Simulation of the impact of people mobility, vaccination rate, and virus variants on the evolution of Covid-19 outbreak in Italy

We have further extended our compartmental model describing the spread of the infection in Italy. As in our previous work, the model assumes that the time evolution of the observable quantities (number of people still positive to the infection, hospitalized and fatalities cases, healed people, and total number of people that has contracted the infection) depends on average parameters, namely people diffusion coefficient, infection cross-section, and population density. The model provides information on the tight relationship between the variation of the reported infection cases and a well-defined observable physical quantity: the average number of people that lie within the daily displacement area of any single person. With respect to our previous paper, we have extended the analyses to several regions in Italy, characterized by different levels of restrictions and we have correlated them to the diffusion coefficient. Furthermore, the model now includes self-consistent evaluation of the reproduction index, effect of immunization due to vaccination, and potential impact of virus variants on the dynamical evolution of the outbreak. The model fits the epidemic data in Italy, and allows us to strictly relate the time evolution of the number of hospitalized cases and fatalities to the change of people mobility, vaccination rate, and appearance of an initial concentration of people positives for new variants of the virus.

ANALISIS PERILAKU PENUMPANG KA BANDARA MANGGARAI – SOETTA PADA MASA PANDEMI DAN PENGARUHNYA TERHADAP POLA PERJALANAN

In the current era of globalization, transportation is a fundamental need for all human, to carry out daily displacement activities. The journey to the airport is one of the activities that occur every day but the heavy traffic in Jakarta, makes people leave early so that the airport train is presented by PT. Railink. But, during COVID-19 pandemic, all transportation experience restrictions to reduce the number positive of COVID-19, restrictions by limiting the number of passengers in all transportation so the risk of it’s spread can be minimized. This affects community activities because all transportation implements health protocols so that community is difficult doing activities. This research was conducted to determine the behavior of airport train passengers towards health protocols implemented by the government, whether they are aware of the dangers of COVID-19 so they realize the importance of implementing health protocols outdoors. The data for research was obtained through questionnaire, then processed using normative and descriptive analysis methods. The results of this study concluded that the awareness of each passenger and officer at the station or train is the most important thing to remind each other in implementing health protocols and obeying to the regulation recommended by the government. ABSTRAKPada era globalisasi seperti saat ini, transportasi merupakan kebutuhan yang mendasar bagi semua manusia, guna melakukan suatu kegiatan perpindahan sehari-hari. Perjalanan menuju ke bandara merupakan salah satu aktivitas yang terjadi setiap hari namun padatnya lalu lintas di Jakarta, membuat masyarakat berangkat lebih awal sehingga dihadirkan kereta api bandara oleh PT. Railink. Namun ditengah pandemi COVID-19 ini semua perjalanan transportasi mengalami pembatasan untuk mengurangi jumlah positif COVID-19, pembatasan yang dilakukan dengan cara membatasi jumlah penumpang di semua transportasi sehingga resiko penyebarannya dapat diminimalisir. Hal ini sangat mempengaruhi aktivitas masyarakat karena semua transportasi menerapkan protokol kesehatan sehingga masyarakat sulit melakukan aktivitas. Penelitian ini dilakukan untuk mengetahui perilaku dari para penumpang kereta api bandara terhadap protokol kesehatan yang diterapkan pemerintah, apakah mereka sadar akan bahaya COVID-19 sehingga menyadari pentingnya melaksanakan protokol kesehatan di luar ruangan. Data untuk penelitian didapatkan melalui kuesioner, lalu diolah menggunakan metode analisis normatif dan deskriptif. Dari hasil penelitian disimpulkan bahwa kesadaran masing-masing penumpang maupun petugas yang berada di stasiun maupun kereta merupakan hal yang terpenting untuk saling mengingatkan dalam melaksanakan protokol kesehatan dan patuh kepada peraturan yang dianjurkan pemerintah.

