Orientation cues and mechanisms used during avian navigation: A review

The navigational systems of different animal species are by a wide margin less notable as compared to birds. Humans have been interested in how migratory birds discover their way more than thousands of miles for quite a long time. This review summarizes the cues and compass mechanisms applied in orientation and navigation by non-migrants, diurnal and nocturnal migrants. The magnetic compass, landmarks, olfactory, and memory of spatial cues en route were utilized in homing and migration. The equivalent is valid for the sun compass despite the fact that its job during migration might be undeniably less significant than commonly presumed. Stellar compass and celestial rotation, as a result of their nighttime accessibility, appear to influence the direction of nighttime migrants during the course of migration. The celestial cues go through notable changes because of the latitude shift during bird migration. Sunset cues alter their location with seasons and latitudes. The recognizable stars lose height and lastly vanish underneath the horizon, whereas new stars show up. These new ones must be calibrated. As celestial rotation not imparting a reference, it is not unexpected that the magnetic compass turns into the main cue that controls the directional importance of stars and sunset cues. Field studies have revealed that, in certain species, a considerable extent of individuals get back to similar breeding, overwintering, and stopover areas in progressive years. This review proposes that migratory birds have advanced uncommon cognitive capacities that empower them to achieve these accomplishments.     

Cognitive deficits in euthymic patients with bipolar disorder: State or trait marker?

Cognitive deficits have been demonstrated in people in the euthymic phase of bipolar disorder. This cross-sectional study compared euthymic bipolar disorder patients (N=30) with never psychiatrically ill controls (N=30) on a neuropsychological test battery containing tasks of executive function, the Wisconsin Card Sorting Test (WCST), attention and working memory, Digits Forward and Backward, and speed of information processing, Digit Symbol. Scores on the Mini Mental State Examination (MMSE) and Vocabulary Test did not differ between the groups. The bipolar group were significantly impaired compared to controls on various indices of executive function on the Wisconsin Card Sort Test and on the Digit tests. The impaired performance on the Digit tests, but not the WCST, was significantly associated with medication status, notably prescribed benzodiazepines. There was no significant effect of severity or course of illness on performance. The findings support the hypothesis that impairments in executive function are present between illness episodes in bipolar disorder, and so are not simply state markers

Short term effects of restricted food availability and peripheral leptin injections in redheaded bunting, Emberiza bruniceps

Migratory birds need continued food supply and efficient metabolic machinery to meet high energy demands of the magnanimous feat of flight. Two questions are important i.e. as to 1) how a bird adapts to a temporary food constrain on a daily basis, and 2) how peripheral leptin, an anorectic hormone, impacted feeding and migratory behaviour in buntings? The aim of this study was to induce a non-photoperiodic tweak in the physiology of redheaded buntings through exogenous leptin administration and study its effect on their food intake and migratory behaviour. Groups of male redheaded buntings, Emberiza bruniceps (n=17) were transferred from short (8L: 16D) to long (16L: 8D) days and presented with food only either for first (morning food presence, MFP) or second (evening food presence, EFP) half of the 16h lighted phase, while control group received food ad libitum. Total daily food intake (FI) did not differ significantly between the MFP, EFP and controls, but hourly FI in MFP and EFP indicated increased activity differences based on time of food availability and bird’s tendency to cache food/ recompense for food scarcity during migration. In another experiment, a chemical tweak in bird’s FI was induced by peripheral administration of leptin, to add to current understanding of transition in buntings’ metabolic efficiency during high energy demanding migratory journey. Exogenous leptin appeared to safeguard cadaveric effect of exogenous injection in migrating buntings through promoting blood cholesterol and reduced liver fibrosis. Food restriction in the morning was better responded by buntings than that in evening. Therefore, migratory buntings exhibited diurnal variation in response to food scarcity

Role of Carbon Nanotube for Flexible Supercapacitor Application

In this current era, with the ever-increasing demand for portable and wearable energy storage devices, the supercapacitor (SC) plays a very positive role to fulfill this gap. Carbon nanotubes (CNTs) are extremely promising material candidate in flexible SC where it works as an electrode to enhance the energy and power densities of the SC because of their remarkable mechanical property, high electrical conductivity, large surface area, and ease to functionalize. Moreover, CNTs can assemble into various macroscopic structures with different dimensions such as single-wall CNTs (SWCNTs), double-wall CNTs (DWCNTs), and multi-wall CNTs (MWCNTs). In this book chapter, a comprehensive discussion on the synthesis, characterization and further utilization of CNTs in metal oxide-based SC has been outlined. Here, the metal oxide can be 1D nanofibers, 2D thin films, and 3D aerogels. Further, a detailed study has been framed on the design methodology and fabrication techniques for the supercapacitor. Recently, various developments and state-of-the-art applications have been proposed for such structures wherein CNTs have been used as electrodes in flexible SCs with varied device configurations such as sandwiched and interdigital in-plane. Furthermore, the flexible CNT-based electrodes have shown great bendability, and compressibility, as well as a long cycle lifetime

