Low Background Levels Research Articles

Carbon Nano-Onion Modified Electrodes for Voltammetric Detection of Propellent Stabiliser 1,3-Diethyl-1,3-Diphenly Urea (Centralite)

The testing of gunshot residue (GSR) has been a fundamental pillar of forensic analysis in the evaluation of evidence and its subsequent use in criminal trials involving firearms. While confirmatory testing of the inorganic fraction of gunshot residue is largely laboratory confined and reliant on scanning electron microscopy for particle analysis and inductively coupled plasma – MS for bulk metal determination, the move to onsite testing of this fraction has been facilitated using electroanalysis. Complementary recovery and analysis of the organic fraction of GSR remains an analytical challenge at the point of use. Such a device would provide more robust dual information due to the low environmental background levels of propellant stabilisers such as diphenylamine (DPA), and urea derivative 1,3-diethyl-1, 3-diphenylurea (Centralite). Electroanalysis of the latter is the key focus of this work, ultimately utilising screen printed electodes functionalised with electrocatalytic materials which serve to enhance the analytical signal.An initial electrochemical examination of Centralite involved voltammetric studies in both aqeuous and non-aqueous environments, with the view to establish an understanding of its redox solution behaviour, pH effects, chemical stability and film formation upon potential sweeping. This allowed both mechanistic and analytical evaluation with the aim to achieve the required selectivity and sensitivity for reliable detection. Centralite electrochemistry was examined at glassy carbon electrodes in both aqueous (3:7 methanol:sodium acetate pH 4.3) and non–aqueous (0.1 M LiClO4 in methanol) electrolytes via potential sweeping. In the case of the aqueous system an irreversible wave at Ep = 1.2 V associated with a weak cathodic signal at 1.0 V vs. Ag/AgCl was observed. This diffusion controlled process resulted in diffusion co-efficient (D)=7.4x10-5 cm2s-1 which, for a one electron process results in transfer coefficient (a)=0.724. Upon cycling, a new anodic signal appeared at 1.0 V with a corresponding decrease in the process at 1.2 V vs. Ag/AgCl. Scan rate studies indicated a mixed diffusion/adsorption process with peak current ratios (anodic/cathodic) decreasing with respect to scan rate. In the acidic environment acid hydrolysis of the 1,3-diethyl-1, 3-diphenylurea can result in N-ethylaniline and N-ethyl-N-phenylformamide (a type of carbamic acid which can revert back to the parent amine with release of CO2). Deposition of poly(N-ethylaniline) could explain the presence of a clearly visible yellow film on the electrode surface (Fig. 1). Upon examination of Centralite in 0.1 M LiClO4 in acetonitrile an irreversible process at 1 V was evident with a cathodic wave at 0.71 V and the appearance of a new anodic peak at 0.75 V vs. Ag/Ag+. Scan rate studies revealed that these processes were diffusion controlled.The electrochemical behaviour of carbon nanomaterials including their capacitance can depend on counter ion film penetration, the double layer structure and electrolyte. Recently, carbon nano-onions (CNOs), an emerging member of the carbon family, have shown promising electrochemical performance towards the oxygen reduction reaction as a consequence of a co-doping process.Herein, both pristine (p-) and boron nitrogen co-doped (BN-) CNOs were examined as solid films which were dropcast onto glassy carbon electrodes from a dispersion of 1 mg/mL in ethanol. There was a capacitive and faradaic component to the current and good mechanical stability was evident upon potential cycling. In the case of BN-CNOs, a quasi-reversible surface confined process was evident at Ep(a) = 0.27 V and Ep(c) = 0.057 vs. Ag/AgCl with DEp = 0.213 V. When examined in an anionic redox probe [Fe(CN)6]3-/4- a two fold decrease in DEp was evident (indicating faster charge transfer at the CNO modified surface). Surface coverage corresponded to 6.73 - 5.44 x 10-10 mol cm-2 using current vs scan rate plots. Specific capacitance was 16.96 F/g and 3.62 F/g for pristine and BN doped CNO material respectively being scan rate dependent. Centralite calibration studies, in the aqueous environment using linear sweep voltammetry resulted in sensitivity values of 0.585 A.cm-1.M-1 for the bare glassy carbon electrode and 0.710 A.cm-1.M-1 in the case of the a CNO modified electrode with further work ongoing. Figure 1

Automated Audiometry in Quiet and Simulated Exam Room Noise for Listeners with Normal Hearing and Impaired Hearing.

