To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
Infection severity and persistence in a host population is affected by variation in host susceptibility. External disturbance can exacerbate/reduce individual variation by affecting the interactions between the host and its parasites and the dynamics of infection and transmission. We investigated the impact of three sources of disturbance (climate change, the presence of a second parasite species and anthelmintic treatment) on the dynamics of infection and shedding of three common parasites of the rabbit. Data were collected from long-term field studies and laboratory experiments and analysed using mathematical modelling and analytical tools. Our studies show that they all affect host–parasite interactions by altering the intensity of infection and/or the degree of parasite shedding. They also generate patterns of infections that could not have been predicted in the absence of these disturbances or from performing analyses at a different temporal scale. Modelling simulations confirmed the complexity of the processes involved and identified the critical interactions shaping the patterns observed.
Terminal heat stress leads to sizeable yield loss in late-sown wheat in tropical environments. Several synthetic compounds are known to counteract plant stress emanating from abiotic factors. A field experiment was conducted in Sabour (eastern India) during 2013–2016 to investigate the field efficacy of two synthetic compounds, calcium chloride (CaCl2) and arginine, for improving grain yield of two contrasting wheat cultivars (DBW 14 and K 307) facing terminal heat stress. For this, foliar spray of 18.0 mM CaCl2 at booting (CCB) or anthesis (CCA), 9.0 mM CaCl2 at both booting and anthesis (CCB+A), 2.5 mM arginine at booting (ARGB) or anthesis (ARGA) and 1.25 mM arginine at both booting and anthesis (ARGB+A) treatments along with no-spray and water-spray treatments were evaluated in late-sown wheat. The highest grain yield was recorded in treatment CCB+A, followed by CCA and ARGB+A. However, the effect of these compounds was marginal on grain yield when applied only at the booting stage. Grains/ear and thousand-grain weight were found to be the critical determinants for yield in late-sown wheat. During the anthesis to grain filling period, flag-leaf chlorophyll degradation and increase in relative permeability in no-spray treatment were 34–36% and 29–52%, respectively, but these values were reduced considerably in CCB+A treatment followed CCA. Thus, foliar spray of 9.0 mM CaCl2 both at booting and anthesis stages may be recommended for alleviating the negative impacts of terminal heat stress in late-sown wheat and improving its productivity (>13%).
In search of a suitable resource conservation technology under pigeonpea (Cajanus cajan L.)–wheat (Triticum aestivum L.) system in the Indo-Gangetic Plains, the effects of conservation agriculture (CA) on crop productivity and water-use efficiency (WUE) were evaluated during a 3-year study. The treatments were: conventional tillage (CT), zero tillage (ZT) with planting on permanent narrow beds (PNB), PNB with residue (PNB + R), ZT with planting on permanent broad beds (PBB) and PBB + R. The PBB + R plots had higher pigeonpea grain yield than the CT plots in all 3 years. However, wheat grain yields under all plots were similar in all years except for PBB + R plots in the second year, which had higher wheat yield than CT plots. The contrast analysis showed that pigeonpea grain yield of CA plots was significantly higher than CT plots in the first year. However, both pigeonpea and wheat grain yields during the last 2 years under CA and CT plots were similar. The PBB + R plots had higher system WUE than the CT plots in the second and third years. Plots under CA had significantly higher WUE and significantly lower water use than CT plots in these years. The PBB + R plots had higher WUE than PNB + R and PNB plots. Also, the PBB plots had higher WUE than PNB in the second and third years, despite similar water use. The interactions of bed width and residue management for all parameters in the second and third years were not significant. Those positive impacts under PBB + R plots over CT plots were perceived to be due to no tillage and significantly higher amount of estimated residue retention. Thus, both PBB and PBB + R technologies would be very useful under a pigeonpea–wheat cropping system in this region.
About a thousand optical absorption features on the interstellar extinction curve popularly known as the Diffuse Interstellar Bands (DIBs) have been observed. The numbers are increasing every year, thanks to the improvement in telescope and spectroscopic technology. Ultra-high resolution spectroscopic observations and emission features corresponding to some of the DIBs suggest that, some if not all, of these features are due to large molecules. The strength of DIBs depend on the amount of reddening which is directly proportional to the amount of material present between the background star and the observer. Since, the strengths of the DIBs are not strongly correlated with each other, there must be several carriers. Time Dependent Density Functional Theory (TDDFT) calculations are useful in narrowing down molecular systems that may be further investigated in the laboratory.
The observations of the unidentified infrared (UIR) bands point towards the widespread presence of Polycyclic Aromatic Hydrocarbon (PAH) molecules. Though, not a single PAH has been discovered in interstellar space, these are the largest molecules suspected to be present. PAHs are stable towards energetic environment prevailing under interstellar conditions rendering these molecules to be good candidates as DIB carriers. We report TDDFT calculations to predict electronic transitions of neutral, protonated-deuteronated and PAHs with five member rings with various sites of protonation and deuteronation. Compared to their neutral forms, these charged isoelectronic forms of PAHs are predicted to have active transitions in the visible region, which means they are suitable candidates as carriers for some of the DIBs and laboratory studies are warranted for these systems.
