Population age structure of the spotted tree frog (Litoria spenceri): insights into population declines

2010 ◽  
Vol 37 (1) ◽  
pp. 19 ◽  
Author(s):  
Graeme Gillespie
Keyword(s):  
Population Density ◽  
Age Structure ◽  
Amphibian Conservation ◽  
First Year ◽  
Tree Frog ◽  
Population Demography ◽  
Population Declines ◽  
Relative Population ◽  
Population Age Structure

Context. Despite increased scientific attention on amphibian conservation in recent years, knowledge of population demography of amphibians remains scarce, hampering evaluation of population declines and development of appropriate management responses. Aims. The aims of this research were to examine variation in population demography of the spotted tree frog (Litoria spenceri), a critically endangered species in Australia, and to evaluate the role of various factors potentially responsible for population declines such as introduced trout, chytridiomycosis and habitat changes. Methods. Skeletochronology combined with mark–recapture sampling were undertaken in two different river systems, Bogong Creek and Taponga River, to determine population age structure. Age-specific survival estimates were derived from each population and were then used to examine variance in age-specific mortality. Key results. Relative population density per 200 m of stream was 67.7 adults and 131.3 juveniles at Bogong Creek and 10.7 adults and 33.8 juveniles at Taponga River. Ages were determined for 578 frogs across the two populations. Age-specific survival was lowest in the first year of life compared to all other age classes, and highest in sexually mature adults. Differences in age-specific survival were similar between the populations, with the exception of first-year survivorship, which averaged 1.9% at Bogong Creek and 0.4% at Taponga River. This difference was large enough to explain most of the marked difference in population density between the two streams. Key conclusions. The difference in first-year age-specific survival is consistent with trout predation as the most parsimonious explanation for the large differences in population density between the populations, and lends further weight to the role of introduced trout in the decline of this species. Implications. This study has contributed to informing management actions for conservation of this species, and demonstrates that population age structure data may provide valuable insights into demographic variability within and between populations and species. This may have important implications for interpretation of population declines, and conservation and management responses.

Moderating role of social support on first-year college student outcomes

2011 ◽  
Author(s):  
Daniel A. Dickson ◽  
Colleen S. Conley ◽  
Kunal A. Patel ◽  
Daniel Cunningham
Keyword(s):  
Social Support ◽  
College Student ◽  
Student Outcomes ◽  
First Year ◽  
First Year College ◽  
College Student Outcomes ◽  
Moderating Role

The Fox Diet

2018 ◽  
Author(s):  
Yochai Benkler ◽  
Robert Faris ◽  
Hal Roberts
Keyword(s):  
First Year ◽  
Right Wing ◽  
Justice Department ◽  
Fox News ◽  
The Core ◽  
Deep State ◽  
Media Ecosystem ◽  
Conservative Media ◽  
The Right

This chapter focuses on the role of the dominant player in conservative media, Fox News, during the first year of Donald Trump’s presidency. It looks at three case studies to illustrate how Fox News used its position at the core of the right-wing media ecosystem repeatedly to mount propaganda attacks in support of Trump: the Michael Flynn firing in March 2017, when Fox adopted the “deep state” framing of the entire controversy; the James Comey firing and Robert Mueller appointment in May 2017; when Fox propagated the Seth Rich murder conspiracy; and in October and November, when the arrests of Paul Manafort and guilty plea of Flynn seemed to mark a new level of threat to the president, Fox reframed the Uranium One story as an attack on the integrity of the FBI and Justice Department officials in charge of the investigation.

