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We present the first results from a new backend on the Australian Square Kilometre Array Pathfinder, the Commensal Realtime ASKAP Fast Transient COherent (CRACO) upgrade. CRACO records millisecond time resolution visibility data, and searches for dispersed fast transient signals including fast radio bursts (FRB), pulsars, and ultra-long period objects (ULPO). With the visibility data, CRACO can localise the transient events to arcsecond-level precision after the detection. Here, we describe the CRACO system and report the result from a sky survey carried out by CRACO at 110-ms resolution during its commissioning phase. During the survey, CRACO detected two FRBs (including one discovered solely with CRACO, FRB 20231027A), reported more precise localisations for four pulsars, discovered two new RRATs, and detected one known ULPO, GPM J1839 $-$10, through its sub-pulse structure. We present a sensitivity calibration of CRACO, finding that it achieves the expected sensitivity of 11.6 Jy ms to bursts of 110 ms duration or less. CRACO is currently running at a 13.8 ms time resolution and aims at a 1.7 ms time resolution before the end of 2024. The planned CRACO has an expected sensitivity of 1.5 Jy ms to bursts of 1.7 ms duration or less and can detect $10\times$ more FRBs than the current CRAFT incoherent sum system (i.e. 0.5 $-$2 localised FRBs per day), enabling us to better constrain the models for FRBs and use them as cosmological probes.
Polymer–filler interactions play a major role in determining the antibacterial activity of organoclay in nanocomposites. The objective of the current study was to determine the effect of polymer type on the antibacterial properties of an organically modified clay – cloisite 10A (C10A) – using poly-ε-caprolactone (PCL) and poly-L-lactic acid (PLA) polymeric systems. Nanocomposite characterization using atomic force microscopy (AFM) showed an increase in roughness upon addition of the clay mineral, and X-ray diffraction (XRD) showed intercalation of the selected polymers into the interlayer spaces of the clay. Transmission electron microscopy (TEM) analysis supported the XRD findings. C10A in PCL thin films enhanced the bactericidal activity against Staphylococcus aureus when compared to the C10A in PLA. The observed change could be the result of pronounced levels of interaction between the filler and polymer matrix in the C10A-PLA nanocomposite when compared to C10A-PCL. The higher interaction levels could hinder the diffusion of bactericidal agents from the nanocomposite membranes. The present study provided insight into the nature of interaction between nanocomposite components and its impact on bioactivity, which can have applications in terms of generating engineered antibacterial materials.
Nipah virus (NiV) outbreak occurred in Kozhikode district, Kerala, India in 2018 with a case fatality rate of 91% (21/23). In 2019, a single case with full recovery occurred in Ernakulam district. We described the response and control measures by the Indian Council of Medical Research and Kerala State Government for the 2019 NiV outbreak. The establishment of Point of Care assays and monoclonal antibodies administration facility for early diagnosis, response and treatment, intensified contact tracing activities, bio-risk management and hospital infection control training of healthcare workers contributed to effective control and containment of NiV outbreak in Ernakulam.
A scalable preparation of in situ N-doped disordered carbon nanosheets from reduced melamine formaldehyde resin is demonstrated. For the first time, nanosheets prepared by such a process have been tested as anodes for lithium ion and sodium ion batteries. Li-ion battery half-cell delivers a reversible capacity of about 500 mA h/g at a specific current of 100 mA/g, and also a capacity of 250 mA h/g at a specific current of 500 mA/g is retained after 600 cycles. For Na-ion batteries, a reasonable capacity of about 150 mA h/g is recorded at a specific current of 50 mA/g, and a capacity of 120 mA h/g at a specific current of 250 mA/g is retained after 350 cycles. The sloppy low-voltage profile obtained for both the lithium ion and sodium ion cells corresponds to the nanosheet anodes, being soft carbon-like, thereby demonstrating superior cycling stability and safety by avoiding metal plating and dendrite formation.
In the Western world, a significant portion of college students have gambled. College gamblers have one of the highest rates of problem gambling. To date, there have been no studies on gambling participation or the rates of problem gambling in India.
Aims
This study evaluated the prevalence of gambling participation and problem gambling in college students in India. It also evaluated demographic and psychosocial correlates of gambling in that population.
Method
We surveyed 5784 college students from 58 colleges in the district of Ernakulam, Kerala, India, using cluster random sampling. Students completed questionnaires that addressed gambling, substance use, psychological distress, suicidality and attention-deficit hyperactivity disorder (ADHD).
