Transgenic mice that overexpress the human trefoil peptide pS2 have an increased resistance to intestinal damage.

pS2 is a member of the trefoil peptide family, all of which are overexpressed at sites of gastrointestinal injury. We hypothesized that they are important in stimulating mucosal repair. To test this idea, we have produced a transgenic mice strain that expresses human pS2 (hpS2) specifically within the jejunum and examined the effect of this overexpression on proliferation and susceptibility to indomethacin-induced damage. A transgenic mouse was produced by microinjecting fertilized oocytes with a 1.7-kb construct consisting of rat intestinal fatty acid binding protein promoter (positions -1178 to +28) linked to full-length (490 bp) hpS2 cDNA. Screening for positive animals was by Southern blot analysis. Distribution of hpS2 expression was determined by using Northern and Western blot analyses and immunohistochemical staining. Proliferation of the intestinal mucosa was determined by assessing the crypt cell production rate. Differences in susceptibility to intestinal damage were analyzed in animals that had received indomethacin (85 mg/kg s.c.) 0-30 h previously. Expression of hpS2 was limited to the enterocytes of the villi within the jejunum. In the nondamaged intestine, villus height and crypt cell production rate were similar in transgenic and negative (control) litter mates. However, there was a marked difference in the amount of damage caused by indomethacin in control and transgenic animals in the jejunum (30% reduction in villus height in controls vs. 12% reduction in transgenic animals, P < 0.01) but the damage sustained in the non-hpS2-expressing ileal region was similar in control and transgenic animals. These studies support the hypothesis that trefoil peptides are important in stimulating gastrointestinal repair.

A dominant-negative mutant of human poly(ADP-ribose) polymerase affects cell recovery, apoptosis, and sister chromatid exchange following DNA damage.

Poly(ADP-ribose) polymerase [PARP; NAD+ ADP-ribosyltransferase; NAD+:poly(adenosine-diphosphate-D-ribosyl)-acceptor ADP-D-ribosyltransferase, EC 2.4.2.30] is a zinc-dependent eukaryotic DNA-binding protein that specifically recognizes DNA strand breaks produced by various genotoxic agents. To study the biological function of this enzyme, we have established stable HeLa cell lines that constitutively produce the 46-kDa DNA-binding domain of human PARP (PARP-DBD), leading to the trans-dominant inhibition of resident PARP activity. As a control, a cell line was constructed, producing a point-mutated version of the DBD, which has no affinity for DNA in vitro. Expression of the PARP-DBD had only a slight effect on undamaged cells but had drastic consequences for cells treated with genotoxic agents. Exposure of cell lines expressing the wild-type (wt) or the mutated PARP-DBD, with low doses of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) resulted in an increase in their doubling time, a G2 + M accumulation, and a marked reduction in cell survival. However, UVC irradiation had no preferential effect on the cell growth or viability of cell lines expressing the PARP-DBD. These PARP-DBD-expressing cells treated with MNNG presented the characteristic nucleosomal DNA ladder, one of the hallmarks of cell death by apoptosis. Moreover, these cells exhibited chromosomal instability as demonstrated by higher frequencies of both spontaneous and MNNG-induced sister chromatid exchanges. Surprisingly, the line producing the mutated DBD had the same behavior as those producing the wt DBD, indicating that the mechanism of action of the dominant-negative mutant involves more than its DNA-binding function. Altogether, these results strongly suggest that PARP is an element of the G2 checkpoint in mammalian cells.

Coverage and invariance for the biological control of pests in mediterranean greenhouses

