Study of the Electrochemical Dissolution Behavior of Nitinol Shape Memory Alloy in Different Electrolytes for Micro-ECM Process

Nickel-Titanium alloy (Nitinol) is an excellent shape memory alloy (SMA) for Micro electro-mechanical systems (MEMS) particularly in biomedical applications owing to its three excellent features like shape memory effect (SME), superelasticity, and biocompatibility. The fabrication of micro features on Nitinol SMAs through conventional machining has been challenging due to its temperature-dependent material transformation properties. Micro electrochemical machining (micro-ECM), a nonconventional machining method for conductive material irrespective of strength and hardness has the potential for microfeature fabrication on Nitinol. This study presents the investigation on electrochemical dissolution behavior of Nitinol in different electrolytes for micro-ECM. The influence of electrolytes on the nature of dissolution of Nitinol has been studied by fabricating microchannels in three levels of parameters containing applied voltage and electrolyte concentration. The first three electrolytes were all aqueous neutral electrolytes i.e. sodium chloride (NaCl), sodium nitrate (NaNO3), and sodium bromide (NaBr). For profound analysis of dissolution behavior and its influence on machining performance, potentiodynamic polarization (PDP) tests of Nitinol were performed in aqueous NaCl, aqueous NaNO3, and aqueous NaBr solutions. The PDP tests that are conducted here are cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The three aqueous solutions were utilized for microchannel fabrication in Nitinol through micro ECM in three levels of parameters out of which aqueous NaNO3 was successful in fabricating microchannel. Then nonaqueous electrolyte of ethylene glycol-based NaNO3 has been used to fabricate microchannels with lower depth overcut (DOC), width overcut (WOC), and length overcut (LOC) with respect to aqueous NaNO3 electrolyte.

Expanding the Gap: An Updated Look Into Sex Differences in Running Performance

Males consistently outperform females in athletic endeavors, including running events of standard Olympic distances (100 m to Marathon). The magnitude of this percentage sex difference, i.e., the sex gap, has evolved over time. Two clear trends in sex gap evolution are evident; a narrowing of the gap during the 20th century, followed by a period of stability thereafter. However, an updated perspective on the average sex gap from top 20 athlete performances over the past two decades reveals nuanced trends over time, indicating the sex gap is not fixed. Additionally, the sex gap varies with performance level; the difference in absolute running performance between males and females is lowest for world record/world lead performances and increases in lower-ranked elite athletes. This observation of an increased sex gap with world rank is evident in events 400 m and longer and indicates a lower depth in female competitive standards. Explanations for the sex difference in absolute performance and competition depth include physical (physiological, anatomical, neuromuscular, biomechanical), sociocultural, psychological, and sport-specific factors. It is apparent that females are the disadvantaged sex in sport; therefore, measures should be taken to reduce this discrepancy and enable both sexes to reach their biological performance potential. There is scope to narrow the sex performance gap by addressing inequalities between the sexes in opportunities, provisions, incentives, attitudes/perceptions, research, and media representation.

Statistical Interpretation and Profiling the Leaching Characteristic of Chromium in the Basic Chrome Sulphate (BCS) Sludge Dumping at Village Khanchandpur-Rania, District Kanpur Dehat, Uttar Pradesh (India)

Without immobilized hazardous waste contaminates soil and groundwater, which can further bio-accumulates and poses serious negative health impact on flora as well as fauna. The present investigation has been conducted to study of leaching behavior of chromium species in immobilized hazardous waste containing Basic Chrome Sulphate (BCS) dumped at dumping site Khanchandpur Kharanja, Rania, Kanpur Dehat district of Uttar Pradesh, India. Results indicated that the pH of sludge ranged from 10.16–11.90 while EC ranged from 840-16160 dSm-1 in a different layer of the dumpsite and significantly varies on increasing depth. A similar trend was also observed in TDS contents which strongly justified the leaching of salts in lower depth. Total Cr concentration (25029.94 mg kg-1) was observed in the top layer which was significantly increased on increasing depth i.e., 36102.0 mg kg-1 and 42811.77 mg kg-1 while TCLP based concentration ( 216.44 mg kg-1 in top layer) was significantly increased on increasing depth i.e., 406.25 mg kg-1 and 517.60 mg kg-1. A similar trend was also observed in total and TCLP hexavalent and trivalent (Cr6+ and Cr3+) chromium concentration. Hierarchical Cluster Analysis is separated all sample based on depth into three different cluster based on dissimilarity. A significant correlation was observed with TCLP Cr6+ in TCLP Cr3+, EC, and TDS at 0.01 levels while EC, TDS, total Cr6+, and TCLP Cr were significant correlated with TCLP Cr3+. The leaching behavior of Cr species was higher as well as increasing of depth in the dumping site.

