scholarly journals Growth and survival over ten years of Brazil-nut trees planted in three anthropogenic habitats in northern Amazonia

2021 ◽  
Vol 51 (1) ◽  
pp. 20-29
Author(s):  
Ricardo SCOLES ◽  
Rogério GRIBEL
Keyword(s):  
Light Exposure ◽  
Canopy Openness ◽  
Brazil Nut ◽  
Anthropogenic Habitats ◽  
Growth And Survival ◽  
Canopy Opening ◽  
Crop Field ◽  
Northern Brazil ◽  
And Control ◽  
Adequate Management

ABSTRACT We examined the growth and survival of Brazil-nut trees, Bertholletia excelsa (Lecythidaceae) under different environmental conditions and levels of canopy openness within experimental plantations in the Trombetas River valley, in northern Brazil. We planted 144 seedlings in three anthropogenic habitats with different levels of sunlight exposition: crop field (100% canopy opening), shrub fallow (20-80% canopy opening) and Brazil-nut forest (< 10% canopy opening). We measured plant height and diameter annually and recorded mortality and resprouting over ten years. The performance of B. excelsa differed significantly among habitats, with the highest growth rate observed at the highest level of canopy openness (crop field). Survival was highest in crop field (85%) and shrub fallow (63%) and lowest in Brazil-nut forest (17%). Resprouting capacity was higher in the crop field, as Brazil-nut plants recovered after fire episodes, with most plants resprouting more than one shoot. Some trees in the crop field began to produce flowers and fruits at 9-10 years. We showed that B. excelsa juveniles are light-demanding, with higher survival and growth under conditions of high light exposure. We suggest the use of Brazil-nut trees for reforestation, restoration of degraded lands and enrichment of secondary vegetation, as long as an adequate management is adopted (e.g., maintaining plants exposed to direct sunlight and control of competing pioneer species).

scholarly journals Wolbachia: endosymbiont of onchocercid nematodes and their vectors

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ranju Ravindran Santhakumari Manoj ◽  
Maria Stefania Latrofa ◽  
Sara Epis ◽  
Domenico Otranto
Keyword(s):  
Control Strategies ◽  
Molecular Data ◽  
Scientific Data ◽  
Growth And Survival ◽  
Vector Borne Diseases ◽  
Wide Range ◽  
Veterinary Importance ◽  
Wolbachia Endosymbiont ◽  
Vector Borne ◽  
And Control

Abstract Background Wolbachia is an obligate intracellular maternally transmitted, gram-negative bacterium which forms a spectrum of endosymbiotic relationships from parasitism to obligatory mutualism in a wide range of arthropods and onchocercid nematodes, respectively. In arthropods Wolbachia produces reproductive manipulations such as male killing, feminization, parthenogenesis and cytoplasmic incompatibility for its propagation and provides an additional fitness benefit for the host to protect against pathogens, whilst in onchocercid nematodes, apart from the mutual metabolic dependence, this bacterium is involved in moulting, embryogenesis, growth and survival of the host. Methods This review details the molecular data of Wolbachia and its effect on host biology, immunity, ecology and evolution, reproduction, endosymbiont-based treatment and control strategies exploited for filariasis. Relevant peer-reviewed scientic papers available in various authenticated scientific data bases were considered while writing the review. Conclusions The information presented provides an overview on Wolbachia biology and its use in the control and/or treatment of vectors, onchocercid nematodes and viral diseases of medical and veterinary importance. This offers the development of new approaches for the control of a variety of vector-borne diseases. Graphic Abstract

scholarly journals Prunus Africana Provenances Growth and Survival Evaluation in the Highland of Awi zone, Amhara Region, North Western Ethiopia

2018 ◽  
Author(s):  
Abraham Demekristos
Keyword(s):  
Light Exposure ◽  
Seedling Survival ◽  
Block Design ◽  
Soil Water Potential ◽  
Mean Value ◽  
Good Growth ◽  
Growth And Survival ◽  
Prunus Africana ◽  
Survival And Growth ◽  
Establishment Rate

