288 research outputs found
Dynamic Unstructured Bargaining with Private Information: Theory, Experiment, and Outcome Prediction via Machine Learning
We study dynamic unstructured bargaining with deadlines and one-sided private information about the amount available to share (the “pie size”). Using mechanism design theory, we show that given the players’ incentives, the equilibrium incidence of bargaining failures (“strikes”) should increase with the pie size, and we derive a condition under which strikes are efficient. In our setting, no equilibrium satisfies both equality and efficiency in all pie sizes. We derive two equilibria that resolve the trade-off between equality and efficiency by favoring either equality or efficiency. Using a novel experimental paradigm, we confirm that strike incidence is decreasing in the pie size. Subjects reach equal splits in small pie games (in which strikes are efficient), while most payoffs are close to either the efficient or the equal equilibrium prediction, when the pie is large. We employ a machine learning approach to show that bargaining process features recorded early in the game improve out-of-sample prediction of disagreements at the deadline. The process feature predictions are as accurate as predictions from pie sizes only, and adding process and pie data together improves predictions even more
Notes on the taxonomy, iconography, and ecology of <i>Aloe pluridens</i> Haw. (Asphodelaceae: Alooideae), an endemic species from southeastern South Africa
The history of the discovery of Aloe pluridens Haw (Asphodelaceae: Alooideae) by the Kew collector James Bowie in 1822–23 in the Eastern Cape Province of South Africa and its subsequent description in 1824 is discussed. The surprising dearth of published illustrations of this long-known species is emphasised and the first known photograph dating from only 1900 is reproduced. It is also shown that a painting at Kew by George Bond that dates from 1829 does not qualify as having been associated with the species by the author of the name, Adrian Hardy Haworth and cannot supersede the specimen on which the name A. pluridens was previously effectively neo-typified. The name A. pluridens Haw. var. beckeri Schönland is lectotypified and it is shown that the name Aloe atherstonei does not have a type as it was previously typified on an apparently non-existent specimen. Additionally the species is illustrated both in habitat and in cultivation. Observations on the ecology and cultivation of the species are also included
Reinstatement of Aloe longibracteata (Asphodelaceae subfam. Alooideae), a maculate aloe from northeastern South Africa
Aloe longibracteata (Asphodelaceae subfam. Alooideae), a South African endemic aloe, which in the past has been regarded
as belonging in the synonymy of A. greatheadii var. davyana, is reinstated as an accepted species. It differs from A. davyana
var. davyana, which recently has been separated from A. greatheadii, in several reproductive morphological characters, most
notably the fewer-branched inflorescences, much longer bracts, and the larger flowers and fruit, as well as the more denselyleaved rosettes. Aloe longibracteata is comprehensively compared to A. davyana var. davyana, illustrated, and a map of its
natural geographical distribution range is provided. The typification of the name A. longibracteata is clarified and resolved,
inter alia through designating an epitype.https://www.mapress.com/ptdm2022Plant Production and Soil Scienc
Aloe immaculata and A. affinis (Asphodelaceae subfam. Alooideae), two endemics from northern and eastern South Africa, are different maculate aloe species
We show that Aloe immaculata and A. affinis (Asphodelaceae subfam. Alooideae) are two different species. Aloe immaculata,
a Limpopo province, South Africa, endemic, is therefore reinstated and treated as distinct from A. affinis, an endemic of
the eastern, mainly Drakensberg escarpment in Mpumalanga, South Africa, and southeastern Limpopo, and northwestern
Eswatini. Vegetatively, the two species mainly differ in terms of leaf colour (dull green to brownish green in the case of
A. immaculata and brighter green in the case of A. affinis). Reproductively, the species differ in inflorescence structure
(subcapitate to conical and round-topped racemes in the case of A. immaculata and cylindric-acuminate ones in the case of A.
affinis) and flower size and colour (pale flesh pink and 28–33 mm long in A. immaculata and scarlet red and 40–45 mm long
in A. affinis). The two species are compared and illustrated, and descriptions for both species and a combined distribution
map are provided.https://www.mapress.com/ptdm2022Plant Production and Soil Scienc
Dynamic Unstructured Bargaining with Private Information: Theory, Experiment, and Outcome Prediction via Machine Learning
We study dynamic unstructured bargaining with deadlines and one-sided private information about the amount available to share (the “pie size”). Using mechanism design theory, we show that given the players’ incentives, the equilibrium incidence of bargaining failures (“strikes”) should increase with the pie size, and we derive a condition under which strikes are efficient. In our setting, no equilibrium satisfies both equality and efficiency in all pie sizes. We derive two equilibria that resolve the trade-off between equality and efficiency by favoring either equality or efficiency. Using a novel experimental paradigm, we confirm that strike incidence is decreasing in the pie size. Subjects reach equal splits in small pie games (in which strikes are efficient), while most payoffs are close to either the efficient or the equal equilibrium prediction, when the pie is large. We employ a machine learning approach to show that bargaining process features recorded early in the game improve out-of-sample prediction of disagreements at the deadline. The process feature predictions are as accurate as predictions from pie sizes only, and adding process and pie data together improves predictions even more
A review and update of the conservation status of Kalanchoe species (Crassulaceae subfam. Kalanchooideae) in the flora of Southern Africa region
An overview and update is provided
of the conservation status of the twenty
species of Kalanchoe (Crassulaceae subfam.
Kalanchooideae) indigenous in southern Africa.
