Molecular Exploration of the First-Century Tomb of the Shroud in Akeldama,Jerusalem

The Tomb of the Shroud is a first-century C.E. tomb discovered in Akeldama, Jerusalem, Israel that had been illegally entered and looted. The investigation of this tomb by an interdisciplinary team of researchers began in 2000. More than twenty stone ossuaries for collecting human bones were found, along with textiles from a burial shroud, hair and skeletal remains. The research presented here focuses on genetic analysis of the bioarchaeological remains from the tomb using mitochondrial DNA to examine familial relationships of the individuals within the tomb and molecular screening for the presence of disease. There are three mitochondrial haplotypes shared between a number of the remains analyzed suggesting a possible family tomb. There were two pathogens genetically detected within the collection of osteological samples, these were Mycobacterium tuberculosis and Mycobacterium leprae. The Tomb of the Shroud is one of very few examples of a preserved shrouded human burial and the only example of a plaster sealed loculus with remains genetically confirmed to have belonged to a shrouded male individual that suffered from tuberculosis and leprosy dating to the first-century C.E. This is the earliest case of leprosy with a confirmed date in which M. leprae DNA was detected.     

A compatible interaction of Alternaria brassicicola with Arabidopsis thaliana ecotype DiG: evidence for a specific transcriptional signature

Background  

The interaction of Arabidopsis with Alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. Infection of most ecotypes, including the widely-studied line Col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. This study examines an ecotype, Dijon G (DiG), which is considered sensitive to A. brassicicola.     

Class similarity and viewpoint invariance in the recognition of 3D objects

 In human vision, the processes and the representations involved in identifying specific individuals are frequently assumed to be different from those used for basic level classification, because classification is largely viewpoint-invariant, but identification is not. This assumption was tested in psychophysical experiments, in which objective similarity between stimuli (and, consequently, the level of their distinction) varied in a controlled fashion. Subjects were trained to discriminate between two classes of computer-generated three-dimensional objects, one resembling monkeys and the other, dogs. Both classes were defined by the same set of 56 parameters, which encoded sizes, shapes, and placement of the limbs, ears, snout, etc. Interpolation between parameter vectors of the class prototypes yielded shapes that changed smoothly between monkey and dog. Within-class variation was induced in each trial by randomly perturbing all the parameters. After the subjects reached 90% correct performance on a fixed canonical view of each object, discrimination performance was tested for novel views that differed by up to 60° from the training view. In experiment 1 (in which the distribution of parameters in each class was unimodal) and in experiment 2 (bimodal classes), the stimuli differed only parametrically and consisted of the same geons (parts), yet were recognized virtually independently of viewpoint in the low-similarity condition. In experiment 3, the prototypes differed in their arrangement of geons, yet the subjects’ performance depended significantly on viewpoint in the high-similarity condition. In all three experiments, higher interstimulus similarity was associated with an increase in the mean error rate and, for misorientation of up to 45°, with an increase in the degree of viewpoint dependence. These results suggest that a geon-level difference between stimuli is neither strictly necessary nor always sufficient for viewpoint-invariant performance. Thus, basic and subordinate-level processes in visual recognition may be more closely related than previously thought. Received: 15 November 1993/Accepted in revised form: 14 July 1994     

Attempts to control sand flies by insecticide-sprayed strips along the periphery of a village.

The customary method for controlling leishmaniasis and sand fly bites in Israel is the spraying of large quantities of residual insecticides on walls of houses and neighboring surfaces. However, the high summer temperatures, strong radiation, and dust limit the efficacy of the method. The sand fly vectors of Leishmania appeared to come uphill to the village of Kfar Adumim. Therefore, to block their path and improve control, beta-cyfluthrine or DDT were repeatedly sprayed on a strip of cloth that was stretched on the ground along and near the peripheral houses. The efficacy of the treatments was examined by comparing the proportions of sand flies that had been caught before and after the treatments, below and above the belt. The capture near the houses of sand flies that had been marked by colored sugar baits below the protective belt indicated that they were moving uphill and crossing the strip. The catches showed a gradual uphill decrease, up to the houses, in the number of sand flies. However, the proportions of sand flies caught in the different sites were similar before and after insecticide treatments showing that the belt was ineffective. Laboratory tests of pieces of the sprayed strip and exposure of sand flies to similar pieces indicated that the lack of effect was not caused by deficiency of insecticides.     

