W artykule badana jest ekonomiczna efektywność działań mających na celu weryfikację potencjalnych beneficjentów programów charytatywnych. Taka weryfikacja ma na celu ograniczenie liczby osób otrzymujących pomoc charytatywną, które nie spełniają kryteriów jej przyznania. Jednocześnie, wiąże się ona z kosztami ponoszonymi przez organizatora programu. W artykule zaproponowano model teoretyczny opisujący to zjawisko. Do przeprowadzania analizy modelu wykorzystano metody optymalizacyjne oraz symulacyjne. Wynika z niej, że w zależności od parametrów programu charytatywnego optymalna może być jedna z trzech decyzji: przyznanie pomocy bez wprowadzania weryfikacji, przyznawanie pomocy po uprzedniej weryfikacji lub przeznaczenie środków pomocowych na inny cel. Optymalność rozwiązania zależy od charakterystyk programu, takich jak średnia kwota pomocy, średni koszt weryfikacji oraz odsetek osób potrzebujących spełniających założenia programu. W zależności od tych zmiennych organizacja charytatywna powinna podjąć decyzję o ewentualnym wprowadzeniu weryfikacji.

Triceratium barbadense Greville, 1861a, T. brachiatum Brightwell, 1856, T. inconspicuum Greville, 1861b and

T. kanayae Fenner, 1984a, are among the most common diatoms reported worldwide from lower to middle Eocene

biosiliceous sediments. Due to complicated nomenclatural histories, however, they are often confused. A morphometric

analysis performed herein indicates that T. brachiatum is conspecific with T. inconspicuum, and that both

were previously often misidentified as T. barbadense. Triceratium barbadense sensu stricto is a distinct species

similar to Triceratium castellatum West, 1860. Triceratium brachiatum and T. kanayae are transferred herein

to a new genus, Fenneria, for which a close phylogenetic relationship with Medlinia Sims, 1998 is proposed.

A review of the geographic and stratigraphic distribution of Fenneria shows that the best constrained records of

its occurrences are found at DSDP Site 338, and ODP Sites 1051 and 1260. The ages of the base (B) and top (T)

of each species’ stratigraphic range are calibrated here to the Geomagnetic Polarity Timescale either directly or

inferred via correlation with dinocyst biostratigraphy. Latitudinal diachroneity of ~7 million years is documented

for F. brachiata, which disappears earlier in tropical and mid-latitude sites than in the northern high latitudes. These

observations, coupled with a preliminary compilation of the Chron C20n taxonomic composition of pelagic diatom

assemblages for Sites 338, 1051 and 1260, indicate that diatoms diversified palaeobiogeographically considerably

earlier than the Eocene−Oligocene Transition, as commonly believed. This study also emphasizes the importance

of the detailed examination of specimens from both museum collections and deep-sea cores as a step toward enhancing

the utility of Palaeogene diatoms in palaeoceanographic and palaeoenvironmental reconstructions.

Upper Miocene (~6 Ma) sediments from a north-south transect of Ocean Drilling Program Holes 848B, 849B, 850B, 851B across the equator in the Eastern Pacific Ocean record an episode of unusual skeletal variability associated with the silicoflagellate Bachmannocena diodon subsp. nodosa (Bukry) Bukry, 1987. Skeletons in this plexus persisted for between 55,000 and 75,000 years and include an arch across a 2-sided basal ring, a highly unusual morphology for the genus. Groups of skeletal morphotypes were common within the plexus episode, and occur in a systematic sequence that is consistent between sites. As a result of this study, silicoflagellates previously placed in the genus Neonaviculopsis Locker and Martini, 1986 are now considered part of the Bachmannocena diodon subsp. nodosa plexus.

Early Palaeocene through early Eocene silicoflagellate assemblages were examined from five southern subtropical

through subpolar deep-sea sites: DSDP Holes 208 and 524, and ODP Holes 700B, 752A, and 1121B. For each

site, the taxonomic composition of the silicoflagellate assemblage is documented in detail; Pseudonaviculopsis

gen. nov., Dictyocha castellum sp. nov. and Stephanocha? fulbrightii sp. nov. are proposed, along with several

new combinations. More importantly, however, these observations enable a considerable refinement to the existing

Palaeocene–Eocene silicoflagellate biostratigraphic zonation that for the first time uses datums calibrated to

the Geomagnetic Polarity Timescale. The Corbisema aspera Interval Zone occurs immediately above the K/Pg

boundary and is here described from Seymour Island. The Corbisema hastata Partial Range Zone extends from

near the K/Pg boundary to late early Palaeocene and has been observed in Hole 208. The Pseudonaviculopsis disymmetrica

Acme Zone occurs in Holes 208 and 700B. The Dictyocha precarentis Partial Range Zone, observed

in Holes 208, 700B, 752A and 1121B, is subdivided into D. precarentis, Naviculopsis primativa, N. cruciata

and Pseudonaviculopsis constricta subzones. The Naviculopsis constricta Partial Range Zone occurs in Holes

524, 700B, 752A and 1121B. This study is also the first to consider syn- and/or diachroneity in Palaeogene

silicoflagellate biostratigraphy.