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Numerical simulation based on the discrete element method (DEM) is used to investigate the flow field generated when a cylindrical obstacle is placed in a supersonic granular stream. Robust validation of the simulation model is performed by comparing numerical results with experiments. Experiments are performed using a two-dimensional set-up generating rapid granular flow owing to gravity. DEM simulations demonstrate that a rapid gas-like stream of grains suddenly decelerates across the shock wave and finally collapses into a slow-moving heap at the cylinder. The volume fraction suddenly increases across the shock layer and remains constant thereafter. The flow physics of the shock wave and the granular heap is elucidated through fundamental fluid dynamic quantities such as the velocity, volume fraction, pressure and granular temperature. It is shown that the interaction of grains with a cylindrical obstacle results in the generation of pressure, which is responsible for sustaining static granular heaps on the cylinder. The total pressure is resolved into collisional and streaming components. A streaming pressure is generated owing to velocity fluctuations, and is found to be significant only in the shock wave region. The observations show that the rheological complexity offered by granular shock waves is a direct manifestation of the dissipative and frictional nature of granular collisions. The new insight into the granular heaps could be relevant to a variety of applications involving granular-fluid–solid interactions.
Child labourers are at risk of poorer mental health and once rescued require urgent mental health interventions to ameliorate the long-term impact. In our review, only two published scientific studies evaluated custom-made interventions; other programmes were obtained from non-governmental organisations (NGOs), which need rigorous trial evaluation. We also sought the viewpoints of stakeholders working directly with rescued young people, as well as consulting young people with lived experiences of child labour. We propose that psychoeducational interventions aimed at employees working directly with young people could represent a fruitful approach for low- and middle-income countries in the Asia-Pacific region but also more generally.
Human sperm cryopreservation is a highly desirable technique for preserving fertility potential and future use in couples desiring to have a biological child. Slow cryopreservation of sperm has been the mainstay technique. The drawback of this technique is the inability to freeze extremely small numbers of sperm as in the case of surgical retrieval of testicular sperm. These sperm are extremely few in number and it is difficult to retrieve motile, viable sperm post-thaw. In the past decade, sperm vitrification has been introduced along with both biological and non-biological carriers to freeze extremely low numbers of sperm. Vitrification also allows the ability to freeze single spermatozoa. These techniques are in many ways more efficient and better than the older techniques. This chapter aims to provide a detailed introduction to various approaches used for preserving spermatozoa. It also discusses indications of sperm cryopreservation based on semen quality and summarizes the advantages and shortcomings of these techniques.
Assessment of sperm vitality is an important component of semen analysis. It helps to distinguish spermatozoa that are alive and immotile from those that are dead. Sperm vitality can be assessed routinely on all semen samples by assessing the membrane integrity of the cell by identifying the spermatozoa with an intact cell membrane. This can be done by using 1) the dye exclusion test or 2) the hypotonic or hypoosmotic swelling test. Sperm vitality can therefore provide a good comparison with the motility of the sample. Eosin is used as a marker for dead cells because eosin can penetrate the cells when the membrane is damaged, while cells that have an intact membrane remain unstained. Nigrosin is a background stain that increases the contrast to the otherwise faintly stained cells [1, 2, 3, 4]. Both the single step and two-step staining using eosin and nigrosin have been used to assess sperm vitality. Both the wet preparation and the air-dried methods have been compared to study the correlation with motility [5, 6, 7]. The wet preparations evaluated by using either positive or negative phase-contrast microscopy consistently showed higher percentage of nonviable cells compared to the air-dried eosin-nigrosin smears. The air-dried smears have consistently shown that the sum of the motile (viable) and stained (presumed dead) preparations never exceeded 100 percent indicating that the air-dried method is the method of choice for determining vitality. In this chapter, we describe the staining protocols for vitality, the cut-off of motility when vitality must be tested, indications for poor motility and quality control recommended for performing sperm vitality in conjunction with basic semen analysis.
