25 research outputs found
A regionally informed abundance index for supporting integrative analyses across butterfly monitoring schemes
1. The rapid expansion of systematic monitoring schemes necessitates robust methods to reliably assess species' status and trends. Insect monitoring poses a challenge where there are strong seasonal patterns, requiring repeated counts to reliably assess abundance. Butterfly monitoring schemes (BMSs) operate in an increasing number of countries with broadly the same methodology, yet they differ in their observation frequency and in the methods used to compute annual abundance indices.
2. Using simulated and observed data, we performed an extensive comparison of two approaches used to derive abundance indices from count data collected via BMS, under a range of sampling frequencies. Linear interpolation is most commonly used to estimate abundance indices from seasonal count series. A second method, hereafter the regional generalized additive model (GAM), fits a GAM to repeated counts within sites across a climatic region. For the two methods, we estimated bias in abundance indices and the statistical power for detecting trends, given different proportions of missing counts. We also compared the accuracy of trend estimates using systematically degraded observed counts of the Gatekeeper Pyronia tithonus (Linnaeus 1767).
3. The regional GAM method generally outperforms the linear interpolation method. When the proportion of missing counts increased beyond 50%, indices derived via the linear interpolation method showed substantially higher estimation error as well as clear biases, in comparison to the regional GAM method. The regional GAM method also showed higher power to detect trends when the proportion of missing counts was substantial.
4. Synthesis and applications. Monitoring offers invaluable data to support conservation policy and management, but requires robust analysis approaches and guidance for new and expanding schemes. Based on our findings, we recommend the regional generalized additive model approach when conducting integrative analyses across schemes, or when analysing scheme data with reduced sampling efforts. This method enables existing schemes to be expanded or new schemes to be developed with reduced within-year sampling frequency, as well as affording options to adapt protocols to more efficiently assess species status and trends across large geographical scales
On the Lebesgue measure of Li-Yorke pairs for interval maps
We investigate the prevalence of Li-Yorke pairs for and
multimodal maps with non-flat critical points. We show that every
measurable scrambled set has zero Lebesgue measure and that all strongly
wandering sets have zero Lebesgue measure, as does the set of pairs of
asymptotic (but not asymptotically periodic) points.
If is topologically mixing and has no Cantor attractor, then typical
(w.r.t. two-dimensional Lebesgue measure) pairs are Li-Yorke; if additionally
admits an absolutely continuous invariant probability measure (acip), then
typical pairs have a dense orbit for . These results make use of
so-called nice neighborhoods of the critical set of general multimodal maps,
and hence uniformly expanding Markov induced maps, the existence of either is
proved in this paper as well.
For the setting where has a Cantor attractor, we present a trichotomy
explaining when the set of Li-Yorke pairs and distal pairs have positive
two-dimensional Lebesgue measure.Comment: 41 pages, 3 figure
Adverse drug reactions of antipsychotics in frail older patients
Marum, R.J. van [Promotor]Derijks, H.J. [Copromotor]Keijsers, C.P.J.W. [Copromotor
Monitoring van Natura 2000 soorten en habitattypen : advies voor een landelijk meetprogramma ten behoeve van de rapportageverplichtingen in het kader van de Europese Vogelrichtlijn en Habitatrichtlijn : : rapport in het kader van het WOT programma informatievoorziening Natuur i.o. (WOT IN)
In deze gezamenlijke uitgave van CBS, VOFF en Alterra wordt aan het Ministerie van LNV advies gegeven over de toekomstige monitoring van soorten en habitattypen. Uitgangspunt bij dit advies zijn de rapportageverplichtingen in het kader van de Europese Vogelrichtlijn en Habitatrichtlijn. De Europese richtlijnen verplichten de lidstaten om op gezette tijden te rapporteren over de staat van instandhouding van soorten en habitattypen. Op basis van dit advies kunnen keuzes gemaakt worden over het wel of niet uitbreiden van bestaande monitoringsprogramma's om aan de rapportageverplichtingen te voldoe
Over a century of data reveal more than 80% decline in butterflies in the Netherlands
