In vitro genotoxic effects of the anticancer drug gemcitabine in human lymphocytes

This research was carried out to investigate in vitro genotoxic effects of the anticancer agent gemcitabine on the induction of chromosomal aberrations and sister-chromatid exchange in human lymphocytes. Three doses of gemcitabine (0.001, 0.002 and 0.004 microg/ml) were applied to lymphocyte cultures from 15 donors. There was a significant increase in the induction of chromosome aberrations and in the occurrence of sister-chromatid exchange in these cells. In addition, gemcitabine significantly decreased the mitotic index and replicative index for all doses. Dose-response regression lines were used to compare the individual susceptibilities to gemcitabine with respect to the chromosome aberration and sister-chromatid exchange frequencies. Our results indicate that gemcitabine is able to induce both cytotoxic and genotoxic effects in human lymphocyte cultures in vitro in a dose-dependent manner.     

Importance of the 5′ regulatory region to bacterial synthetic biology applications

The field of synthetic biology is evolving at a fast pace. It is advancing beyond single-gene alterations in single hosts to the logical design of complex circuits and the development of integrated synthetic genomes. Recent breakthroughs in deep learning, which is increasingly used in de novo assembly of DNA components with predictable effects, are also aiding the discipline. Despite advances in computing, the field is still reliant on the availability of pre-characterized DNA parts, whether natural or synthetic, to regulate gene expression in bacteria and make valuable compounds. In this review, we discuss the different bacterial synthetic biology methodologies employed in the creation of 5′ regulatory regions – promoters, untranslated regions and 5′-end of coding sequences. We summarize methodologies and discuss their significance for each of the functional DNA components, and highlight the key advances made in bacterial engineering by concentrating on their flaws and strengths. We end the review by outlining the issues that the discipline may face in the near future.     

The effects and interactions of three invasive fish species introduced to the aquatic ecosystem of a Turkish Lake (Eğirdir Lake)

We studied feeding behavior and prey selection of topmouth gudgeon (Pseudorasbora parva), big-scale sand smelt (Atherina boyeri) and pike-perch (Sander lucioperca) in Lake E?irdir, the second largest freshwater lake in Turkey. Fish specimens were collected between January and August in 2010 and 2011 using gill-nets and purse seines. A total of 941 specimens were analyzed for stomach contents analysis. We expressed the importance of the food items present in their guts with the relative importance index (IRI) and estimated their diet selectivity indices with Pearre’s index. Pseudorasbora parva had a diverse diet comprising mainly Nitokra hibernica (copepod), Chydorus sphaericus, and Bosmina longirostris (cladoceran) (each, at p?<?0.01), but Chironomus sp. (insect) was not a significant component of its diet (p?>?0.05). Big-scale sand smelt often preferred B. longirostris, N. hibernica, and Alona quadrangularis (each at p?<?0.01). Pike-perch positively, but not statistically significant, selected Atherina boyeri (p?>?0.05), Carassius gibelio was not preferred by pike-perch as food item (p?>?0.05). Our results indicate that invasive species altered the food chain in Lake E?irdir. Thus, because these fish species constitute a major threat for native fish species for food and breeding grounds, extensive care should be taken to prevent invasive fish species entering lakes in Turkey.

     

Germination responses to GA3 and stratification of threatened Festuca L. species from Eastern Mediterranean

The seed germination characteristics of three threatened Festuca sp. [F. punctoria Sm., F. cyllenica Boiss. et Heldr. subsp. uluana Markgr.-Dannenb., F. paphlagonica (St.-Yves) Markgr.-Dannenb. subsp. paphlagonica] were investigated. These species are endemic and spread on alpine belt. The study was carried out with wet-cold and dry-cold stratification throughout 15 days, different doses of GA3 (50, 100 and 150 ppm) and hormone-stratification combined treatments, and non-treatment series. We found that the germination rates of three fescue seeds for various treatment series were different. The mean germination percentage of F. cyllenica was higher (80%) than that of F. punctoria and F. paphlagonica which were fairly low (50-60%). Germination rates increased by wet-stratification treatment in F. punctoria and also increased with 100 ppm GA3 application to the seeds of F. paphlagonica. When taken into consideration the germination percentages of all fescue species, the seeds of F. punctoria and F. paphlagonica can be dormant, but the seeds of F. cyllenica are non-dormant.     

Asymmetrically reliable caches for multicore architectures under performance and energy constraints

Cache structures in a multicore system are more vulnerable to soft errors due to high transistor density. Protecting all caches unselectively has notable overhead on performance and energy consumption. In this study, we propose asymmetrically reliable caches to supply reliability need of the system using sufficient additional hardware under the performance and energy constraints. In our framework, a chip multiprocessor is composed of a high reliability core which has ECC protection, and a set of low reliability cores which have no protection on their data caches. Between two types of cores, there is also a middle-level reliability core which has only parity check. Application threads are mapped on the different cores in terms of reliability based on their critical data usage. The experimental results for selected applications show that our proposed techniques improve reliability with considerable performance and energy overhead on the average compared to traditional unsafe caches.     

Acceleration of germination and early growth of wheat and bean seedlings grown under various magnetic field and osmotic conditions

Magnetic field (MF) can have different effects on plant metabolism depending on its application style, intensity, and environmental conditions. This study reports the effects of different intensities of static MF (4 or 7 mT) on seed germination and seedling growth of bean or wheat seeds in different media having 0, 2, 6, and 10 atmosphere (atm) osmotic pressure prepared with sucrose or salt. The germination percentages of the treated seeds were compared with untreated seeds germinated in different osmotic pressure during 7 days of incubation. The application of both MFs promoted the germination ratios of bean and wheat seeds, regardless of increasing osmotic pressure of sucrose or salt. Growth data measured on the 7th day showed that the treated plants grew faster than control. After 7 days of incubation, the mean length of treated seedlings was statistically higher than control plants in all the media. The greatest germination and growth rates in both plants were from the test groups exposed to 7 mT MF. Strikingly, effects of static MF on germination and growth increased positively with increasing osmotic pressure or salt stress compared to their respective controls. On the other hand, MF application caused an increase in dry biomass accumulation of root and shoots of both seedlings; however, this effect was found statistically important in all the conditions for wheat but not for bean, in general. Bioelectromagnetics 31:120–129, 2010. © 2009 Wiley‐Liss, Inc.