Up to 80% of audiograms could be automated which would allow more time for provision of specialty services. Ideally, automated audiometers would provide accurate results for listeners with impaired hearing as well as normal hearing. Additionally, accurate results should be provided both in controlled environments like a sound-attenuating room but also in test environments that may support greater application when sound-attenuating rooms are unavailable. Otokiosk is an iOS-based system that has been available for clinical use, but there are not yet any published validation studies using this product. The purpose of this project was to complete a validation study on the OtoKiosk automated audiometry system in quiet and in low-level noise, for listeners with normal hearing and for listeners with impaired hearing. Pure tone air conduction thresholds were obtained for each participant for three randomized conditions: standard audiometry, automated testing in quiet, and automated testing in noise. Noise, when present, was 35 dBA overall and was designed to emulate an empty medical exam room. Participants consisted of 11 adults with hearing loss and 15 adults with normal hearing recruited from the local area. Thresholds were measured at 500, 1,000, 2,000, and 4,000 Hz using the Otokiosk system that incorporates a modified Hughson-Westlake method. Results were analyzed using descriptive statistics and also by a linear mixed-effects model to compare thresholds obtained in each condition. Across condition and participant group 73.6% of thresholds measured with OtoKiosk were within ± 5 dB of the conventionally measured thresholds; 92.8% were within ± 10 dB. On average, differences between tests were small. Pairwise comparisons revealed thresholds were ∼3.5-4 dB better with conventional audiometry than with the mobile application in quiet and in noise. Noise did not affect thresholds measured with OtoKiosk. The OtoKiosk automated hearing test measured pure tone air conduction thresholds from 500 to 4,000 Hz at slightly higher thresholds than conventional audiometry, but less than the smallest typical 5 dB clinical step-size. Our results suggest OtoKiosk is a reasonable solution for sound booths and exam rooms with low-level background noise.

Sensitive and Low‐background Electrochemical Immunosensor Employing Glucose Dehydrogenase and 1,10‐Phenanthroline‐5,6‐dione

AbstractWe report a sensitive electrochemical immunosensor with a low electrochemical background level, which results from electrochemical‐enzymatic (EN) redox cycling based on mediated electrochemical oxidation of an electro‐inactive reductant (glucose) at 0.0 V. The EN redox cycling employs flavin adenine dinucleotide‐dependent glucose dehydrogenase and 1,10‐phenanthroline‐5,6‐dione (PD). When PD was compared with five common quinone‐based electron mediators, PD enabled the highest signal‐to‐background ratio, due to a very low electrochemical background level. When EN redox cycling was applied to a sandwich‐type immunosensor, parathyroid hormone (PTH) in serum could be detected with a very low detection limit of ∼0.1 pg/mL.

EVOS and the Prince William Sound Long Term Environmental Monitoring Program

ABSTRACT Following the 1989 Exxon Valdez oil spill (EVOS), the Prince William Sound Regional Citizens' Advisory Council began the Long-Term Environmental Monitoring Program (LTEMP) in 1993 to track oil hydrocarbon chemistry of recovering sediments and mussel tissues along the path of the spill in Prince William Sound (PWS) and across the Northern Gulf of Alaska (NGOA) region. The program also samples sites near the Alyeska Marine Terminal (AMT) within Port Valdez, primarily to monitor tanker operations and the resulting treatment and discharge of oil-contaminated tanker ballast water. Over the last 28 years, the program has documented EVOS oil's disappearance at the spill-impacted sites (albeit buried oil still exists at a few unique sheltered locations in PWS). Within the Port, a few tanker- and diesel-spill incidents have been documented over the years, but all were minor and with recovery times of < 1 yr. Of highest concern has been the permitted chronic release of weathered oil from tankers' ballast-water that is treated and discharged at the Alyeska Marine Terminal (AMT). In earlier years (1980s–90s), with discharge volumes reaching 17–18 MGD, up to a barrel of finely dispersed weathered oil would be released into the fjord daily. Over the last two decades, total petrogenic inputs (TPAH43) into the Port have declined as measured in the monitored mussels and sediments. This trend reflects a combination of decreased Alaska North Slope (ANS) oil production and thus, less tanker traffic, plus less ballast from the transition to double-hulled tankers with segregated ballast tanks, and improved treatment-facility efficiency in removing PAH. From the 2018 collections, mussel-tissue hydrocarbon concentrations from all eleven LTEMP stations (within Port Valdez as well as PWS and NGOA regions) were below method detection limits and similar to laboratory blanks (TPAH43 < 44 ng/g dry wt.). At these low background levels, elevated TPAH values from a minor 2020 spill incident at the Terminal were easily detected at all three Port Valdez stations.

