| 1. |
- Isidor, Marie S., et al.
(författare)
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Pyruvate kinase M2 represses thermogenic gene expression in brown adipocytes
- 2020
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 594:7, s. 1218-1225
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Tidskriftsartikel (refereegranskat)abstract
- Utilizing the thermogenic capacity of brown adipose tissue is a potential anti-obesity strategy; therefore, the mechanisms controlling expression of thermogenesis-related genes are of interest. Pyruvate kinase (PK) catalyzes the last step of glycolysis and exists as four isoenzymes: PK, liver, PK, red blood cell, PK, muscle (PKM1 and PKM2). PKM2 has both glycolytic and nuclear functions. Here, we report that PKM2 is enriched in brown adipose compared with white adipose tissue. Specific knockdown of PKM2 in mature brown adipocytes demonstrates that silencing of PKM2 does not lead to a decrease in PK activity, but causes a robust upregulation of thermogenic uncoupling protein 1 (Ucp1) and fibroblast growth factor 21 (Fgf21) gene expression. This increase is not mediated by any of the known mechanisms for PKM2-regulated gene expression, thus implying the existence of a novel mechanism for PKM2-dependent effects on gene expression.
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| 2. |
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| 3. |
- Ahmed Aamir, Syed, et al.
(författare)
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Frequency compensation of high-speed, low-voltage CMOS multistage amplifiers
- 2013
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Ingår i: IEEE International Symposium on Circuits and Systems (ISCAS), 2013. - : IEEE conference proceedings. - 9781467357609 ; , s. 381-384
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Konferensbidrag (refereegranskat)abstract
- This paper presents the frequency compensation of high-speed, low-voltage multistage amplifiers. Two frequency compensation techniques, the Nested Miller Compensation with Nulling Resistors (NMCNR) and Reversed Nested Indirect Compensation (RNIC), are discussed and employed on two multistage amplifier architectures. A four-stage pseudo-differential amplifier with CMFF and CMFB is designed in a 1.2 V, 65-nm CMOS process. With NMCNR, it achieves a phase margin (PM) of 59° with a DC gain of 75 dB and unity-gain frequency (fug) of 712 MHz. With RNIC, the same four-stage amplifier achieves a phase margin of 84°, DC gain of 76 dB and fug of 2 GHz. Further, a three-stage single-ended amplifier is designed in a 1.1-V, 40-nm CMOS process. The three-stage OTA with RNIC achieves PM of 81°, DC gain of 80 dB and fug of 770 MHz. The same OTA achieves PM of 59° with NMCNR, while maintaining a DC gain of 75 dB and fug of 262 MHz. Pole-splitting, to achieve increased stability, is illustrated for both compensation schemes. Simulations illustrate that the RNIC scheme achieves much higher PM and fug for lower values of compensation capacitance compared to NMCNR, despite the growing number of low voltage amplifier stages.
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| 4. |
- Ali Malik, Muhammad, et al.
(författare)
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Imaging fingerprinting of excitation emission matrices
- 2009
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 635:2, s. 196-201
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Tidskriftsartikel (refereegranskat)abstract
- The spectral fingerprinting of the excitation emission matrix (EEM) of fluorescent substances is demonstrated using polychromatic light sources and tri-chromatic image detectors. A model of the measured fingerprints explaining their features and classification performance, based on the polychromatic excitation of the indicators is proposed.Substantial amount of spectral information is retained in the fingerprints as corroborated by multivariate analysis and experimental conditions that favor such situation are identified.In average, for five different substances, the model shows a fitting goodness measured by the Pearsons r coefficient and the root mean square deviation of 0.8541 and 0.0247 respectively, while principal component classification patterns satisfactorily compare with the EEM spectroscopy classification and respectively explain 96% and 93% of the information in the fist two principal components.The measurements can be performed using regular computer screens as illumination and web cameras as detectors, which constitute ubiquitous and affordable platforms compatible with distributed evaluations, in contrast to regular instrumentation for EEM measurements.
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| 5. |
- Bargues Tobella, Aida
(författare)
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Assessing soil and land health across two landscapes in eastern Rwanda to inform restoration activities
- 2021
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Ingår i: Soil. - : Copernicus GmbH. - 2199-3971 .- 2199-398X. ; 7, s. 767-783
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Tidskriftsartikel (refereegranskat)abstract
- Land degradation negatively impacts water, food, and nutrition security and is leading to increased competition for resources. While landscape restoration has the potential to restore ecosystem function, understanding the drivers of degradation is critical for prioritizing and tracking interventions. We sampled 300–1000 m2 plots using the Land Degradation Surveillance Framework across Nyagatare and Kayonza districts in Rwanda to assess key soil and land health indicators, including soil organic carbon (SOC), erosion prevalence, vegetation structure and infiltration capacity, and their interactions. SOC content decreased with increasing sand content across both sites and sampling depths and was lowest in croplands and grasslands compared to shrublands and woodlands. Stable carbon isotope values (δ13C) ranged from −15.35 ‰ to −21.34 ‰, indicating a wide range of historic and current plant communities with both C3 and C4 photosynthetic pathways. Field-saturated hydraulic conductivity (Kfs) was modeled, with a median of 76 mm h−1 in Kayonza and 62 mm h−1 in Nyagatare, respectively. Topsoil OC had a positive effect on Kfs, whereas pH, sand, and erosion had negative effects. Soil erosion was highest in plots classified as woodland and shrubland. Maps of soil erosion and SOC at 30 m resolution were produced with high accuracy and showed strong variability across the study landscapes. These data demonstrate the importance of assessing multiple biophysical properties in order to assess land degradation, including the spatial patterns of soil and land health indicators across the landscape. By understanding the dynamics of land degradation and interactions between biophysical indicators, we can better prioritize interventions that result in multiple benefits as well as assess the impacts of restoration options.