Radio frequency (RF) and microwave amplifier research has been largely focused on solid-state technology in recent years. This paper presents design and performance characterization of a 50-kW modular solid-state amplifier, operating at 505.8 MHz. It includes architecture selection and design procedures based on circuit and EM simulations for its building blocks like solid-state amplifier modules, combiners, dividers, and directional couplers. Key performance objectives such as efficiency, return loss, and amplitude/phase imbalance are discussed for this amplifier for real-time operation. This amplifier is serving as the state-of-the-art RF source in Indus-2 synchrotron radiation source. Characterization on component level as well as system level of this amplifier serves useful data for RF designers working in communication and particle accelerator fields.
Thin films of InSb with different thickness (t = 5, 10 and 15 kÅ) were
deposited on to glass substrate by flash evaporation technique. The
structural and electrical properties were investigated and the effect of
films thickness on films properties was discussed. XRD analysis of the films
as a function of film thickness revealed that crystallinity improves with
film thickness. Temperature dependence of the Hall parameters were studied
in a wide range, 20 < T < 300 K. The temperature variation of the Hall
coefficient and conductivity shows an activated nature with negative
temperature coefficient confirming that the prepared films of InSb are
semiconducting in nature with n-type conductivity. Size effect was observed
as the defect density is much smaller for thicker films and as a result
electrical conductivity of the films increases with increasing film
thickness with the increase of the charge carriers through the film. An
increase in mobility with sample thickness has been observed. The mobility
variations with temperature revealed a transition from lattice to impurity
scattering in the observed temperature range.
The spectroscopic properties of protonated and deprotonated PAHs are investigated through
Density Functional Theory (DFT) calculations, with reference to their potential
astrophysical significance. Attention is focussed on electronic and rotational
The electronic transport properties of p-type tin selenide (SnSe)
grown by direct vapor transport (DVT) technique were investigated via Hall
effect in the temperature range 40 <T< 300 K. The temperature
dependence of conductivity revealed the existence of impurity energy level
in the band gap of the crystal. The temperature dependence of the carrier
concentration was analyzed using the single-donor – single-acceptor model.
The Hall mobility increases by decreasing temperature up to 120 K and then
decreases along with temperature. The observed temperature dependant
mobility in the temperature range 120 <T< 300 K and 40 <T< 120 K
was found to be limited by homopolar and ionized impurity mode scatterings
The characteristics of heterojunction diode pSe-nMoSe2
fabricated from thermally evaporated p-Se films on n-type Molybdenum
diselenide (MoSe2) grown by direct vapour transport (DVT) technique
have been examined by using current-voltage measurements. To investigate the
dark current transport mechanism in pSe-nMoSe2 heterojunctions the
current-voltage characteristics were measured in the temperature range
100–300 K. The prepared diode shows a rectification ratio of the order of
103 within the range –2 to 2 V. A multi-step tunnelling model was used
to analyze the I-V-T characteristics of the prepared device. The activation
energy determined from the saturation current was about 1.16 eV.
Understanding seasonal changes in age-related incidence of infections can be revealing for disentangling how host heterogeneities affect transmission and how to control the spread of infections between social groups. Seasonal forcing has been well documented in human childhood diseases but the mechanisms responsible for age-related transmission in free-living and socially structured animal populations are still poorly known. Here we studied the seasonal dynamics of Bordetella bronchiseptica in a free-living rabbit population over 5 years and discuss the possible mechanisms of infection. This bacterium has been isolated in livestock and wildlife where it causes respiratory infections that rapidly spread between individuals and persist as subclinical infections. Sera were collected from rabbits sampled monthly and examined using an ELISA. Findings revealed that B. bronchiseptica circulates in the rabbit population with annual prevalence ranging between 88% and 97%. Both seroprevalence and antibody optical density index exhibited 1-year cycles, indicating that disease outbreaks were seasonal and suggesting that long-lasting antibody protection was transient. Intra-annual dynamics showed a strong seasonal signature associated with the recruitment of naive offspring during the breeding period. Infection appeared to be mainly driven by mother-to-litter contacts rather than by interactions with other members of the community. By age 2 months, 65% of the kittens were seropositive.
Y2Ba4CuNbO12 (Y-24Nb1) and silver (Ag) are recognized as potential candidates for improving both flux pinning and the mechanical properties of bulk rare earth (RE)–Ba–Cu–O [(RE)BCO] high-temperature superconductors (HTS). Recent attempts to add Ag2O to superconducting Y-123/Y2Ba4CuNbO12 composites, however, have produced a highly anisotropic morphology of Ag particles in samples grown by top-seeded melt growth (TSMG). This morphology has been attributed to strong particle pushing effects due to the presence of Y-24Nb1 nanoparticles in the composite microstructure. An investigation of the formation of anisotropic Ag particles in the YBCO bulk microstructure indicates that these pushing effects generate different morphological microstructural zones in the composite. These include a zone free of inclusions other than acicular Ag particles, a zone of segregated additives (i.e., Y-24Nb1, Y-211, and Ag), and a zone containing fine Ag and other particles distributed uniformly throughout the local microstructure. The particle pushing/trapping theory has been used to explain these extraordinary features of the distribution of Ag inclusions. The superconducting and mechanical properties of samples containing very fine silver inclusions are also discussed briefly.