Results
A total of 5580 completed questionnaires were returned, and while only 1090 (19.5%) college students reported having ever gambled, 415 (7.4%) reported problem gambling. Lotteries were the most popular form of gambling. Problem gamblers in comparison with non-gamblers were significantly more likely to be male, have a part-time job, greater academic failures, higher substance use, higher psychological distress scores, higher suicidality and higher ADHD symptom scores. In comparison with non-problem gamblers, problem gamblers were significantly more likely to have greater academic failures, higher psychological distress scores, higher suicidality and higher ADHD symptom scores.
Conclusions
This study, the first to look at the prevalence of gambling in India, found relatively low rates of gambling participation in college students but high rates of problem gambling among those who did gamble. Correlates of gambling were generally similar to those noted in other countries. Since 38% of college students who had gambled had a gambling problem, there is a need for immediate public health measures to raise awareness about gambling, and to prevent and treat problem gambling in this population.
In this study, we present the case of a neonate with obstructed infracardiac total anomalous pulmonary venous connection with severe pulmonary hypertension and a patent ductus arteriosus with right-to-left shunting. The patient had an unusual finding of pandiastolic flow reversal in the upper descending thoracic aorta. He underwent emergency surgical re-routing of the pulmonary veins to the left atrium, and postoperative echocardiography showed disappearance of the descending aortic flow reversal. We hypothesise that in severely obstructed total anomalous pulmonary venous connection the left ventricular output may be extremely low, resulting in flow reversal in the descending aorta.
Broiler stunning is conducted to produce a rapid onset of insensibility prior to slaughter. Though most broiler plants use electrical stunning applications, gas stunning, and low-atmosphere pressure stunning are also available for commercial applications. All three of these stunning methods are able to meet animal welfare requirements and produce meat with acceptable quality. However, each method differs in their mechanisms of stunning, rigor mortis patterns, and physical meat characteristics. In addition, gas stunning and low-atmosphere pressure stunning have received interest over the past decade as part of an effort to further improve animal welfare. Researchers have reported that gas and low-atmosphere pressure stunning both have potential advantages over electrical stunning with respect to broiler welfare and deboning time, which has been attributed to shackling post-stunning. This review paper will focus on these three stunning methods and their impact on animal welfare, physiology, rigor mortis patterns, carcass characteristics, and meat quality.
In the last decades many techniques have been proposed to manufacture thin (<50µm) silicon solar cells. The main issues in manufacturing thin solar cells are the unavailability of a reliable method to produce thin silicon foils with contained material losses (kerf-losses) and the difficulties in handling and processing such fragile foils. A way to solve both issues is to grow an epitaxial foil on top of a weak sintered porous silicon layer. The porous silicon layer is formed by electrochemical etching on a thick silicon substrate and then annealed to close the top surface. This surface is employed as seed layer for the epitaxial growth of a silicon layer which can be partially processed while attached on the substrate that provides mechanical support. Afterward, the foil can be bonded on glass, detached and further processed at module level. The efficiency of the final solar cell will depend on the quality of the epitaxial layer which, in turn, depends on the seed layer smoothness.
Several parameters can be adjusted to change the morphology and, hence, the properties of the porous layer, both in the porous silicon formation and the succeeding thermal treatment. This work focuses on the effect of the parameters that control the porous silicon formation on the structure of the porous silicon layer after annealing and, more specifically, on the roughness of the top surface. The reported analysis shows how the roughness of the seed layer can be reduced to improve the quality of the epitaxial growth.
This study was carried out to define the anatomical criteria for the diagnosis of inferior-type caval vein defect and compare the echocardiographic findings with surgical findings.
Methods
The records of 19 patients – 13 male and six female patients in the age group of 18 months to 27 years, who were diagnosed as inferior-type caval vein defect with or without anomalous drainage of right pulmonary vein(s) on echocardiography – were retrospectively reviewed and compared with surgical findings.
Results
Surgical diagnosis of inferior-type caval vein defect was confirmed in 17 of the 19 patients. In two patients, the surgical diagnosis was that of a large fossa ovalis atrial septal defect – confluent defect and fossa ovalis atrial septal defect with deficient inferior rim in one patient each. Surgical diagnosis of anomalous drainage of pulmonary vein(s) was based on the course of the superior rim of the defect in relation to the pulmonary veins. Our echocardiographic impression of the pulmonary veins appearing in its normal position but showing abnormal drainage to right atrium was in agreement with the surgical notes. Discrepancy was found in the number of pulmonary veins draining anomalously. The discordance was related to overdiagnosis of anomalous drainage in all except one, that is, three out of four. In one, only the right lower pulmonary vein was diagnosed to be anomalous, whereas both right upper and lower pulmonary veins were found to be anomalous.
