Duration discrimination of brief visual stimuli

Visual flash duration discrimination and decision theory analysis of effects of temporal and brightness difference

Two Epiparasitic Species of Phoradendron (Viscaceae) from Honduras: one New and for the Other a Range Extension and Host Determination

A new species of Phoradendron, Ph. mathiasenii, is described, and a range extension and host are given for Ph. tikalense. Both species are from Honduras and grow as epiparasites, i.e., mistletoes parasitizing other mistletoes. The parasitic host for both epiparasitic species of Phoradendron is Psittacanthus angustifolius (Loranthaceae), which in turn is parasitic on the terrestrial host, Pinus oocarpa, a common forest tree in the collection area. Although the two species of Phoradendron parasitize the same parasitic host and co-occur in the area, they are distinct morphologically. Many plants of Ph. mathiasenii were observed at several collection sites in the study area while plants of Ph. tikalense were observed at only one site

Vertrauen: Substitut oder Komplement zu formellen Institutionen?

In diesem Beitrag diskutieren wir den in der Literatur heftig umstrittenen Aspekt, ob Vertrauen (Institutionen) nur ein Komplement zu formellen Institutionen (Vertrauen) sein oder diese(s) möglicherweise sogar substituieren kann (können). Wir fassen Vertrauen als spezifische, kooperative Investition auf. Dem Vertrauensgeber geht es dabei um die Verlässlichkeit des Vertrauensnehmers ("reliability"). Der Wert einer Vertrauensbeziehung besteht in nicht weniger als in dem sozialen Überschuss, den sie entstehen lassen kann. Ohne weiteres (Reputationseffekte, Trigger Strategien etc.) kommt diese Beziehung aber nicht zustande. Auch anreizkompatible Verträge können das Dilemma nicht lösen. Dafür aber kann die Zahlung des individuell geregelten Schadensersatzes (perfekte Jurisdiktion) dafür Sorge tragen, die Parteien zur Realisierung der sozial optimalen Lösung zu bewegen. Ein ähnlich hoher sozialer Überschuss kann auch dann erreicht werden, wenn bei imperfekter Jurisdiktion der Vertrauensgeber den größeren Teil dieses Überschusses verantwortet.In this paper, we discuss the heavily debated issue whether trust (formal institutions) can only serve as complement(s) or rather as substitute(s) of formal institutions (trust). We take trust as a specific, cooperative investment. The trustor is mainly interested in the reliability of the trustee. The value of a trust relationship amounts and equals to not less than the social surplus which it can generate. Without additional provisions such as trigger strategies, reputation effects etc., however, a trust relationship will not evolve in a one shot game. Not even incentive compatible contracts can solve the dilemma. In a perfect jurisdiction world, a social optimal solution is feasible in the case where both parties agree on "liquidated damages". A comparable social surplus can also be achieved in a non-perfect jurisdiction world. A necessary condition is that the trustor is responsible for the larger part of the social surplus

Vertrauen : Substitut oder Komplement zu formellen Institutionen?

In diesem Beitrag diskutieren wir den in der Literatur heftig umstrittenen Aspekt, ob Vertrauen (Institutionen) nur ein Komplement zu formellen Institutionen (Vertrauen) sein oder diese(s) möglicherweise sogar substituieren kann (können). Wir fassen Vertrauen als spezifische, kooperative Investition auf. Dem Vertrauensgeber geht es dabei um die Verlässlichkeit des Vertrauensnehmers ("reliability"). Der Wert einer Vertrauensbeziehung besteht in nicht weniger als in dem sozialen Überschuss, den sie entstehen lassen kann. Ohne weiteres (Reputationseffekte, Trigger Strategien etc.) kommt diese Beziehung aber nicht zustande. Auch anreizkompatible Verträge können das Dilemma nicht lösen. Dafür aber kann die Zahlung des individuell geregelten Schadensersatzes (perfekte Jurisdiktion) dafür Sorge tragen, die Parteien zur Realisierung der sozial optimalen Lösung zu bewegen. Ein ähnlich hoher sozialer Überschuss kann auch dann erreicht werden, wenn bei imperfekter Jurisdiktion der Vertrauensgeber den größeren Teil dieses Überschusses verantwortet. -- In this paper, we discuss the heavily debated issue whether trust (formal institutions) can only serve as complement(s) or rather as substitute(s) of formal institutions (trust). We take trust as a specific, cooperative investment. The trustor is mainly interested in the reliability of the trustee. The value of a trust relationship amounts and equals to not less than the social surplus which it can generate. Without additional provisions such as trigger strategies, reputation effects etc., however, a trust relationship will not evolve in a one shot game. Not even incentive compatible contracts can solve the dilemma. In a perfect jurisdiction world, a social optimal solution is feasible in the case where both parties agree on "liquidated damages". A comparable social surplus can also be achieved in a non-perfect jurisdiction world. A necessary condition is that the trustor is responsible for the larger part of the social surplus.Vertrauen,Ökonomische Theorie des Rechts,Neue Institutionenökonomik

THE CONTRIBUTION OF BODY CENTER OF MASS VELOCITY TO BASKETBALL BALL RELEASE VELOCITY ACROSS SHOT DISTANCES

This study investigated the contribution of the body center of mass velocity to basketball ball velocity at release when taking shots from different distances from the hoop. Seven basketball players with ten years of experience performed at least ten shots from progressively greater distances: close (\u3c 2.5 m), medium (4.57 m, free throw line), and long (6.02 m, American high school three-point line). As the distance from the hoop increases, the ball velocity required at release increases. Our hypothesis was that an increase in the shot distance would increase the contribution of the body center of mass velocity to ball velocity at release was hypothesized. Kinematics of the ball were recorded using video. Reaction forces generated by each leg were measured using two force plates and used to determine the velocity of the body center of mass during the shooting motion. The results indicate that the percent contribution of the body center of mass velocity to ball velocity at release increased, and the arm contribution decreased with an increase in shot distance. Releasing the ball earlier in the body center of mass trajectory before the apex resulted in a greater percent body contribution of the center of mass vertical velocity to ball vertical velocity

