ◽  
Samantha Morais ◽  
Ana Rute Costa ◽  
Raquel Braga ◽  
Ana Filipa Carneiro ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cognitive Decline ◽  
Cognitive Performance ◽  
Androgen Deprivation Therapy ◽  
Survival Rates ◽  
Cardiovascular Complications ◽  
Androgen Deprivation ◽  
High Survival ◽  
The Impact

IntroductionProstate cancer is the most prevalent oncological disease among men in industrialised countries. Despite the high survival rates, treatments are often associated with adverse effects, including metabolic and cardiovascular complications, sexual dysfunction and, to a lesser extent, cognitive decline. This study was primarily designed to evaluate the trajectories of cognitive performance in patients with prostate cancer, and to quantify the impact of the disease and its treatments on the occurrence of cognitive decline.MethodsParticipants will be recruited from two main hospitals providing care to approximately half of the patients with prostate cancer in Northern Portugal (Portuguese Institute of Oncology of Porto and São João Hospital Centre), and will comprise a cohort of recently diagnosed patients with prostate cancer proposed for different treatment plans, including: (1) radical prostatectomy; (2) brachytherapy and/or radiotherapy; (3) radiotherapy in combination with androgen deprivation therapy and (4) androgen deprivation therapy (with or without chemotherapy). Recruitment began in February 2018 and is expected to continue until the first semester of 2021. Follow-up evaluations will be conducted at 1, 3, 5, 7 and 10 years. Sociodemographic, behavioural and clinical characteristics, anxiety and depression, health literacy, health status, quality of life, and sleep quality will be assessed. Blood pressure and anthropometrics will be measured, and a fasting blood sample will be collected. Participants’ cognitive performance will be evaluated before treatments and throughout follow-up (Montreal Cognitive Assessment and Cube Test as well as Brain on Track for remote monitoring). All participants suspected of cognitive impairment will undergo neuropsychological tests and clinical observation by a neurologist.Ethics and disseminationThe study was approved by the Ethics Committee of the hospitals involved. All participants will provide written informed consent, and study procedures will be developed to ensure data protection and confidentiality. Results will be disseminated through publication in peer-reviewed journals and presentation in scientific meetings.

scholarly journals Comparison of Prevalence of Periodontitis with Different Indices in Population of District Ghaziabad

2016 ◽  
Vol 04 (01) ◽  
pp. 023-030
Author(s):  
Vimal Kumar ◽  
Pallak Arora ◽  
Manish Khatri ◽  
Shivani Sharma ◽  
Sumit Malhotra ◽  
...  
Keyword(s):  
Periodontal Disease ◽  
Total Population ◽  
Age Groups ◽  
Cross Sectional Study ◽  
Sample Population ◽  
Age Group ◽  
Cross Sectional ◽  
Multi Stage ◽  
Younger Age ◽  
Study Population

Abstract Objective: To estimate the prevalence of periodontal disease with different indices. Methods & materials: The study population consisted of multistage stratified random sample of 1300 subjects from total population of district Ghaziabad. A cross-sectional study was conducted with multi stage stratified random sampling techniques to select the sample population. The subjects were divided into different age groups and the periodontal assessment was made on the basis of CPITN index and ESI Index. Results: The CPITN has shown to estimate incorrect periodontal disease prevalence because of its underestimation of the disease severity. A huge difference was noticed in the prevalence rate of periodontitis when subjects were examined with ESI index. Conclusion Periodontal disease was found to be highly prevalent in the study population and severity of disease increased with age. More number of subjects in younger age group were found to be healthy.

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