Black carbon over a high altitude Central Himalayan Glacier: Variability, transport, and radiative impacts.

Ambient equivalent black carbon (BC) measurements spanning from June to October have been carried out over an adjoining location of Satopanth and Bhagirath-Kharak Glaciers (3858m, amsl) of Central Himalaya during the year 2019. Hourly BC varied from 12 ng m-3 to 439 ng m-3 during the entire period of observation. Monthly averaged BC values showed the highest concentration during June (230.96 ± 85.46 ng m-3) and the lowest in August (118.02 ± 71.63 ng m-3). The decrease in BC during monsoon months is attributed to limited long-range transport and rapid wet scavenging processes. Transport model studies indicate a higher retention time of tracer in Uttarakhand, Punjab, Haryana, and adjacent polluted valley regions with increased biomass burning (BB) incidences. The high rate of BC influx during June, September, and October was attributed to transport from the polluted Indo-Gangetic Plain (IGP) region, wildfires, and vehicular emissions in the valley region. Higher equivalent brown carbon (BrC) influx is linked to BB, especially wood-burning, during intense forest fires at slopes of mountains. Data obtained from limited BC observations during the 2011-19 period showed no significant BC influx change during post-monsoon. The strong correlation between BC mass and BB affirms the dominant role of BB in contributing BC to the Glacier region. Increased TOA forcing induced by surface darkening and BC atmospheric radiative heating indicate an additional warming and possible changes of the natural snow cycle over the glacier depending on the characteristics and extent of debris cover.

Black carbon over a central Himalayan Glacier (Satopanth): Pathways and direct radiative impacts.

Continuous measurement of Black Carbon (BC) concentration was carried out during May-October 2018 periods over Satopanth Glacier in the central Himalayas. BC concentrations varied between 28 and 287 ngm-3 on different days during the observational period. High concentration of BC was observed in the month of May (monthly mean of 221 ± 79 ngm-3), and a lower concentration was observed in August (monthly mean of 92 ± 58 ngm-3). Biomass burning was found to contribute up to 58% of BC mass over the region, with lower contribution during June and higher during the month of May. Compensation parameter (K) values were found to vary between -0.005 and 0.005 in different months, asserting the presence of aged BC in June to October months and relatively fresh BC in the month of May. Concentration weighted trajectory (CWT) analysis showed that the air mass from Indo Gangetic Plains (IGP) was responsible for the majority of transported BC in July & August months (up to 65%) and partially in September (up to 40%). However, the transport from Middle East and far north-western regions was found to be the major contributor to BC concentrations in other months. The estimated BC direct radiative forcing was found to induce 4.5 to 7.6 Wm-2 reduction of radiation at the surface (SFC) and the forcing was +2.3 to +3.5 Wm-2 at the Top of the Atmosphere (TOA). The BC induced atmospheric heating rates were found to be up to 0.35 k day-1 over the region. The sensitivity of snow albedo to radiative forcing was studied, and it is found that BC albedo changes tend to decrease albedo with an increase in BC-snow deposition, leading to a decrease in atmospheric absorption.

Ambient black carbon particulate matter in the coal region of Dhanbad, India.

Light-absorbing, atmospheric particles have gained greater attention in recent years because of their direct and indirect impacts on regional and global climate. Atmospheric black carbon (BC) aerosol is a leading climate warming agent, yet uncertainties in the global direct aerosol radiative forcing remain large. Based on a year of aerosol absorption measurements at seven wavelengths, BC concentrations were investigated in Dhanbad, the coal capital of India. Coal is routinely burned for cooking and residential heat as well as in small industries. The mean daily concentrations of ultraviolet-absorbing black carbon measured at 370nm (UVBC) and black carbon measured at 880nm (BC) were 9.8±5.7 and 6.5±3.8µgm-3, respectively. The difference between UVBC and BC, Delta-C, is an indicator of biomass or residential coal burning and averaged 3.29±4.61µgm-3. An alternative approach uses the Ǻngstrom Exponent (AE) to estimate the biomass/coal and traffic BC concentrations. Biomass/coal burning contributed ~87% and high temperature, fossil-fuel combustion contributed ~13% to the annual average BC concentration. The post-monsoon seasonal mean UVBC values were 10.9µgm-3 and BC of 7.2µgm-3. Potential source contribution function analysis showed that in the post-monsoon season, air masses came from the central and northwestern Indo-Gangetic Plains where there is extensive agricultural burning. The mean winter UVBC and BC concentrations were 15.0 and 10.1µgm-3, respectively. These higher values were largely produced by local sources under poor dispersion conditions. The direct radiative forcing (DRF) due to UVBC and BC at the surface (SUR) and the top of the atmosphere (TOA) were calculated. The mean atmospheric heating rates due to UVBC and BC were estimated to be 1.40°Kday-1 and 1.18°Kday-1, respectively. This high heating rate may affect the monsoon circulation in this region.