Vertebral column adaptations in juvenile Atlantic salmon Salmo salar, L. as a response to dietary phosphorus

Deficiency in dietary phosphorus (P) is considered as a nutritional risk factor for the development of vertebral column deformities in farmed Atlantic salmon Salmo salar, L. This mono-factorial study examines how 11-week deficiency and excess of dietary P influence the structure and microstructure of the vertebral bodies in juvenile, freshwater stages of Atlantic salmon. Animals were fed continuously with three diets containing different levels of total P (tP) and soluble P (sP), respectively: low P (LP) = 6.8 g/kg tP, 3.5 g/kg sP, regular P (RP) = 10.0 g/kg tP, 5.6 g/kg sP, and high P (HP) = 13.0 g/kg tP, 9.3 g/kg sP. Animals were analysed for plasma and bone mineral content, vertebral column deformities (x-ray), vertebral centra stiffness, bone mineralisation pattern and vertebral body microanatomy (cells and connective tissue structures). A low (background) level of deformities was observed on a gross morphological level but no increase and no specific type of vertebral column deformity was associated with either of the three groups. While feed intake was comparable among all diet groups animals fed LP showed a 50% reduction in total calcium (Ca) and P content in abdominal vertebrae and opercula. Regular P and HP animals showed similar levels of total Ca and P in abdominal vertebrae and opercula. Animals in all diet groups showed well-developed vertebral bodies. Low P animals had vertebral centra, neural and haemal arches with large areas of non-mineralised bone. Vertebral centra stiffness in LP animals was reduced accordingly. Regular P and HP animals showed comparable values for vertebral centra stiffness. Non-mineralised vertebral body end plates of LP animals developed a slight inward bending and intervertebral ligaments increased in length and thickness. The cellular and extracellular components of the intervertebral joints remained intact without structural alterations that would indicate the development of vertebral centra compression or fusion. Animals from all three diet groups showed active osteoblasts at the vertebral body growth zone. Despite the three-fold decline in plasma inorganic P in LP animals growth continued at the same rate as in RP and HP animals. It is discussed whether the use of a P-reduced diet under a continuous feeding regime can maintain growth without adverse effects for animal health and welfare. This study further discusses that a HP diet relative to an RP diet has no beneficial effect concerning bone formation, bone mineralisation, growth and prevention of vertebral centra deformities in Atlantic salmon parr.

Obstacles Facing Faculty Members in Sana'a Community College from their Perspective

The study aimed to identify the obstacles that faculty members face at Sana'a Community College. To achieve the objectives of the study, the researcher used the analytical descriptive method and the questionnaire as a tool for collecting data. The study population consisted of (176) faculty members. As the population was small, the sample was selected by the complete census method. The study results showed that the most important academic constraints were absence of support for conducting research, lack of department support to participate in courses, seminars and conferences and scarcity of training programs. The most important financial and administrative constraints were lack of adequate attention to the problems of faculty members, lack of suitable places to practice scientific activities, and absence of incentives for distinguished faculty member. The most important obstacles associated with students were low background level of accepted students, lack of clear syllabus for courses, and the reluctance of students to research and refer to scientific references. The most important technical constraints facing faculty members were lack of participation in academic sites, lack of appropriate learning resources, permanent power cut-offs in classrooms and laboratories and lack of printing and photocopy machines for the faculty members when needed. The study also showed that there were no statistically significant differences between the responses of faculty members about the obstacles due to variables of gender, academic rank and years of experience. The study recommended providing material and moral support to faculty members to conduct research, holding training courses to raise their efficiency, taking care of their own financial aspects and involving them in important decisions related to the educational process, applying appropriate criteria for admitting students, avoiding favoritism, paying attention to updating study plans, and providing recent references.
 Keywords: obstacles, faculty, community college.

