scholarly journals Past, present, future: tracking and simulating genetic differentiation over time in a closed metapopulation system

2021 ◽  
Author(s):  
Florian Kunz ◽  
Annette Kohnen ◽  
Ursula Nopp-Mayr ◽  
Joy Coppes
Keyword(s):  
Genetic Differentiation ◽  
Extinction Risk ◽  
Recent Time ◽  
Conservation Strategies ◽  
Tetrao Urogallus ◽  
Migration Rates ◽  
Time Period ◽  
Conservation Concern ◽  
Set Up ◽  
Over Time

AbstractGenetic differentiation plays an essential role in the assessment of metapopulation systems of conservation concern. Migration rates affect the degree of genetic differentiation between subpopulations, with increasing genetic differentiation leading to increasing extinction risk. Analyses of genetic differentiation repeated over time together with projections into the future are therefore important to inform conservation. We investigated genetic differentiation in a closed metapopulation system of an obligate forest grouse, the Western capercaillieTetrao urogallus, by comparing microsatellite population structure between a historic and a recent time period. We found an increase in genetic differentiation over a period of approximately 15 years. Making use of forward simulations accounting for population dynamics and genetics from both time periods, we explored future genetic differentiation by implementing scenarios of differing migration rates. Using migration rates derived from the recent dataset, simulations predicted further increase of genetic differentiation by 2050. We then examined effects of two realistic yet hypothetical migration scenarios on genetic differentiation. While isolation of a subpopulation led to overall increased genetic differentiation, the re-establishment of connectivity between two subpopulations maintained genetic differentiation at recent levels. Our results emphasize the importance of maintaining connectivity between subpopulations in order to prevent further genetic differentiation and loss of genetic variation. The simulation set-up we developed is highly adaptable and will aid researchers and conservationists alike in anticipating consequences of conservation strategies for metapopulation systems.

scholarly journals Dynamics of the woody vegetation of two areas of Cerrado sensu stricto located on different substrates

Rodriguésia ◽  
2016 ◽  
Vol 67 (4) ◽  
pp. 859-870 ◽  
Author(s):  
Letícia Gomes ◽  
Leandro Maracahipes ◽  
Simone Matias Reis ◽  
Beatriz Schwantes Marimon ◽  
Ben Hur Marimon-Junior ◽  
...  
Keyword(s):  
Plant Community ◽  
Basal Area ◽  
Sensu Stricto ◽  
Conservation Strategies ◽  
Woody Vegetation ◽  
Dynamic Parameters ◽  
Differential Evaluation ◽  
Set Up ◽  
Effective Conservation ◽  
Over Time

Abstract Differences in substrates can provoke distinct responses in the dynamics of a plant community. We compared changes the floristic, structural and dynamic parameters of the woody vegetation between burned sites dominated by cerrado típico (CT) and cerrado rupestre (CR), which is characterized by the presence of rocky outcrops, over time. We set up 10 plots (20 m × 50 m) at each site. All individuals (diameter of ≥ 3 cm at 30 cm height above the ground) were identified in the two censuses (2009 and 2012) and measured (stem diameter), after an accidental fire in 2008. Changes in floristic parameters between the CT and CR were not significant. However, we found significant differences (p < 0.05) in structural and dynamic parameters, such as density (CT = 1,523; CR = 2,171 ind.ha-1), basal area (CT = 8.70; CR = 13.00 m2.ha-1), recruitment rates (CT = 24.35; CR = 15.14% year-1; p = 0.01), gain (CT = 8.58; CR= 3.58% year-1), and the loss rates of basal area (CT = 3.88; CR= 2.45% year-1). These differences emphasize the need for a differential evaluation of these sites for the development of effective conservation strategies.

Trends In Incidence, Presentation, and Outcomes Of Chronic Graft-Versus-Host Disease In Allogeneic Transplantation- Report From The Center For International Blood and Marrow Transplant Research

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3309-3309
Author(s):  
Sally Arai ◽  
Mukta Arora ◽  
Tao Wang ◽  
Wensheng He ◽  
Daniel R. Couriel ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cord Blood ◽  
Allogeneic Transplantation ◽  
Recent Time ◽  
Unrelated Donor ◽  
Graft Versus Host ◽  
Time Period ◽  
Matched Sibling ◽  
Time Periods ◽  
Over Time

Abstract There have been considerable changes in the practice of allogeneic transplantation over the last several years. In this study, we evaluate the impact of these changes on chronic graft-versus-host disease (cGVHD), the most important long-term complication. Our study utilized the central database of the CIBMTR to describe time trends for cGVHD incidence, presentation, nonrelapse mortality and overall survival from 1995-2007. The 12-year period was divided into three time periods- 1995-1999, 2000-2003, 2004-2007 to allow for the systematic analysis and description of trends. The trends of cGVHD severity (mild, moderate, severe), type of onset (progressive, interrupted, de novo), and major organ involved over the past years were analyzed using chi-square tests. Cumulative incidence was used to estimate cGVHD incidence and nonrelapse mortality. Death/ 2nd transplant/donor cell infusion/relapse were treated as competing risks for estimation of cumulative incidence of cGVHD. A test of trend was used to estimate HR across time periods. Multivariate logistic regression analysis was used to determine clinical variables affecting the incidence of cGVHD, including the time period of transplant. The study included 26,563 patients with acute leukemia (AML= 10,737, ALL= 6756), chronic myeloid leukemia (n=6341) and myelodysplastic syndrome (n=2729). In the univariate analysis, the incidence of cGVHD was significantly increased in the recent time periods (HR= 1.14, p for test of trend <0.0001). This trend persisted when the incidence was evaluated by donor type (HLA identical sibling-HR=1.17; unrelated donor-HR=1.07; cord blood-HR=1.24, all p < 0.01), graft type (PBSC-HR=1.19; cord blood-HR=1.24, p < 0.01), or conditioning intensity (myeloablative-HR=1.13; reduced intensity-HR=1.16, p< 0.01). In mismatched-related donors (HR=1.08, p=0.24) and bone marrow grafts (HR=1.01,p=0.54) there was no significant change in the incidence of cGVHD. Progressive cGVHD was found to be less frequently diagnosed over time, possibly from the recognition of the late acute classification introduced in 2005. Extensive, moderate and severe categories of cGVHD were more frequent in the two most recent time periods (2000-2003 and 2004-2007), as compared to the earliest time period (1995-1999). Skin was more frequently involved in the recent time period (2004-2007), with greater association of skin involvement at maximum severity reported in peripheral blood (33%), compared with bone marrow (25%), thus graft type appears to have impacted cGVHD presentation. In multivariate analysis, the recent time period (2004-2007) was associated with higher risk of cGVHD when compared to the two earlier time periods (2004-2007 versus 1995-1999, OR 1.19, p<0.0001; 2004-2007 versus 2000-2003, OR 1.13, p=0.002). Use of bone marrow with an unrelated donor (matched or mismatched), and peripheral blood graft with all categories of donor group were associated with higher risk of cGVHD, as compared to the use of bone marrow with a matched sibling donor. The risk of cGVHD was similar between marrow with a matched sibling donor and cord blood (matched or mismatched). In conclusion, this analysis of cGVHD trends over time demonstrates an increased cGVHD incidence in recent years despite controlling for factors in the donor, the graft and the conditioning that are associated with that trend, and serves as a useful reference for future research in the management of cGVHD. Disclosures: No relevant conflicts of interest to declare.

Getting Away With Murder: Homicide Clearance by Arrest in Chicago and Its Community Areas

2020 ◽  
pp. 108876792094156
Author(s):  
Joseph Ferrandino
Keyword(s):  
Justice System ◽  
Recent Time ◽  
Future Research ◽  
Factors Associated ◽  
Elapsed Time ◽  
Research Areas ◽  
Time Period ◽  
Homicide Clearance ◽  
Over Time

This work explores the decline in murder clearances through arrest in Chicago from 1965 through 2015, specifically focusing on the most recent time period since 2001. The findings suggest that clearance by arrest has decreased significantly, that elapsed time is a limited factor in clearing more murders through arrest and that factors associated with clearance by arrest in Chicago have changed over time. These results lead to a discussion on the missing variance that cannot explain murder clearance by arrest as well as future research areas that can explore why many murderers in Chicago are increasingly escaping the justice system.

scholarly journals Male fertility thermal limits predict vulnerability to climate warming

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Belinda van Heerwaarden ◽  
Carla M. Sgrò
Keyword(s):  
Climate Warming ◽  
Experimental Evolution ◽  
Male Fertility ◽  
Extinction Risk ◽  
Conservation Strategies ◽  
Tropical Species ◽  
Adaptive Responses ◽  
Widespread Species ◽  
Thermal Limits ◽  
Critical Thermal Limits

AbstractForecasting which species/ecosystems are most vulnerable to climate warming is essential to guide conservation strategies to minimize extinction. Tropical/mid-latitude species are predicted to be most at risk as they live close to their upper critical thermal limits (CTLs). However, these assessments assume that upper CTL estimates, such as CTmax, are accurate predictors of vulnerability and ignore the potential for evolution to ameliorate temperature increases. Here, we use experimental evolution to assess extinction risk and adaptation in tropical and widespread Drosophila species. We find tropical species succumb to extinction before widespread species. Male fertility thermal limits, which are much lower than CTmax, are better predictors of species’ current distributions and extinction in the laboratory. We find little evidence of adaptive responses to warming in any species. These results suggest that species are living closer to their upper thermal limits than currently presumed and evolution/plasticity are unlikely to rescue populations from extinction.

scholarly journals Condensation/immersion mode ice-nucleating particles in a boreal environment

2020 ◽  
Vol 20 (11) ◽  
pp. 6687-6706
Author(s):  
Mikhail Paramonov ◽  
Saskia Drossaart van Dusseldorp ◽  
Ellen Gute ◽  
Jonathan P. D. Abbatt ◽  
Paavo Heikkilä ◽  
...  
Keyword(s):  
Field Campaign ◽  
Particle Species ◽  
Entire Field ◽  
Time Period ◽  
Regional Sources ◽  
Range Transport ◽  
Thermodynamic Conditions ◽  
Set Up ◽  
Boreal Environment ◽  
Measurement Location

Abstract. Ice-nucleating particle (INP) measurements were performed in the boreal environment of southern Finland at the Station for Measuring Ecosystem–Atmosphere Relations (SMEAR II) in the winter–spring of 2018. Measurements with the Portable Ice Nucleation Chamber (PINC) were conducted at 242 K and 105 % relative humidity with respect to water. The median INP number concentration [INP] during a 6-week measurement period was 13 L−1. The [INP] spanned 3 orders of magnitude and showed a general increase from mid-February until early April. No single dominant local or regional sources of INPs in the boreal environment of southern Finland could be identified. Rather, it is hypothesised that the INPs detected at SMEAR II are a result of long-range transport and dilution of INPs sourced far from the measurement site. Despite high variability, the measured [INP] values fall within the range expected for the [INP] measured elsewhere under similar thermodynamic conditions. The [INP] did not correlate with any of the examined parameters during the entire field campaign, indicating that no one single parameter can be used to predict the [INP] at the measurement location during the examined time period. The absence of a correlation across the entire field campaign also suggests that a variety of particles act as INPs at different times, although it was indirectly determined that ambient INPs are most likely within the size range of 0.1–0.5 µm in diameter on average. On shorter timescales, several particle species correlated well with the [INP]. Depending on the meteorological conditions, black carbon (BC), supermicron biological particles and sub-0.1 µm particles, most likely nanoscale biological fragments such as ice-nucleating macromolecules (INMs), correlated with the INP signal. However, an increase in the concentration of any of these particle species may not necessarily lead to the increase in the [INP]; the reasons for this remain unknown. Limitations of the instrumental set-up and the necessity for future field INP studies are addressed.

Changes in survival characteristics ofDiplostomum spathaceumcercariae emerged from cadmium-exposedLymnaea stagnalis

2005 ◽  
Vol 79 (1) ◽  
pp. 55-59 ◽  
Author(s):  
N.J. Morley ◽  
M. Crane ◽  
J.W. Lewis
Keyword(s):  
Life Span ◽  
Lymnaea Stagnalis ◽  
Control Population ◽  
Survival Period ◽  
Parasite Transmission ◽  
Tail Loss ◽  
Diplostomum Spathaceum ◽  
Time Period ◽  
Potential Indicator ◽  
Over Time

AbstractThe effect of exposingLymnaea stagnalis(Gastropoda: Pulmonata), infected withDiplostomum spathaceum(Trematoda: Diplostomatidae), to 100 μg l−1cadmium for 7 days on survival characteristics (survival, tail loss, decaudized cercarial life-span) of emerged cercariae was investigated. Exposure ofL. stagnalisto cadmium resulted in significantly increasedD. spathaceumcercarial survival and an inhibited tail loss compared to controls. The normal parallel relationship which exists over time between decreasing cercarial survival and increasing tail loss in controls was changed in cercariae from cadmium-exposed hosts with an increased proportion of cercarial deaths occurring without tail loss. The decaudized cercarial life-span over the survival period of the cercarial population did not significantly change. However comparisons between individuals decaudized during the initial 24 h time period with those which were decaudized during the final period of cercarial survival showed a significantly altered life span which did not occur in the control population. As a potential indicator of penetration ‘fitness’ comparisons were also undertaken between control and exposed cercariae decaudized during the initial 24 h time period, which revealed that the decaudized cercarial life-span from the exposed hosts was significantly different from controls. This may have important implications for the ability of cercariae to migrate through the tissues of their target host. The importance and relevance of these results to parasite transmission are discussed.

scholarly journals Faculty Publishing Productivity: Comparisons over Time

2006 ◽  
Vol 67 (3) ◽  
pp. 230-239 ◽  
Author(s):  
John M. Budd
Keyword(s):  
Academic Librarians ◽  
Tenure Track ◽  
Data Set ◽  
Part Time Faculty ◽  
Time Period ◽  
Rate Of Increase ◽  
Part Time ◽  
Per Capita ◽  
Time Faculty ◽  
Over Time

Concerns about higher education abound, and these include concerns about productivity. The present study extends two previous examinations of faculty publishing productivity covering the years 1991 to 1993 and 1995 to 1997. Both members of ARL and a group of institutions included in ACRL’s data set are included. For both groups there are some increases in mean total numbers of publications, although the rate of increase has decreased since the second time period. Per capita rates of publication demonstrate an even flatter pattern. In recent years, there have been some changes in the dynamics of universities’ faculties; there are more part-time faculty and more faculty who are not on the tenure track. These factors, coupled with the publishing data, point to activities that all academic librarians should be aware of.

scholarly journals Creating relationship continuity across projects in the construction industry

IMP Journal ◽  
2017 ◽  
Vol 11 (2) ◽  
pp. 207-229 ◽  
Author(s):  
Malena Ingemansson Havenvid ◽  
Elsebeth Holmen ◽  
Åse Linné ◽  
Ann-Charlott Pedersen
Keyword(s):  
Construction Industry ◽  
Empirical Studies ◽  
Mutual Orientation ◽  
Content Type ◽  
Construction Firms ◽  
Relationship Continuity ◽  
Time Period ◽  
Strategy Types ◽  
The Relationship ◽  
Over Time

Purpose The purpose of this paper is to investigate the relationship continuity across projects among actors in the construction industry, and to discuss why and how such continuity takes place. Design/methodology/approach The authors draw on the results from four in-depth case studies illustrating different strategies for pursuing relationship continuity. The results are analysed and discussed in light of the oft-mentioned strategies suggested by Mintzberg (1987): emergent, deliberate and deliberately emergent strategies. Furthermore, the ARA-model is used to discuss why the relationship continuity strategies are pursued, and which factors might enable and constrain the relationship continuity. Findings The main findings are twofold. First, the authors found that the strategy applied for pursuing relationship continuity may, in one-time period, contain one type of strategy or a mix of strategy types. Second, the type of strategy may evolve over time, from one type of strategy being more pronounced in one period, to other strategies being more pronounced in later periods. The strategies applied by construction firms and their counterparts can thus contain elements of emergent, deliberate and deliberately emergent strategies, in varying degrees over time. It is also shown that the strategies of the involved actors co-evolve as a result of interaction. Also, the main reasons for pursuing continuity appear to lie in the re-use and development of important resources and activities across projects to create efficiency and the possibility to develop mutual orientation, commitment and trust over time, and thus reduce uncertainty. Research limitations/implications Further empirical studies are needed to support the findings. For managers, the main implication is that relationship continuity can arise as part of an emerging interaction pattern between firms or as part of a planned strategy, but that elements of both might be needed to sustain it. Originality/value The authors combine Mintzberg’s strategy concepts with the ARA-model to bring new light to the widely debated issue of discontinuity and fragmentation in the construction industry.

Grafinscripties

Lampas ◽  
2021 ◽  
Vol 54 (1) ◽  
pp. 39-65
Author(s):  
Onno van Nijf
Keyword(s):  
Late Antiquity ◽  
Archaic Period ◽  
Social Strategies ◽  
Public And Private ◽  
Content Type ◽  
Frequent Type ◽  
The Social ◽  
Funerary Inscriptions ◽  
Set Up ◽  
Over Time

Abstract This article offers a brief introduction to the most frequent type of inscription: funerary inscriptions or epitaphs. The article offers a chronological overview from the Archaic period to late Antiquity, with an emphasis on Athens. It opens with a brief discussion of the archaeological and ritual contexts in which funerary inscriptions were set up, followed by a discussion of archaic epigrams and the social strategies that lay behind them. This is followed by a discussion of public and private graves that shows how epigraphic habits changed over time. The article continues with a discussion of funerary epigraphic habits outside Athens and closes with a few examples of Christian epitaphs.

scholarly journals Visualizing Belief in Meritocracy, 1930–2010

2018 ◽  
Vol 4 ◽  
pp. 237802311881180 ◽  
Author(s):  
Jonathan J. B. Mijs
Keyword(s):  
Survey Data ◽  
Representative Sample ◽  
Western World ◽  
Birth Cohorts ◽  
Popular Belief ◽  
Time Period ◽  
Level Data ◽  
Two Measures ◽  
Time Periods ◽  
Over Time

In this figure I describe the long trend in popular belief in meritocracy across the Western world between 1930 and 2010. Studying trends in attitudes is limited by the paucity of survey data that can be compared across countries and over time. Here, I show how to complement survey waves with cohort-level data. Repeated surveys draw on a representative sample of the population to describe the typical beliefs held by citizens in a given country and period. Leveraging the fact that citizens surveyed in a given year were born in different time-periods allows for a comparison of beliefs across birth cohorts. The latter overlaps with the former, but considerably extends the time period covered by the data. Taken together, the two measures give a “triangulated” longitudinal record of popular belief in meritocracy. I find that in most countries, popular belief in meritocracy is (much) stronger for more recent periods and cohorts.

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