Modeling population dynamics for information dissemination through Facebook

Author(s):  
Hiep Xuan Huynh ◽  
Be Ut Lai ◽  
Nghia Duong‐Trung ◽  
Hai Thanh Nguyen ◽  
Thuong‐Cang Phan
2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.


2019 ◽  
Vol 13 (2) ◽  
pp. 115-123
Author(s):  
Ratu Mutialela Caropeboka

The environment is also called the natural environment is a phenomenon that forms around life rather than humans, either biotic or abiotic. The surrounding phenomenon that affects people is not limited to physical factors solely, on the contrary social factors play an important role to explain how human activity can affect the environment and the natural surroundings. The essence and falsafa of development is a change, growth and equity in all fields and dimensions to a better state. Development communication is part of a major process that requires social, economic, political and cultural change in line with the requirements of the local community. The simultaneous formulation of information dissemination carried out by radio, is no longer the only option of society, because the community has designed and determined what information they need. Television broadcasting has an influence on patterns of public action to model, imitate information gained through impressions. Community participation in safeguarding the environment to achieve harmonious and balanced development is the driving and driving force for social change to achieve sustainable development. Lingkungan disebut juga alam sekitar adalah fenomena yang wujud di sekeliling kehidupan daripada manusia,baik biotik ataupun abiotik. Fenomena sekeliling yang mempengaruhi manusia tidak terbatas kepada faktor fisikal semata-mata, sebaliknya faktor sosial turut berperanan penting bagi menerangkan bagaimana aktivitas manusia dapat mempengaruhi lingkungan dan alam sekitar. Hakikat dan Falasafah pembangunan ialah suatu perubahan, pertumbuhan dan pemerataan dalam segala bidang dan dimensinya menuju keadaan yang lebih baik. Komunikasi pembangunan merupakan bahagian dari proses besar yang menghendaki adanya perubahan sosial, ekonomi, politik dan budaya yang sejalan dengan persyaratan keperluan masyarakat lokal. Formula keserentakan penyebaran informasi yang dilakukan melalui radio, tidak lagi menjadi satu-satunya pilihan masyarakat, karena masyarakatlah telah merancang dan menentukan informasi apa yang mereka perlukan. Siaran televisi mempunyai pengaruh pada pola tindakan masyarakat untuk mencontoh, meniru informasi yang didapat melalui tayangan. Partisipasi masyarakat menjaga lingkungan untuk mewujudkan pembangunan yang serasi dan seimbang adalah penggerak dan pengarah bagi perubahan sosial untuk mewujudkan pembangunan yang berkelanjutan


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