Leadership and Gender: An Experiment

We present an information based model of leadership in a setting that exhibits the familiar problems of free riding and coordination failure. Leaders have superior information about the value of the project in hand and can send a costly signal to their uninformed followers to persuade them to cooperate in the project. Followers voluntarily choose whether or not to follow the better informed leader. We provide experimental evidence that, when the leaders� gender is revealed to their followers, female subjects hesitate to lead (send a costly signal) while followers� behavior does not indicate any gender discrimination. Such behavior is not observed among the male leaders.Leadership, Information, Gender, Free Riding, Coordination Problem

Are Claims Of Transparency All They Are Cracked Up To Be?

The current “buzzword” among leaders is “transparency.” Hardly a day goes by that a group leader (politician, manager, or administrator) doesn’t state that he values transparency and will provide full disclosure of his information and actions. This project tests experimentally whether or not leaders, when given a choice, actually reveal a preference for transparency. Our experiment is based on a theoretical model by Komai, Stegeman, and Hermalin (2007). Fifteen subjects are randomly assigned to five groups of three. Each group separately participates in an investment game with three possible return scenarios (high, average, and low) that are equally likely to happen. Investing in the low-return scenario is not profitable to either individual group members or the whole group. In the average-return scenario, group well-being is maximized if all the group members invest in the project, but full cooperation may not be achieved simply because the dominant strategy of the individuals is to free ride on others. In the high-return scenario full cooperation is also optimal for the group, but subjects may or may not coordinate on full cooperation because they may fail to coordinate their efforts with the others. We consider a leader-follower setting. Only one member of the group (the leader) observes the scenario. The leader moves before the rest of the group members and first decides whether or not to invest in the project. The leader then chooses between two information regimes: revealing his decision and the return scenario to the rest of the group or revealing his decision but not the return scenario. Absent any information provided by their leader, followers know only the possible return scenarios and their likelihoods. They do not know which scenario is assigned to their group. Given the leaders’ information choices and investment decisions, the relevant information will be conveyed to the followers. The followers then will separately and simultaneously decide whether or not to invest in the project (followers do not know anything about the different information regimes). This is realistic in many real-world circumstances because in many business or political environments the leaders have exclusive access to critical information and are in charge of deciding whether or not to reveal the details of their information and actions to their potential followers; in many circumstances it is practically difficult for the followers to verify the real information or the leaders’ actions.Transparency, leading by example, free-riding, cooperation.

Comparison of the INRIM and PTB lattice-spacing standards

To base the kilogram definition on the atomic mass of the silicon 28 atom, the present relative uncertainty of the silicon 28 lattice parameter must lowered to 3E-9. To achieve this goal, a new experimental apparatus capable of a centimetre measurement-baseline has been made at the INRIM. The comparison between the determinations of the lattice parameter of crystals MO*4 of INRIM and WASO4.2a of PTB is intended to verify the measurement capabilities and to assess the limits of this experiment.Comment: 10 pages, 8 figures, submitted to Metrologi

Effect of Rice Husk and Rice Husk Ash to Properties of Bricks

AbstractThis research has aims to study effect between rice husk and rice husk ash to properties of bricks. Comparative adding between rice husk and rice husk ash were varied by 0 -10% by weight. The results showed that more adding rice husk less compressive strength and density of specimens. Otherwise the porosity increases when adding rice husk. By adding 2% of rice husk ash by weight is the best of bricks properties which 6.20MPa of compressive strength, 1.68g/cm3 of density, and 15.20% of water absorption

Counting atoms

partially_open2articolo su invitoopenMassa, Enrico; Mana, GiovanniMassa, Enrico; Mana, Giovann

Genetic and antigenic characterisation of serotype A FMD viruses from East Africa to select new vaccine strains

Vaccine strain selection for emerging foot-and-mouth disease virus (FMDV) outbreaks in enzootic countries can be addressed through antigenic and genetic characterisation of recently circulating viruses. A total of 56 serotype A FMDVs isolated between 1998 and 2012, from Central, East and North African countries were characterised antigenically by virus neutralisation test using antisera to three existing and four candidate vaccine strains and, genetically by characterising the full capsid sequence data. A Bayesian analysis of the capsid sequence data revealed the viruses to be of either African or Asian topotypes with subdivision of the African topotype viruses into four genotypes (Genotypes I, II, IV and VII). The existing vaccine strains were found to be least cross-reactive (good matches observed for only 5.4–46.4% of the sampled viruses). Three bovine antisera, raised against A-EA-2007, A-EA-1981 and A-EA-1984 viruses, exhibited broad cross-neutralisation, towards more than 85% of the circulating viruses. Of the three vaccines, A-EA-2007 was the best showing more than 90% in-vitro cross-protection, as well as being the most recent amongst the vaccine strains used in this study. It therefore appears antigenically suitable as a vaccine strain to be used in the region in FMD control programmes

Bayesian Probabilities and the Histories Algebra

We attempt a justification of a generalisation of the consistent histories programme using a notion of probability that is valid for all complete sets of history propositions. This consists of introducing Cox's axioms of probability theory and showing that our candidate notion of probability obeys them. We also give a generalisation of Bayes' theorem and comment upon how Bayesianism should be useful for the quantum gravity/cosmology programmes.Comment: 10 pages, accepted by Int. J. Theo. Phys. Feb 200

Temporal and Stratigraphic Framework for Paleoanthropology Sites Within East-Central Area 130, Koobi Fora, Kenya

In the Koobi Fora region of the northeast Lake Turkana Basin (Kenya) dozens of archeological sites have been studied for decades in order to understand the behavior of Early Pleistocene hominins. Data collected from these sites have been important for demonstrating the manufacture styles of Oldowan stone-tool users, hominin dietary preferences, and processes of Early Stone Age site formation. A particularly rich locality is collection Area 130. Area 130 is noteworthy for hominin fossils KNM-ER 1805 (Homo) and 1806 (Paranthropus) as well as the FxJj 18 site complex, which represents one of the type localities for the Developed Oldowan of Koobi Fora. However, despite research beginning in the late 1960s, and several revisions to the stratigraphy and dating of the Koobi Fora Formation, few published studies provide a detailed chronostratigraphy for Area 130. The lack of a detailed chronostratigraphy has contributed to conflicting interpretations for the dates of the hominin fossils and archaeological sites. Here we present new geochronologic and paleomagnetic data to develop a chronostratigraphic framework that allows us to directly assess the age of the sediments, fossils, and artifacts from Area 130. Individual pumices from the Orange Tuff marker level and a previously unnamed tuff exposed near the FxJj 18 archaeological site complex (referred here as the FxJj 18 tuff) were analyzed for high-precision single crystal 40Ar/39Ar dating and dated at 1.763 ± 0.007 Ma and 1.520 ± 0.005 Ma respectively. Concurrently, we collected orientated paleomagnetic samples from stratigraphic levels of the KBS Member in Area 130 and used them to develop a magnetostratigraphic section. Our findings can be used to refine the sequence and chronology of the archaeological and fossils sites from Area 130 and other penecontemporaneous sites within the Lake Turkana Basin. Our data show that the first appearance of the Developed Oldowan for Koobi Fora does not correlate with any obvious evolutionary changes represented by the local hominin hypodigm nor with the arrival of a cognitively advanced hominin. Therefore we speculate that the advent of this more sophisticated type of stone tool was a response to a change in the diet of the genus Homo