Climatic response of various tree ring parameters of fir (Abies pindrow) from Chandanwadi in Jammu and Kashmir, western Himalaya, India

Total ring width (TRW) and earlywood width (ERW) of fir (Abies pindrow) compared to latewood width (LRW) are strongly correlated with Palmer Drought Severity Index (PDSI) during summer season (March to October). Correlation coefficients for the period 1876-1948 between PDSI and TRW as well as ERW are 0.43 and 0.50 respectively, which is found to be significant at 0.01 level. Thereafter, their relationship weakened as temperature changed over the region, whereas maximum latewood density (MXD) reveals significant negative association with PDSI during summer season. Moreover, monthly mean, maximum and minimum temperatures during August to September of the region indicate significant positive response with MXD. Correlation coefficients of MXD with mean, maximum and minimum temperatures are 0.60, 0.61 and 0.51 respectively, which is significant at 0.01 level. There is also high temporal stability in the relationship between MXD and temperature from 1916 onwards over the region

Growth response of conifer trees from high-altitude region of western himalaya

Tree-ring width index chronologies of some species (Abies pindrow and Picea smithiana) of Western Hima-laya are sensitive to the moisture availability and amount of soil moisture of the region. The first prin-cipal component among the site chronologies explain-ing 61.2 of the common variance is strongly correlated with Palmer Drought Severity Index dur-ing summer season (May-July). Whereas increased temperature of the region had significant adverse effect on tree growth. The moisture availability, espe-cially in the growing season is found more conducive in developing the annual tree-ring width compared to rainfall during the season. Moreover, the increasing temperature and vapour pressure during November and December of the previous year might play an important role for early snow melt over region, which maintains enough soil moisture favouring trees growth during subsequent growing season of the trees as well as in physiological processes

Tree-ring analysis of teak (Tectona grandis L.F.) in central India and its relationship with rainfall and moisture index

Tree-ring-width index chronologies of teak (Tectona grandis L.F.) from three sites in central India have been studied for their dendroclimatic potential. The existence of good correlation among the three site chronologies indicates the in.uence of common forcing factor to the tree growth of the region. Tree growth and climate relationship based on correlation analysis revealed the important contribution of moisture index and rainfall rather than the direct influence of the temperature on tree growth during different seasons. Signi.cant positive relationship of moisture index and rainfall during the monsoon months as well as on the annual scale with tree-ring width variations over the region indicates the important role of moisture availability at the root zone. The results suggest that the teak tree-ring chronologies can be used as high resolution proxy for past precipitation and moisture level in the environment

Tree-ring variation in teak (Tectona grandis L.) from Allapalli, Maharashtra in relation to moisture and Palmer Drought Severity Index, India

We developed a ring-width chronology of teak (Tectona grandis L.) from a moisture stressed area in Maharashtra, India. Bootstrapped correlation analysis indicated that moisture index (MI) and Palmer Drought Severity Index (PDSI) showed better performance rather than same year rainfall over the region. Tree-ring variations were most correlated positively with PDSI during different seasons compared with MI. Significant strong positive correlation with MI, and negative association with temperature and potential evapotranspiration (PET) were found during previous and current year post-monsoon (ON). This study shows that the moisture availability during the post-monsoon of the previous year has a significant role in the development of annual growth rings. The reconstructed previous year post-monsoon (ON) moisture index for the period 1866-1996 indicates 3.5 and 29.3 years periodicities

Estimation of past atmospheric carbon dioxide levels using tree-ring cellulose Delta 13 C

We study the applicability of the Farquhar model for carbon isotopic discrimination (change in carbon isotopic composition from air CO2 to tree-ring cellulose) in C3 plants to trees growing in the field. Two new carbon isotope datasets from Himalayan conifers with published data from another eight sites across the world show disparate trends in the plot of carbon isotope discrimination versus atmospheric carbon dioxide concentration, in contrast to the model prediction of absence of any trend. This is because the model assumes that the tree adjusts its stomatal conductance for water-use efficiency to maintain a constant ratio of carbon dioxide concentrations inside and outside the leaf and treats the diffusive and biochemical fractionation factors as constants. By introducing a simple linear dependence of these fractionation factors with ambient temperature and humidity, we have enhanced the applicability of the model to naturally growing trees. Further, despite the disparate trends exhibited by the 10 trees, we show using the inverse modelling that it is possible to derive a unique record of past atmospheric CO2 concentrations using tree cellulose 13C data. The reconstructions also replicate the summer pCO2 gradient from tropics to mid-latitudes. We also discuss the merits and demerits of the model, and compare the model-derived pCO2 with that of the ice core-based records from Law Dome

Intra-annual oxygen isotope variations in Central Indian teak cellulose: possibility of improved resolution for past monsoon reconstruction