Conclusions
Echocardiography provides definite diagnosis of inferior-type caval vein defect. Inferior caval vein straddling and an intact fossa ovalis are prerequisites for diagnosis. Anomalous pulmonary venous drainage of the right pulmonary veins is very common in our series, although accurate diagnosis of the number of pulmonary veins was not possible in all cases. Multiple views on transthoracic echocardiography starting from the subxiphoid views delineate the morphology accurately. Transoesophageal echocardiography is required only in patients in whom the windows, especially the subxiphoid, are not adequate.
Vitamin E is divided into two subgroups; tocopherols and tocotrienols. Both have protective roles in biological systems. The present study was conducted to compare the effect of short-term supplementation at 200 mg/d of either α-tocopherol or a tocotrienol-rich fraction (TRF) from palm oil on immune modulation and plasma vitamin E levels in normal healthy Asian volunteers. In a randomised, double-blind placebo-controlled trial conducted, fifty-three healthy volunteers aged 20–50 years were recruited based on the study's inclusion and exclusion criteria. They were randomly assigned into three groups, i.e. two experimental groups that received daily supplementation at 200 mg of either α-tocopherol or the TRF, and the control group that received a placebo. Blood was drawn on days 0, 28 and 56 for several laboratory analyses. Differences in the production of IL-4 or interferon-γ by concanavalin A-stimulated lymphocytes isolated from these volunteers were not significant (P>0·05). There were no significant differences observed in immune parameters between the healthy volunteers who received daily supplementation with either α-tocopherol or the TRF. As these observations were made in the absence of any immunogenic challenge, we feel it would be of benefit to study if there would be any differences observed when an immunogenic challenge such as vaccination were introduced.
Numerical solutions are presented for the detailed characteristics of the drift current and Langmuir circulation system produced according to a theory described in part 1 of this paper. The motions that develop are traced from an initially quiescent state, and the results are compared with field observations of currents in Langmuir circulations. Qualitative features of the phenomenon appear to be reproduced by the theory and, with the appropriate choice of an empirical parameter, the solutions seem to be quantitatively consistent with field data.
We have carried out experiments on dual-damascene Cu interconnects with different lengths. We find that at short lengths, similar to Al-based interconnects, the reliability of Cubased interconnects improves. Also like Al interconnects, some short Cu segments do not form voids that cause failure before back-stresses prevent the further growth of voids. However, unlike Al-based interconnects, there is no apparent deterministic current-density line-length product (jL) for which all lines are immortal. This is related to the absence of a conducting refractory-metal overlayer in Cu-technology that can shunt current around small voids. Also unlike Al, we find that at long lengths a sub-population of Cu lines is immortal. We propose that this is the result of rupture of the thin refractory metal liner at the base of the dual-damascene Cu vias. As a consequence of this complex behavior, median times to failure and lifetime variations are minimum at intermediate line lengths.
Conducting polyaniline/barium titanate (PANI/BaTiO3) composites exhibiting piezoresistivity properties have been synthesized by the in situ deposition technique by placing a fine grade powder of BaTiO3 in the polymerization reaction mixture. The polyaniline was formed preferentially on the ceramic particles giving a much higher yield for PANI than in absence of the BaTiO3 These composites exhibited piezoresistivity with the piezosensitivity being maximum at a certain composition. The current–voltage characteristics clearly revealed a nonlinear space charge controlled charge transport process. A large hysteresis in these characteristics was also observed which was dependent on the BaTiO3 content in a composite. The various results have been explained on the basis of the charge transport mechanism in the heterogeneous conducting material having insulating domains dispersed in it.
Raman scattering studies have been recently used to relate the strain in the semiconductor layer structure with the line shape of allowed modes. It can yield important information about the nature of the solid on a scale of the order of a few lattice constants. It can also provide an evaluation on the carrier concentration in the channel layer of high electron mobility transistors (HEMTs). In this investigation, Raman scattering was used to study the effect of varying the In mole fraction (x) from 0.53 to 0.81 in the InxGa1−xAs channel layer of InGaAs/InP heterostructures. The effect of varying the doping concentration in the donor layer from 6×1017/cm3 to 2.5×1018/cm3, and the effect of varying the In0.75Ga0.25As channel thickness from 140 Å to 260 Å are also reported.