Homing behaviour by destructive crown-of-thorns starfish is triggered by local availability of coral prey

Corallivorous crown-of-thorns starfishes ( Acanthaster spp.) can decimate coral assemblages on Indo-Pacific coral reefs during population outbreaks. While initial drivers of population irruptions leading to outbreaks remain largely unknown, subsequent dispersal of outbreaks appears coincident with depletion of coral prey. Here, we used in situ time-lapse photography to characterize movement of the Pacific crown-of-thorns starfish ( Acanthaster cf. solaris ) in the northern and southern Great Barrier Reef in 2015, during the fourth recorded population outbreak of the starfish, but prior to widespread coral bleaching. Daily tracking of 58 individuals over a total of 1117 h revealed all starfish to move a minimum of 0.52 m, with around half of all tracked starfish showing negligible daily displacement (less than 1 m day −1 ), ranging up to a maximum of 19 m day −1 . Movement was primarily nocturnal and daily displacement varied spatially with variation in local availability of Acropora spp., which is the preferred coral prey. Two distinct behavioural modes emerged: (i) homing movement, whereby tracked paths (as tested against a random-walk-model) involved short displacement distances following distinct ‘outward' movement to Acropora prey (typically displaying ‘feeding scars') and ‘homebound' movement to nearby shelter; versus (ii) roaming movement, whereby individuals showed directional movement beyond initial tracking positions without return. Logistic modelling revealed more than half of all tracked starfish demonstrated homing when local abundance (percentage cover) of preferred Acropora coral prey was greater than 33%. Our results reveal facultative homing by Acanthaster with the prey-dependent behavioural switch to roaming forays providing a mechanism explaining localized aggregations and diffusion of these population irruptions as prey is locally depleted.

Spatial ecology of the giant armadillo Priodontes maximus in Midwestern Brazil

The giant armadillo (Priodontes maximus) is the largest living armadillo. This naturally rare and poorly known species is endemic to South America and classified as “Vulnerable” by the IUCN. Here we explored aspects of the spatial ecology of P. maximus in Midwestern Brazil to gain insights on its ecology and biology to support conservation efforts. In 8 years, we identified 50 individuals of P. maximus and monitored 23 of them using telemetry methods. To characterize site fidelity and home range, we fitted individual continuous-time movement models and estimated Autocorrelated Kernel Density Estimates. We built a Structural Equation Model to evaluate how home-range area and daily displacement are related to each other, to sampling effort, and to individual characteristics. We estimated home-range overlap between pairs of different sexes using a bias-corrected Bhattacharyya coefficient. Finally, we formulated a canonical density estimation formula to characterize minimum population density. We gathered a total of 12,168 locations of P. maximus. The best-fitted movement models indicated site fidelity for all individuals and a median adult home-range area of 2,518 ha. Median adult daily displacement was 1,651 m. Home-range area scales positively with daily displacement and daily displacement scales positively with body mass. Median home-range overlap between pairs was low (4%) and adult females presented exclusive home ranges among themselves. Median minimum density was 7.65 individuals per 100 km2 (CI = 5.68–10.19 ind/100 km2). Our results are congruent with characterizing P. maximus as a generally asocial species, most likely promiscuous/polygynous, that establishes large, long-term home ranges, which grants the population a naturally low density. Spatial patterns and biological characteristics obtained in this study can be used to guide future conservation strategies for P. maximus in the Pantanal wetlands and elsewhere.

Movement patterns in the green sea urchin, Strongylocentrotus droebachiensis

Time-lapse video was used to record movement paths of Strongylocentrotus droebachiensis on a rocky bottom at 8 m depth, both at a grazing front and in recently formed barrens in the wake of the front. Urchins did not exhibit strong directionality in movement and we did not detect any differences in movement variables between the front and barrens. Density of conspecifics had a negative effect on the speed, move length (distance), and daily displacement of urchins, but did not significantly affect the proportion of time spent moving, the linearity index and the number of moves taken per day. The frequency distributions of turning angles between moves and steps were non-uniformly distributed, indicating directionality in individual paths. A correlated random walk model was used to predict the displacement of urchins through time and provided a good fit with observed data. Our results provide insight into the foraging behaviour of S. droebachiensis and are consistent with previous observations of small-scale movement in this species.

Diffusion of fish from a single release point

In a field experiment, 3529 turbot (Psetta maxima) were released in order to estimate and describe the movements of hatchery-reared fish by applying diffusion theory. After liberation, the development of the population density was estimated during the following 9 days, and from that, the rate of diffusion and the advection were determined. Two approaches were followed to describe the data: a normal distribution approximation (NDA) model and a partial differential equation (PDE) model. In the latter, it was possible to include the effect of sampling. The two models gave similar results, indicating that the sampling of fish during the experiment did not have any detectable effect on the population density. The activity of the released turbot resulted in an individual daily displacement of 151 m·day–1, except for the first 2 days at liberty, where the displacement was estimated to be considerably lower. Advection was significant and was related to the displacement of the water body. Further, it was possible to estimate the postrelease mortality as 14%·day–1 and the catchability of the turbot when caught with a young fish trawl as 28%.