Obstacles Facing Faculty Members in Sana'a Community College from their Perspective

The study aimed to identify the obstacles that faculty members face at Sana'a Community College. To achieve the objectives of the study, the researcher used the analytical descriptive method and the questionnaire as a tool for collecting data. The study population consisted of (176) faculty members. As the population was small, the sample was selected by the complete census method. The study results showed that the most important academic constraints were absence of support for conducting research, lack of department support to participate in courses, seminars and conferences and scarcity of training programs. The most important financial and administrative constraints were lack of adequate attention to the problems of faculty members, lack of suitable places to practice scientific activities, and absence of incentives for distinguished faculty member. The most important obstacles associated with students were low background level of accepted students, lack of clear syllabus for courses, and the reluctance of students to research and refer to scientific references. The most important technical constraints facing faculty members were lack of participation in academic sites, lack of appropriate learning resources, permanent power cut-offs in classrooms and laboratories and lack of printing and photocopy machines for the faculty members when needed. The study also showed that there were no statistically significant differences between the responses of faculty members about the obstacles due to variables of gender, academic rank and years of experience. The study recommended providing material and moral support to faculty members to conduct research, holding training courses to raise their efficiency, taking care of their own financial aspects and involving them in important decisions related to the educational process, applying appropriate criteria for admitting students, avoiding favoritism, paying attention to updating study plans, and providing recent references.
 Keywords: obstacles, faculty, community college.

Design of experiments for the optimization of SOFI super-resolution microscopy imaging.

Super-resolution optical fluctuation imaging (SOFI) is a well-known super-resolution technique appreciated for its versatility and broad applicability. However, even though an extended theoretical description is available, it is still not fully understood how the interplay between different experimental parameters influences the quality of a SOFI image. We investigated the relationship between five experimental parameters (measurement time, on-time t on, off-time t off, probe brightness, and out of focus background) and the quality of the super-resolved images they yielded, expressed as Signal to Noise Ratio (SNR). Empirical relationships were modeled for second- and third-order SOFI using data simulated according to a D-Optimal design of experiments, which is an ad-hoc design built to reduce the experimental load when the total number of trials to be conducted becomes too high for practical applications. This approach proves to be more reliable and efficient for parameter optimization compared to the more classical parameter by parameter approach. Our results indicate that the best image quality is achieved for the fastest emitter blinking (lowest t on and t off), lowest background level, and the highest measurement duration, while the brightness variation does not affect the quality in a statistically significant way within the investigated range. However, when the ranges spanned by the parameters are constrained, a different set of optimal conditions may arise. For example, for second-order SOFI, we identified situations in which the increase of t off can be beneficial to SNR, such as when the measurement duration is long enough. In general, optimal values of t on and t off have been found to be highly dependent from each other and from the measurement duration.

Integrase Strand Transfer Inhibitor Resistance in Integrase Strand Transfer Inhibitor-Naive Persons.