NPGREAT: Assembly of the human subtelomere regions with the use of ultralong Nanopore reads and Linked-Reads

Background Human subtelomeric DNA regulates the length and stability of adjacent telomeres that are critical for cellular function, and contains many gene/pseudogene families. Large evolutionarily recent segmental duplications and associated structural variation in human subtelomeres has made complete sequencing and assembly of these regions difficult to impossible for many loci, complicating or precluding a wide range of genetic analyses to investigate their function. Results We present a hybrid assembly method, NanoPore Guided REgional Assembly Tool (NPGREAT), which combines Linked-Read data with ultralong nanopore reads spanning subtelomeric segmental duplications to potentially overcome these difficulties. Linked-Read sets identified by matches with 1-copy subtelomere sequence adjacent to segmental duplications are assembled and extended into the segmental duplication regions using Regional Extension of Assemblies using Linked-Reads (REXTAL). Telomere-containing ultralong nanopore reads are then used to provide contiguity and correct orientation for matching REXTAL sequence contigs as well as identification/correction of any misassemblies (associated primarily with tandem repeats). While we focus on subtelomeres, the method is generally applicable to assembly of segmental duplications and other complex genome regions. Our method was tested for a subset of representative subtelomeres with ultralong nanopore read coverage in GM12878. 10X Linked-Read datasets with high depth of coverage and a TELL-seq Linked-Read dataset with lower depth of coverage were each combined with the ultralong nanopore reads from the same genome to provide improved assemblies. Tandem repeat regions of the short-read assemblies, which are especially prone to misassembly due to collapse of matching tandemly repeated reads, were readily identified and properly sized by comparison with the nanopore reads. Conclusion The NPGREAT method resulted in extension of high-quality assemblies into otherwise inaccessible segmental duplication regions near telomeres, enhancing our ability to accurately assemble human subtelomere DNA. This information will enable improved analyses of the structure, function, and evolution of these key regions.

Assessment of Groundwater Quality and Soil Salinity/Status Under Various Irrigation Systems in Arid Region of Jamshoro District

The agricultural lands are being affected due to groundwater (GW) quality issues. To address this worldwide problematic situation, various irrigation studies have been practiced to identify the effects on the soil conditions. The current study has been designed to assess the GW quality and soil salinity/sodicity by different irrigation techniques in the remote mountainous area of Jamshoro district at Gul Muhammad Khaskheli farm Thana Boula Khan. The experimental plot was designed under furrow, pitcher and poly ethylene bag irrigation system. These soil characteristics indicated that the drain-ability of the soil was high, with an infiltration rate of 1.60 cm/h and water holding capacity was low. Water samples were collected at each irrigation time from sowing to harvest. The soil understudy was non-saline (ECe < 4.0 dS/m) and non-sodic (pH < 8.0, SAR < 7.5 and ESP < 15.0) before crop sowing in all the three methods of irrigation at all the three sampling depths, i.e., 0-15 cm, 15-30 cm and 30-60 cm. Thus, the quality of water used for cultivation of ladyfinger/Okra crop under all irrigation methods was Class-I quality water.The investigated results shown that ECw (electrical conductivity of water) was < 1.5 dS/m, pH < 8.0, SAR (sodium adsorption ratio) < 10.0 and RSC (residual sodium carbonate) were non detective. After crop harvest changed a little bit, change was observed in the soil, i.e., under furrow and pitcher irrigation method, the ECe, SAR. and ESP (exchangeable sodium percentage) decreased in the wetted zone and increased at the wetted periphery. Under the polyethylene bag irrigation method, ECe, SAR and ESP decreased at depths 0-15 cm and 15-30 cm but these increased at lower depth, i.e., 30-60 cm after crop harvest. However, the soil remained non-saline and non-sodic.

Determination of Biodegradation Zone in Central Sumatra Basin

It is commonly known that heavy oil is mostly formed through biodegradation process within reservoir or on the surface both by aerobic and/or anaerobic bacteria that can live under specfi c temperature level(s). In order to investigate heavy oil occurences in Central Sumatra Basin, eff orts have been spent to determine the depths that represent the maximum temperature. By integrating the maximum viable temperature of typical bacteria and temperature gradient data, the depth of heavy oil zone is determined. The work is a combination of establishment of geothermal gradient map and laboratory analysis on fi eld sampled oil for determining types and temperature characteristics of microorganism living in the samples. Heavy oil sampling is made on seepages in areas nearby Minas fi eld. Subsequent laboratory analysis reveals Burkholderia multivorans ATCC BAA-247 as the predominant bacteria having maximum viabl temperature of 60° C. Based on the established geothermal gradient map, this maximum temperature correspond to average depth of 1818 ft (555.5 m). This average depth is used as the lower depth for the biodegradation zone over which investigation over presence of heavy oil bearing reservoirs/traps is made.