Oxidative stress (OS) is the consequence of an imbalance between reactive oxygen species (ROS) and the failure of antioxidants to neutralize excessive ROS production. Although many sperm functions require physiological levels of ROS, excessive levels of ROS are detrimental to the sperm . OS is one of the most common etiologies of male infertility affecting 30–80 percent of infertile men [2, 3]. The role of OS in men with unexplained infertility has been clearly established . OS affects sperm quality as a result of alterations in proteins, lipid peroxidation, DNA damage and apoptosis . Damage to sperm DNA can compromise the contribution of paternal genome to the embryo . Hence the advent of numerous tests to diagnose OS in the semen. There are several laboratory tests available to measure OS – both direct and indirect. Direct tests measure OS or free radicals such as ROS and reactive nitrogen species. These include chemiluminescence, nitroblue tetrazolium, cytochrome C reduction test, electron spin resonance, fluorescein isothiocynate (DFITC)-labeled lectins, and measurement of oxidation reduction potential. Indirect tests measure oxidized products resulting from ROS sources such as the oxidized form of nicotinamide adenine dinucleotide (NADPH)-oxidase in the sperm, the reduced form of NAD (NADH)-dependent oxidoreductase in mitochondria, or leukocytospermia. These include myeloperoxidase or Endtz test, antioxidants (both enzymatic and non-enzymatic), lipid peroxidation, and DNA damage. In this chapter we will discuss the indirect tests that are available to assess OS and also elaborate on the interpretation and their clinical significance [4, 5].
Male infertility affects men worldwide with about 20 percent of couples having male factor infertility . The routine semen analysis is the first step in the assessment of male infertility. However, conventional semen analysis does not provide a complete understanding of fertility potential, especially in patients with idiopathic infertility . In this scenario, DNA integrity is the most important feature to ensure normal fertilization, implantation, pregnancy and embryonic development. Sperm DNA fragmentation (SDF) can be due to several intrinsic factors such as varicocele, oxidative stress, apoptosis, and chromatin packaging defects. Further, SDF can be caused by extrinsic factors such as lifestyle alterations, infections, exposure to xenobiotics, etc. [3–7].
To evaluate whether Kawasaki disease predisposes to premature atherosclerosis and to assess status of coronary artery abnormalities at least 10 years after diagnosis.
Material and methods:
A prospective study was carried out on 21 patients who were diagnosed with Kawasaki disease at least 10 years back and are on regular follow-up. The study was conducted on 128 Slice Dual Source computed tomography scanner with electrocardiography-triggered radiation optimised protocols for assessment of coronary artery abnormalities and calcifications.
Study cohort had 21 subjects – 15 males and 6 females (age range: 11–23 years; mean: 15.76 + 3.72 years). Mean age at time of diagnosis was 3.21 + 2.48 years. Mean time interval from diagnosis of Kawasaki disease to computed tomography coronary angiography was 12.59 + 2.89 years. Four children had evidence of coronary artery abnormalities on transthoracic echocardiography at time of diagnosis. Of these, two had persistent abnormalities on computed tomography coronary angiography. One subject (4.76%) had coronary calcification that was localised to abnormal coronary artery segment. Four coronary artery abnormalities (one saccular; three fusiform aneurysms) were noted in two subjects.
Prevalence of coronary artery calcification is low and, if present, is localised to abnormal segments. This calcification is likely dystrophic rather than atherosclerotic. It appears that coronary artery abnormalities can persist for several years after acute episode of Kawasaki disease. Periodic follow-up by computed tomography coronary angiography is now a feasible non-invasive imaging modality for long term surveillance of patients with Kawasaki disease who had coronary artery abnormalities at time of diagnosis.
Tendencies to attend to threatening cues in the environment and to interpret ambiguous situations with negative/hostile intent maintain and may even precipitate internalizing and externalizing problems in young people with a history of maltreatment. Challenging maladaptive information-processing styles using cognitive bias modification (CBM) training may reduce symptoms.
To investigate the acceptability of CBM training in nine young people attending alternate education provision units in the UK, and 10 young people living in out-of-home care institutions in Nepal with a history of maltreatment.