There has been no systematic review of the prevalence of transmitted integrase strand transfer inhibitor (INSTI) resistance. We systematically searched the English-language PubMed database and GenBank to identify studies published since 2010 reporting 50 or more INSTI-naive HIV-1-infected adults undergoing integrase genotyping. We extracted data related to country, sample year, specimen type, sequencing method, and subtype. For studies with sequences in GenBank, we determined the prevalence of three categories of INSTI-associated resistance mutations: (1) nonpolymorphic INSTI-selected drug resistance mutations (DRMs) that we refer to as surveillance DRMs; (2) rarely selected nonpolymorphic INSTI-associated DRMs; and (3) common polymorphic accessory INSTI-selected DRMs. A total of 103 studies met inclusion criteria including 75 studies in GenBank containing integrase sequences from 16,481 INSTI-naive persons. The median sample year was 2013 (interquartile range: 2008-2014). The prevalence of INSTI surveillance DRMs, rarely selected DRMs, and common polymorphic accessory INSTI-selected DRMs were 0.5%, 0.8%, and 6.2%, respectively. There was no association between the presence of nonpolymorphic surveillance DRM and region, sample year, or subtype. Two surveillance DRMs, E138K and R263K occurred in 0.15% and 0.10% of naive sequences, respectively. Several lines of evidence suggested that the 0.5% prevalence of surveillance DRMs partly reflects the cumulative natural occurrence of these mutations in the absence of selective drug pressure. There was an unexplained temporal increase in the proportion of sequences with polymorphic accessory mutations. The prevalence of INSTI-associated surveillance DRMs is low even in regions where INSTIs have been a major component of antiretroviral therapy for several years. The presence of INSTI-associated surveillance DRMs in INSTI-naive persons likely results from actual cases of transmitted INSTI resistance and from a low background level reflecting the cumulative rare natural occurrence of several nonpolymorphic mutations.

Radiolytic ozone yield G(O3) from 210Po alpha-particle radiation in air

Radioactive materials ionize air surrounding them and produce molecules such as ozone and nitrogen oxides. Concentrations of these species above background can serve as a marker for radioactive materials and provide a means for stand-off detection of nuclear materials. Ozone is one of the primary radiolytic products in air and has a lower background level than oxides of nitrogen, so it is a molecule of interest for this study. Actinides of interest include 239Pu and 235U, which are strong alpha emitters which have a high linear energy transfer in air. Ozone yield, saturation, and decay time are dependent on creation and destruction processes which change with charge density, ozone density, radiation dose rate, and type of radiation, motivating measurements of ozone yield and saturation level from alpha radiation with dose rates more typical of actinide sources. As a stand in for Pu and U, studies were performed on ozone yield in air from the alpha particle emitter 210Po. The sample was enclosed in a 0.96 ± 0.01 L Teflon cylinder and both air flow and build-up measurements were performed, with air flow of ~1 L/min and build up times to 3966 min corresponding with 2640 Gy. Build up measurements showed an ozone concentration increase at short times (t ≤ 10 min) with a yield of G(O3) = 7.7 ± 0.3 molecules/100 eV. Air flow measurements showed a radiation chemical yield for ozone of G(O3) = 7.6 ± 0.2 molecules/100 eV. These yields are larger than in previous, very old alpha particle studies but consistent with low rate gamma and electron beam studies. To use ozone as a secondary marker of special nuclear materials the saturation level in still air is important. The extracted ozone saturation level in the cylinder is 1.35 ppm with a half life of 74 ± 3 min.

New approach allowing detection of Cl using a pulsedcarbon dioxide (CO2) laser-induced breakdown spectroscopy (LIBS)

A new approach to allow detection of Cl emission using atransversely excited atmosphere (TEA) carbon dioxide (CO2) laser-induced breakdown spectroscopy (LIBS), namely utilization of a metal sub-target, was introduced. The Cl sample was prepared from pure chemical powder in the form of a solutiondeposited on the metal sub-target. A zinc selenium lens was used to focus the CO2 laser beam (10.6Mm, 2.5 J, 10 Hz, 200 ns) onto the deposited sample under the surrounding gas of helium (pressure of 1 atm) for generated luminous plasma. An optical multichannel analyzer (OMA) system was used for collecting plasma and acquiring the emission spectrum. It was found that luminous plasma can be produced upon focusing the laser irradiation onto the deposited layer of the sample on the subtarget metal while leaving no ablation from the sub-target metal. Many ionic emission lines from Cl can be detected in the visible region.The ionic emission lines occur withfavorable spectrochemical features, namely strong emission intensity and low background level. Thus, this new approach is promising for conducting Cl analysis using a CO2 LIBS.

