7,073 research outputs found
Quality Comparison of Vegetables Dehydrated in Solar Drier and Electrical Oven
Ascorbic acid, sugars, dehydration ratio and moisture were determined in the vegetables dehydrated separately in solar drier and in electrical oven under similar conditions by standard methods. Vegetables examined were cabbage, cauliflower, tomato, radish, turnip, lahi, methi and palak. It was revealed that in each case, contents of ascorbic acid were higher in solar-dried vegetables in comparison to oven-dried stuffs. This finding indicated superiority of solar driers over electrical ovens, both in reference to quality of the dehydrated vegetables and its overall cost of operation
Nature of Intra-night Optical Variability of BL Lacertae
We present the results of extensive multi-band intra-night optical monitoring
of BL Lacertae during 2010--2012. BL Lacertae was very active in this period
and showed intense variability in almost all wavelengths. We extensively
observed it for a total for 38 nights; on 26 of them observations were done
quasi-simultaneously in B, V, R and I bands (totaling 113 light curves), with
an average sampling interval of around 8 minutes. BL Lacertae showed
significant variations on hour-like timescales in a total of 19 nights in
different optical bands. We did not find any evidence for periodicities or
characteristic variability time-scales in the light curves.
The intranight variability amplitude is generally greater at higher
frequencies and decreases as the source flux increases.
We found spectral variations in BL Lacertae in the sense that the optical
spectrum becomes flatter as the flux increases but in several flaring states
deviates from the linear trend suggesting different jet components contributing
to the emission at different times.Comment: 12 Pages, 5 figures, 3 Tables, Accepted for Publication in MNRA
An electron paramagnetic resonance study of Pr_{0.6}Ca_{0.4}MnO_{3} across the charge ordering transition
We report the first electron paramagnetic resonance studies of single
crystals and powders of Pr_{0.6}Ca_{0.4}MnO_{3} in the 300-4.2 K range,
covering the charge ordering transition at ~ 240 K and antiferromagnetic
transition (T_N) at ~ 170 K. The asymmetry parameter for the Dysonian single
crystal spectra shows anomalous increase at T_{co}. Below T_{co} the g-value
increases continuously, suggesting a gradual strengthening of orbital ordering.
The linewidth undergoes a sudden increase at T_{co} and continues to increase
down to T_N. The intensity increases as the temperature is decreased till
T_{co} due to the renormalization of magnetic susceptibility arising from the
build up of ferromagnetic correlations. The value of the exchange constant, J,
is estimated to be 154 K.Comment: Uses Revtex3.
Frost maintains forests and grasslands as alternate states in a montane tropical forest–grassland mosaic; but alien tree invasion and warming can disrupt this balance
1. Forest–grassland mosaics, with abrupt boundaries between the two vegetation types, occur across the globe. Fire and herbivory are widely considered primary drivers that maintain these mosaics by limiting tree establishment in grasslands, while edaphic factors and frosts are generally considered to be secondary factors that reinforce these effects. However, the relative importance of these drivers likely varies across systems. In particular, although frost is known to occur in many montane tropical mosaics, experimental evidence for its role as a driving factor is limited.
2. We used replicated in situ transplant and warming experiments to examine the role of microclimate (frost and freezing temperatures) and soil in influencing germination and seedling survival of both native forest trees and alien invasive Acacia trees in grasslands of a tropical montane forest–grassland mosaic in the Western Ghats of southern India.
3. Seed germination of both native and alien tree species was higher in grasslands regardless of soil type, indicating that germination was not the limiting stage to tree establishment. However, irrespective of soil type, native seedlings in grasslands incurred high mortality following winter frosts and freezing temperatures relative to native seedlings in adjoining forests where freezing temperatures did not occur. Seedling survival through the tropical winter was thus a primary limitation to native tree establishment in grasslands. In contrast, alien Acacia seedlings in grasslands incurred much lower levels of winter mortality. Experimental night‐time warming in grasslands significantly enhanced over‐winter survival of all tree seedlings, but increases were much greater for alien Acacia than for native tree seedlings.