CBM training consisted of five sessions of training over a 2-week period; each training session consisted of one module targeting attention biases and one module targeting interpretation biases for threat. A feedback form administered after training measured acceptability. Pre- and post-intervention measures of internalizing and externalizing symptoms were also taken.
Most young people (89%) found the training helpful and 84% found the training materials realistic. There were reductions in many symptom domains, but with individual variation. Although limited by the lack of a control condition, we established generalizability of acceptability across participants from two cultural settings.
Replication of these findings in larger feasibility randomized controlled trials with measures of attention and interpretation bias before and after intervention, are needed to assess the potential of CBM in reducing anxiety symptoms and its capacity to engage targeted mechanisms.
This paper highlights unique sites in Ladakh, India, investigated during our 2016 multidisciplinary pathfinding expedition to the region. We summarize our scientific findings and the site's potential to support science exploration, testing of new technologies and science protocols within the framework of astrobiology research. Ladakh has several accessible, diverse, pristine and extreme environments at very high altitudes (3000–5700 m above sea level). These sites include glacial passes, sand dunes, hot springs and saline lake shorelines with periglacial features. We report geological observations and environmental characteristics (of astrobiological significance) along with the development of regolith-landform maps for cold high passes. The effects of the diurnal water cycle on salt deliquescence were studied using the ExoMars Mission instrument mockup: HabitAbility: Brines, Irradiance and Temperature (HABIT). It recorded the existence of an interaction between the diurnal water cycle in the atmosphere and salts in the soil (which can serve as habitable liquid water reservoirs). Life detection assays were also tested to establish the best protocols for biomass measurements in brines, periglacial ice-mud and permafrost melt water environments in the Tso-Kar region. This campaign helped confirm the relevance of clays and brines as interest targets of research on Mars for biomarker preservation and life detection.
A nonlinear mathematical model for innovation diffusion is proposed. The system of ordinary differential equations incorporates variable external influences (the cumulative density of marketing efforts), variable internal influences (the cumulative density of word of mouth) and a logistically growing human population (the variable potential consumers). The change in population density is due to various demographic processes such as intrinsic growth rate, emigration, death rate etc. Thus the problem involves two dynamic variables viz. a non-adopter population density and an adopter population density. The model is analysed qualitatively using the stability theory of differential equations, with the help of the corresponding characteristic equation of the system. The interior equilibrium point can be stable for all time delays to a critical value, beyond which the system becomes unstable and a Hopf bifurcation occurs at a second critical value. Employing normal form theory and a centre manifold theorem applicable to functional differential equations, we derive some explicit formulas determining the stability, the direction and other properties of the bifurcating periodic solutions. Our numerical simulations show that the system behaviour can become extremely complicated as the time delay increases, with a stable interior equilibrium point leading to a limit cycle with one local maximum and minimum per cycle (Hopf bifurcation), then limit cycles with more local maxima and minima per cycle, and finally chaotic solutions.
Oxygen isotope analysis was performed on enamel phosphate of mammalian teeth from archaeological sites Kalli Pachchhim and Dadupur in the central Ganga plain and Charda in the northern Ganga plain. The bulk oxygen isotopic compositions of enamel phosphate from third molars (M3) of Bos indicus individuals belonging to different cultural periods were used to understand the climatic changes during the past 3600 cal yr B.P. Oxygen isotope ratios indicate humid conditions around 3600 cal yr B.P., followed by a trend toward drier conditions until around 2800 cal yr B.P. Then from 2500 to 1500 cal yr B.P. there is a trend toward higher humidity, followed by the onset of a dry period around 1300 cal yr B.P. The study of intratooth δ18O variations in teeth from different periods demonstrates that the monsoon seasonality was prominent. Spatial changes in the amount of annual rainfall are also reflected in the δ18O values. Teeth derived from areas with intense rainfall have lighter isotope ratios compared to teeth from regions receiving less rain, but they show similar seasonal patterns. The long-term paleoclimatic variations reflected by fluctuations in bulk δ18Op values from M3 teeth match well with the regional paleoenvironmental records and show a good correlation to the cultural changes that took place during this time span in Ganga plain.