Cell cycle-dependent phosphorylation of Theileria annulata schizont surface proteins

The invasion of Theileria sporozoites into bovine leukocytes is rapidly followed by the destruction of the surrounding host cell membrane, allowing the parasite to establish its niche within the host cell cytoplasm. Theileria infection induces host cell transformation, characterised by increased host cell proliferation and invasiveness, and the activation of anti-apoptotic genes. This process is strictly dependent on the presence of a viable parasite. Several host cell kinases, including PI3-K, JNK, CK2 and Src-family kinases, are constitutively activated in Theileria-infected cells and contribute to the transformed phenotype. Although a number of host cell molecules, including IkB kinase and polo-like kinase 1 (Plk1), are recruited to the schizont surface, very little is known about the schizont molecules involved in host-parasite interactions. In this study we used immunofluorescence to detect phosphorylated threonine (p-Thr), serine (p-Ser) and threonine-proline (p-Thr-Pro) epitopes on the schizont during host cell cycle progression, revealing extensive schizont phosphorylation during host cell interphase. Furthermore, we established a quick protocol to isolate schizonts from infected macrophages following synchronisation in S-phase or mitosis, and used mass spectrometry to detect phosphorylated schizont proteins. In total, 65 phosphorylated Theileria proteins were detected, 15 of which are potentially secreted or expressed on the surface of the schizont and thus may be targets for host cell kinases. In particular, we describe the cell cycle-dependent phosphorylation of two T. annulata surface proteins, TaSP and p104, both of which are highly phosphorylated during host cell S-phase. TaSP and p104 are involved in mediating interactions between the parasite and the host cell cytoskeleton, which is crucial for the persistence of the parasite within the dividing host cell and the maintenance of the transformed state

Characterisation of Float Rocks at Ireson Hill, Gale Crater

Float rocks discovered by surface missions on Mars have given unique insights into the sedimentary, diagenetic and igneous processes that have operated throughout the planets history. In addition, Gale sedimentary rocks, both float and in situ, record a combination of source compositions and diagenetic overprints. We examine a group of float rocks that were identified by the Mars Science Laboratory missions Curiosity rover at the Ireson Hill site, circa. sol 1600 using ChemCam LIBS, APXS and images from the MastCam, Mars Hand Lens Imager (MAHLI) and ChemCam Remote Micro-Imager (RMI) cameras. Geochemical data provided by the APXS and ChemCam instruments allow us to compare the compositions of these rocks to known rock types from Gale crater, as well as elsewhere on Mars. Ireson Hill is a 15 m long butte in the Murray formation with a dark cap-ping unit with chemical and stratigraphic consistency with the Stimson formation. A total of 6 float rocks have been studied on the butte

Studies of a Lacustrine-Volcanic Mars Analog Field Site with Mars-2020-like Instruments

On the upcoming Mars‐2020 rover two remote sensing instruments, Mastcam‐Z and SuperCam, and two microscopic proximity science instruments, SHERLOC and PIXL, will collect compositional (mineralogy, chemistry, and organics) data essential for paleoenvironmental reconstruction. The synergies between and limitations of these instruments were evaluated via study of a Mars analog field site in the Mojave Desert, using instruments approximating the data that will be returned by Mars‐2020. A ground truth dataset was generated for comparison to validate the results. The site consists of a succession of clay‐rich mudstones of lacustrine origin, interbedded tuffs, a carbonate‐silica travertine deposit, and gypsiferous mudstone strata. The major geological units were mapped successfully using simulated Mars‐2020 data. Simulated Mastcam‐Z data identified unit boundaries and Fe‐bearing weathering products. Simulated SuperCam passive shortwave infrared and green Raman data were essential in identifying major mineralogical composition and changes in lacustrine facies at distance; this was possible even with spectrally downsampled passive IR data. LIBS and simulated PIXL data discriminated and mapped major element chemistry. Simulated PIXL revealed mm‐scale zones enriched in zirconium, of interest for age dating. SHERLOC‐like data mapped sulfate and carbonate at sub‐mm scale; silicates were identified with increased laser pulses/spot or by averaging of hundreds of spectra. Fluorescence scans detected and mapped varied classes of organics in all samples, characterized further with follow‐on spatially targeted deep‐UV Raman spectra. Development of dedicated organics spectral libraries is needed to aid interpretation. Given these observations, the important units in the outcrop would be sampled and cached for sample return

Homocysteine and Cardiac Neural Crest Cell Cytoskeletal Proteins in the Chick Embryo

Elevated serum homocysteine (Hcys) is correlated with cardiovascular disease and with embryonic malformations related to neural crest cells (NCCs). We predicted Hcys may alter the balance of actin networks, stress fibers and focal adhesions, altering migration. We cultured neural tube explants in control and Hcys-treated medium and visualized actin, α-actinin, vinculin, filamin, and LIM3 protein in NCCs migrating outward. In Hcys, phalloidin-stained actin in stress fibers was brighter, and vinculin was more abundant in focal adhesions and lamellipodia. α-actinin and LIM3 were also enhanced around nuclei and in focal adhesions, and α-actinin also in filopodia. Filamin was unchanged. Hcys caused more spreading and migration of NCCs, but not more cell-cell adhesions. The findings support our hypothesis that Hcys adjusts NCCs for greater adhesion and migration. Its effect on LIM3 suggests it may modulate signaling that adjusts the cytoskeleton for enhanced migration, leading to mistimed and defective development of target tissues