Ancient dominance of the Quercus calliprinos - Pistacia palaestina association in mediterranean Israel

Abstract. The natural Mediterranean maquis and forest vegetation of Israel is commonly considered to be composed mainly of four, roughly equal components: Pinus halepensis, deciduous oak, evergreen oak, and Ceratonia - Pistacia communities. They represent the past climax and subclimax of this region. Evidence accumulated from pollen analysis and wood remnant research in geological and archaeological excavations, as well as from written historical sources, shows that this view is wrong: the ancient vegetation in this area was dominated by Quercus calliprinos.     

Lentil domestication: On the quality of evidence and arguments

The current views on lentil domestication are based on biological attributes of the wild progenitorLens culinaris ssp. orientalis and on assumptions which have never been tested. Seed dormancy, a major factor in the adaptation of ssp.orientalis to its natural habitat, makes it inappropriate for cultivation, because poor germination causes seed yield following cultivation to be equal to the amount of sown seeds. Higher yield, resulting from the evolution of a non-dormant type can be obtained only after five or six cycles of unprofitable cultivation. It is doubtful that incipient farmers would have undertaken such an endeavor without preexisting knowledge that non-dormant types could eventually be obtained. Experiments involving the sowing of wild lentil would have been much more successful if the non-dormant types were present in appreciable quantities in the seed stock. Establishment of that type in the natural population would have required a period of seven to eight years with favorable growing conditions allowing the non-dormant type to become widespread in the population, followed by massive predation by man reducing the hazard of a population explosion. The close similarity between isozyme profiles of the cultivated lentil and its wild progenitor indicates that lentil cultivation was attempted with seeds derived from different populations and in different areas.     

Vulnerability, livelihood assets and institutional dynamics in the management of wetlands in Lake Victoria watershed basin

This paper uses data from 600 households in the Lake Victoria watershed in Tanzania, Kenya, and Uganda to analyze the effects of vulnerabilities and shocks on the management and exploitation of wetlands within the context of agricultural activities and high poverty levels. A multinomial logit model is used to determine variables that influence the perception of wetlands degradation, while a tobit model is used to establish the determinants of willingness to pay for wetland conservation and the imputed value of wetland product extracts. The model results show that although the perception of wetland degradation is modest, it is influenced by attributes of social capital. Variables such as floods, diseases and droughts significantly influence the households’ willingness to pay for wetland conservation. Land size and ownership, education level and household size all influence households’ likelihood to actively engage in wetland resource exploitation and willingness to pay for its conservation. The implications of these results hinge on measures that would moderate the effects of shocks, mobilize collective action, and improve physical infrastructure within the context of sustainable wetland resource use.     

Predicting the Maximum Earthquake Magnitude from Seismic Data in Israel and Its Neighboring Countries

This paper explores several data mining and time series analysis methods for predicting the magnitude of the largest seismic event in the next year based on the previously recorded seismic events in the same region. The methods are evaluated on a catalog of 9,042 earthquake events, which took place between 01/01/1983 and 31/12/2010 in the area of Israel and its neighboring countries. The data was obtained from the Geophysical Institute of Israel. Each earthquake record in the catalog is associated with one of 33 seismic regions. The data was cleaned by removing foreshocks and aftershocks. In our study, we have focused on ten most active regions, which account for more than 80% of the total number of earthquakes in the area. The goal is to predict whether the maximum earthquake magnitude in the following year will exceed the median of maximum yearly magnitudes in the same region. Since the analyzed catalog includes only 28 years of complete data, the last five annual records of each region (referring to the years 2006–2010) are kept for testing while using the previous annual records for training. The predictive features are based on the Gutenberg-Richter Ratio as well as on some new seismic indicators based on the moving averages of the number of earthquakes in each area. The new predictive features prove to be much more useful than the indicators traditionally used in the earthquake prediction literature. The most accurate result (AUC = 0.698) is reached by the Multi-Objective Info-Fuzzy Network (M-IFN) algorithm, which takes into account the association between two target variables: the number of earthquakes and the maximum earthquake magnitude during the same year.     

Mechanisms of initial endplate failure in the human vertebral body

Endplate failure occurs frequently in osteoporotic vertebral fractures and may be related to the development of high tensile strain. To determine whether the highest tensile strains in the vertebra occur in the endplates, and whether such high tensile strains are associated with the material behavior of the intervertebral disc, we used micro-CT-based finite element analysis to assess tissue-level strains in 22 elderly human vertebrae (81.5±9.6 years) that were compressed through simulated intervertebral discs. In each vertebra, we compared the highest tensile and compressive strains across the different compartments: endplates, cortical shell, and trabecular bone. The influence of Poisson-type expansion of the disc on the results was determined by compressing the vertebrae a second time in which we suppressed the Poisson expansion. We found that the highest tensile strains occurred within the endplates whereas the highest compressive strains occurred within the trabecular bone. The ratio of strain to assumed tissue-level yield strain was the highest for the endplates, indicating that the endplates had the greatest risk of initial failure. Suppressing the Poisson expansion of the disc decreased the amount of highly tensile-strained tissue in the endplates by 79.4±11.3%. These results indicate that the endplates are at the greatest risk of initial failure due to the development of high tensile strains, and that such high tensile strains are associated with the Poisson expansion of the disc. We conclude that initial failure of the vertebra is associated with high tensile strains in the endplates, which in turn are influenced by the material behavior of the disc.     

Sleep/Wake Dynamics Changes during Maturation in Rats

Objectives

Conventional scoring of sleep provides little information about the process of transitioning between vigilance states. We applied the state space technique (SST) using frequency band ratios to follow normal maturation of different sleep/wake states, velocities of movements, and transitions between states of juvenile (postnatal day 34, P34) and young adult rats (P71).