Goats make up the largest group of ruminant livestock in Nigeria and are strategic in bridging animal protein supply gap and improving the economy of rural households. The hypervariable region 1 (HVR1) of the caprine mitochondrial genome was investigated to better understand genetic diversity important for improving selection for animal breeding and conservation programs. We sequenced and analysed the mitochondrial DNA (mtDNA) HVR1 in 291 unrelated indigenous Nigerian goats (West African Dwarf (WAD), Red Sokoto (RSO) and Sahel (SAH)), randomly sampled from around the country, and compared them with the HVR1 sequences of 336 Indian goats and 12 other sequences in five different species in the genus Capra (C. falconeri, C. ibex nubiana, C. aegagrus, C. cylindricornis and C. sibirica). A total of 139 polymorphic sites from 291 individuals were captured in 204 haplotypes. Within and among population variations were 77.25 and 22.74 percent, respectively. Nigerian goats showed high genetic diversity (0.87) and high FST values, and separate from Indian goats and other wild species. Haplogroups in WAD separates it from RSO and SAH concomitant with a different demographic history. Clear genetic structure was found among Nigerian goat breeds with appreciable variation in mtDNA HVR1 region. This study grouped Nigerian goat breeds into two major groups suggesting two different demographic origins for Northern and Southern breeds. High genetic admixing denotes different maternal origins and in contrast to evidence from goats from Levant and Central Asia, where goats were originally domesticated.
Genetic diversity of a red clover global collection was assessed using 36 simple sequence repeat (SSR) primers representing all seven linkage groups (LGs). The number of fragments amplified ranged from 1 to 6 for all the primers. Primer RCS0060 detected highest number of fragments, whereas four SSRs viz., RCS0899, RCS1594, TPSSR40 and RCS6927 amplified single fragment. Size range of amplicons generated by all the primers varied from 100 to 400 bp. Polymorphism information content values ranged from 0.301 to 0.719 with an average value of 0.605. LG wise diversity analysis showed that LG 3 was most diverse (I = 0.65, Ht = 0.44), whereas LG-1 showed minimum diversity (I = 0.48, Ht = 0.26) for the microsatellites used. Bayesian model-based clustering inferred three genetically distinct populations in the red clover germplasm holding and showed considerable admixture in individuals within clusters. Neighbour-joining analysis showed intermixing of accessions within groups. Principal component analysis plot complemented the clustering shown by Structure and distinguished three populations to greater extent. Analysis of molecular variance showed that 91% of the genetic variation was residing within populations, while 9% variation was among populations. Overall, the results showed that a high level of genetic diversity is prevailing in this worldwide collection of red clover, which can be exploited for its genetic improvement through breeding approaches.
To observe the impact of internal mammary node irradiation (IMNI) on disease-free survival (DFS) and overall survival (OS) in postmastectomy women with breast cancer.
Materials and methods
Between 1978 and 1996, 153 women with stage II–III breast cancer were treated with postmastectomy radiation therapy (RT) with IMNI. Their clinical, pathological and treatment characteristics were matched with 166 patients without IMNI. The RT dose was 35 Gy to the chest wall and 40 Gy to the supraclavicular fossa and IMN in 15 fractions over 3 weeks with photons. All patients were planned with two-dimensional technique. Adjuvant chemotherapy was administered to 41% and endocrine therapy to 52% of the patients. Symptomatic patients were further assessed for late pulmonary and late cardiac effects.
The median follow-up period was 203 months (range, 182–224), and the median age was 44 years (range 20–73 years). The IMNI group had significantly more right-sided and inner/central quadrant tumours. Other characteristics were comparable between both the groups. DFS at 15 years with and without IMNI was 64 and 49%, respectively (p=0·0001). On multivariate analysis, IMNI was an independent, positive predictor of DFS [hazard ratio (HR), 2·89; p=0·0001]. Benefit of IMNI on DFS was more apparent in inner/central tumours [HR, 1·48; 95% confidence interval (CI), 1·02–2·88], N2–N3 patients (HR, 1·44; 95% CI, 1·09–2·10) and in those who received chemotherapy (HR, 1·70; 95% CI, 1·07–2·71). OS at 15 years with and without IMNI was 68 and 54%, respectively (p=0·0001). Late pulmonary toxicity was 1·5 versus 1% with and without IMNI, respectively. Late cardiac toxicity was 2·6 versus 1·8% with and without IMNI, respectively.