Endocrinological effects of social exclusion and inclusion: Experimental evidence for adaptive regulation of female fecundity

When current conditions are probabilistically less suitable for successful reproduction than future conditions, females may prevent or delay reproduction until conditions improve. Throughout human evolution, social support was likely crucial to female reproductive success. Women may thus have evolved fertility regulation systems sensitive to cues from the social environment. However, current understanding of how psychological phenomena might affect female ovarian function is limited. In this study, we examined whether cues of reduced social support—social ostracism—impact women's hormone production. Following an in-lab group bonding task, women were randomly assigned to a social exclusion (n = 88) or social inclusion (n = 81) condition. After social exclusion, women with low background levels of social support experienced a decrease in estradiol relative to progesterone. In contrast, socially-included women with low background social support experienced an increase in estradiol relative to progesterone. Hormonal changes in both conditions occurred specifically when women were in their mid-to-late follicular phase, when baseline estradiol is high and progesterone is low. Follow-up analyses revealed that these changes were primarily driven by changes in progesterone, consistent with existing evidence for disruption of ovarian function following adrenal release of follicular-phase progesterone. Results offer support for a potential mechanism by which fecundity could respond adaptively to the loss or lack of social support.

Regulation of the subseasonal variability of winter rainfall in South China by the diversity of El Niño Southern Oscillation

Winter precipitation over South China tends to increase with enhancement of the 10–30-day intraseasonal oscillation (ISO) during El Nino Southern Oscillation (ENSO) events from 1981 to 2017. This study shows that, in contrast with central Pacific El Nino and La Nina events, the 10–30-day ISO of rainfall particularly intensify during eastern Pacific (EP) El Nino events. The seasonal evolution of the anomalous circulation, indicated as the annual cycle (AC), bridges the slow-varying ENSO and the transient 10–30-day ISO of winter rainfall over South China. As to the AC component, the EP El Nino events not only enhance the Philippine Sea anticyclone to provide a wetter low-level background over South China, but develop the mid-latitude cyclone and westerly winds in the upper-level over East Asia by changing tropical convection. The moisture over South China further increases due to the low-level wind convergence on a 10–30-day timescale. In the upper troposphere, the AC component of the anomalous westerly redistributes the 10–30-day relative vorticity by modulating the subseasonal mid-latitude wave train to strengthen the positive vorticity advection and ascending motion over South China. Their collaboration amplifies the subseasonal variance of winter precipitation in situ. By contrast, the AC component of the upper level circulation at mid-latitudes is not well organized in other ENSO subsets, corresponding to their lack of influence on the ISO variability of rainfall over South China.

Impact of 12-month cryopreservation on endogenous DNA damage in whole blood and isolated mononuclear cells evaluated by the comet assay

The comet assay is an electrophoretic technique used to assess DNA damage, as a marker of genotoxicity and oxidative stress, in tissues and biological samples including peripheral blood mononuclear cells (PBMCs) and whole blood (WB). Although numerous studies are performed on stored samples, the impact of cryopreservation on artifactual formation of DNA damage is not widely considered. The present study aims to evaluate the impact of storage at different time-points on the levels of strand breaks (SBs) and formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites in isolated PBMCs and WB. Samples were collected, aliquoted and stored at − 80 °C. DNA damage was analyzed on fresh samples, and subsequently on frozen samples every 2 months up to a year. Results have shown no changes in DNA damage in samples of PBMCs and WB stored for up to 4 months, while a significant increase in SBs and Fpg-sensitive sites was documented starting from 6-month up to 12-month storage of both the samples. In addition, fresh and frozen WB showed higher basal levels of DNA damage compared to PBMCs. In conclusion, WB samples show high levels of DNA damage compared to PBMCs. One-year of storage increased the levels of SBs and Fpg-sensitive sites especially in the WB samples. Based on these findings, the use of short storage times and PBMCs should be preferred because of low background level of DNA damage in the comet assay.