Evaluation Of Diffusion-Weighted Imaging And Apparent Diffusion Coefficient Mapping Using Different B-Values For Magnetic Resonanceguided Focused Ultrasound Surgery: A Preliminary Study For Uterine Fibroid And Adenomyoma

The study was taken to assess the feasibility of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping using different b-values for magnetic resonance-guided focused ultrasound (MRgFUS) treatment of uterine fibroid and adenomyoma. The contrast-enhanced T1-weighted image (cT1WI) as well as DWIs and ADC maps of different b-values (i.e. 200, 600 and 800 s/mm2) were obtained from nine fibroid and five adenomyoma patients, immediately after, and 12 months after MRgFUS treatment. The image contrast score, non-perfused volume (NPV) and NPV ratio obtained were compared to determine the feasibility of DWI and ADC mapping for MRgFUS treatment outcome evaluation. Our finding showed thatimmediately after MRgFUS treatment, the DWI acquired using 200 s/mm2 b-value gave the highest image contrast score among all other b-values. The NPV calculated from DWI of 200 s/mm2 showed the best correlation (R2 = 0.938) with post-contrast NPV. At 12 months follow-up, there was no specific b-value considered as significantly superior to others in terms of image contrast. However, the NPVs and NPV ratios obtained from all DWIs and ADC maps of different b-values were in good agreement with the post-contrast NPV and NPV ratio. We observed that the DWI, particularly obtained with a low b-value (i.e. 200 s/mm2), is feasible for delineation and quantitative volumetric evaluation of the ablated region immediately after the MRgFUS treatment. At 12 months follow-up, both DWIs and ADC maps are feasible for NPV and NPV ratio calculation.

Significant cooling effect on the surface due to soot particles over Brahmaputra River Valley region, India: An impact on regional climate.

Black carbon (BC) is an important atmospheric aerosol constituent that affects the climate by absorbing (directly) the sunlight and modifying cloud characteristics (indirectly). Here, we present first time yearlong measurements of BC and carbon monoxide (CO) from an urban location of Guwahati located in the Brahmaputra River valley (BRV) in the northeast region of India from 1st July 2013 to 30th June 2014. Daily BC concentrations varied within the range of 2.86 to 11.56µgm(-3) with an annual average of 7.17±1.89µgm(-3), while, CO varied from 0.19 to 1.20ppm with a mean value of 0.51±0.19ppm during the study period. The concentrations of BC (8.37µgm(-3)) and CO (0.67ppm) were ~39% and ~55% higher during the dry months (October to March) than the wet months (April to September) suggesting that seasonal changes in meteorology and emission sources play an important role in controlling these species. The seasonal ΔBC/ΔCO ratios were highest (lowest) in the pre-monsoon (winter) 18.1±1.4µgm(-3)ppmv(-1) (12.6±2.2µgm(-3)ppmv(-1)) which indicate the combustion of biofuel/biomass as well as direct emissions from fossil fuel during the pre-monsoon season. The annual BC emission was estimated to be 2.72Gg in and around Guwahati which is about 44% lower than the mega city 'Delhi' (4.86Gg). During the study period, the annual mean radiative forcing (RF) at the top of the atmosphere (TOA) for clear skies of BC was +9.5Wm(-2), however, the RF value at the surface (SFC) was -21.1Wm(-2) which indicates the net warming and cooling effects, respectively. The highest RF at SFC was in the month of April (-30Wm(-2)) which is coincident with the highest BC mass level. The BC atmospheric radiative forcing (ARF) was +30.16 (annual mean) Wm(-2) varying from +23.1 to +43.8Wm(-2). The annual mean atmospheric heating rate (AHR) due to the BC aerosols was 0.86Kday(-1) indicates the enhancement in radiation effect over the study region. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) captured the seasonal cycle of observed BC fairly well but underestimated the observed BC during the month of May-August. Model results show that BC at Guwahati is controlled mainly by anthropogenic emissions except during the pre-monsoon season when open biomass burning also makes a similar contribution.

Double blanket effect caused by two layers of black carbon aerosols escalates warming in the Brahmaputra River Valley.

First ever 3-day aircraft observations of vertical profiles of Black Carbon (BC) were obtained during the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) conducted on 30(th) August, 4(th) and 6(th) September 2009 over Guwahati (26° 11'N, 91° 44'E), the largest metropolitan city in the Brahmaputra River Valley (BRV) region. The results revealed that apart from the surface/near surface loading of BC due to anthropogenic processes causing a heating of 2 K/day, the large-scale Walker and Hadley atmospheric circulations associated with the Indian summer monsoon help in the formation of a second layer of black carbon in the upper atmosphere, which generates an upper atmospheric heating of ~2 K/day. Lofting of BC aerosols by these large-scale circulating atmospheric cells to the upper atmosphere (4-6 Km) could also be the reason for extreme climate change scenarios that are being witnessed in the BRV region.

Oxytocin receptors in non-human primate brain visualized with monoclonal antibody.

The identity of putative oxytocin receptors visualized in autoradiographic studies of primate brain is unclear because the ligand used is much less selective in primate than rodent brains. This study tests the feasibility of utilizing a new monoclonal antibody (MoAb) developed against human uterine OTRs to visualize OTRs in primate brain. A block containing ventral hypothalamus of cynomolgus macaque brain, paraformaldehyde, glutaraldehyde-fixed and paraffin-embedded, and positive control tissue (human endometrium) were sectioned at 8 microm and studied with immunohistochemistry. OTRs were located in fibers in septal nucleus and in both cell bodies and fibers of preoptic area. These results indicate that OTRs in primate brain may be visualized with this MoAb, and are located in primate brain sites linked to the regulation of social behavior.

Large-scale expression, refolding, and purification of the catalytic domain of human macrophage metalloelastase (MMP-12) in Escherichia coli.

We have cloned, overexpressed, and purified the catalytic domain (residues Gly106 to Asn268) of human macrophage metalloelastase (MMP-12) in Escherichia coli. This construct represents a truncated form of the enzyme, lacking the N-terminal propeptide domain and the C-terminal hemopexin-like domain. The overexpressed protein was localized exclusively to insoluble inclusion bodies, in which it was present as both an intact form and an N-terminally truncated form. Inclusion bodies were solubilized in an 8 M guanidine-HCl buffer and purified by gel filtration chromatography under denaturing conditions. Partial refolding of the protein by dialysis into a 3 M urea buffer caused selective degradation of the truncated form of the protein, while the intact catalytic domain was unaffected by proteolysis. An SP-Sepharose chromatography step purified the protein to homogeneity and served also to complete the refolding. The purified protein was homogeneous by mass spectrometry and had an activity similar to that of the recombinant enzyme purified from mammalian cells. The protein was both soluble and monodisperse at a concentration of 9 mg/ml. This purification procedure enables the production of 23 mg of protein per liter of E. coli culture and is amenable to large-scale protein production for structural studies.

AP lesions block suppression of estrous behavior, but not estrous cyclicity, in food-deprived Syrian hamsters.

Food deprivation inhibits ovulatory cycles and estrous behavior in Syrian hamsters. Lesions of the area postrema (AP) prevented the suppression of estrous behavior in food-deprived hamsters, but they did not prevent the suppression of estrous cyclicity or the increase in running-wheel activity caused by food deprivation. Food deprivation or treatment with pharmacological inhibitors of glycolysis and fatty acid oxidation decreased estrogen-receptor immunoreactivity (ERIR) in the ventromedial hypothalamus (VMH), increased ERIR in the arcuate nucleus (Arc) and the posterior parvicellular paraventricular nucleus (PaPo), but had no effect on ERIR in the posterodorsal medial amygdala or the anterior parvicellular paraventricular nucleus. Lesions of the AP prevented the food deprivation-induced decrease in VMH ERIR and the increase in Arc ERIR, but they did not prevent the increase in ERIR in the PaPo. Thus, whatever physiological cues are produced by food deprivation, an intact AP is required for their transmission to the neural circuits controlling estrous behavior, VMH ERIR, and Arc ERIR. The AP is not essential for transmission of this information to the neural circuits controlling estrous cyclicity, running-wheel activity, or PaPo ERIR.

Insulin-induced repartitioning of metabolic fuels inhibits hamster estrous behavior: role of area postrema.

