Analysis of the replication of HIV-1 forced to use tRNA(Met(i) )supports a link between primer selection, translation and encapsidation

BACKGROUND: Previous studies have suggested that the process of HIV-1 tRNA primer selection and encapsidation of genomic RNA might be coupled with viral translation. In order to further investigate this relationship, proviruses were constructed in which the primer-binding site (PBS) was altered to be complementary to elongator tRNA(Met )(tRNA(Met(e))) (HXB2-Met(e)) or initiator tRNA(Met )(tRNA(Met(i))) (HXB2-Met(i)). These tRNA(Met )not only differ with respect to the 3' terminal 18-nucleotides, but also with respect to interaction with host cell proteins during protein synthesis. RESULTS: Consistent with previous studies, HXB2-Met(e) were infectious and maintained this PBS following short-term in vitro culture in SupT1 cells. In contrast, transfection of HBX2-Met(i) produced reduced amounts of virus (as determined by p24) and did not establish a productive infection in SupT1 cells. The low infectivity of the virus with the PBS complementary to tRNA(Met(i) )was not due to differences in endogenous levels of cellular tRNA(Met(i) )compared to tRNA(Met(e)); tRNA(Met(i) )was also capable of being selected as the primer for reverse transcription as determined by the endogenous reverse transcription reaction. The PBS of HXB2-Met(i) contains an ATG, which could act as an upstream AUG and syphon scanning ribosomes thereby reducing initiation of translation at the authentic AUG of Gag. To investigate this possibility, a provirus with an A to G change was constructed (HXB2-Met(i)AG). Transfection of HXB2-Met(i)AG resulted in increased production of virus, similar to that for the wild type virus. In contrast to HXB2-Met(i), HXB2-Met(i)AG was able to establish a productive infection in SupT1 cells. Analysis of the PBS following replication revealed the virus favored the genome with the repaired PBS (A to G) even though tRNA(Met(i) )was continuously selected as the primer for reverse transcription. CONCLUSION: The results of these studies suggest that HIV-1 has access to both tRNA(Met )for selection as the replication primer and supports a co-ordination between primer selection, translation and encapsidation during virus replication

Comparative Studies on the Reproductive and Productive Traits of New Hampshire and Sombor Crested Chicken Breeds Reared in Semi-Extensive Production System

Research was conducted on New Hampshire (in further text NH) and Sombor Crested (in further text SC) breeds which were kept in semi extensive system. 56 birds of each breed were used (50 females and 6 males) in the experiment. 100 eggs from every chicken breed were used for natural hatching, and remained eggs were sold. From the total number of the naturally incubated eggs, 83 (NH) and 85 (SC) chickens were hatched, and they were used for the study of performance and related parameters. Eggs and chickens originating from NH breed were statistically significantly heavier (P<0.001; P<0.01) compared with SC breed. Egg shape index and chicken percentage in egg weight were significantly higher at SC (P<0.001; P<0.05) compared to NH breed. Very strong positive correlation was determined between egg weight and chicken weight in both breeds. Very weak negative correlation was determined between egg weight and relative chicken intake in the egg weight. Similarly, between egg shape index and chicken weight, negative correlation coefficient was determined in both breeds. However, between egg shape index and chicken percentage, statistically significant (P<0.001) negative correlation coefficient was determined in NH breed. Significant (P<0.05) positive correlation for the same performances was determined in SC breed

Color measurement of animal source foods

Rapid and objective assessment of food color is necessary in quality control. The color evaluation of animal source foods using a computer vision system (CVS) and a traditional colorimeter is examined. With the same measurement conditions, color results deviated between these two approaches. The color returned by the CVS had a close resemblance to the perceived color of the animal source foods, whereas the colorimeter returned not typical colors. The effectiveness of the CVS is confirmed by the study results. Considering these data, it could be concluded that the colorimeter is not representative method for color analysis of animal source foods, therefore, the color read by the CVS seemed to be more similar to the real ones

Techno-functional, textural and sensorial properties of frankfurters as affected by the addition of bee pollen powder

The objective of this study was to determine whether the addition of different pollen powder concentrations (0.5; 1.0 and 1.5 g/100 g) had an influence on techno-functional, textural and sensorial traits of frankfurters. Examining the techno-functional characteristics of pollen, a conclusion was reached that the higher the concentration, the higher the emulsification and better techno-functional properties. Also, FTIR-ATR analysis has shown that specific pollen molecules provided good emulsifying properties of sausages. On the other hand, sensory analysis showed that sausages with the addition of 1.0% and 1.5% of pollen powder have a more pronounced floral odor. Warner-Bratzler shear force test has shown that the incorporation of pollen caused a more stable product throughout sixty days of storage than the control sample. It could be explained by the formation of more protein-protein interactions due to the addition of non-meat proteins in the formulation of frankfurters and obtaining a more stable product than the control one. All things considered, it can be concluded that pollen exhibits good techno-functional properties and could be utilized in the formulation of frankfurters with improved and steady techno-functional properties during two months of refrigerated storage