Design

24-h sleep recordings of eight P34 and nine P71 were analyzed using conventional scoring criteria and SST one week following implantation of telemetric transmitter. SST is a non-categorical approach that allows novel quantitative and unbiased examination of vigilance-states dynamics and state transitions. In this approach, behavioral changes are described in a 2-dimensional state space that is derived from spectral characteristics of the electroencephalography.

Measurements and Results

With maturation sleep intensity declines, the duration of deep slow wave sleep (DSWS) and light slow wave sleep (LSWS) decreases and increases, respectively. Vigilance state determination, as a function of frequency, is not constant; there is a substantial shift to higher ratio 1 in all vigilance states except DSWS. Deep slow wave sleep decreases in adult relative to juvenile animals at all frequencies. P71 animals have 400% more trajectories from Wake to LSWS (p = 0.005) and vice versa (p = 0.005), and 100% more micro-arousals (p = 0.021), while trajectories from LSWS to DSWS (p = 0.047) and vice versa (p = 0.033) were reduced by 60%. In both juvenile and adult animals, no significant changes were found in sleep velocity at all regions of the 2-dimensional state space plot; suggesting that maturation has a partial effect on sleep stability.

Conclusions

Here, we present novel and original evidence that SST enables visualization of vigilance-state intensity, transitions, and velocities that were not evident by traditional scoring methods. These observations provide new perspectives in sleep state dynamics and highlight the usefulness of this technique in exploring the development of sleep-wake activity.     

The evolution of an ideal stent design and its impact on the aortic endothelium during and after percutaneous replacement

Vascular support structures are important devices for treating valve stenosis. A large population of patients is treated for valvular disease and the preferred mode of treatment is percutaneous valve replacement. Stent devices are proving to be an improved technology in minimally invasive cardiac surgery. This new technology provides highly effective results at minimal cost and with a short duration of hospitalisation. Stents as a supporting structure for tissue valves have evolved over the years into remarkably useful and effective devices. During this process, a number of specific designs have come and gone, and a few have remained. Many design changes were successful, and many were not. This article describes the merits and demerits of various stent designs and details the specific reasons why a particular novel design is expected to be the most suitable implant during and after percutaneous aortic valve replacement.     

The alpha-glucuronidase,GlcA67A,of Cellvibrio japonicus utilizes the carboxylate and methyl groups of aldobiouronic acid as important substrate recognition determinants

alpha-Glucuronidases are key components of the ensemble of enzymes that degrade the plant cell wall. They hydrolyze the alpha1,2-glycosidic bond between 4-O-methyl-d-glucuronic acid (4-O-MeGlcA) and the xylan or xylooligosaccharide backbone. Here we report the crystal structure of an inactive mutant (E292A) of the alpha-glucuronidase, GlcA67A, from Cellvibrio japonicus in complex with its substrate. The data show that the 4-O-methyl group of the substrate is accommodated within a hydrophobic sheath flanked by Val-210 and Trp-160, whereas the carboxylate moiety is located within a positively charged region of the substrate-binding pocket. The carboxylate side chains of Glu-393 and Asp-365, on the "beta-face" of 4-O-MeGlcA, form hydrogen bonds with a water molecule that is perfectly positioned to mount a nucleophilic attack at the anomeric carbon of the target glycosidic bond, providing further support for the view that, singly or together, these amino acids function as the catalytic base. The capacity of reaction products and product analogues to inhibit GlcA67A shows that the 4-O-methyl group, the carboxylate, and the xylose sugar of aldobiouronic acid all play an important role in substrate binding. Site-directed mutagenesis informed by the crystal structure of enzyme-ligand complexes was used to probe the importance of highly conserved residues at the active site of GlcA67A. The biochemical properties of K288A, R325A, and K360A show that a constellation of three basic amino acids (Lys-288, Arg-325, and Lys-360) plays a critical role in binding the carboxylate moiety of 4-O-MeGlcA. Disruption of the apolar nature of the pocket created by Val-210 (V210N and V210S) has a detrimental effect on substrate binding, although the reduction in affinity is not reflected by an inability to accommodate the 4-O-methyl group. Replacing the two tryptophan residues that stack against the sugar rings of the substrate with alanine (W160A and W543A) greatly reduced activity.     

A PEX6-defective peroxisomal biogenesis disorder with severe phenotype in an infant, versus mild phenotype resembling Usher syndrome in the affected parents

Sensorineural deafness and retinitis pigmentosa (RP) are the hallmarks of Usher syndrome (USH) but are also prominent features in peroxisomal biogenesis defects (PBDs); both are autosomal recessively inherited. The firstborn son of unrelated parents, who both had sensorineural deafness and RP diagnosed as USH, presented with sensorineural deafness, RP, dysmorphism, developmental delay, hepatomegaly, and hypsarrhythmia and died at age 17 mo. The infant was shown to have a PBD, on the basis of elevated plasma levels of very-long- and branched-chain fatty acids (VLCFAs and BCFAs), deficiency of multiple peroxisomal functions in fibroblasts, and complete absence of peroxisomes in fibroblasts and liver. Surprisingly, both parents had elevated plasma levels of VLCFAs and BCFAs. Fibroblast studies confirmed that both parents had a PBD. The parents' milder phenotypes correlated with relatively mild peroxisomal biochemical dysfunction and with catalase immunofluorescence microscopy demonstrating mosaicism and temperature sensitivity in fibroblasts. The infant and both of his parents belonged to complementation group C. PEX6 gene sequencing revealed mutations on both alleles, in the infant and in his parents. This unique family is the first report of a PBD with which the parents are themselves affected individuals rather than asymptomatic carriers. Because of considerable overlap between USH and milder PBD phenotypes, individuals suspected to have USH should be screened for peroxisomal dysfunction.