Depth of tillage and its effect on field watershed size in Ejigbo zone, Osun State, Nigeria

The study investigated effects of different depths of tillage on flow of runoff in watersheds on fields tilled and planted with maize (Zea mays) hybrids and open pollinated variety (OPV) of maize. Twelve 1 m × 1 m × 2 m pits were dug and overlaid at all sides and at its bottom with impermeable membrane to accumulate watershed’s runoff from the fields. Twelve compartmental plots of 400 m2 each comprising 2 depths of tillage (0-15 cm and 0-30 cm) and 2 varieties of maize (hybrids and open pollinated) were used. Each of the treatments was replicated thrice to make 2 × 2 × 3 factorial design. Each plot measured 4 m × 10 m at 2 m apart. Among the data collected were the volume of water accumulated in the small earthen pits dug, flow velocity (v m/s) of water in runoff channels/collectors that fed earthen pits, slopes of the collectors, cross-sectional area of collectors and wetted perimeter. Results revealed that average infiltrometer values of 15.00±0.24 mm/h and 16.50±0.40 mm/h respectively in the upper part and the lower part were recorded. The 0-15 cm depth of tillage accumulated more volume of runoff water than the 0-30 cm depth of tillage in the pits and it was 23.33% higher in the lower depth of tillage used on the field than the 0-30 cm depth of tillage. Implying that 0-30 cm tillage depth retained more water from the rainfall compare to the water retained by the 0-15 cm depth. Even though, volume of runoff water of 0-15 cm depth of tillage was higher than that of the 0-30 cm depth of tillage, 0-15 cm depth of tillage had the highest yield of maize (9.30±4.26 t ha-1).

A beginner's guide to low-coverage whole genome sequencing for population genomics

Low-coverage whole genome sequencing (lcWGS) has emerged as a powerful and cost-effective approach for population genomic studies in both model and non-model species. However, with read depths too low to confidently call individual genotypes, lcWGS requires specialized analysis tools that explicitly account for genotype uncertainty. A growing number of such tools have become available, but it can be difficult to get an overview of what types of analyses can be performed reliably with lcWGS data, and how the distribution of sequencing effort between the number of samples analyzed and per-sample sequencing depths affects inference accuracy. In this introductory guide to lcWGS, we first illustrate how the per-sample cost for lcWGS is now comparable to RAD-seq and Pool-seq in many systems. We then provide an overview of software packages that explicitly account for genotype uncertainty in different types of population genomic inference. Next, we use both simulated and empirical data to assess the accuracy of allele frequency and genetic diversity estimation, detection of population structure, and selection scans under different sequencing strategies. Our results show that spreading a given amount of sequencing effort across more samples with lower depth per sample consistently improves the accuracy of most types of inference, with a few notable exceptions. Finally, we assess the potential for using imputation to bolster inference from lcWGS data in non-model species, and discuss current limitations and future perspectives for lcWGS-based population genomics research. With this overview, we hope to make lcWGS more approachable and stimulate its broader adoption.

No Tillage Improved Soil Pore Space Indices under Cover Crop and Crop Rotation

Assessment of the effects of crop management practices on soil physical properties is largely limited to soil moisture content, air content or bulk density, which can take considerable time to change. However, soil pore space indices evolve rapidly and could quickly detect changes in soil properties resulting from crop management practices, but they are not often measured. The objective of this study was to investigate how soil pore space indices—relative gas diffusion coefficient (Ds/Do) and pore tortuosity factor (τ)—are affected by tillage system (TL), cover crop (CC) and crop rotation (CR). A study was conducted on silt loam soil at Freeman farm, Lincoln University of Missouri during the 2011 to 2013 growing seasons. The experiment design was a randomized complete block with two tillage systems (no tillage or no-till vs conventional tillage), two cover crops (no rye vs cereal rye (Secale cereale L.)) and four crop rotations (continuous corn (Zea mays L.), continuous soybean (Glycine max L.), corn–soybean and soybean–corn successions). All the treatments were replicated three times for a total of 48 experimental units. Soils were collected from two sampling depths (SD), 0–10 and 10–20 cm, in each treatment and soil physical properties, including bulk density (BD), air-filled porosity (AFP, fa) and total pore space (TPS, Φ), were calculated. Gas diffusivity models following AFP and/or TPS were used to predict Ds/Do and τ values. Results showed that, overall, Ds/Do was significantly increased in no-tilled plots planted to cereal rye in 2012 (p = 0.001) and in 2013 (p = 0.05). No-tilled continuous corn, followed by continuous soybean and no-tilled soybean–corn rotations had the highest Ds/Do values, respectively. In magnitude, Ds/Do was also increased in no-till plots at the lower depth (10–20 cm). No-tilled plots planted with cereal rye significantly reduced τ in 2012 (p = 0.001) and in 2013 (p = 0.05). Finally, at the upper depth (0–10 cm), the no-tilled corn–soybean rotation and the tilled soybean–corn rotation had the lowest τ. However, at the lower depth (10–20 cm), the four crop rotations were not significantly different in their τ values. These results can be useful to quickly assess the changes in soil physical properties because of crop management practices and make necessary changes to enhance agricultural resilience.