4. Synthesis. Our results provide evidence for a primary role for frost and freezing temperatures in limiting tree establishment in grasslands of this tropical montane forest–grassland mosaic. Future increases in temperature are likely to release trees from this limitation and favour tree expansion into grasslands, with rates of expansion of non‐native Acacia likely to be much greater than that of native trees. We suggest that studies of frost limitation to plant establishment are needed across a range of tropical ecosystems to re‐evaluate the general importance of frost as a driver of vegetation transitions in the tropics
Translating evidence into policy for cardiovascular disease control in India
Cardiovascular diseases (CVD) are leading causes of premature mortality in India. Evidence from developed countries shows that mortality from these can be substantially prevented using population-wide and individual-based strategies. Policy initiatives for control of CVD in India have been suggested but evidence of efficacy has emerged only recently. These initiatives can have immediate impact in reducing morbidity and mortality. Of the prevention strategies, primordial involve improvement in socioeconomic status and literacy, adequate healthcare financing and public health insurance, effective national CVD control programme, smoking control policies, legislative control of saturated fats, trans fats, salt and alcohol, and development of facilities for increasing physical activity through better urban planning and school-based and worksite interventions. Primary prevention entails change in medical educational curriculum and improved healthcare delivery for control of CVD risk factors-smoking, hypertension, dyslipidemia and diabetes. Secondary prevention involves creation of facilities and human resources for optimum acute CVD care and secondary prevention. There is need to integrate various policy makers, develop effective policies and modify healthcare systems for effective delivery of CVD preventive care
Symmetry between absorption and amplification in disordered media
We address the issue of whether amplification, like absorption, suppresses
wave transmission at large gain, as has been claimed in previous studies of
wave propagation in active random media. A closer examination reveals that the
paradoxical symmetry between absorption and amplification is an artifact of
unphysical solutions from the time-independent wave equation. Solutions from
the time-dependent equation demonstrate clearly that when gain is above the
threshold, the amplitude of both the transmitted and the reflected wave
actually increases with time, apparently without bound. The implications of the
current finding is discusse
Finger Millet Improvement in Post-genomic Era: Hundred Years of Breeding and Moving Forward
Finger millet, grown on about 5 Mha globally under semi-arid environments of East Africa and South Asia, serves as an important dual-purpose crop to address food, forage, and nutritional needs in these marginal regions. Despite the tremendous yield potential, the area cultivated for small millets, including finger millet, decreased by 25.7% globally between 1961 and 2018. Finger millet improvement program began in 1913 in India; however, concentrated efforts to realize genetic gains in this climate-resilient crop are yet to be deployed compared to the efforts invested in improving other major cereals. This has resulted in lower productivity of finger millet in farmer’s fields than its potential yield even after more than 100 years of breeding. However, significant genetic variability is available for traits of importance. The breeding programs in Asia and Africa have refined the hybridization techniques and breeding objectives as per local needs. ICRISAT, an international center with finger millet as one of its mandate crops, is engaged with partners to generate new germplasm to enhance the productivity of this crop in marginal regions. This program, based in India and Kenya, has developed and distributed germplasm and breeding lines globally in the last few decades. Many promising and widely adapted cultivars have been released and adopted in many countries. Hybridization between the Indian and African gene pools of finger millet in the 1990s brought a paradigm shift in finger millet production in India. Now, breeding pipelines have been strengthened with the identification of newly identified germplasm for traits of importance, especially for blast resistance. Recently, finger millet genome sequencing was accomplished, and with the availability of advanced phenotyping protocols for various traits of importance, it has opened new opportunities to enhance genetic gains in this crop. This chapter informs about historical breeding efforts and discusses the prospects and challenges of finger millet breeding to enhance breeding efficiency and genetic gains in finger millet. International collaborative efforts toward improving agronomic traits, value addition, and the trade value of finger millet would help marginal farmers of southeast Asia and Africa but will also help enhance the commercial value of this underutilized millet
CD44v6 Regulates Growth of Brain Tumor Stem Cells Partially through the AKT-Mediated Pathway
Identification of stem cell-like brain tumor cells (brain tumor stem-like cells; BTSC) has gained substantial attention by scientists and physicians. However, the mechanism of tumor initiation and proliferation is still poorly understood. CD44 is a cell surface protein linked to tumorigenesis in various cancers. In particular, one of its variant isoforms, CD44v6, is associated with several cancer types. To date its expression and function in BTSC is yet to be identified. Here, we demonstrate the presence and function of the variant form 6 of CD44 (CD44v6) in BTSC of a subset of glioblastoma multiforme (GBM). Patients with CD44high GBM exhibited significantly poorer prognoses. Among various variant forms, CD44v6 was the only isoform that was detected in BTSC and its knockdown inhibited in vitro growth of BTSC from CD44high GBM but not from CD44low GBM. In contrast, this siRNA-mediated growth inhibition was not apparent in the matched GBM sample that does not possess stem-like properties. Stimulation with a CD44v6 ligand, osteopontin (OPN), increased expression of phosphorylated AKT in CD44high GBM, but not in CD44low GBM. Lastly, in a mouse spontaneous intracranial tumor model, CD44v6 was abundantly expressed by tumor precursors, in contrast to no detectable CD44v6 expression in normal neural precursors. Furthermore, overexpression of mouse CD44v6 or OPN, but not its dominant negative form, resulted in enhanced growth of the mouse tumor stem-like cells in vitro. Collectively, these data indicate that a subset of GBM expresses high CD44 in BTSC, and its growth may depend on CD44v6/AKTpathway
An analysis of the distribution of background star polarization in dark clouds
The polarization observed for stars background to dark clouds (Bok Globules)
is often used as diagnostic to study the ongoing star formation processes in
these clouds. Such polarization in the optical have been reported for eight
nearby clouds CB3, CB25, CB39, CB52, CB54, CB58, CB62 and CB246 in one of our
previous work (Sen et. al. 2000). With a view to understand the origin of this
polarization, the the present work attempts are made to look for any possible
relation between this observed polarization and other physical parameters in
the cloud (like temperature, turbulence etc.). The observed polarization does
not seem to be clearly related to the dust and gas temperatures (T_d and T_g)
in the cloud as expected from the Davis-Greenstein grain alignment mechanism
(Davis & Greenstein, 1952). However, the average observed polarization p_av
appears to be related to the turbulence delta V (measured by 12CO line width)
by the mathematical relation p_av=2.95exp(-0.24delta V). The possible realtion
between the direction of polarization vector and other physical parameters are
also discussed. For this analysis, in addition to the data on above eight
clouds, the data on CB4 (Kane et. al., 1995) are also included for comparison.Comment: 15 pages, 12 figures, To appear in MNRAS, 200
Prevalence of microalbuminuria and associated electrocardiographic abnormalities in an Indo-Asian population
Background. Microalbuminuria (MA) is a known predictor of cardiovascular disease (CVD) in European origin populations, but such data are lacking in native Indo-Asian populations, where CVD risks are high. Major electrocardiographic (ECG) changes are predictive of cardiovascular mortality. We determined the association of MA with major ECG changes in the general population of Pakistan
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