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We show that there are many compact subsets of the moduli space Mg of Riemann surfaces of genus g that do not intersect any symmetry locus. This has interesting implications for N=2 supersymmetric conformal field theories in four dimensions. [ABSTRACT FROM AUTHOR]

Motivated by engineering vector-like (Higgs) pairs in the spectrum of 4d F-theory compactifications, we combine machine learning and algebraic geometry techniques to analyze line bundle cohomologies on families of holomorphic curves. To quantify jumps of these cohomologies, we first generate 1.8 million pairs of line bundles and curves embedded in dP3, for which we compute the cohomologies. A white-box machine learning approach trained on this data provides intuition for jumps due to curve splittings, which we use to construct additional vector-like Higgs-pairs in an F-Theory toy model. We also find that, in order to explain quantitatively the full dataset, further tools from algebraic geometry, in particular Brill-Noether theory, are required. Using these ingredients, we introduce a diagrammatic way to express cohomology jumps across the parameter space of each family of matter curves, which reflects a stratification of the F-theory complex structure moduli space in terms of the vector-like spectrum. Furthermore, these insights provide an algorithmically efficient way to estimate the possible cohomology dimensions across the entire parameter space. [ABSTRACT FROM AUTHOR]

Nicotiana tabacum L. Bel-W3, which is highly sensitive to ozone, was grown in two glass chambers and exposed to the ambient air at the periphery of Tel-Aviv, during winter, spring, summer and autumn 1978. During the exposure time, atmospheric ozone was continuously measured by a chemiluminescent monitor. Throughout the experiments, plants' height was measured and the number of leaves was determined three times weekly. The extent of injury to the tobacco plants was measured by the percentage of injured plants, the percentage of injured leaves and the percentage of leaves' area injured. Necrotic lesions, typical for ozone injury, appeared on the mature leaves of the exposed tobacco plants in three out of four exposures. Appearance of incipient injury and the extent of injury differed among the experiments and depended not only on exposure duration and on ozone concentrations, but also on the exposure conditions. The percentage of injured leaves and the percentage of leaves' area injured, increased with the duration of exposure and with rising cumulative ozone concentrations.

An epidemiological monitoring program has been designed and put into operation in response to a health monitoring requirement of a permit to build a coal-fired power plant. It will consist of four 350 megawatt units and is being built on the Mediterranean coast about halfway between Tel-Aviv and Haifa; the first unit became operational in 1981. The resident population within a 10 km. radius consists of about 69,000 persons. The permit to build this power plant required the installation of a comprehensive monitoring network including environmental, health and agricultural monitoring. Four types of studies are included in the epidemiological monitoring program: mortality analyses, monitoring of requests for health services, studies of pulmonary symptoms and lung function in school children, and panel studies of children and adults with chronic pulmonary conditions. Areas of maximal expected exposure risk and two other comparable areas of lesser risk were chosen, based on expected emissions, meterological and topographical considerations; baseline data were gathered for a year prior to the operation of the first unit of the power plant. Subsequent data are planned to be collected for another 10 years. The program permits detection of short-term effects based on increases in health service requests, medium-term effects by repeat examination of panelists, and long-term effects based on pulmonary conditions among school children. The initial survey, before plant operations showed, among other things, lower flow rates for children in the area expected to have medium levels of exposure.

A massive epidemic of psychogenic aetiology occurred in three districts of the West Bank over two weeks in March-April, 1983. It affected 949 individuals, 727 (77%) of them adolescent females. The symptoms were not accompanied by positive physical signs or by laboratory findings. The epidemiological pattern was pathognomonic of that of a psychogenic disorder. The initial trigger was probably the odour of H2S escaping from a faulty latrine in the schoolyard of the first affected school. Subsequent spread of the disease was due to psychological and extra-medical factors, including publicity by the mass media. Spread was stopped immediately after closure of schools.