Excessive diversion of metabolic fuels away from oxidation and into adipose tissue storage depots, such as underfeeding or extraordinary levels of energy expenditure, can induce nutritional infertility. Treatment with pharmacological doses of insulin reduces metabolic fuel availability and suppresses both ovulatory cyclicity and pulsatile luteinizing hormone release in females of several mammalian species, but little attention has been paid to the effects of insulin treatments on reproductive behaviors. Ovariectomized Syrian hamsters were injected with long-acting insulin every 12 h for 72 h and were prevented from overeating by limiting their intake to approximately 110% of pretreatment levels. When given estradiol and progesterone, insulin-treated hamsters exhibited significantly reduced levels of sexual receptivity compared with saline-treated controls. This insulin-induced inhibition of estrous behavior was prevented by lesions of the area postrema. Insulin treatments also caused changes in the number of detectable estrogen receptor immunoreactive cells in the hypothalamus and preoptic area. Therefore, insulin-induced repartitioning of metabolic fuels induces changes in estrous behavior and neural estrogen receptors that are indistinguishable from those caused by food deprivation, cold exposure, or treatment with metabolic inhibitors.

Leptin facilitates and inhibits sexual behavior in female hamsters.

Food deprivation decreases fertility in female mammals in part by inhibiting sexual behaviors. Genetically obese ob/ob mice, like food-deprived wild-type animals, are also infertile; treatment of ob/ob mice with leptin, the adipocyte-derived protein that they lack, corrects some of their reproductive deficiencies. We tested the hypothesis that leptin treatment would prevent the suppression of sexual receptivity that is caused by food deprivation in female Syrian hamsters. Instead, we found that treatment with murine leptin facilitated female sexual behavior in ad libitum-fed hamsters, but not in food-deprived animals. In food-deprived hamsters, leptin treatment actually intensified the inhibition of lordosis. Food deprivation decreased detectable estrogen receptor immunoreactivity (ERIR) in the ventromedial hypothalamus (VMH), but the leptin-induced changes in female sexual behavior were not accompanied by parallel changes in VMH ERIR. Thus leptin facilitates estrous behavior in hamsters, but it does not overcome the lordosis-inhibiting metabolic cues produced by acute food deprivation. Because circulating leptin levels are directly related to body fat content, an implication of these findings is that elevated levels of adipose tissue could have a positive influence on sexual responsiveness.

Detection of mRNAs for urokinase-type plasminogen activator, its receptor, and type 1 inhibitor in giant cell tumors of bone with in situ hybridization.

Although giant cell tumor of bone (GCT) is generally considered to be an uncommon benign neoplasm, it can pursue an aggressive course with local recurrence and metastasis. Attempts to predict the biological behavior of GCT with histopathological parameters, however, have not been successful. The urokinase-type plasminogen activation system has been implicated in tumor invasion and metastasis and abnormalities of the components of this system have been found in several malignancies. In this study we postulated that the urokinase-type plasminogen activation system associated with bone destruction and local invasion is present in GCT. We therefore evaluated the mRNA levels for urokinase-type plasminogen activator (u-PA), urokinase-type plasminogen activator receptor (u-PAR), and plasminogen activator inhibitor type 1 (PAI-1) by using Northern blot analysis and in situ hybridization in four cases of GCT and spindle-shaped mononuclear cells at the 35th passage from a GCT. Our results showed that giant cell tumors of bone contained variable levels of u-PA, u-PAR, and PAI-1 mRNA, respectively, 2.3, 1.4, and 3.2 kb in size. In situ hybridization showed that u-PA, u-PAR, and PAI-1 mRNA were expressed in both the mononuclear cells and the osteoclast-like giant cells; the signal for u-PA mRNA in the spindle-shaped mononuclear cells was more intense than that in the osteoclast-like multinuclear giant cells. Some spherical mononuclear cells (macrophage-like cells) expressed high levels of PAI-1 mRNA in comparison with the spindle-shaped mononuclear cells. In addition, the 35th passaged spindle-shaped mononuclear cells were used to study the gene expression of u-PA during cell proliferation. The results showed that the level of u-PA mRNA increases after adding 10% fetal calf serum to quiescent cells. The induction was maximal at 16 hours and remained high during 48 hours of treatment. In conclusion, even though osteoclast-like cells are ultimately responsible for the bone resorption of GCT, the mononuclear neoplastic cells of GCT may also be involved in degradation of the extracellular matrix during invasive growth by facilitating the urokinase plasminogen activation system. In addition, our observation of upregulation of u-PA mRNA in spindle-shaped mononuclear cells after serum stimulation indicated that u-PA production may be linked to tumor growth.