Opportunistic butterfly records from 1890 to 2017 were analysed to quantitatively estimate the overall long-term change in occurrence of butterfly species in the Netherlands. For 71 species, we assessed trends in the number of occupied 5 km × 5 km sites by applying a modified List Length method, which takes into account changes in observation effort. We summarised the species trends in a Multi-Species Indicator (MSI) by taking the geometric mean of the species indices. Between 1890–1930 and 1981–1990, the MSI decreased by 67%; downward trends were detected for 42 species, many of which have disappeared completely from the Netherlands. Monitoring count data available from 1992 showed a further 50% decline in MSI. Combined, this yields an estimated decline of 84% in 1890–2017. We argue that in reality the loss is likely even higher. We also assessed separate MSIs for three major butterfly habitat types in the Netherlands: grassland, woodland and heathland. Butterflies strongly declined in all three habitats alike. The trend has stabilised over recent decades in grassland and woodland, but the decline continues in heathland
Stimuleren van toptalent in het onderwijs: effect op negatieve gevoelens bij uitblinken
Stimulating outperformance has high priority in Dutch education. Aim is to change the Dutch egalitarian culture to a more performanceoriented culture that rewards outperformance. Although privately satisfying, outperformance can also lead to interpersonal strain. Elxine and Lobel (1999) introduced the term Sensitivity about being the Target of a Threatening Upward Comparison (STTUC) to refer to this outperformance-related distress. Through a systematic review of 39 studies (37 samples) evidence was found for the STTUC-framework and characteristics of the outperformer, situation and relation were found to influence STTUC. An interesting finding in relation to Dutch educational policy is that in individualistic, performanceoriented cultures that accept inequality, outperformers experience more STTUC. Furthermore sociotropy proves to be a consistent predictor of STTUC while narcissism predicts positive emotions in response to outperformance. Findings suggest that the aimed cultural change in Dutch education can increase STTUC and can favour outperformers high in narcissism over those high in sociotropy. Implications for policy and practice are discussed
Stimulating top talent in Dutch education:The effect on outperformance-related distress
Stimulating outperformance has high priority in Dutch education. Aim is to change the Dutch egalitarian culture to a more performanceoriented culture that rewards outperformance. Although privately satisfying, outperformance can also lead to interpersonal strain. Elxine and Lobel (1999) introduced the term Sensitivity about being the Target of a Threatening Upward Comparison (STTUC) to refer to this outperformance-related distress. Through a systematic review of 39 studies (37 samples) evidence was found for the STTUC-framework and characteristics of the outperformer, situation and relation were found to influence STTUC. An interesting finding in relation to Dutch educational policy is that in individualistic, performanceoriented cultures that accept inequality, outperformers experience more STTUC. Furthermore sociotropy proves to be a consistent predictor of STTUC while narcissism predicts positive emotions in response to outperformance. Findings suggest that the aimed cultural change in Dutch education can increase STTUC and can favour outperformers high in narcissism over those high in sociotropy. Implications for policy and practice are discussed.</p
Over a century of data reveal more than 80% decline in butterflies in the Netherlands
Opportunistic butterfly records from 1890 to 2017 were analysed to quantitatively estimate the overall long-term change in occurrence of butterfly species in the Netherlands. For 71 species, we assessed trends in the number of occupied 5 km × 5 km sites by applying a modified List Length method, which takes into account changes in observation effort. We summarised the species trends in a Multi-Species Indicator (MSI) by taking the geometric mean of the species indices. Between 1890–1930 and 1981–1990, the MSI decreased by 67%; downward trends were detected for 42 species, many of which have disappeared completely from the Netherlands. Monitoring count data available from 1992 showed a further 50% decline in MSI. Combined, this yields an estimated decline of 84% in 1890–2017. We argue that in reality the loss is likely even higher. We also assessed separate MSIs for three major butterfly habitat types in the Netherlands: grassland, woodland and heathland. Butterflies strongly declined in all three habitats alike. The trend has stabilised over recent decades in grassland and woodland, but the decline continues in heathland.</p