The aims of the study were to evaluate seedling growth and survival of Prunus africana provenances in awi highland based on ecological requirement of the tree. We measured survival and growth of three P.africana provenances seedlings found in Ethiopia (provenances sources namely: Gedeo, Jibat and Munnessa). Design of experiment with randomized complete block design (RCBD) with three replications. Seedlings planted at 2m, 2.5m and 3m distance between plants, plot, and blocks respectively. A plot size of 10mx10m and 25 plants are found per plot (0.01ha). We used ANOVA to test differences in survival, and growth among provenances over time. Results concluded that, provenances have no significant variation among in establishment rate, plant height and collar diameter growth. Of these provenances, Jibat was the first in establishment (56%), second in height (1.97m) and diameter (2.89cm). Gedeo was stood first in height (2.30m) but second in establishment rate (52%) and thickness(3.45cm), but Munessa with very good growth in diameter(3.59cm) might be prefreed for bark extraction followed by Gedeo, last in height (1.75m),but established second (52%). Contrary to expectations, seedlings were still at substantial risk of mortality &ge;3 years after planting. Probably the plants survival rate and growth probably affected by altitude, soil water potential, light exposure, and wild animal presence in the surrounding. In steep slope sites, canopy shade, existing weed vegetation as well as wild animals such as apes is unlikely to enhance seedling survival after planting. Our results suggest that seedling mean growth increased with 0.008mm thickness and 0.41mm per day while 2.8mm thickness and 146.8mm tall increment recorded in 2560meter elevated high land or injibara with mean value of 18.5&deg;C and rain fall is 1300mm.

scholarly journals Role of Mineral and Bio-fertilizers on Some Soil Properties and Rice Productivity under Reclaimed Saline Soils

2019 ◽  
pp. 1-12
Author(s):  
Mohamed I. Mohaseb ◽  
Mona H. M. Kenawy ◽  
Khaled A. H. Shaban
Keyword(s):  
Soil Properties ◽  
Agricultural Research ◽  
Nutrient Content ◽  
Mineral Fertilizers ◽  
Research Station ◽  
Available N ◽  
Rice Productivity ◽  
Rice Plants ◽  
Crop Field ◽  
And Control

A field experiment (randomized complete blocks with three replicates) was conducted during two successive summer seasons of 2016 and 2017 at Sahl El-Houssinia Agriculture Research Station in El-Shakia Governorate, Egypt. Its lies between 32˚00/00 to 32˚15/00/ N latitude and 30˚50 / 00// to 31˚15 00// E longitude. The combined effect of bio-fertilizers inoculated with Rhizobium radiobacter sp strain (salt tolerant PGPR); Bacillus megatherium (dissolving phosphate) and Bacillus circulans (enhancing potassium availability) and yeast strains (Saccharomyces cerevisiae) combined with different rates of N, P and K fertilizers (50, 75 and 100%) was evaluated on some soil properties, nutrient content in rice plants, and rice productivity in a reclaimed saline soil. From the crop field of the Agricultural Research Institute (ARC), Egypt, 101 grain kernels from rice (Oryza sativa) var. Sakha were selected.   The results indicated that soil pH and EC were decreased in soil treated with bio-fertilizers combined with different rates of mineral fertilizers in comparison with soil treated with yeast and control. Available N, P, K, Fe, Mn and Zn in the soil increased with the use of bio-fertilizers. Application of mineral fertilizers (N, P and K) alone or combined with bio-fertilizers (bacteria and yeast) resulted in increased yield grains and straw of rice plant. Macro- and micronutrients concentrations and uptake in grain and straw of rice plants increased in soil treated with bacteria + 75% N+P+K fertilizers compared with other treatments.                          

Growth and Survival of Hormone-Sterilized Coho (Oncorhynchus kisutch) and Kokanee Salmon (O. nerka) in a Lacustrine Environment

1988 ◽  
Vol 45 (8) ◽  
pp. 1490-1494 ◽  
Author(s):  
Eric A. Parkinson ◽  
Kanji Tsumura
Keyword(s):  
Survival Rates ◽  
Oncorhynchus Kisutch ◽  
Control Fish ◽  
Lacustrine Environment ◽  
Growth And Survival ◽  
Kokanee Salmon ◽  
Return Rates ◽  
Differential Vulnerability ◽  
Normal Life Span ◽  
And Control

Coho (Oncorhynchus kisutch) and kokanee salmon (O. nerka) were sterilized using 17α-methyltestosterone treatments and released into a lacustrine environment. The treatment appeared to be successful and sizes at capture were similar for treated and control fish. Return rates of hormone-treated groups of fish were much lower than those of the control groups. Differences in return rates were assumed to be due to differences in survival rates but the possibility of differential vulnerability to the capture gear could not be ruled out. The proportion of treated kokanee in the catch increased with age, indicating that treated kokanee survived beyond the normal life span of the species.

scholarly journals The lysosome as a command-and-control center for cellular metabolism