Melt-Spun SiGe Nano-Alloys: Microstructural Engineering Towards High Thermoelectric Efficiency

Silicon-germanium (SiGe) alloys are prominent high-temperature thermoelectric (TE) materials used as a powering source for deep space applications. In this work, we employed rapid cooling rates for solidification by melt-spinning and rapid heating rates for bulk consolidation employing spark plasma sintering to synthesize high-performance p-type SiGe nano-alloys. The current methodology exhibited a TE figure-of-merit (ZT) approximate to 0.94 at 1123 K for a higher cooling rate of similar to 3.0 x 10(7) K/s. This corresponds to approximate to 88% enhancement in ZT when compared with currently used radioisotope thermoelectric generators (RTGs) in space flight missions, approximate to 45% higher than pressure-sintered p-type alloys, which results in a higher output power density, and TE conversion efficiency (eta) approximate to 8% of synthesized SiGe nano-alloys estimated using a cumulative temperature dependence (CTD) model. The ZT enhancement is driven by selective scattering of phonons rather than of charge carriers by the high density of grain boundaries with random orientations and induced lattice-scale defects, resulting in a substantial reduction of lattice thermal conductivity and high power factor. The TE characteristics of synthesized alloys presented using the constant property model (CPM) and CTD model display their high TE performance in high-temperature regimes along with wide suitability of segmentation with different mid-temperature TE materials

Expression of 3-hydroxy-3-methylglutaryl-CoA reductase, p-hydroxybenzoate-m-geranyltransferase and genes of phenylpropanoid pathway exhibits positive correlation with shikonins content in arnebia [Arnebia euchroma (Royle) Johnston]

<p>Abstract</p> <p>Background</p> <p>Geranyl pyrophosphate (GPP) and <it>p</it>-hydroxybenzoate (PHB) are the basic precursors involved in shikonins biosynthesis. GPP is derived from mevalonate (MVA) and/or 2-<it>C</it>-methyl-D-erythritol 4-phosphate (MEP) pathway(s), depending upon the metabolite and the plant system under consideration. PHB, however, is synthesized by only phenylpropanoid (PP) pathway. GPP and PHB are central moieties to yield shikonins through the synthesis of <it>m</it>-geranyl-<it>p</it>-hydroxybenzoate (GHB). Enzyme <it>p</it>-hydroxybenzoate-<it>m</it>-geranyltransferase (PGT) catalyses the coupling of GPP and PHB to yield GHB.</p> <p>The present research was carried out in shikonins yielding plant arnebia [<it>Arnebia euchroma </it>(Royle) Johnston], wherein no molecular work has been reported so far. The objective of the work was to identify the preferred GPP synthesizing pathway for shikonins biosynthesis, and to determine the regulatory genes involved in the biosynthesis of GPP, PHB and GHB.</p> <p>Results</p> <p>A cell suspension culture-based, low and high shikonins production systems were developed to facilitate pathway identification and finding the regulatory gene. Studies with mevinolin and fosmidomycin, inhibitors of MVA and MEP pathway, respectively suggested MVA as a preferred route of GPP supply for shikonins biosynthesis in arnebia. Accordingly, genes of MVA pathway (eight genes), PP pathway (three genes), and GHB biosynthesis were cloned. Expression studies showed down-regulation of all the genes in response to mevinolin treatment, whereas gene expression was not influenced by fosmidomycin. Expression of all the twelve genes vis-à-vis shikonins content in low and high shikonins production system, over a period of twelve days at frequent intervals, identified critical genes of shikonins biosynthesis in arnebia.</p> <p>Conclusion</p> <p>A positive correlation between shikonins content and expression of <it>3-hydroxy-3-methylglutaryl-CoA reductase </it>(<it>AeHMGR</it>) and <it>AePGT </it>suggested critical role played by these genes in shikonins biosynthesis. Higher expression of genes of PP pathway was a general feature for higher shikonins biosynthesis.</p

Electron attachment to valence-excited CO

The possibility of electron attachment to the valence $^{3}\Pi$ state of CO is examined using an {\it ab initio} bound-state multireference configuration interaction approach. The resulting resonance has $^{4}\Sigma^{-}$ symmetry; the higher vibrational levels of this resonance state coincide with, or are nearly coincident with, levels of the parent $a^{3}\Pi$ state. Collisional relaxation to the lowest vibrational levels in hot plasma situations might yield the possibility of a long-lived CO$^-$ state.Comment: Revtex file + postscript file for one figur

