BACKGROUND Semen is the major vehicle for HIV-1 infection as it contains free and cell-associated virions and infected cells. However, the presence of HIV-1 in spermatozoa has been a matter of debate, since the sperm cell fraction may contain somatic infected cells that jeopardize the attribution of the detected virus to the spermatozoa. METHODS Spermatozoa from 12 HIV-1 seropositive subjects...

In this paper, we introduce a computational model for the simulation of hypervelocity impact (HVI) phenomena which is based on the Discrete Element Method (DEM). Our paper constitutes the first application of DEM to the modeling and simulating of impact events for velocities beyond 5 kms-1. We present here the results of a systematic numerical study on HVI of solids. For modeling the solids, we...

Habitat fragmentation and its genetic consequences are a critically important issue in evaluating the evolutionary penalties of human habitat modification. Here, we examine the genetic structure and diversity in naturally subdivided and artificially fragmented populations of the endangered tidewater goby (Eucyclogobius newberryi), a small fish restricted to discrete coastal lagoons and estuarie...

Electrophoretic properties of chromatin subunits--nucleosomes--obtained by treatment of chromatin with the Serratia marcescens endonuclease have been studied. Double-stranded breaks of DNA between adjacent nucleosomes do not necessarily lead to their disjunction. Fragmentation of the DNA within the nucleosomes may proceed simultaneously with the breakdown of the DNA between the nucleosomes at e...

sam shepard is one of the foremost living american playwrights. he has always been concerned with the problem of identity, specifically the fragmented identity of man living in the postmodern era. such characterization is evident in his plays: true west, fool for love, and a lie of the mind. thus, the present article is to demonstrate the fragmented identity of lee and austin, eddie and may, an...

Forensic biological evidence often contains low quantities of DNA or substantially degraded DNA which makes samples refractory to genotype analysis. One approach that shows promise to overcome the limited quantity of DNA is whole genome amplification (WGA). One WGA technique, termed rolling circle amplification (RCA), involves the amplification of circular DNA fragments and this study evaluates...

background: recurrent spontaneous abortion impacts almost 1% of couples. the sera from women with unexplained recurrent spontaneous abortion (ursa) have toxic effects on embryos that grow in the uterus. therefore, the abnormal condition of the uterus may also affect sperm qualities. objective: the objectives of this study were to search if these sera could induce dna denaturation in sperm nucle...

OBJECTIVE To investigate lipopolysaccharide (LPS)-induced DNA damage in preimplanting embryonic and uterine cells during preimplantation period of pregnancy that may ultimately inhibit the process of implantation in mouse. DESIGN Animal study. SETTING Academic research environment. ANIMAL(S) Sixty four Park strain female mice. INTERVENTION(S) The "minimum dose" (MD) of LPS was injected ...

We describe a device for automated fragmentation of genomic DNA by hydrodynamic shearing using a filter screen with uniform pores. Human genomic DNA can be fragmented reproducibly to a range of 2000-12,000 bp by using various fluid flow rates and screens with 0.5-10-microm pores. The utilization of disposable screens eliminates sample cross-contamination and the tendency of device clogging, com...

The Montecarlo method is used to computer simulate a random distribution of molecular lengths generated by inducing T4 DNA fragmentation through the decay of 32P atoms introduced in the molecule. Taking into account the experimental conditions we find that the value of alpha for alkali sucrose gradients is 0.46 +/- 0.02 and does not depend on the running time. Our findings also prove that the c...