IMNI significantly improved DFS and OS in postmastectomy breast cancer patients. Benefit of IMNI was seen in patients with central/inner tumours and N2–N3 disease. Late cardiopulmonary toxicities were comparable between the two groups.
Skin contamination is one of the most likely risks after accidental or occupational radiological accidents. Using scintigraphy, we assessed a topical lotion for its decontamination efficacy (DE) after exposure with short-lived medical radioisotopes technetium Tc 99m (99mTc) and thallium 201Tl (201Tl).
Using 99mTc (300 ± 5 μCi/100 μl) and 201Tl (100 ± 5 μCi/100 μl), the thoracoabdominal region (shaved skin) of Sprague Dawley rats and human tissue equivalent were contaminated and then decontaminated using cotton swabs soaked in formulated lotion at different time intervals. Static counts were recorded and calculated for DE. Histologic examination was performed on the animal model.
The DE of the formulation for 99mTc and 201Tl was 85% ± 5 and 88% ± 2, respectively. The prepared formulation effectively removed the radionuclides from the tissue surface.
The formulated lotion assisted in the effective removal of radiocontaminants by decontaminating the radionuclides. Moreover, minimal and easily manageable radioactive waste was generated by this process. Further investigation regarding the infusion of formulated lotion into ready-to-use skin wipes for self-decontamination may be useful for mass casualty scenarios. (Disaster Med Public Health Preparedness. 2014;0:-)
Radioactive contamination can occur as a result of accidental or intentional release of radioactive materials (RM) into the environment. RM may deposit on clothing, skin, or hair. Decontamination of contaminated persons should be done as soon as possible to minimize the deleterious health effects of radiation. The goal of this study was to evaluate the decontamination efficiency (for residual contaminant) of the active components of “Shudhika,” an indigenously developed skin decontamination kit. The study kit is for external radioactive decontamination of intact skin.
Decontamination efficiency was evaluated on the skin surface of rabbit (n = 6) and human volunteers (n = 13). 99mTc sodium pertechnetate (200-250 μCi) was used as the radio-contaminant. Skin surface area (5 × 5 cm2) of thoracic abdominal region of the rabbit and the forearm and the palm of human volunteers were used for the study. Decontamination was performed by using cotton swabs soaked with chemical decontamination agents of the kit.
Decontamination efficiency (% of the contaminant removed) was calculated for each component of the study. Overall effectiveness of the kit was calculated to be 85% ± 5% in animal and 92% ± 3% in human skin surfaces. Running water and liquid soap with water was able to decontaminate volunteers' hand and animal skin up to 70% ± 5%. Chemical decontamination agents were applied only for trace residues (30% ± 5%). Efficiency of all the kit components was found up to be 20% ± 3% (animal) and 28% ± 2 (human), respectively. Residual contamination after final decontamination attempt for both the models was observed to be 12% ± 3% and 5% ± 2%. After 24 and 48 hours of the decontamination procedure, skin was found to be normal (no redness, erythema and edema were observed).
Decontaminants of the study kit were effective in removal of localized radioactive skin contamination when water is ineffective for further decontamination. By using the chemical decontaminants of the study kit, the use of water and radioactive waste generation could be reduced. Cross-contamination could also be avoided. During radiologic emergencies where water may be radioactively contaminated, the study kit could be used.
Rana S, Dutta M, Soni NL, Chopra MK, Kumar V, Goel R, Bhatnagar A, Sultana S, Sharma RK. Decontamination of human and rabbit skin experimentally contaminated with 99mTc radionuclide using the active components of “Shudika”—a skin decontamination kit. Prehosp Disaster Med. 2012;27(2):1-5.