2016 ◽  
Vol 214 (6) ◽  
pp. 653-664 ◽  
Author(s):  
Chun-Yan Lim ◽  
Roberto Zoncu
Keyword(s):  
Building Blocks ◽  
Eukaryotic Cell ◽  
Nutrient Sensing ◽  
Cellular Growth ◽  
Metabolic Homeostasis ◽  
Waste Products ◽  
Control Center ◽  
Growth And Survival ◽  
Membrane Bound ◽  
And Control

Lysosomes are membrane-bound organelles found in every eukaryotic cell. They are widely known as terminal catabolic stations that rid cells of waste products and scavenge metabolic building blocks that sustain essential biosynthetic reactions during starvation. In recent years, this classical view has been dramatically expanded by the discovery of new roles of the lysosome in nutrient sensing, transcriptional regulation, and metabolic homeostasis. These discoveries have elevated the lysosome to a decision-making center involved in the control of cellular growth and survival. Here we review these recently discovered properties of the lysosome, with a focus on how lysosomal signaling pathways respond to external and internal cues and how they ultimately enable metabolic homeostasis and cellular adaptation.

Effects of the Insecticide Sevin on Various Stages of the Dungeness Crab, Cancer magister

1970 ◽  
Vol 27 (1) ◽  
pp. 93-104 ◽  
Author(s):  
David V. Buchanan ◽  
Raymond E. Millemann ◽  
Nelson E. Stewart
Keyword(s):  
Sea Water ◽  
Field Application ◽  
Dungeness Crab ◽  
Cancer Magister ◽  
Egg Hatching ◽  
Growth And Survival ◽  
Life History Stages ◽  
And Control ◽  
Control Survival ◽  
Early Larvae

Of the life-history stages of the Dungeness crab, Cancer magister, the early larvae are more sensitive to Sevin than are juveniles and adults. A concentration of 1.0 mg/liter did not affect egg hatching but prevented molting of all prezoeae to zoeae. The concentration that killed 50% of the first stage zoeae during a 96-hr exposure (96-hr EC50 for death) was estimated to be 0.01 mg/liter. Few zoeae were killed in 24 hr by 82.0 mg/liter, but the 24-hr EC50 for death within 15 days after the exposure was estimated to be 0.015 mg/liter. The 24-hr EC50 for cessation of swimming, which was not always permanent, was 0.0065 mg/liter. Survival of zoeae after 25 days exposure to concentrations of 0.0001, 0.00032, 0.001, 0.0032, and 0.01 mg/liter were 83, 60, 69, 21, and 0%, respectively, and control survival was 79%. Molting was delayed at a concentration as low as 0.0001 mg/liter.Young juvenile crabs are more sensitive to Sevin than are older juveniles or adults. The 24-hr EC50's for death or irreversible paralysis were estimated to be 0.076 and 0.35 to 0.62 mg/liter for second and ninth stage juveniles, respectively. The behavior, growth, and survival of juvenile crabs were not affected when the animals were exposed to 0.032 mg/liter of Sevin for 24 hr and then held in clean sea water for 44 days. The 24-hr and 96-hr EC50's for death or irreversible paralysis were 0.49 and 0.26 mg/liter, respectively, for adult crabs. After eating cockle clams that had just been exposed for 24 hr to 1.0, 3.2, and 10.0 mg/liter of Sevin, 22, 77, and 100% of adult crabs, respectively, were irreversibly paralyzed within 6 hr. The significance of these findings in field application of Sevin to control oyster pests and predators is discussed.

scholarly journals NUTRITION IN THE PRODUCTION AND QUALITY OF SEEDLINGS OF THE BRAZIL NUT (Bertholletia excelsa H.B.K.) IN NORTHERN BRAZIL

2019 ◽  
Vol 9 (3) ◽  
Author(s):  
Aline das Graças Souza ◽  
Oscar josé Smiderle
Keyword(s):  
Nutrient Solution ◽  
Dry Weight ◽  
Production Costs ◽  
Brazil Nut ◽  
Bertholletia Excelsa ◽  
Shoot Dry Weight ◽  
Northern Brazil ◽  
Total Dry Weight ◽  
Shoot Weight

The Brazil nut (Bertholletia excelsa H.B.K.) is fast-growing, and can be used in reforestation. However, the use of the species in reforestation is still uncommon, mainly due to production costs, with substrate and fertiliser being the most-costly components. Based on the above, the aim of this study was to evaluate growth and quality in seedlings of the Brazil nut both with and without nutrient solution. The experimental design was completely randomised in a 2 x 10 factorial scheme: treatments with and without the addition of nutrient solution and 10 evaluations at intervals of 45 days. The variables to be analysed were height, stem diameter, dry shoot weight, root dry weight, total dry weight and the Dickson quality index. When analysing shoot dry weight (SDW), a gain of 85% was found from adding the nutrient solution, compared to the absence of nutrient solution, whereas for the variable, root-system dry weight, (RDW) the gain was 43%. The addition of nutrient solution is suggested for accelerating the growth and development of high-quality seedlings of Bertholletia excelsa for commercial use.