Food safety and environmental risks based on meat and dairy consumption surveys

This paper gives an overview of the possibilities of using meat and dairy consumption studies in food safety and environmental risk scenarios. For both types of risk-based scenarios, common denominators are consumption patterns such as frequency and quantity of consumed food, demographic profile of consumers and food safety hazard or environmental impact of a specific type of food. This type of data enables development of simulation models where the Monte Carlo method is considered as a useful mathematical tool. Synergy of three dimensions - field research used in consumption studies, advanced chemometric tools necessary for quantifying chemical food safety hazards or environmental impacts and simulation models - has the potential to adapt datasets from various sources into useful food safety and/or environmental information

Exposure assessment to essential elements through the consumption of canned fish in Serbia

The aim of this study was to provide a quantitative exposure assessment to essential elements through the consumption of canned fish in Serbia. This objective was fulfilled by analyzing content of essential elements in canned fish and by using data from a food consumption survey. Consumption survey of canned fish was designed and performed to general principles and EFSA guidelines on data collection of national food consumption. The questionnaire was performed on 1,000 respondents during 2018. Determination of copper, zinc and iron levels were performed on 454 canned fish and seafood samples divided into four groups (canned tuna, canned sardines, canned other sea fish and canned seafood) during five consecutive years (2014–2018). This study showed significant association between sex, BMI and weight and consumption patterns. Obtained average weekly consumption of canned fish confirms our assumption that consumption of canned fish is significant in Serbia. Zinc and iron were found in all 454 samples (100%), and copper in 222 samples (48.9%). The average obtained concentration in all samples were 1.268 mg kg–1 for Cu, 5.661 mg kg–1 for Zn and 9.556 mg kg–1 for Fe. The highest concentration for all three minerals were found in canned sardines (Cu — 6.49 mg kg–1, Zn — 37.2 mg kg–1 and Fe — 21.8 mg kg–1). Obtained mean exposure to intake of copper, zinc and iron from canned fish was 1.2241 μg/kg bw/day, 5.4634 μg/kg bw/day and 9.2231 μg/kg bw/day, respectively. Exposure of Serbian population to zinc, copper, and iron through consumption of canned fish is less than recommended daily reference intakes and there is no risk of reaching toxic levels by consuming fish

A 0.1 THD, 1 M ohm to 1 G Ohm Tunable, Temperature Compensated Transimpedance Amplifier Using a Multi Element Pseudo Resistor

In this paper, a transimpedance amplifier TIA is presented that utilizes a modified pseudo resistor PR with improved robustness against temperature and process variations, enhanced linearity, and reduced parasitics. Using a biasing scheme named pseudo current mirror, the conventional dependence on absolute process parameters is reduced to a dependence on matching of alike devices. The linearity and noise performance as well as the immunity against process variations of the presented TIA are improved by the series connection of multiple PR elements. Moreover, it is shown how implementing the design in a silicon on insulator SOI technology reduces critical parasitics, which in turn enables the use of the multi element PR in highspeed, high gain, and low distortion TIAs. A prototype realization in a 180 nm CMOS SOI technology achieves a tunability in transimpedance of three orders of magnitude from 1 G down to 1 M with corresponding bandwidths from 8 kHz to 2 MHz. By design, the contribution of shot noise is rendered negligible and the white noise floor of the prototype realization approaches the theoretical thermal noise limit, e.g., 5.5 fA Hz for a transimpedance of 1 G and 140 fA Hz for 1 M . Total harmonic distortion values of less than 0.1 are achieved for an input amplitude of 300 pAp p for 1 G , 4.0 nAp p for 100 M , and 40 nAp p for 10 M , and less than 1 is achieved for an input amplitude of 550 nAp p for 1 M . The presented TIA consumes an area of 0.07 mm2 and dissipates a power of 9.3 mW for the opamp and a maximum power of 0.2 mW for the PR from a 1.8 V suppl

Uticaj mineralne ishrane na prinos ozime pšenice (Triticum aestivum L.)

Investigations were carried out during the 2006/2007 year on stationary field trial, the Center for Small Grains in Kragujevac. The objective of this study was to investigate the influence of mineral nutrition on the yield of winter wheat varieties (Lazarica, Takovčanka, Kg 56S, Kg 100 i Ana Morava). For these investigations were conducted two experiments (N1-80 kg ha-1 and N2-120 kg ha-1). Analysis of variance indicates very significant effects of cultivar on the grain yield, 1000-grain weight and test weight. Analysis of variance for the impact of nitrogen rates (N1 and N2) on investigated traits was found that doses of nitrogen in combination with NPK fertilizers significantly affected only on grain yield.Istraživanja su izvedena tokom 2006/2007. godine na stacionarnom poljskom ogledu, Centra za strna žita u Kragujevcu. Cilj ovog istraživanja je bio da se ispita uticaj mineralne ishrane na prinos ozime pšenice sorte (Lazarica, Takovčanka, Kg 56S, Kg 100 i Ana Morava). Za ova istraživanja su izvedena dva ogleda (N1-80 kg ha-1 i N2-120 kg ha-1). Analizaom varijanse je utvrđen vrlo visoko značajan uticaj sorte na prinos, masu 1000 zrna i hektolitarsku masu. Analizom varijanse za uticaj doze azota (N1 i N2) na ispitivane osobine utvrđeno je da su doze azota u kombinaciji sa NPK đubrivima značajno uticale samo na prinos zrna