Clinical symptoms of iodine and zinc deficiency in dairy cows

Numerous clinical observations indicate that the silage-concentrate type of dairy cows feeding causes a cascade of pathobiochemical processes occurring by the type of metabolic acidosis, ketosis, hepatosis, with a violation of protein, fat and carbohydrate metabolism. Animals cannot realize the genetically inherent productivity potential.The culling of cows from the main herd is more than 37%. The main reasons for culling cows are hypo - and agalactia as a result of mastitis and ketosis, as well as infertility against the background of repeated infertile inseminations. Allotriophagy, unsteadiness of teeth, resorption of the last tail vertebrae, curvature of the vertebral column, traces of rib fractures, difficulty in lifting and moving when the content of total calcium and inorganic phosphorus in the blood is at the lower limit of physiological values indicate osteodystrophy. Exo-or endophthalmos, myxedema, forelock and mane, disheveled and curly hair, abortions, the birth of premature, ugly, stillborn, sparsely haired or “naked” calves against the background of low levels of protein bound iodine (PBI) in the blood indicate iodine deficiency in their body (hypomicroelementosis J). Coarsening and increased folding of the skin in the area of the head, neck and withers, active keratization on the skin in the area of articular surfaces and croup, thickening of the corolla zone and the border of the hooves in the form of a roller, ski-like growth and deformation of the hoof horn, enlargement and deformation of the joints, decreased reproductive function and low levels of zinc in the blood indicate parakeratosis of cattle (zinc deficiency).

Increased Right Frontal Brain Activity During the Mandarin Hearing-in-Noise Test.

PurposePrevious studies have revealed increased frontal brain activation during speech comprehension in background noise. Few, however, used tonal languages. The normal pattern of brain activation during a challenging speech-in-nose task using a tonal language remains unclear. The Mandarin Hearing-in-Noise Test (HINT) is a well-established test for assessing the ability to interpret speech in background noise. The current study used Mandarin HINT (MHINT) sentences and functional magnetic resonance imaging (fMRI) to assess brain activation with MHINT sentences.MethodsThirty native Mandarin-speaking subjects with normal peripheral hearing were recruited. Functional MRI was performed while subjects were presented with either HINT “clear” sentences with low-level background noise [signal-to-noise ratio (SNR) = +3 dB] or “noisy” sentences with high-level background noise (SNR = −5 dB). Subjects were instructed to answer with a button press whether a visually presented target word was included in the sentence. Brain activation between noisy and clear sentences was compared. Activation in each condition was also compared to a resting, no sentence presentation, condition.ResultsNoisy sentence comprehension showed increased activity in areas associated with tone processing and working memory, including the right superior and middle frontal gyri [Brodmann Areas (BAs) 46, 10]. Reduced activity with noisy sentences was seen in auditory, language, memory and somatosensory areas, including the bilateral superior and middle temporal gyri, left Heschl’s gyrus (BAs 21, 22), right temporal pole (BA 38), bilateral amygdala-hippocampus junction, and parahippocampal gyrus (BAs 28, 35), left inferior parietal lobule extending to left postcentral gyrus (BAs 2, 40), and left putamen.ConclusionIncreased frontal activation in the right hemisphere occurred when comprehending noisy spoken sentences in Mandarin. Compared to studies using non-tonal languages, this activation was strongly right-sided and involved subregions not previously reported. These findings may reflect additional effort in lexical tone perception in this tonal language. Additionally, this continuous fMRI protocol may offer a time-efficient way to assess group differences in brain activation with a challenging speech-in-noise task.

AMUR AND PRIMORYE

The annual review of seismicity of Amur and Primorye based on the data of permanent seismic stations of Sakhalin branch GS RAS and the data of other Russian and foreign seismological agencies for 2014 is made. A detailed description of the seismic situation in different areas of the region is given. For the first time the Sikhote-Alin area (№5), where an earthquake of intensity I0=5 occurred, has dominated by terms of the released seismic energy level. Three tangible earthquakes were recorded in the region during the year. The most significant of them (Imax=5) earthquake occurred on April 12 at 21h22m east of Lake Khanka, in the ter-ritory of Primorye. Previously this territory was in the state of a seismic calm. A comparative analysis of the seismic situation in 2014 with the data of long-term observations is carried out. In 2014 the seismic energy of crustal earthquakes released in the region was one of the lowest for the past 15 years (2000–2014), except for 2006. The level of deep focus seismicity in 2014 also has low indicators. According to the methodology for assessing the level of seismic activity, the SOUS*09 scale, in 2014 the territory of Amur and Primorye is characterized by a lower background level of seismic activity.

