The moduli space M of surfaces of general type with pg = q = 1, K 2 = g = 3 (where g is the genus of the Albanese fibration) was constructed by Catanese and Ciliberto in [CaCi93]. In this paper we characterize the subvariety M 2 ⊂ M corresponding to surfaces containing a genus 2 pencil, and moreover we show that there exists a non-empty, dense subset M 0 ⊂ M which parametrizes isomorphism class...

We prove a necessary and sufficient condition for the existence of spreads in the projective Hjelmslev geometries PHG Rn 1 R . Further, we give a construction of projective Hjelmslev planes from spreads that generalizes the familiar construction of projective planes from spreads in PG n q .

The present paper is devoted to the classification of irregular surfaces of general type with pg = q = 2 and non birational bicanonical map. The main result is that, if S is such a surface and if S is minimal with no pencil of curves of genus 2, then S is a double cover of a principally polarized abelian surface (A,Θ), with Θ irreducible. The double cover S → A is branched along a divisor B ∈ |...

The anti-depressant fluoxetine is widely present in the aquatic environment. Typical river concentrations are in the low ng/L range. Many ecotoxicity studies have assessed the effects of this pharmaceutical on a range of aquatic species. Some studies report that ng, or even pg, per litre concentrations cause effects, whereas other studies report that effects only occur when the water concentrat...

Let V be a 2m-dimensional vector space over a field F (m ≥ 2) and let k ∈ {1, . . . , 2m − 1}. Let A2m−1,k denote the Grassmannian of the (k − 1)-dimensional subspaces of PG(V ) and let egr denote the Grassmann embedding of A2m−1,k into PG( ∧k V ). Let S be a regular spread of PG(V ) and let XS denote the set of all (k − 1)-dimensional subspaces of PG(V ) which contain at least one line of S. T...

In order to reduce the silicon area of the chip and optimize the power of arithmetic circuits, this paper proposes a low power carry look-ahead BCD (Binary Coded Decimal) adder which uses a four bit MOCLA (Multiplexer and Or gate based Carry Look Ahead Adder) that forms the basic building block. This proposed MOCLA style uses a 2 input MUX, OR gate and GDI (Gate Diffusion Input) based full adde...

Let G be the group of projectivities stabilizing a unital U in PG(2, q2) and let A,B be two distinct points of U . In this paper we prove that, if G has an elation group of order q with center A and a group of projectivities stabilizing both A and B of order a divisor of q − 1 greater than 2(√q − 1), then U is an ovoidal Buekenhout–Metz unital. From this result two group theoretic characterizat...

Some Water-soluble Vitamins in the Sweat of Tropically Acclimatized European Men BY J. W. H. LUGG AND I?. P. ELLIS Vol. 8 (1954), no. I P. 75, Table I , heading to ninth column: For Thiamine (mg/Ioo ml.) read Thiamine (pg/Ioo ml.). P. 76, lines 41 and 42: For (range 0.095-0.140 mg/Ioo ml.; mean 0.123 mg/Ioo ml.) read (range o*og5-0.140 ,ug/Ioo ml.; mean 0.123 ,ug/Ioo ml.) P. 77, Summary, para. ...

Abstract. In the projective space PG(3, q) with odd prime q ≡ 2 (mod 3), q ≥ 11, a new infinite family of complete (q + q + 8)/2-caps is constructed. It gives a new lower bound on the second largest size m′2(3, q) of complete caps: (q 2 + q + 8)/2 ≤ m ′2(3, q). The structure of one of the two existing complete 20-caps in PG(3, 5) is described. The new upper bounds on the smallest size of comple...