Global, regional, and national sex-specific burden and control of the HIV epidemic, 1990-2019, for 204 countries and territories: the Global Burden of Diseases Study 2019

Background: The sustainable development goals (SDGs) aim to end HIV/AIDS as a public health threat by 2030. Understanding the current state of the HIV epidemic and its change over time is essential to this effort. This study assesses the current sex-specific HIV burden in 204 countries and territories and measures progress in the control of the epidemic. Methods: To estimate age-specific and sex-specific trends in 48 of 204 countries, we extended the Estimation and Projection Package Age-Sex Model to also implement the spectrum paediatric model. We used this model in cases where age and sex specific HIV-seroprevalence surveys and antenatal care-clinic sentinel surveillance data were available. For the remaining 156 of 204 locations, we developed a cohort-incidence bias adjustment to derive incidence as a function of cause-of-death data from vital registration systems. The incidence was input to a custom Spectrum model. To assess progress, we measured the percentage change in incident cases and deaths between 2010 and 2019 (threshold >75% decline), the ratio of incident cases to number of people living with HIV (incidence-to-prevalence ratio threshold <0·03), and the ratio of incident cases to deaths (incidence-to-mortality ratio threshold <1·0). Findings: In 2019, there were 36·8 million (95% uncertainty interval [UI] 35·1–38·9) people living with HIV worldwide. There were 0·84 males (95% UI 0·78–0·91) per female living with HIV in 2019, 0·99 male infections (0·91–1·10) for every female infection, and 1·02 male deaths (0·95–1·10) per female death. Global progress in incident cases and deaths between 2010 and 2019 was driven by sub-Saharan Africa (with a 28·52% decrease in incident cases, 95% UI 19·58–35·43, and a 39·66% decrease in deaths, 36·49–42·36). Elsewhere, the incidence remained stable or increased, whereas deaths generally decreased. In 2019, the global incidence-to-prevalence ratio was 0·05 (95% UI 0·05–0·06) and the global incidence-to-mortality ratio was 1·94 (1·76–2·12). No regions met suggested thresholds for progress. Interpretation: Sub-Saharan Africa had both the highest HIV burden and the greatest progress between 1990 and 2019. The number of incident cases and deaths in males and females approached parity in 2019, although there remained more females with HIV than males with HIV. Globally, the HIV epidemic is far from the UNAIDS benchmarks on progress metrics. Funding: The Bill & Melinda Gates Foundation, the National Institute of Mental Health of the US National Institutes of Health (NIH), and the National Institute on Aging of the NIH

Spatial, temporal, and demographic patterns in prevalence of chewing tobacco use in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019

Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Findings In 2019, 273 center dot 9 million (95% uncertainty interval 258 center dot 5 to 290 center dot 9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 center dot 72% (4 center dot 46 to 5 center dot 01). 228 center dot 2 million (213 center dot 6 to 244 center dot 7; 83 center dot 29% [82 center dot 15 to 84 center dot 42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global agestandardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 center dot 21% [-1 center dot 26 to -1 center dot 16]), similar progress was not observed for chewing tobacco (0 center dot 46% [0 center dot 13 to 0 center dot 79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 center dot 94% [-1 center dot 72 to -0 center dot 14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Summary Background Chewing tobacco and other types of smokeless tobacco use have had less attention from the global health community than smoked tobacco use. However, the practice is popular in many parts of the world and has been linked to several adverse health outcomes. Understanding trends in prevalence with age, over time, and by location and sex is important for policy setting and in relation to monitoring and assessing commitment to the WHO Framework Convention on Tobacco Control. Methods We estimated prevalence of chewing tobacco use as part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 using a modelling strategy that used information on multiple types of smokeless tobacco products. We generated a time series of prevalence of chewing tobacco use among individuals aged 15 years and older from 1990 to 2019 in 204 countries and territories, including age-sex specific estimates. We also compared these trends to those of smoked tobacco over the same time period. Findings In 2019, 273 & middot;9 million (95% uncertainty interval 258 & middot;5 to 290 & middot;9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 & middot;72% (4 & middot;46 to 5 & middot;01). 228 & middot;2 million (213 & middot;6 to 244 & middot;7; 83 & middot;29% [82 & middot;15 to 84 & middot;42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global age standardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 & middot;21% [-1 & middot;26 to -1 & middot;16]), similar progress was not observed for chewing tobacco (0 & middot;46% [0 & middot;13 to 0 & middot;79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 & middot;94% [-1 & middot;72 to -0 & middot;14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Copyright (c) 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe