scholarly journals Supervivencia de una cohorte de plántulas de Abies religiosa bajo diferentes condiciones postincendio

2019 ◽  
Vol 84 ◽  
pp. 25 ◽  
Author(s):  
Efraín Ángeles Cervantes ◽  
Lauro López Mata

The survival of a cohort of <em>Abies religiosa </em> seedlings was investigated during eight years in an intact forest (NAF) and forest patches affected by: shallow fi res (SUPAF), intermediate canopy fi res (ICAF), and full canopy fi res (FCAF). The objective of this paper was to provide a better understanding on the natural regeneration processes of <em>A. religiosa </em>. In each patch eight 1m2 plots were established and all rooted seedlings within each plot from the 1998 cohort were tagged. Seedling mortality and type of associated damage were recorded throughout censuses from 1998 to 2006. Fallen branches and desiccation of seedlings were the two most important factors associated with their death. Survival probabilities were the lowest in SUPAF and none in NAF. The highest survival probabilities were under ICAF condition, and it suggests that this type of fi re is an important component of the <em>A. religiosa </em> regeneration niche.

2018 ◽  
Vol 48 (4) ◽  
pp. 324-332 ◽  
Author(s):  
Nicola A. Kokkonen ◽  
S. Ellen Macdonald ◽  
Ian Curran ◽  
Simon M. Landhäusser ◽  
Victor J. Lieffers

Given a seed source, the quality of available substrates is a key factor in determining the success of white spruce (Picea glauca (Moench) Voss) natural regeneration. We examined the influence of substrate and competing vegetation on survival and growth of natural regeneration of white spruce up to 4 years following harvesting in deciduous-dominated upland boreal mixedwood sites. Feather moss, thick soil surface organic layers, litter, and solid wood were poor substrates for establishment. Early successional mosses establishing on mineral soil, thin organics, and rotten wood were generally favourable microsites but were not highly available on postharvest sites. Mineral soil substrates were not as suitable as expected, likely because on a postlogged site, they are associated with unfavourable environmental characteristics (e.g., low nutrient availability, exposure). There was some evidence that survival and growth of seedlings were improved by surrounding vegetation in the first years, but heavy competing vegetation had a negative impact on older seedlings. Burial by aspen litter greatly increased seedling mortality, especially when combined with a brief period of submergence due to heavy spring snowmelt. The results provide insight into conditions under which natural regeneration could be an option for establishing white spruce following harvesting of deciduous-dominated boreal mixedwood forests.


2007 ◽  
Vol 240 (1-3) ◽  
pp. 178-185 ◽  
Author(s):  
Michael J. O’Brien ◽  
Kevin L. O’Hara ◽  
Nadir Erbilgin ◽  
David L. Wood

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 371-371
Author(s):  
Raffi Tchekmedyian ◽  
Tomas Radivoyevitch ◽  
Aaron T. Gerds ◽  
Aziz Nazha ◽  
Hetty E. Carraway ◽  
...  

Abstract Background: The development of therapy-related MDS (t-MDS) is a rare but highly fatal complication of cancer therapies, with varying leukemogenicity associated with individual chemotherapeutic agents and radiation modalities. In recent years, an increase in t-MDS incidence explained by increased use of cancer treatment combined with an increasing number of cancer survivors has been reported. We investigated changes in t-MDS outcomes over time among cancer patients (pts) treated with chemotherapy and radiation using data from population-based cancer registries in the Surveillance, Epidemiology and End Results (SEER) Program of the US. Methods: A previously validated R package (SEERaBomb) was used to query all 18 SEER registries to identify adult pts (≥15 years of age) with multiple types of primary malignancies who were treated with chemotherapy and radiation as part of their initial cancer treatment, and subsequently developed MDS. Pts were observed from the date of first diagnosis of a primary malignancy until occurrence of MDS as second cancer, death, loss to follow-up, or end of the study period, whichever occurred earlier. Cases of MDS that developed at least 1 year (yr) following diagnosis and treatment of a primary malignancy were classified as t-MDS according to the World Health Organization classification. Primary cancers associated with at least 100 t-MDS cases were included in the analysis. Survival probabilities were compared for pts with: (1) primary cancers who did and did not subsequently develop MDS, (2) primary (de novo) MDS, and (3) t-MDS. Multivariate Cox regression analysis was performed to identify factors associated with overall survival (OS) in the t-MDS cohort, including the following covariates: age group [adolescents and young adults (AYA) (15-39 yrs); middle-aged (40-59 yrs); and older adults (≥60 yrs)], sex, year of diagnosis, race, and primary cancer type. Tests of significance were based on two-sided hypothesis at the .05 level. Results: A total of 933,789 adult cancer pts diagnosed between the years 2001-2015 were assembled from all 18 SEER registries which included 926,552 primary cancers, 5,478 primary MDS cases, and 1,759 t-MDS cases [breast (528), lung (207), lymphoma (663) and prostate (361)]. Median survival of t-MDS in months (m) with (range) by primary site was as follows: breast: 17.5m (0.5-172.5); lymphoma: 10.5m (0.5-168.5); lung: 5.5m (0.5-88.5); prostate: 21.5m (0.5-170.5); and combined: 13.5m (0.5-172.5). Median latency periods in yrs with (range) to develop t-MDS were as follows: breast: 5 yrs (1-40); lymphoma: 5 yrs (1-38); lung: 2 yrs (1-21); prostate: 5 yrs (1-25); combined: 5 yrs (1-40). Figure 1 shows comparison of survival probabilities of primary malignancies with and without subsequent development of t-MDS over two treatment eras (2001-2006 and 2007-2015), organized by yr of diagnosis and primary cancer type. As expected, development of t-MDS was significantly associated with worse survival for all four primaries that contribute to the bulk of t-MDS cases. Figure 2 shows survival probabilities of primary (de novo) MDS versus t-MDS. In multivariate analyses of factors associated with survival in the t-MDS cohort, the hazard ratio (HR) of death was significantly higher in middle aged adults [vs AYA, 2.20 (95% CI 1.34-3.62)] and older adults (vs AYA, 2.39 (95% CI 1.47-3.90)], in lung cancer [vs breast, 2.98 (95% CI 2.31-3.84)] and in lymphomas [vs breast, 1.467 (95% CI 1.18-1.83)], but was not influenced by sex [female vs male, 0.94 (95% CI 0.819-1.079)], race {[white vs black, 1.0 (95% CI 0.839-1.195)], [white vs other, 0.957 (95% CI 0.795-1.151)]}, or year of diagnosis of t-MDS [2001-2006 vs 2007-2015, 1.025 (95% CI 0.923-1.139)]. Conclusions: In population-based analyses, the survival of t-MDS remains dismal with outcomes particularly worse with advancing age and following primary cancer sites that are typically managed with combined modality regimens including chemotherapy and radiation. Findings from the real-world population level data such as this should be used as outcome benchmarks in clinical trials to assess therapeutic effectiveness of experimental treatments. Disclosures Gerds: Apexx Oncology: Consultancy; Celgene: Consultancy; Incyte: Consultancy; CTI Biopharma: Consultancy. Nazha:MEI: Consultancy. Carraway:Jazz: Speakers Bureau; FibroGen: Consultancy; Balaxa: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Agios: Consultancy, Speakers Bureau. Maciejewski:Ra Pharmaceuticals, Inc: Consultancy; Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Apellis Pharmaceuticals: Consultancy; Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Apellis Pharmaceuticals: Consultancy; Ra Pharmaceuticals, Inc: Consultancy. Majhail:Incyte: Honoraria; Anthem, Inc.: Consultancy; Atara: Honoraria. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees; Opsona: Membership on an entity's Board of Directors or advisory committees; Opsona: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.


