scholarly journals Seed mass diversity along resource gradients: the role of allometric growth rate and size-asymmetric competition

Ecology ◽  
2018 ◽  
Vol 99 (10) ◽  
pp. 2196-2206 ◽  
Author(s):  
Niv DeMalach ◽  
Ronen Kadmon
Author(s):  
Utkarsh Kumar ◽  
Anil Kumar Gope ◽  
Shweta Singh

In India, the position of mobile banking was in saga and this time, it is in pic position. The speedof reaching the people is going high and high. This is time of wireless world and sense of prestige; no doubt the mobile commerce is contributing to enhance the beauty of life and playing the role of metaphor and has become the part and parcel of our life. This growth has changed people to do business in mobile commerce (М- Commerce). Peoples are transferring to M-Commerce to attain good and fast transaction into market and saving their precious time. M-Commerce has become distinguished in Indian people, quickly during last few years. Due to large number of mobile application, growth rate in mobile penetration in India is increasing with the rapid speed. The mobile users has shifted to use the android phone from simple and black and white phone and taking the service of internet, the role of telecom companies is also important in the being popular of mobile commerce. Although many people have started E-Commerce but still a separate part of the society feel uncomfortable and hesitate to use M-Commerce because of security problems, payment issues and complexity of mobile applications. This paper identifies facts about the feasibility of MCommercein India today its growth and the Strength and opportunity, weakness and threats lying ahead.


1995 ◽  
Vol 46 (5) ◽  
pp. 1027 ◽  
Author(s):  
FP Smith ◽  
PS Cocks ◽  
MA Ewing

Cluster clover is a widely distributed and ecologically successful introduced legume in southern Australia. In an attempt to understand the role of genetic variation in this success, morphological and physiological traits were measured in 94 accessions from southern Australia and 6 from the Mediterranean basin. Flowering time ranged from 105 to 185 days after sowing, but was not strongly correlated with annual rainfall or length of growing season at the site of collection. Variation in other traits partitioned the populations into two morphs which, apart from flowering time and leaf marker, were largely homogeneous. The morphs differed significantly in floret number per inflorescence (22 v. 32-37) and seed mass (379 8g v. 523 8g), had different growth habits and strong within-morph associations between leaf markers and stipule and petal coloration. The morphs differed in their distributions within southern Australia and the pattern of distribution was related to summer maximum temperatures, winter minimum temperatures and spring rainfall. These results demonstrate that genetic variation has been important to the success of cluster clover and suggests that the variation is organized. The pattern of variation observed and its relationship to ecogeography is consistent with findings for other highly inbreeding species. A map of the species distribution in Western Australia is presented.


2021 ◽  
Vol 483 ◽  
pp. 118908
Author(s):  
Mizanur Rahman ◽  
Masum Billah ◽  
Md Obydur Rahman ◽  
Debit Datta ◽  
Muhammad Ahsanuzzaman ◽  
...  

2005 ◽  
Vol 25 (23) ◽  
pp. 10315-10328 ◽  
Author(s):  
Yukinori Minoshima ◽  
Tetsuya Hori ◽  
Masahiro Okada ◽  
Hiroshi Kimura ◽  
Tokuko Haraguchi ◽  
...  

ABSTRACT We identified CENP-50 as a novel kinetochore component. We found that CENP-50 is a constitutive component of the centromere that colocalizes with CENP-A and CENP-H throughout the cell cycle in vertebrate cells. To determine the precise role of CENP-50, we examined its role in centromere function by generating a loss-of-function mutant in the chicken DT40 cell line. The CENP-50 knockout was not lethal; however, the growth rate of cells with this mutation was slower than that of wild-type cells. We observed that the time for CENP-50-deficient cells to complete mitosis was longer than that for wild-type cells. Centromeric localization of CENP-50 was abolished in both CENP-H- and CENP-I-deficient cells. Coimmunoprecipitation experiments revealed that CENP-50 interacted with the CENP-H/CENP-I complex in chicken DT40 cells. We also observed severe mitotic defects in CENP-50-deficient cells with apparent premature sister chromatid separation when the mitotic checkpoint was activated, indicating that CENP-50 is required for recovery from spindle damage.


1994 ◽  
Vol 24 (2) ◽  
pp. 306-320 ◽  
Author(s):  
P.B. Reich ◽  
J. Oleksyn ◽  
M.G. Tjoelker

Seedlings of 24 European Scots pine (Pinussylvestris L.) populations were grown in controlled environment chambers under simulated photoperiodic conditions of 50 and 60°N latitude to evaluate the effect of seed mass on germination and seedling growth characteristics. Seeds of each population were classified into 1-mg mass classes, and the four classes per population with the highest frequencies were used. Photoperiod had minimal influence on seed mass effects. Overall, seed mass was positively related to the number of cotyledons and hypocotyl height. Populations differed significantly in seed mass effect on biomass. In northern populations (55–61°N), dry mass at the end of the first growing season was little affected by seed mass. However, dry mass in 9 of 15 central populations (54–48°N) and all southern (<45°N) populations correlated positively with seed mass. Relative growth rate was not related to seed mass within or across populations, and thus early growth is largely determined by seed mass. Relative growth rate also did not differ among populations, except for a geographically isolated Turkish population with the highest seed mass and lowest relative growth rate. After one growing season, height was positively correlated (r2 > 0.6) with seed mass in 15 populations. To check the duration of seed mass effects, height growth of 1- to 7-year-old field experiments established with the same seed lots were compared. Seed mass effects on height were strongest for 1-year-old seedlings and declined or disappeared by the age of 5–7 years among central and southern populations, but remained stable over that time in northern populations.