Atypical Cohesin-Dockerin Complex Responsible for Cell Surface Attachment of Cellulosomal Components: BINDING FIDELITY,PROMISCUITY, AND STRUCTURAL BUTTRESSES*

The rumen bacterium Ruminococcus flavefaciens produces a highly organized multienzyme cellulosome complex that plays a key role in the degradation of plant cell wall polysaccharides, notably cellulose. The R. flavefaciens cellulosomal system is anchored to the bacterial cell wall through a relatively small ScaE scaffoldin subunit, which bears a single type IIIe cohesin responsible for the attachment of two major dockerin-containing scaffoldin proteins, ScaB and the cellulose-binding protein CttA. Although ScaB recruits the catalytic machinery onto the complex, CttA mediates attachment of the bacterial substrate via its two putative carbohydrate-binding modules. In an effort to understand the structural basis for assembly and cell surface attachment of the cellulosome in R. flavefaciens, we determined the crystal structure of the high affinity complex (K_d = 20.83 nm) between the cohesin module of ScaE (CohE) and its cognate X-dockerin (XDoc) modular dyad from CttA at 1.97-Å resolution. The structure reveals an atypical calcium-binding loop containing a 13-residue insert. The results further pinpoint two charged specificity-related residues on the surface of the cohesin module that are responsible for specific versus promiscuous cross-strain binding of the dockerin module. In addition, a combined functional role for the three enigmatic dockerin inserts was established whereby these extraneous segments serve as structural buttresses that reinforce the stalklike conformation of the X-module, thus segregating its tethered complement of cellulosomal components from the cell surface. The novel structure of the RfCohE-XDoc complex sheds light on divergent dockerin structure and function and provides insight into the specificity features of the type IIIe cohesin-dockerin interaction.     

Contagious sterility in the parasitoid wasp Eretmocerus mundus (Hymenoptera: Aphelinidae)

The parasitoid wasp Eretmocerus mundus (Hymenoptera: Aphelinidae) is used commercially to control the sweet potato whitefly Bemisia tabaci (Homoptera: Aleyrodidae). Recently, a rapid deterioration of E. mundus populations has been documented under mass-rearing conditions. We found that deteriorating cultures consist of increasing proportions of sterile individuals, up to 90% within 6 months. Microscopic examination revealed that the gonads of wasps from both sexes are severely underdeveloped. Preliminary screening for potential pathogen candidates by means of polymerase chain reaction and denaturating-gradient gel electrophoresis did not provide any indication of possible causative agents.     

Structural and magnetic behavior of mono- and dinuclear nickel (II) complexes of N,N′-bis-(3,5-dipiperidin-1-yl-[2,4,6]triazin-1-yl)-pyridin-2-ylmethyl-ethane-1,2-diamine

Reaction of nickel (II) perchlorate with the ligand N,N′-bis-(3,5-dipiperidin-1-yl-[2,4,6]triazin-1-yl)-pyridin-2-ylmethyl-ethane-1,2-diamine yields an octahedral Ni(II) high-spin complex 1 ([C₄₀H₅₆N₁₄Ni(H₂O)(CH₃OH)](ClO₄)₂(CH₃OH)₂) with moderate zero-field splitting (ZFS) axial distortion parameter D/k_B = 5.37 K. The ligand contributes a N4 donor set; the remaining two coordinating positions are occupied by coordinating solvents molecules. Exchange of the coordinating solvents molecules in complex 1 to thiocyanate moieties leads to formation of complex 2 ([C₄₀H₅₆N₁₄Ni(NCS)₂](CHCl)₃) with an extended parameter D/k_B = 8.80 K. The analysis of the structural and magnetic properties of complexes 1 and 2 led to the design of dinuclear complex 3 ([C₄₀H₅₆N₁₄NiN₃]₂(ClO₄)₂(CH₃OH)₂), where two azido groups were utilized as bridging ligands. The double azido bridges in complex 3 cross each other to form a rarely observed non-coplanar (N₃)₂ structure. The magnetic behavior of complex 3 reveals ferromagnetic coupling interactions characterized by J/k_B = 23.25 K, D₁/k_B = 7.90 K, D₂/k_B = 0.54 K.