A clear seasonal cycle has been detected in the intraannual oxygen isotope variations (δ18O) of cellulose from several annual growth rings of teak trees that grew in central India. This persistent cycle is marked by higher δ18O values at the ring boundaries and lower δ18O values at intermediate parts. The amplitude of this seasonal cycle varies up to 6.8‰. Based on the pattern of teak growth reported in the literature and a plant physiological model that interprets the δ18O of plant cellulose, it seems possible to identify subsections of a ring that formed during pre-monsoon, peak-monsoon and post-monsoon. Comparison of the δ18O profile of a ring (year AD 1971), analysed with the highest resolution, and a model profile based on concurrent local meteorological data indicates the possibility of achieving a ~20 day resolution in monsoon reconstruction by intra-annual δ18O measurements

Formulation and Evaluation of Pulsatile Drug Delivery System of Metoprolol Tartarate Using Core in Cup Tablet

Abstract The purpose of this work is to formu late a pulsatile drug delivery system using metoprolol tartarate as model drug. A core in cup (three component tablet) is prepared where in core tablet, an impermeable material surrounding the tablet except the top and soluble hydrophilic poly mer layer at the top is designed. The core tablet contains metoprolol tartarate, cellu lose acetate propionate is used as impermeable memb rane and sodium alginate 500 cps and sodium alginate 2000 cps used as soluble hydrophilic poly mer layer .The top cover layer is prepared using 3 2 factorial design. Quantification of water uptake, top layer expansion, in-v itro dissolution studies, radial and axial expansion, stereomicroscopic image, and short term stability studies are performed. The concentration of top layer of hydrophilic poly mer is a critical factor governing the release pattern, increase in the concentration increased lag t ime and delay the release .The T70% and T90 % values are also influenced by the polymer concentration with less polymer concentration of hydrophilic poly mer lesser T70% and T90 % values are obtained and as the concentration increased higher values are obtained. It can be concluded from the study that pulsatile drug delivery system useful in chronotherapy of hypertension can be prepared by this technique

The MeerKAT Absorption Line Survey (MALS) data release I: Stokes I image catalogs at 1-1.4 GHz

The MeerKAT Absorption Line Survey (MALS) has observed 391 telescope pointings at L-band (900 - 1670 MHz) at $\delta\lesssim$ $+20\deg$. We present radio continuum images and a catalog of 495,325 (240,321) radio sources detected at a signal-to-noise ratio (SNR) $>$5 over an area of 2289 deg$^2$ (1132 deg$^2$) at 1006 MHz (1381 MHz). Every MALS pointing contains a central bright radio source ($S_{1\,\mathrm{GHz}} \gtrsim 0.2$ Jy). The median spatial resolution is $12^{\prime\prime}$ ($8^{\prime\prime}$). The median rms noise away from the pointing center is 25 $\mu$Jy beam$^{-1}$ (22 $\mu$Jy beam$^{-1}$) and is within $\sim$ 15% of the achievable theoretical sensitivity. The flux density scale ratio and astrometric accuracy deduced from multiply observed sources in MALS are less than 1% (8% scatter) and $1^{\prime\prime}$, respectively. Through comparisons with NVSS and FIRST at 1.4 GHz, we establish the catalog's accuracy in the flux density scale and astrometry to be better than 6% (15% scatter) and $0.8^{\prime\prime}$, respectively. The median flux density offset is higher (9%) for an alternate beam model based on holographic measurements. The MALS radio source counts at 1.4 GHz are in agreement with literature. We estimate spectral indices ($\alpha$) of a subset of 125,621 sources (SNR$>$8), confirm the flattening of spectral indices with decreasing flux density and identify 140 ultra steep-spectrum ($\alpha<-1.3$) sources as prospective high-$z$ radio galaxies ($z>2$). We have identified 1308 variable and 122 transient radio sources comprising primarily of AGN that demonstrate long-term (26 years) variability in their observed flux densities. The MALS catalogs and images are publicly available at https://mals.iucaa.in.Comment: 64 pages, 25 figures, accepted for publication in the ApJS (full version of the paper with complete tables is available at DR1 release notes

Current perspectives on coronavirus disease 2019 and cardiovascular disease: a white paper by the JAHA editors

Coronavirus Disease 2019 (COVID‐19) has infected more than 3.0 million people worldwide and killed more than 200,000 as of April 27, 2020. In this White Paper, we address the cardiovascular co‐morbidities of COVID‐19 infection; the diagnosis and treatment of standard cardiovascular conditions during the pandemic; and the diagnosis and treatment of the cardiovascular consequences of COVID‐19 infection. In addition, we will also address various issues related to the safety of healthcare workers and the ethical issues related to patient care in this pandemic

Data Descriptor: A global multiproxy database for temperature reconstructions of the Common Era

Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python.(TABLE)Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013').This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product.This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike