Preliminary feasibility torque mechanical evaluation for 3D printed orthodontic springs with different parameters: in vitro study

Background The purpose of the presented investigation is to evaluate the resulting torque on loaded 3D printed springs using different coil thickness and length. Methods Specimens were designed and printed using the 3D printer MAX (Asiga, Sydney, Australia) with 3D printable, experimental, flexible material (Code:BM2008, GC, Tokyo, Japan). The specimens were divided into three groups according to spring coil design. Control group (n = 18), length group (n = 19) and thickness group (n = 22). Groups were tested using a Sauter Machine for torque calculation (DB, Grindelwald, Switzerland) in conjunction with a universal testing machine (Zwick Z010, Ulm, Germany) for clock-wise and anti-clockwise testing. Statistical analysis was performed using the Steel–Dwass test to compare median values of the three groups in both testing directions (p < 0.001). Results The highest torque value was determined in the thickness group for both clockwise and anti-clockwise testing directions, achieving 44.00 N/mm and 39.62 N/mm respectively. The length group ranged from 21.65 to 11.04 N/mm in clockwise direction and from 18.04 to 11.38 N/mm in counter-clockwise testing. The control group ranged from 22.72 to 17.18 N/mm in the clock-wise direction while in the anti-clock wise testing it ranged from 21.34 to 16.02 N/mm. Conclusions The amount of torque produced from the computer aided designing/computer aided manufacturing (CAD/CAM) springs is being affected by diameter more than the length design parameter in comparison to the control group. The values of the thickness group are significantly higher than those of the length group (P < 0.001).

Monitoring of the trophic ecology of pipefish species (Syngnathus abaster, Syngnathus acus) in an alluvial lake habitat (Lake Bafa, Turkey)

The present study investigated the trophic ecology of two species living in an alluvial lake ecosystem in terms of season, length groups, sex, and mouth morphology. The fish were caught in a coastal lake area between December 2014 and March 2016 using a seine. In general, C. aquaedulcis was the most important prey for S. abaster, accounting for 10.99% of all prey, while amphipods accounted for 54.04% of the S. acus diet. Amphipods were the most frequently consumed prey in autumn, while C. aquaedulcis was the most important prey in spring. This result indicates that the species preferred similar prey groups and generated food competition depending on the season. The short-length group contained samples of S. abaster with empty guts, whereas S. acus in the same group consumed C. aquaedulcis. Length group II and III of individuals indicated that both species consumed amphipods and juvenile Syngnathus sp. Thus, the two species had statistically different preferences in terms of prey length. The mouth width of S. abaster was larger than that of S. acus. In conclusion, zooplankton constituted the main prey for both species in the lake and the morphological differences between the mouth apparatus of the species were due to the differences in feeding habits.

Age and growth analysis of the fish Mastacembelus armatus (Lacepede) from River Nayar, Garhwal Himalaya, Uttarakhand

The ability to age fish accurately is essential in understanding the dynamics of fish population. Age and growth determination in Mastacembelus armatus was assessed by the scale method which was verified by the length-frequency distribution method. The scales were small, elongated and the focus was shifted slightly uppish from the centre. The fish length and scale radius relationship was found linear (Scale radius = 6.974 + 0.452 Fish length; r = 0.9746) and authenticated the age analysis. Back calculation method was used to find out the size of fish at annulus formation, which confirmed four age rings in M. armatus at the size of 14.07±0.92, 26.05±4.99, 37.96± 2.59 and 48.48±6.06 cm respectively. First two age rings were observed in the fish length group 30-40 cm, the third ring was observed in 40-50 cm and the fourth ring in 50-60 cm length group. The finding was dully validated by length-frequency distribution method. The growth annual increment (h) of M. armatus shows that the length increment was 14.07, 13.32, 11.91 and 10.52 cm during 1st, 2nd, 3rd and 4th year respectively. It shows that the fish grows continuously during its entire life period. The average growth (? h) was observed as 12.12 cm. annually. The assessment of age and growth rate of fish is a prerequisite to generate the information on recruitment, longevity and fluctuations in fishery caused by various year classes which is an important tool for rational exploitation of fish stock.