A major problem related to the treatment of ecosystems is that they have no available mathematical formalization. This implies that many of their properties are not presented as short, rigorous modalities, but rather as long expressions which, from a biological standpoint, totally capture the significance of the property, but which have the disadvantage of not being sufficiently manageable, from a mathematical standpoint. The interpretation of ecosystems through networks allows us to employ the concepts of coverage and invariance alongside other related concepts. The latter will allow us to present the two most important relations in an ecosystem – predator–prey and competition – in a different way. Biological control, defined as “the use of living organisms, their resources or their products to prevent or reduce loss or damage caused by pests”, is now considered the environmentally safest and most economically advantageous method of pest control (van Lenteren, 2011). A guild includes all those organisms that share a common food resource (Polis et al., 1989), which in the context of biological control means all the natural enemies of a given pest. There are several types of intraguild interactions, but the one that has received most research attention is intraguild predation, which occurs when two organisms share the same prey while at the same time participating in some kind of trophic interaction. However, this is not the only intraguild relationship possible, and studies are now being conducted on others, such as oviposition deterrence. In this article, we apply the developed concepts of structural functions, coverage, invariant sets, etc. (Lloret et al., 1998, Esteve and Lloret, 2006a, Esteve and Lloret, 2006b and Esteve and Lloret, 2007) to a tritrophic system that includes aphids, one of the most damaging pests and a current bottleneck for the success of biological control in Mediterranean greenhouses.

Influence of drill speed and feed rate on bone damage

Implant failures and postoperative complications are often associated to the bone drilling. Estimation and control of drilling parameters are critical to prevent mechanical damage to the bone tissues. For better performance of the drilling procedures, it is essential to understand the mechanical behaviour of bones that leads to their failures and consequently to improve the cutting conditions. This paper investigates the effect of drill speed and feed-rate on mechanical damage during drilling of solid rigid foam materials, with similar mechanical properties to the human bone. Experimental tests were conducted on biomechanical blocks instrumented with strain gauges to assess the drill speed and feed-rate influence. A three-dimensional dynamic finite element model to predict the bone stresses, as a function of drilling conditions, drill geometry and bone model, was developed. These simulations incorporate the dynamic characteristics involved in the drilling process. The element removal scheme is taken into account and allows advanced simulations of tool penetration and material removal. Experimental and numerical results show that generated stresses in the material tend to increase with tool penetration. Higher drill speed leads to an increase of von-Mises stresses and strains in the solid rigid foams. However, when the feed-rate is higher, the stresses and strains are lower. The numerical normal stresses and strains are found to be in good agreement with experimental results. The models could be an accurate analysis tool to simulate the stresses distribution in the bone during the drilling process.

Quo vadis Aethina tumida? Biology and control of small hive beetles

Small hive beetles (SHBs) are generalists native to sub-Saharan Africa and reproduce in association with honeybees, bumblebees, stingless bees, fruits and meat. The SHB has recently become an invasive species, and introductions have been recorded from America, Australia, Europe and Asia since 1996. hile SHBs are usually considered a minor pest in Africa, they can cause significant damage to social bee colonies in their new ranges. Potential reasons for differential impact include differences in bee behaviour, climate and release from natural enemies. Here, we provide an overview on biology, distribution, pest status, diagnosis, control and prevention to foster adequate mitigation and stimulate future research. SHBs have become a global threat to both apiculture and wild bee populations, but our knowledge of this pest is still limited, reating demand for more research in all areas of its biology.

Damage to vehicle safety and engine exhaust emissions systems in collision. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Beach erosion control study on Pinellas County, Fla.

"Serial no. 5."

Addendum to Strategic planning study for flood control : Crystal Creek, Villages of Franklin Park & Schiller Park, Cook County, Illinois.

"OWR/SPS/99-003."

Ashland Flood Control Project : Village of Ashland, Cass County Illinois : Division of Water Resources, small projects program.

"DOWR/SPR/95-002."

Ashland Flood Control Project : Village of Ashland, IL, Cass County /

"May 2009."

Buffalo Creek Tributary A flood control project in Palatine Township, Cook County, Illinois : executive summary /

Description of a project to replace box culverts with bridges and to widen the channel bottom of Tributary A of Buffalo Creek.

City of Sycamore flood control project (Martin's Ditch Reservoir) : Small Projects Program : city of Sycamore, DeKalb County, Illinois.

Cover title.

City of Sycamore flood control project (Bethany Road Detention Pond) : Small Projects Program : city of Sycamore, DeKalb County, Illinois.

"OWR/SPR/01-001"

Crossville Flood Control Project : village of Crossville, White County, Illinois : small projects program.

"DOWR/SPR/94-001."

Environmental assessment, Hickory/Spring Creek flood control project : report to the Illinois Department of Transportation, Division of Water Resources /

Includes bibliography.