1702–1703

2017 ◽  
Author(s):  
Frances Harris
Keyword(s):  
First Year ◽  
The Third

The third chapter traces the beginning of the partnership through the first year of Queen Anne’s reign, as Marlborough persuades Godolphin to return to office as Lord Treasurer and his ministerial partner, with the declared aim of ‘moderation’, that is, holding the balance between the Tories and Whigs on the basis of their support of the war. The role of Queen Anne’s husband Prince George is examined and Marlborough’s and Godolphin’s separate roles are explored, along with the significance of their extensive correspondence. Marlborough is unexpectedly successful in his first campaign, but his determination to obtain a grant from Parliament to support his dukedom jeopardizes Godolphin’s project for war-supply, and their rival Rochester contests control of the Treasury and therefore the war. Marlborough forces Rochester’s resignation and the partnership is confirmed when Marlborough’s only son dies shortly before he leaves for the Continent and he adopts Godolphin’s son as his heir.

scholarly journals Polarized nature of the COVID-19 pandemic in Japan: associations with population age structure and behaviours

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Junko Okumura
Keyword(s):  
Age Structure ◽  
Public Transportation ◽  
Perceived Risk ◽  
Online Survey ◽  
Preventive Measures ◽  
Age Groups ◽  
Cumulative Number ◽  
Population Age Structure ◽  
Major Factors ◽  
Drinking Places

Abstract Background Although the scale of the coronavirus disease (COVID-19) pandemic was relatively small in Japan compared with the rest of the world, the polarisation of areas into high- and low-COVID-19-incidence areas was observed among the 47 prefectures. The aims of this study were not only identifying the factors associated with the polarised COVID-19 pandemic in Japan but also discussing effective preventive measures. Methods This was an ecological study using online survey data which was cross-sectionally conducted by the author. A total of 6000 respondents who resided in 10 low- and 10 high-COVID-19 incidence prefectures, with a wide gap in terms of COVID-19 incidence, in Japan were recruited. Data on COVID-19 cases and geodemographic information were obtained from official government sites. Statistical analyses were conducted to compare variables between the two areas and age groups. Results This study revealed that that age influenced people’s behaviours and perceptions, except one behaviour of ‘wearing facemasks’. The major factors significantly associated with the cumulative number of COVID-19 cases per 100,000 people were ‘commuting by private automobile’ (adjusted odds ratio [AOR], 0.444; 95% confidence interval [CI], 0.394–0.501), ‘commuting by public transportation’ (AOR, 6.813; 95% CI, 5.567–8.336), ‘washing hands’ (AOR, 1.233; 95% CI, 1.005–1.511), ‘opening windows regularly’ (AOR, 1.248; 95% CI, 1.104–1.412), ‘avoiding crowded places (AOR, 0.757; 95% CI, 0.641–0.893), ‘non-scheduled visits to drinking places’ (AOR, 1.212; 95% CI, 1.054–1.392) and ‘perceived risk of contracting COVID-19’ (AOR, 1.380; 95% CI, 1.180–1.612). These factors were strongly associated with age groups. Conclusions Effective preventive measures for COVID-19 transmission can be developed by understanding the characteristics of populated areas, such as public transportation infrastructure and younger people’s movements and behaviours in relation to the population age structure to contain the current epidemic and protect the most vulnerable elderly people.

scholarly journals Sperm Cryopreservation in American Flamingo (Phoenicopterus Ruber): Influence of Cryoprotectants and Seminal Plasma Removal

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 203
Author(s):  
María Gemma Millán de la Blanca ◽  
Eva Martínez-Nevado ◽  
Cristina Castaño ◽  
Juncal García ◽  
Berenice Bernal ◽  
...  
Keyword(s):  
Seminal Plasma ◽  
Genetic Material ◽  
First Year ◽  
Sperm Cryopreservation ◽  
Straight Line ◽  
The Family ◽  
Second Year ◽  
American Flamingo ◽  
Phoenicopterus Ruber