2018 ◽  
Vol 115 (31) ◽  
pp. E7361-E7368 ◽  
Author(s):  
Bernardo García-Carreras ◽  
Sofía Sal ◽  
Daniel Padfield ◽  
Dimitrios-Georgios Kontopoulos ◽  
Elvire Bestion ◽  
...  

Relating the temperature dependence of photosynthetic biomass production to underlying metabolic rates in autotrophs is crucial for predicting the effects of climatic temperature fluctuations on the carbon balance of ecosystems. We present a mathematical model that links thermal performance curves (TPCs) of photosynthesis, respiration, and carbon allocation efficiency to the exponential growth rate of a population of photosynthetic autotroph cells. Using experiments with the green alga, Chlorella vulgaris, we apply the model to show that the temperature dependence of carbon allocation efficiency is key to understanding responses of growth rates to warming at both ecological and longer-term evolutionary timescales. Finally, we assemble a dataset of multiple terrestrial and aquatic autotroph species to show that the effects of temperature-dependent carbon allocation efficiency on potential growth rate TPCs are expected to be consistent across taxa. In particular, both the thermal sensitivity and the optimal temperature of growth rates are expected to change significantly due to temperature dependence of carbon allocation efficiency alone. Our study provides a foundation for understanding how the temperature dependence of carbon allocation determines how population growth rates respond to temperature.


2017 ◽  
Vol 4 (6) ◽  
pp. 170463 ◽  
Author(s):  
Julian Sheats ◽  
Bianca Sclavi ◽  
Marco Cosentino Lagomarsino ◽  
Pietro Cicuta ◽  
Kevin D. Dorfman

We present experimental data on the nematic alignment of Escherichia coli bacteria confined in a slit, with an emphasis on the effect of growth rate and corresponding changes in cell aspect ratio. Global alignment with the channel walls arises from the combination of local nematic ordering of nearby cells, induced by cell division and the elongated shape of the cells, and the preferential orientation of cells proximate to the side walls of the slit. Decreasing the growth rate leads to a decrease in alignment with the walls, which is attributed primarily to effects of changing cell aspect ratio rather than changes in the variance in cell area. Decreasing confinement also reduces the degree of alignment by a similar amount as a decrease in the growth rate, but the distribution of the degree of alignment differs. The onset of alignment with the channel walls is coincident with the slits reaching their steady-state occupancy and connected to the re-orientation of locally aligned regions with respect to the walls during density fluctuations.


1992 ◽  
Vol 66 (2) ◽  
pp. 100-107 ◽  
Author(s):  
V. G. M. Swarnakumari ◽  
R. Madhavi

ABSTRACTFifty day-old chicks were each infected with 10 excysted metaccreariae of Philophthalimus nocturnus Looss. 1907 around each orbit and growth, development and allometry were studied. The growth rate showed two phases over a period of 35 days, a limited lag phase lasting two days post-infection in which flukes did not exceed 440 μm in length, and a rapid phase during which growth was rapid and flukes reached a size of 3·008–3·504 mm on day 35. Five developmental stages were noticed during the course of development of the metacercaria to the egg-producing adult stage. Eggs appeared in the uterus on day 14 and oculate miracidia on day 25. The hindhody, testes and ovary showed positive allometric growth, the pharnyx less so, whereas negative allometric growth was shown by the forebody. Body width, oral sucker and ventral sucker were close to isometry, growing at the same rate as the body length.


ICR Journal ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 97-100
Author(s):  
Shahino Mah Abdullah

The most frequent transboundary haze in the world takes place in Southeast Asia. It is usually caused by land-use changes, open burning, peat combustion, wildfires, and other farming activities. Serious haze occurred in 1983, 1997, 2005, 2006, 2009, 2010, 2013, 2015 and 2016, originating from large-scale forest fires in western Sumatra and southern Kalimantan, Indonesia. It caused adverse effects to locals as well as neighbouring countries, affecting their health, economy, agriculture, and biodiversity. Among the serious effects of haze are increased respiratory-related mortality due to toxic airborne particles, jet crashs and ship collisions due to restricted visibility, reduction of crop growth rate due to limited solar radiation, and extinction of endangered primates due to habitat loss. Neighbouring countries like Malaysia and Singapore sometimes have to close schools to prevent people from being exposed to air pollution, and its consequent respiratory ailments.  


2017 ◽  
Vol 3 (2) ◽  
pp. 159
Author(s):  
Yulia Yulia ◽  
Lukman Mohammad Baga ◽  
Netti Tinaprilla

Agam District Government has the goal of improving economic growth rate of 5.94 percent in 2011 to 7.98 percent in 2017. However, the constraints experienced by the development of the animal husbandry sector is a decrease in the growth rate of the animal husbandry sector and the contribution to the GDP, it is necessary for the development of the animal husbandry subsector in Agam by taking into account various aspects. This study aims to analyze the potential and role of formulating priority strategies of alternative development strategy animal husbandry subsector. Results of the analysis of the animal husbandry subsector LQ is a commodity basis. The shift results proportional growth 10.72 percent negative growth. Region share growth of 2.33 percent. The results obtained from the alternative strategies SWOT matrix were analyzed using QSPM. development and coaching each region based on the existing potential (6.278), increasing the promotion and development of human resources breeder (5.773), to build and develop patterns of cooperation and mutual benefit (5.618), examination of animal health and disease prevention (5.406), implementation and development appropriate technology (5.330) and optimization in securing local resources (4.982). Selected strategic alternatives of highest appeal total development strategy as well as coaching is done each region based on the existing potential (6.278), then the suggestions can be made to the Government Agam namely increasing the number of livestock extension workers and attract investors to develop the livestock subsector in Agam District.


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