Fourteen of the species grow abundantly in
extensive natural geographical distribution ranges
and from a conservation perspective are of Least
Concern. One species, K. laciniata, has a very
wide global distribution range but is restricted to
Namibia in the southern African region. The other
five Kalanchoe species that are of conservation
concern are all southern African endemics,
being additionally endemic to specific Regions
or Centres of Endemism. These are: K. alticola
(Barberton Centre of Endemism), K. crouchii
(Wolkberg Centre of Endemism), K. crundallii
(Soutpansberg Centre of Endmism), K. longiflora
(Maputaland-Pondoland Region of Endemism)
and K. winteri (Wolkberg Centre of Endemism).Es wird ein Ăśberblick und
eine Aktualisierung des Erhaltungszustands der
20 im sĂĽdlichen Afrika heimischen Kalanchoe-
Arten (Crassulaceae subfam. Kalanchooideae)
gegeben. Vierzehn der Arten kommen zahlreich
in weiträumigen natürlichen Verbreitungsgebieten
vor und sind aus Artenschutzsicht ungefährdet.
Eine Art, K. laciniata, hat ein sehr groĂźes, weltweites
Verbreitungsgebiet, ist aber im sĂĽdlichen Afrika auf
Namibia beschränkt. Die anderen fünf Kalanchoe-
Arten, die aus Sicht des Artenschutzes relevant
sind, sind alle im sĂĽdlichen Afrika endemisch,
d. h. sie kommen nur in bestimmten Regionen oder Endemismuszentren vor. Diese sind: K.
alticola (Barberton-Endemiszentrum), K. crouchii
(Wolkberg-Endemismuszentrum), K. crundallii
(Soutpansberg-Endemismuszentrum), K. longiflora
(Maputaland-Pondoland-Endemiszentrum) und K.
winteri (Wolkberg-Endemismuszentrum).https://bioone.org/journals/bradleyaam2022Plant Production and Soil Scienc
Kalanchoe winteri Gideon F.Sm., N.R.Crouch & Mich.Walters (Crassulaceae), a new species from the Wolkberg Centre of Endemism, South Africa
A new Kalanchoe species, K. winteri
Gideon F.Sm., N.R.Crouch & Mich.Walters, is described
from rocky grasslands of the Wolkberg region
of Limpopo province, South Africa. The
species is closely allied to both K. thyrsiflora
Harv. and K. luciae Raym.-Hamet, from which it
is readily separable on vegetative and reproductive
characteristics.Eine neue Kalanchoe-Art, K.
winteri Gideon F. Sm., N. R. Crouch & Mich.Walters,
wird aus felsigen Grasländern der Wolkberg-
Region in der Provinz Limpopo, SĂĽdafrika,
beschrieben. Die Art ist nah mit K. thyrsiflora
Harv. und K. luciae Raym.-Hamet verwandt, von
denen sie leicht durch vegetative und generative
Merkmale unterschieden werden kann.http://www.bcss.org.uk/brad.phpam2017Centre for Wildlife Managemen
Reinstatement of Aloe candelabrum A.Berger (Asphodelaceae: Alooideae), a tree-like aloe of KwaZulu-Natal province, South Africa
Aloe candelabrum A.Berger (Asphodelaceae:
Alooideae), a stately, single-stemmed
species from the KwaZulu-Natal province in eastern
South Africa, which had been included in the
synonymy of A. ferox Mill. for some years, is reinstated.
The entire distribution range of A. candelabrum
falls within the Maputoland-Pondoland
Region of Endemism on the eastern seaboard of
South Africa. In contrast, Aloe ferox occurs widely
in the Western and Eastern Cape provinces of
South Africa, the southern Free State province, as
well as southern Lesotho. It does not occur in
KwaZulu-Natal.Aloe candelabrum A. Berger
(Asphodelaceae: Alooideae), eine stattliche, einstämmige
Art aus der Provinz KwaZulu-Natal im
östlichen Südafrika, die jahrelang in die Synonymie
von A. ferox Mill. gestellt wurde, wird
wieder anerkannt. Das gesamte Verbreitungsgebiet
von A. candelabrum liegt innerhalb der Endemismus-
Region Maputoland-Pondoland an der
östlichen Meeresküste von Südafrika. Im Gegensatz
dazu ist Aloe ferox weit verbreitet in den
sĂĽdafrikanischen Provinzen Western Cape und
Eastern Cape, der sĂĽdlichen Provinz Free State
sowie im sĂĽdlichen Lesotho; in KwaZulu-Natal
kommt sie nicht vor.http://www.bcss.org.uk/brad.phpam2017Plant Scienc
A revised generic classification for <em>Aloe</em> (Xanthorrhoeaceae subfam. Asphodeloideae)
Grace, Olwen M., Klopper, Ronell R., Smith, Gideon F., Crouch, Neil R., Figueiredo, Estrela, Rønsted, Nina, Van Wyk, Abraham E. (2013): A revised generic classification for Aloe (Xanthorrhoeaceae subfam. Asphodeloideae). Phytotaxa 76 (1): 7-14, DOI: 10.11646/phytotaxa.76.1.2, URL: http://dx.doi.org/10.11646/phytotaxa.76.1.
Aloiampelos tenuior var. ernstii, a new orange-flowered variety of rambling aloe (Asphodelaceae subfam. Alooideae)
A red- and several yellow-flowered variants of Aloiampelos tenuior (Asphodelaceae subfam. Alooideae), a species of
scrambling aloe, are well known, including in cultivation, and apart from the autonymic variety, at least four others have
been given taxonomic recognition at that rank. The yellow-flowered varieties of A. tenuior are predominantly, but not
exclusively, based on vegetative characters, while the red-flowered variety is distinguished by its flower colour, as well as
vegetative characters. The orange-flowered form of A. tenuior, which is much less common in cultivation than A. tenuior
var. tenuior or A. tenuior var. rubriflora, is here described as A. tenuior var. ernstii.https://www.mapress.com/ptdm2022Plant Production and Soil Scienc
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