A framework is proposed that develops the dimensions of vertical integration strated and proposes key factors that might augment their uses within various scenarios. These represent new hypotheses and conjectures about make-or-buy decisions that require empirical testing. If the framework is valid, strategists could formulate better hybrid vertical integration strategies by recogniang the hypot...

Buttons & Scissors is a popular single-player puzzle. A level is played on an n-by-n grid, where each position is empty or has a single coloured button sewn onto it. The player’s goal is to remove all of the buttons using a sequence of horizontal, vertical, and diagonal scissor cuts. Each cut removes all buttons between two distinct buttons of the same colour, and is not valid if there is an in...

Interval temporal logics provide both an insight into a nature of time and a framework for temporal reasoning in various areas of computer science. In this paper we present sound and complete relational proof systems in the style of dual tableaux for relational logics associated with modal logics of temporal intervals and we prove that the systems enable us to verify validity and entailment of ...

Male-killing bacteria are bacteria that are transmitted vertically through the females of their insect hosts. They can distort the sex ratio of their hosts by killing infected male offspring. In nature, male-killing endosymbionts (male killers) often have a 100% efficient vertical transmission, and multiple male-killing bacteria infecting a single population are observed. We use different model...

BACKGROUND To identify potential environmental drivers of Japanese Encephalitis virus (JE) transmission in Nepal, we conducted an ecological study to determine the spatial association between 2005 Nepal JE incidence, and climate, agricultural, and land-cover variables at district level. METHODS District-level data on JE cases were examined using Local Indicators of Spatial Association (LISA) ...

We investigated the dynamics of Plasmodium falciparum gametocytemia in symptomatic patients attending a local dispensary in the Kilombero district, Tanzania. Consenting individuals aged one and above, with varying asexual and sexual parasitemias were treated appropriately and asked to return weekly for 28 days. Gametocyte prevalence was highest on Day 7 of follow-up in all age groups (overall 3...

A number of pathogens may be transmitted from parent to child at or before birth (vertically) or from one individual to another by contact (horizontally). A natural deterministic and non-spatial model, introduced by Lipsitch et al. [Proc. Roy. Soc. London Ser. B 260 (1995) 321] shows that an epidemic is possible if the vertical transmission or the horizontal transmission is high enough. In cont...

The spectral sensitivities of the short (S-), middle (M-) and long (L-) wave-sensitive cones have been measured in normal trichromats and in dichromats and monochromats of known genotype. For the S-cone sensitivities, three blue-cone monochromats and five normals were used; for the M-cone sensitivities, nine protanopes (three with a single L1M2 gene, three with a single L2M3 gene, one with both...

Proposals to make prenatal HIV testing routine and universal dramatize ethical issues regarding early detection of HIV. These proposals would abolish pretest counseling and written informed consent for prenatal HIV testing. Ethical concerns include whether pregnant women are adequately informed that they may refuse such testing and whether patients have an opportunity to obtain more detailed in...