Silva Fennica ◽  
2020 ◽  
Vol 54 (5) ◽  
Author(s):  
Tiina Laine ◽  
Ville Kankaanhuhta ◽  
Juho Rantala ◽  
Timo Saksa

In Nordic forests, consistent evidence about better seedling survival rate and increased growth due to site preparation have been obtained in numerous studies. Proper site preparation method can reduce costs of the whole regeneration chain through its effects on survival of planted seedlings, abundance of natural regeneration and competition in early stand development. This study compared the natural regeneration of birches (silver birch ( Roth) and downy birch ( Ehrh.)), amount of exposed mineral soil, and growth of planted seedlings between spot mounding and inverting site preparation methods. Present study was conducted in eight forest stands established in 2012 or 2015. Even though difference was not statistically significant, inverting exposed less mineral soil than spot mounding and thus reduced the natural regeneration of birch seedlings by 6135 seedlings ha compared to spot mounding. However, the variation between regeneration areas was remarkable. There was no difference in seedling mortality or growth between the site preparation methods. In order to achieve high growth of conifers, moderate amount of exposed mineral soil and thus less naturally regenerated birch, inverting should be favored over spot mounding.Betula pendulaB. pubescens–1


2021 ◽  
Vol 27 (07) ◽  
pp. 648-655
Author(s):  
Nour Abdo ◽  
Majd Alsoukhni ◽  
Anwar Batieha ◽  
Kamal Arqoub

Background: Urinary bladder cancer is the fourth most common cancer in Jordan. No research on survival from bladder cancer at the national level has been conducted before. Aims: This study aimed to estimate the probability of survival in patients with bladder cancer in Jordan and identify factors associated with survival. Methods: Data were obtained from the database of the Jordan cancer registry. All cases of urinary bladder cancer in Jordanians registered during 2005–2014 were included in the study (n = 2139). Data collected for each case included: age, sex, date of diagnosis, and stage and grade at diagnosis. Actuarial life table survival analysis was used to determine the overall survival probabilities. Cox proportional hazard regression was used to identify independent factors associated with survival. Results: The overall 1-, 3-, 5- and 10-year survival probabilities for urinary bladder cancer were 85%, 73%, 69% and 59%, respectively (standard error = 0.01 for each). No significant difference in survival probabilities was found between males and females (P = 0.642). The overall survival probabilities decreased significantly as age at diagnosis increased (P < 0.005). Better survival was observed in patients with early stage and well differentiated tumours at diagnosis. Conclusions: The survival of patients with bladder cancer in Jordan is comparable to that reported from developed countries. A high percentage of data was missing and the reporting of some variables was inconsistent. To improve the quality of cancer data, regular training is needed for hospital focal points on recording complete data


1997 ◽  
Vol 99 (1-2) ◽  
pp. 203-214 ◽  
Author(s):  
Kate Hardwick ◽  
John Healey ◽  
Stephen Elliott ◽  
Nancy Garwood ◽  
Vilaiwan Anusarnsunthorn

1988 ◽  
Vol 15 (6) ◽  
pp. 637 ◽  
Author(s):  
RJ Taylor ◽  
NM Savva

Roosting requirements and movements between foraging areas and roost sites were studied in Eptesicus regulus, E. sagittula, Chalinolobus morio and Nyctophilus geoffroyi in an area of artificially regenerated eucalypt (Eucalyptus) forest surrounded by mature eucalypt forest. Movements between traps and roost sites were normally about 1 km, with the maximum distance recorded being 4.8 km for a female N. geoffroyi. Different species of eucalypts were used as roost sites in proportion to their occurrence in the forest. However, large trees over 80 cm d.b.h. were favoured. There was no tendency to avoid roost sites close to the ground. Spaces used as roost sites had one dimension little greater than the bat itself. Five types of roost sites were distinguished: in fissures, inside burnt-out boles, in hollows, under bark and on the ground. Individuals changed roost sites frequently but roosts used by any one individual were in the same general vicinity. The factors associated with production of roost sites in trees were: large size, overmaturity, death, rot and fire. No bats were found to roost in regenerated forest. Patches of mature forest will need to be retained to ensure a shortage of roosts does not occur as more areas of mature forest are converted to production forest.


2014 ◽  
Vol 67 (4) ◽  
pp. 344-357 ◽  
Author(s):  
Daniel R. Schlaepfer ◽  
William K. Lauenroth ◽  
John B. Bradford

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