Associations between short term exposure to ambient particulate matter from dust storm and anthropogenic sources and inflammatory biomarkers in healthy young adults

This study examined the association between particulate matter from anthropogenic and natural sources and inflammatory biomarkers, including hs-CRP, IL-6, sTNF-RII, and WBCs, in two groups of healthy young subjects. We followed up subjects of two panels (16 to 22 years old), including 22 subjects selected from the urban area (Tehran city) with high-level pollution background and 22 subjects selected from the rural area (Ahmadabad) with low-level pollution background. In each group, we collected 4 times blood samples in various air pollution conditions, In the subjects of the urban group, there was a substantial difference (p < 0.05) between inversion days and cold season control days, and between dust storm days and warm season control days for concentrations of hs-CRP, IL-6, and WBCs biomarkers. In the subjects of the rural group, a significant difference could be detected in the concentration of hs-CRP, IL-6, and WBCs biomarkers (p < 0.05) between inversion days and cold season control days, and between dust storm and warm control days. We found that the difference in concentrations of hs-CRP, IL-6, and WBCs biomarkers between dust storm days and warm control conditions in the rural group were higher than the difference in inversion and cold control conditions, which can be attributed to low background air pollution in the rural area. In the urban area, the health effect of anthropogenic sources of PM is higher than the dust storm condition, which can be attributed to the stronger effect of anthropogenic pollution effect.

Automated skin lesion segmentation using attention-based deep convolutional neural network

Edge detection for dermoscopic images has always been a crucial task for automatic lesion delineation processes. A skin lesion is an area of the skin that takes the form an abnormal growth or appearance when compared to the skin surrounding it. The abnormal appearance is the colored area of the skin that is advised for urgent referral and treatment. The manual way of diagnosing the disease is time-consuming and not quantifiable. However, computer-aided diagnosis (CADx)-based treatment can provide aid to manual delineation by the experts in diagnosing the disease with more proficiency. To advance the digital process of segmentation, a deep learning-based end-to-end framework is proposed for automatic dermoscopic image segmentation. The framework has the modified form of U-Net, which effectively uses Group Normalization (GN) in the encoder and the decoder layers. Attention Gates (AG) focusing on minute details in the skip connection later incorporates with Tversky Loss (TL) as the output loss function are added. Instead of Batch Normalization (BN), GN is used to extract the feature maps generated by the encoding path efficiently. To distinguish high dimensional information from low-level irrelevant background regions in the input image, AGs are used. Tversky Index (TI)-based TL is applied to accomplish better alliance between recall and precision. To further strengthen feature propagation and encourage feature reuse, atrous convolutions are applied in the connecting bridge between the encoder path and the decoder path of the network. The proposed model is evaluated on the ISIC 2018 image dataset, outshone the state-of-the-art segmentation methods.

Trypsin Detection Using Electrochemical Reduction‐based Redox Cycling

It is more difficult to obtain high signal‐to‐background ratios in biosensors using electrochemical reduction than using electrochemical oxidation. Here, we present a method for trypsin detection using electrochemical reduction‐based redox cycling. Electrochemical‐enzymatic (EN) redox cycling and electrochemical‐chemical (EC) redox cycling for trypsin detection were tested and compared. Trypsin cleaves a peptide bond in an electrochemically inactive p‐aminophenol (AP)‐conjugated oligopeptide, and this cleavage results in the release of electrochemically active AP, which is involved in EN and EC redox‐cycling reactions. Horseradish peroxidase and cytochrome c (Cyt c) were tested as redox enzymes for EN redox cycling involving a redox enzyme and H2O2. Cyt c was better than horseradish peroxidase, as its use resulted in lower background levels. The trypsin detection based on the EN redox cycling involving Cyt c and H2O2 (~50 ng/mL) exhibited lower detection limits than the detection based on EC redox cycling involving IO3− (~100 ng/mL), because of higher signal levels.