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| 6. |
- Biswas, Animesh, 1978-, et al.
(författare)
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Rescue and emergency management of a man-made disaster : Lesson learnt from a collapse factory building, Bangladesh
- 2015
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Ingår i: Scientific World Journal. - New York, USA : Hindawi Publishing Corporation. - 2356-6140 .- 1537-744X. ; 2015
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Tidskriftsartikel (refereegranskat)abstract
- A tragic disaster occurred on April 24, 2013, in Bangladesh, when a nine storied building in a suburban area collapsed and killed 1115 people and injured many more. The study describes the process of rescue operation and emergency management services provided in the event. Data were collected using qualitative methods including in-depth interviews and a focus group discussion with the involved medical students, doctors, volunteers, and local people. Immediately after the disaster, rescue teams came to the place from Bangladesh Armed Forces, Bangladesh Navy, Bangladesh Air Force, and Dhaka Metropolitan and local Police and doctors, medical students, and nurses from nearby medical college hospitals and private hospitals and students from colleges and universities including local civil people. Doctors and medical students provided 24-hour services at the disaster place and in hospitals. Minor injured patients were treated at health camps and major injured patients were immediately carried to nearby hospital. Despite the limitations of a low resource setting, Bangladesh faced a tremendous challenge to manage the man-made disaster and experienced enormous support from different sectors of society to manage the disaster carefully and saved thousands of lives. This effort could help to develop a standard emergency management system applicable to Bangladesh and other counties with similar settings. © 2015 Animesh Biswas et al.
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| 7. |
- Bustos, Emil, et al.
(författare)
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Financing Constraints and Risk Management: Evidence From Micro-Level Insurance Data
- 2023
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Ingår i: SSRN Electronic Journal. - Stockholm, Sweden : Swedish House of Finance (SHOF). - 1556-5068.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We study the impact of financing constraints on corporate risk management. Using data on credit scores matched with unique information on firm level commercial insurance purchases, we find that financing constraints lead to higher insurance spending. We adopt a regression discontinuity design and show that financially constrained firms spend 5–14% more on insurance than otherwise similar unconstrained firms. Our findings add new insights to the longstanding empirical puzzle whether financially constrained firms engage more in risk management. Furthermore, our results, shed light on risk management in smaller, mostly private firms.
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| 8. |
- Chowdhary, Ramesh, et al.
(författare)
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Influence of Micro Threads Alteration on Osseointegration and Primary Stability of Implants : An FEA and In Vivo Analysis in Rabbits
- 2015
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Ingår i: Clinical Implant Dentistry and Related Research. - : John Wiley & Sons. - 1523-0899 .- 1708-8208. ; 17:3, s. 562-569
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To describe the early bone tissue response to implants with and without micro threads designed to the full length of an oxidized titanium implant. MATERIALS AND METHODS: A pair of two-dimensional finite element models was designed using a computer aided three-dimensional interactive application files of an implant model with micro threads in between macro threads and one without micro threads. Oxidized titanium implants with (test implants n=20) and without (control implants n=20) micro thread were prepared. A total of 12 rabbits were used and each received four implants. Insertion torque while implant placement and removal torque analysis after 4 weeks was performed in nine rabbits, and histomorphometric analysis in three rabbits, respectively. RESULTS: Finite element analysis showed less stress accumulation in test implant models with 31Mpa when compared with 62.2 Mpa in control implant model. Insertion and removal torque analysis did not show any statistical significance between the two implant designs. At 4 weeks, there was a significant difference between the two groups in the percentage of new bone volume and bone-to-implant contact in the femur (p< .05); however, not in the tibia. CONCLUSIONS: The effect of micro threads was prominent in the femur suggesting that micro threads promote bone formation. The stress distribution supported by the micro threads was especially effective in the cancellous bone.
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| 9. |
- Das, Satyajit, et al.
(författare)
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Interlocked structures on active duty
- 2023
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Ingår i: Nature Chemistry. - : Springer Nature. - 1755-4330 .- 1755-4349. ; 15:2, s. 160-162
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Tidskriftsartikel (refereegranskat)abstract
- Interlocking macrocyclic carbon nanomaterials is an exciting way to tune their molecular properties, but all-conjugated catenanes and rotaxanes are extremely challenging to make. Now, fully π-conjugated [2]- and [3]catenanes as well as a [3]rotaxane have been prepared through an ‘active metal template’ approach.
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| 10. |
- Desai, A., et al.
(författare)
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Probing the EBL Evolution at High Redshift Using GRBs Detected with the Fermi-LAT
- 2017
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 850:1
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Tidskriftsartikel (refereegranskat)abstract
- The extragalactic background light (EBL), from ultraviolet to infrared wavelengths, is predominantly due to emission from stars, accreting black holes and reprocessed light due to Galactic dust. The EBL can be studied through the imprint it leaves, via gamma-gamma absorption of high-energy photons, in the spectra of distant.-ray sources. The EBL has been probed through the search for the attenuation it produces in the spectra of BL Lacertae (BL Lac) objects and individual.-ray bursts (GRBs). GRBs have significant advantages over blazars for the study of the EBL especially at high redshifts. Here we analyze a combined sample of 22 GRBs, detected by the Fermi Large Area Telescope between 65 MeV and 500 GeV. We report a marginal detection (at the similar to 2.8 sigma level) of the EBL attenuation in the stacked spectra of the source sample. This measurement represents a first constraint of the EBL at an effective redshift of similar to 1.8. We combine our results with prior EBL constraints and conclude that Fermi-LAT is instrumental to constrain the UV component of the EBL. We discuss the implications on existing empirical models of EBL evolution.
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