The American flamingo is a useful model for the development of successful semen cryopreservation procedures to be applied to threatened related species from the family Phoenicopteridae, and to permit genetic material banking. Current study sought to develop effective sperm cryopreservation protocols through examining the influences of two permeating cryoprotectants and the seminal plasma removal. During two consecutive years (April), semen samples were collected and frozen from American flamingos. In the first year, the effect of two permeating cryoprotectants, DMA (dimethylacetamide) (6%) or Me2SO (dimethylsulphoxide) (8%), on frozen–thawed sperm variables were compared in 21 males. No differences were seen between DMA and Me2SO for sperm motility, sperm viability, and DNA fragmentation after thawing. In the second year, the role of seminal plasma on sperm cryoresistance was investigated in 31 flamingos. Sperm samples were cryopreserved with and without seminal plasma, using Me2SO (8%) as a cryoprotectant. The results showed that samples with seminal plasma had higher values than samples without seminal plasma for the following sperm variables: Straight line velocity (22.40 µm/s vs. 16.64 µm/s), wobble (75.83% vs. 69.40%), (p < 0.05), linearity (62.73% vs. 52.01%) and straightness (82.38% vs. 73.79%) (p < 0.01); but acrosome integrity was lower (55.56% vs. 66.88%) (p < 0.05). The cryoresistance ratio (CR) was greater in samples frozen with seminal plasma than without seminal plasma for CR-progressive motility (138.72 vs. 54.59), CR-curvilinear velocity (105.98 vs. 89.32), CR-straight line velocity (152.77 vs. 112.58), CR-average path velocity (122.48 vs. 98.12), CR-wobble (111.75 vs. 102.04) (p < 0.05), CR-linearity (139.41 vs. 113.18), and CR-straightness (124.02 vs. 109.97) (p < 0.01). This research demonstrated that there were not differences between Me2SO and DMA to successful freezing sperm of flamingos; seminal plasma removal did not provide a benefit for sperm cryopreservation.

scholarly journals The role of accommodation environments in student mental health and wellbeing

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Joanne D. Worsley ◽  
Paula Harrison ◽  
Rhiannon Corcoran
Keyword(s):  
Mental Health ◽  
First Year ◽  
Student Mental Health ◽  
North West ◽  
Human Element ◽  
Health And Wellbeing ◽  
Physical Attributes ◽  
Attachment To Place ◽  
Pastoral Staff

Abstract Background Due to the increasing concern over student mental health and wellbeing, attention has turned to the matter of creating environments, communities, and institutions which enable students to flourish. Methods To explore the role of accommodation environments in first year student mental health and wellbeing, eight focus groups were conducted in two universities in North West England and analysed using thematic analysis. Results Three overarching themes were identified: ‘The betwixt space’; ‘Accommodations as vessels to cultivate friendships and communities’; and ‘The importance of accommodation-based pastoral staff’. As attachment to place and relationships with significant others are disrupted by the transition, this leaves young people vulnerable whilst they go through a process to re-attach to new people and a new environment, and loneliness and social isolation were keenly felt during this period. Physical attributes of place that prevent social cohesion further exacerbated feelings of loneliness. Conclusions As it is common for students to withdraw physically and psychologically when they do not form friendships within their flat, accommodation-based pastoral staff have an important role to fulfil. Although these findings demonstrate the importance of the human element within accommodation, designing places that facilitate community, a sense of we-ness, and belonging is crucial.

scholarly journals Population Density or Populations Size. Which Factor Determines Urban Traffic Congestion?

2021 ◽  
Vol 13 (8) ◽  
pp. 4280
Author(s):  
Yu Sang Chang ◽  
Sung Jun Jo ◽  
Yoo-Taek Lee ◽  
Yoonji Lee
Keyword(s):  
Population Density ◽  
Population Size ◽  
Traffic Congestion ◽  
Critical Role ◽  
Small Population ◽  
High Density ◽  
Urban Traffic ◽  
Contradictory Result ◽  
Low Density

A large number of articles have documented that as population density of cities increases, car use declines and public transit use rises. These articles had a significant impact of promoting high-density compact urban development to mitigate traffic congestion. Another approach followed by other researchers used the urban scaling model to indicate that traffic congestion increases as population size of cities increases, thus generating a possible contradictory result. Therefore, this study examines the role of both density and population size on traffic congestion in 164 global cities by the use of Stochastic Impacts by Regression on Population, Affluence and Technology model. We divide 164 cities into the two subgroups of 66 low density cities and 98 high density cities for analysis. The findings from the subgroups analysis indicated a clear-cut difference on the critical role of density in low-density cities and the exclusive role of population size in high-density cities. Furthermore, using threshold regression model, 164 cities are divided into the two regions of large and small population cities to determine population scale advantage of traffic congestion. Our findings highlight the importance of including analysis of subgroups based on density and/or population size in future studies of traffic congestion.

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