Evaluation of growth performance of Penaeus monodon (Fabricius) fed diet with partial replacement of fishmeal by Spirulina platensis (Sp) meal

2018 ◽  
Author(s):  
Natesan Sivakumar ◽  
Muthuraman Sundararaman ◽  
Gopal Selvakumar
Keyword(s):  
Growth Rate ◽  
Spirulina Platensis ◽  
Fish Meal ◽  
Control Diet ◽  
Penaeus Monodon ◽  
Carcass Composition ◽  
Partial Replacement ◽  
Protein Ratio ◽  
Growth And Survival ◽  
And Control

A partial replacement of fish meal with Spirulina platensis (Sp) meal for the diet of juvenile shrimp Penaeus monodon (Fabricius) was analyzed for the growth and survival under laboratory condition. A total of five experimental diets were formulated with partial replacement of fishmeal by Sp meal, Sp-1 (14.3%), Sp-2 (28.6%), Sp-3 (42.8%), Sp-4 (57.14%), and the control diet (Sp meal free diet). The feeding trial was conducted for the period of 60 days. Juveniles fed with Sp meal supplemented diet showed significant (P less than 0.05) improvement of carcass composition (protein ratio and edible flesh). Higher growth and survival were obtained in P. monodon fed with Sp-3 diet, it was significantly (P less than 0.05) greater than the Sp meal free diet. The feeding efficiency (FE), specific growth rate (SGR) and survival (93.3%) of the shrimp was significantly (P less than 0.05) high in the Sp-3 diet. Survival rate was also higher in diet Sp-3 (42.8% substitution), but lower survival and growth rate observed in Sp-4 (57.14% substitution) and control diets. The Physico-chemical quality of the experimental tank water was better in Sp-3, and Sp-2 diet groups. This study recommended that Sp meal as alternative protein substitute of fish meal in shrimp diet.

Expression of a mutant opsin gene increases the susceptibility of the retina to light damage

1997 ◽  
Vol 14 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Min Wang ◽  
Tim T. Lam ◽  
Mark O.M. Tso ◽  
Muna I. Naash
Keyword(s):  
Retinitis Pigmentosa ◽  
Transgene Expression ◽  
Light Exposure ◽  
Point Mutations ◽  
Transgenic Animals ◽  
The United States ◽  
Opsin Gene ◽  
Light Damage ◽  
Retinal Structure ◽  
And Control

AbstractThe question of whether the expression of mutant opsin predisposes the retina to light damage was addressed using transgenic mice that express rhodopsin with three point mutations near the N-terminus of the molecule. The mutations involve the substitution of histidine for proline at position 23 (P23H), glycine for valine at position 20 (V20G), and leucine for proline at position 27 (P27L). These mice express equal amounts of mutant and wild-type transcripts, and develop a progressive photoreceptor degeneration that is similar to that seen in human retinitis pigmentosa (RP). The P23H mutation is associated with the most frequently occurring form of human autosomal dominant retinitis pigmentosa (ADRP) in the United States. Transgenic and normal littermates were exposed to illuminance of 300 foot-candles (ft-c) for 24 h, then placed in darkness for either 6 h, 6 days, or 14 days. Histological and biochemical techniques were used to evaluate the outer retina in light-exposed and control animals reared on 12-h light/12-h dark cycle. The results indicate that light exposure accelerates the pathological changes associated with the transgene expression. Compared with transgenic animals reared in ambient cyclic light, retinas from light-exposed mice had a reduced rhodopsin content, fewer photoreceptor cell bodies, and less preservation of retinal structure. Data obtained from normal mice did not differ for the lighting regimens used. These findings suggest that the expression of VPP mutations in the opsin gene predisposes the transgenic photoreceptors to be more susceptible to light damage. The data also suggest that reducing photic exposure may be beneficial to any patient with RP mediated by an opsin mutation.

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