Influence of Allowances on Taking Log Deliveries

This paper deals with differences between the declared and actually supplied volume of round wood, which can be seen in the sawmill log yards in taking log deliveries. These differences usually mean the losses for the suppliers. Authors focus on the length accuracy of supplied logs. They start with a comprehensive manual checking of log deliveries (2639 logs) and with calibration of electronic measuring equipment (238 logs) made by an accredited laboratory. Authors analyse the origins of the differences, they quantify the volume “voluntarily” given by the suppliers in the form of oversized allowances and the volume of the losses caused by classifying the logs to a lower length group if the necessary allowance lengths are not observed (the volume is counted using e.g. 1 m shorter nominal length). The term “extra allowance” is introduced for allowances longer than wanted, and the dependences among the length of extra allowances, log diameter, volume of extra allowances and number of logs with too short allowance are defined. Losses caused by both of these defects (over- or under-sized logs) are counted and compared. If the log length value is exactly the required one or close to it (it means nominal length and required allowance), the measuring equipment can still measure a lower value because of the required precision of 1 %. Losses are also caused by reclassifying the logs to a lower group. Suppliers cut the logs longer (make “extra allowances”) to ensure that the volume calculation is based on the right nominal length and not shorter. The research shows big differences between particular suppliers and their losses caused by extra allowances or reclassification of logs. The authors searched the optimum allowance in order to minimise the losses of the supplier. The results of the analysis give the following recommendations: for suppliers who do not use harvesters for felling and logging, it would be preferable to supply round timber in tree lengths due to the volume lost by reclassification. Today, however, this is not possible in most cases because large customers buy only logs because of technological reasons. Another aspect is the price, which is usually higher for raw material in logs. In the production of logs, it is preferable to increase the required 2 % allowance by 4-5 cm, if it is possible to produce the logs relatively accurately. If accuracy cannot be maintained, it is preferable to increase the allowance to about 7 cm (e.g. mountainous terrain, poor quality and curved timber, lack of experienced staff).

The correlation of salivary telomere length and single nucleotide polymorphisms of the ADIPOQ, SIRT1 and FOXO3A genes with lifestyle-related diseases in a Japanese population

Background It has been reported that genetic factors are associated with risk factors and onset of lifestyle-related diseases, but this finding is still the subject of much debate. Objective The aim of the present study was to investigate the correlation of genetic factors, including salivary telomere length and three single nucleotide polymorphisms (SNPs) that may influence lifestyle-related diseases, with lifestyle-related diseases themselves. Methods In one year at a single facility, relative telomere length and SNPs were determined by using monochrome multiplex quantitative polymerase chain reaction and TaqMan SNP Genotyping Assays, respectively, and were compared with lifestyle-related diseases in 120 Japanese individuals near our university. Results In men and all participants, age was inversely correlated with relative telomere length with respective p values of 0.049 and 0.034. In men, the frequency of hypertension was significantly higher in the short relative telomere length group than in the long group with unadjusted p value of 0.039, and the difference in the frequency of hypertension between the two groups was of borderline statistical significance after adjustment for age (p = 0.057). Furthermore, in men and all participants, the sum of the number of affected lifestyle-related diseases, including hypertension, was significantly higher in the short relative telomere length group than in the long group, with p values of 0.004 and 0.029, respectively. For ADIPOQ rs1501299, men’s ankle brachial index was higher in the T/T genotype than in the G/G and G/T genotypes, with p values of 0.001 and 0.000, respectively. For SIRT1 rs7895833, men’s body mass index and waist circumference and all participants’ brachial-ankle pulse wave velocity were higher in the A/G genotype than in the G/G genotype, with respective p values of 0.048, 0.032 and 0.035. For FOXO3A rs2802292, women’s body temperature and all participants’ saturation of peripheral oxygen were lower in the G/T genotype than in the T/T genotype, with respective p values of 0.039 and 0.032. However, relative telomere length was not associated with physiological or anthropometric measurements except for height in men (p = 0.016). ADIPOQ rs1501299 in men, but not the other two SNPs, was significantly associated with the sum of the number of affected lifestyle-related diseases (p = 0.013), by genotype. For each SNPs, there was no significant difference in the frequency of hypertension or relative telomere length by genotype. Conclusion Relative telomere length and the three types of SNPs determined using saliva have been shown to be differentially associated with onset of and measured risk factors for lifestyle-related diseases consisting mainly of cardiovascular diseases and cancer.