High fluences of low energy Ge+ ions were implanted into Si matrix. We have also deposited Ge and SiO2 composite films by using the Atom beam sputtering (ABS). The as implanted/as-deposited films were irradiated by Swift Heavy Ions (SHI) with various energies and fluences. These pristine and irradiated samples were subsequently characterized by XRD and Raman to understand the crystallization behavior. Raman studies of the films indicate the formation of Ge crystallites as a result of SHI irradiation. Glancing angle X-ray diffraction results also confirm the presence of Ge crystallites in the irradiated samples. Moreover, the crystalline nature of Ge improves with an increase in fluence. Rutherford back scattering was used to quantify the concentration of Ge in SiO2 matrix and the film thickness. These detailed results have been discussed and compared with the ones available in literature. The basic mechanism for crystallization induced by SHI in these films will be presented.
Multi quantum wells of InGaAs/InP grown by metal organic chemical vapor deposition have been irradiated using swift heavy ions. Irradiation has been performed using 150MeV Ag and 200MeV Au ions. Both as-grown and irradiated samples were subjected to rapid thermal annealing at 500 and 7000C for 60s. As-grown, irradiated and annealed samples were subjected to high resolution x-ray diffraction studies. Both symmetric and asymmetric scans were analyzed. The as-grown and Ag ion irradiated samples show sharp and highly ordered satellite peaks whereas, the Au ion irradiated samples show broad and low intense peaks. The higher order satellite peaks of the annealed samples vanished with increase of annealing temperature from 500 to 7000C, indicating mixing induced interfacial disorder. Annealing of irradiated samples show higher mixing and disorder and no higher order satellite peaks were observed. Negligible strain was observed after high temperature annealing of as grown samples. Strain values calculated from the X-ray studies indicate that the irradiated samples have higher strain which has been reduced upon annealing. This indicates that the annealing induced mixing occurs maintaining the lattice parameter close to that of the substrate. The effect of electronic energy loss for interface mixing has been discussed in detail. The role of incident ion fluence in combination with the electronic energy loss will also be discussed in detail. The results have been compared with the literature and discussed in detail.
The pectoralis major myocutaneous (PMMC) flap is commonly used for head and neck reconstruction especially in impoverished nations. PMMC is a sturdy pedicled flap with relatively fewer complications, the learning curve is short and no specialized training in microvascular surgery is needed in order to use this flap. In a defect that requires a large skin and mucosal lining the authors routinely use either a bi-paddle PMMC or a combination of PMMC (for the mucosal lining) and a delto-pectoral flap (for the skin defect). It is indisputable that free tissue transfer is a better way of reconstruction for the majority of most such defects. Unfortunately, not all patients can be offered this form of reconstruction due to the cost, time, expertise and infrastructural constraints in high volume centres such as ours. Bi-paddling of PMMC is hazardous in obese males and most female patients. In such patients the skin defect is reconstructed usually by the delto-pectoral (DP) flap but this, for obvious reasons, is less welcomed by the patients. The authors suggest a technique wherein mucosal lining is created by the myofascial lining (inner surface) of the flap and the skin defect is reconstructed by the skin paddle of the single paddle PMMC. It should be considered wherever a DP flap is unacceptable, or bi-paddling or free tissue transfer is not possible.
Objectives: Most studies typically measure health preferences excluding health states perceived as worse than death. The objective of this study is to test the impact of including (versus excluding) health states perceived to be worse than death on utility measurementusing standard gamble (SG) and visual analogue scale (VAS) methods.
Methods: By means of a cross-sectional descriptive study design, women were asked to rate the utility of three hypothetical breast cancer health states: cure, treatment, and recurrence (n=119). Preference weights were estimated, allowing for negative utilities with death (perfect health) scaled at zero (1.0).
Results: Unpaired t-test analysis showed significantly greater change in SG and VAS weights for individuals perceiving cancer recurrence as worse than death than those perceiving death as least desirable state. Excluding negative utilities from the study resulted in significantly smaller changes in utility. Study results show that preference elicitation methods can be successfully adapted to acquire negative utilities.
Conclusions: Changes in utility were greater when negative preferences were permitted. Addressing negative preference scores could significantly affect quality adjusted life year estimates in economic analyses.
In this paper, we introduce a new class of set-valued mappings in a non-convex setting called D-KKM mappings and prove a general D-KKM theorem. This extends and improves the KKM theorem for several families of set-valued mappings, such as (X, Y), C(X, Y), C (X, Y), C (X, Y) and C (X, Y). In the sequel, we apply our theorem to get some existence results for maximal elements, generalised variational inequalities, and price equilibria.