A two-mode Raman characteristic for all InxGa1−xAs/InP HEMTs is clearly seen, with the two LO modes (InAs-like LO and GaAs-like LO) located at 229cm−1 and 268.6cm−1, respectively. At a Raman frequency of 347cm−1, a small peak is observed due to InP LO mode. As the In composition increases from 0.53 to 0.81, the InAs-like LO mode peak intensity increases while that of GaAs-like LO mode decreases. The peak intensity ratio of InAs-like LO mode and GaAs-like LO mode increases from 0.78 to 1.10. By increasing the doping concentration in the donor layer (ND), there is also an increase in the carrier concentration in the InGaAs channel assuming that the donors are fully ionised. The coupled mode between the InGaAs longitudinal optical phonons and electrons in the InGaAs channel shifts continuously to a low wave number with the increasing ND in the InP donor layer. The increase in the lnGaAs channel thickness from 140Å to 260Å causes the InAs-like LO mode peak to shift to a lower wave number from 235.5 to 228.5cm−1. There is no change in the GaAs-like LO peak position located at 268.4cm−1.
Growth of In0.52Al0.48As epilayers on InP(100) substrates by molecular beam epitaxy at a wide range of substrate temperatures (470–550 °C) is carried out. Low temperature photoluminescence (PL) and double-axis x-ray diffraction (XRD) measurements showed a strong dependence of the PL and XRD linewidths and lattice mismatch on the substrate temperature. Minimum PL and XRD linewidths and lattice mismatch were found to occur at substrate temperatures of between ≈500 and 520 °C under the beam fluxes used in this study. The XRD intensity ratios (Iepi/Isub) were generally higher within the same substrate temperature range at which the lattice mismatch was the lowest. XRD rocking curves of samples grown at low temperatures showed the main epilayer peak to be composed of smaller discrete peaks, suggesting the presence of regions with different lattice constants in the material. PL spectra taken at increasing temperatures showed the quenching of the main emission peak followed by the evolution of a distinct lower energy peak which is possibly associated with deep lying centers.
Low temperature photoluminescence measurements were carried out on pseudomorphically strained InxGa1−xAs-Al0.28Ga0.72As ternary-on-ternary heterostructures grown by molecular beam epitaxy to investigate the change in the transition energy, linewidth, and intensity as a function of InGaAs well thickness at two different indium compositions, x = 0.10 and x = 0.15, respectively. Sharp exciton peaks as narrow as 4-6 meV were observed from the InGaAs wells grown at 530 °C with 1 min of growth interruption at the top and bottom heterointerfaces. The linewidth decreases as the well thickness is increased up to 300 Å. In addition, there are signs of linewidth broadening and sharp decrease in the photoluminescence intensity at higher well thicknesses that may indicate the onset of plastic relaxation. Relatively small variations in the transition energy were observed at well thicknesses that are up to ≍3 times the theoretical critical layer thickness calculated by the Matthews-Blakeslee model,10 suggesting that the small density of dislocations that may be present may not have a significant effect on the band structure of the well.
Low-temperature photoluminescence measurements have been taken to monitor the changes in the properties of strained GaAs/InGaAs/GaAs quantum wells grown by molecular beam epitaxy at different substrate (well) temperatures with and without a 90 s-growth-interruption at the heterointerfaces. Sharp exciton peaks with average linewidths as low as 1.7 meV were observed in all the spectra. The spectra from the samples grown employing interrupts were narrower than those without interrupts, indicating structurally improved interfaces. Further linewidth narrowing was also seen in samples employing an additional interrupt of the same duration at the bottom InGaAs/GaAs interface, or by increasing the interrupt time at the top GaAs/InGaAs interface to 180 s. A consistent reduction in the linewidth was also observed in wells grown at higher temperatures. This is most likely due to greater indium re-evaporation leading to a reduction in strain, well width, and interface fluctuations.
Several attempts were made to detect the possible radio recombination lines of positronium near the galactic center. An absorption feature seen at λ6cm, in the D-configuration of the VLA was not confirmed by subsequent observations at λ6cm and λ20cm using the B and C configurations of the VLA. An observation at λ3mm using the IRAM 30m telescope also did not detect any line. On the basis of one recombination line photon for every positron (McClintock 1984), our non-detections imply an upper limit to the positron production rate of < 3.1 × 1043 s−1, within about 2″ of the galactic center.
UVB Flight curves and spectrograms of R CMa obtained with the 48-inch telescope of Japal-Rangapur Observatory during 1980-82 have been used for deriving the eclipse and orbital elements as well as the absolute dimensions of the components. The primary is found to be a Main-Sequence F2V star of mass 1.52 M⊙ and the secondary a subgiant star of spectral type G8 and mass 0.20 M⊙ which fills its Roche lobe, in agreement with Kopal and Shapley (1956) results, Kopal (1959), or Sahade's (1963) results. From a consideration of the possible evolution of this system it is concluded that a large fraction of the original mass of the secondary is lost from the system. A study of the period changes indicates the possible presence of a third component of mass of about 0.5 M⊙ which is most likely to be an M dwarf.
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