Ocean tidal currents, water waves and thermal gradients are a great source of renewable energy. Ocean tidal, osmotic, wave and thermal sources have annual potentials of 800, 2,000, 8000–80,000 and ...10,000–87,600TWh, which are more than global 16,000TWh/y electricity demand. Ocean wave generators produce relatively lower output, however, four to eleven meters tidal range stations have large power generation capacities. Abundant ocean heat energy potentially harvested using ocean thermal energy conversion (OTEC) devices and ocean thermo-electric generators (OTEG). Tidal stations may be tidal range or current types, but a wave energy converter (WEC) may be an oscillating water column (OWC), overtopping, heaving, pitching and surging devices. Ocean thermal energy can be harnessed by open, close Rankine cycles, thermo-electric generators and osmotic power plants. Large bays like Turnagain (USA), Annapolis/Minas Passage (Canada), Seven Barrages/Pentland Firth (UK), La Rance (France), Garorim (South Korea) and Mezen/Penzhin (Russia) have huge tidal current power generation capacities. Power Potential from tidal current stations is more than WEC devices which in turn is more than osmotic, OTEC and OTEG technologies. This paper reviews the current state-of-the-art of tidal, wave, OTEC and OTEG ocean energy technologies.
Fasciolosis an economically important global disease of ruminants in the temperate and tropical regions, caused by Fasciola hepatica and F. gigantica, respectively, also poses a potential zoonotic ...threat. In India alone it causes huge losses to stakeholders. Anthelmintics including triclabendazole have been used to control this menace but the emerging resistance against the available compounds necessitates identification of novel and alternative therapeutic measures involving plant derived natural compounds for their anthelmintic potential. Thymoquinone (T) and curcumin (C), the active ingredients of Nigella sativa and Curcuma longa respectively have been used as antiparasitic agents but the information on their flukicidal effect is very limited. Adult flukes of F. gigantica were in vitro exposed to different concentrations of thymoquinone and curcumin separately for 3h at 37+ 1°C. A significant (p<0.05) reduction in the worm motility at 60 μM concentration of both T and C was observed though all the worms remained alive after 3h exposure, whereas the effect on egg shedding was statistically insignificant. Pronounced tegumental disruptions and erosion of spines in the posterior region and around the acetabulum was evident. A significant (p<0.05) decrease in glutathione-S-transferase and superoxide dismutase activity and reduced glutathione (GSH) level was observed, while protein carbonylation increased differentially. A significant inhibition of CathepsinL (CatL) gene expression in thymoquinone treated worms was also evident. Further, in silico molecular docking of T and C with CatL revealed a stronger interaction of curcumin with the involvement of higher number of amino acids as compared to thymoquinone that could be more effective in inhibiting the antioxidant enzymes of F. gigantica. It is concluded that both the compounds understudy will decrease the detoxification ability of F. gigantica, while inhibition of CatL will significantly affect their virulence potential. Thus, both thymoquinone and curcumin appeared to be promising anthelmintic compounds for further investigations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The gut microbiome is well recognized to have a pivotal role in regulation of the health and behaviour of the host, affecting digestion, metabolism, immunity, and has been linked to changes in bones, ...muscles and the brain, to name a few. However, the impact of microgravity environment on gut bacteria is not well understood. In space environments, astronauts face several health issues including stress, high iron diet, radiation and being in a closed system during extended space missions. Herein, we discuss the role of gut bacteria in the space environment, in relation to factors such as microgravity, radiation and diet. Gut bacteria may exact their effects by synthesis of molecules, their absorption, and through physiological effects on the host. Moreover we deliberate the role of these challenges in the dysbiosis of the human microbiota and possible dysregulation of the immune system.
A
bstract
We explore the possibility of relating extra dimensions with light and heavy Dirac-type neutral leptons and develop a framework for testing them in various laboratory experiments. The ...Kaluza-Klein modes in the large extra dimension models of the light neutral leptons could mix with the standard model neutrinos and produce observable effects in the oscillation experiments. We show that the chirality flipping up-scattering processes occurring through either neutrino magnetic dipole moment or the weakly coupled scalar interactions can also produce heavy Kaluza-Klein modes of the corresponding right-handed neutral leptons propagating in one or more extra dimensions. However, to conserve the four- dimensional energy-momentum, their masses must be below the maximum energy of the neutrinos in the initial state. The appreciable size of extra dimensions connected with these heavy neutral leptons can thus affect the cross-sections of these processes. This framework applies to any up-scattering process. Our work here focuses only on its application to the coherent elastic neutrino-nucleus scattering process. We derive constraints on the size of extra dimensions using the COHERENT data in oscillation and up-scattering processes. For model with one large extra dimension for the light neutral leptons, we obtain the limits,
R
~ 3
μ
m (NH) and
R
~ 2
.
5
μ
m (IH), on the size of extra dimension corresponding to the absolute mass limit,
m
0
≤ 3 × 10
−
3
eV at 90% C.L. from the short-baseline oscillations. Using the up-scattering process for heavy neutral leptons, we obtain new parameter spaces between the size of extra dimensions and parameters of the dipole or scalar interactions.
Mangroves under sea level rise
The rate of sea level rise has doubled from 1.8 millimeters per year over the 20th century to ∼3.4 millimeters per year in recent years. Saintilan
et al.
investigated ...the likely effects of this increasing rate of rise on coastal mangrove forest, a tropical ecosystem of key importance for coastal protection (see the Perspective by Lovelock). They reviewed data on mangrove accretion 10,000 to 7000 years before present, when the rate of sea level rise was even higher than today as a result of glacial ice melt. Their analysis suggests an upper threshold of 7 millimeters per year as the maximum rate of sea level rise associated with mangrove vertical development, beyond which the ecosystem fails to keep up with the change. Under projected rates of sea level rise, they predict that a deficit between accretion and sea level rise is likely to commence in the next 30 years.
Science
, this issue p.
1118
; see also p.
1050
Mangrove response to sea level rise in the final stages of deglaciation reveals survival thresholds that may be exceeded within 30 years.
The response of mangroves to high rates of relative sea level rise (RSLR) is poorly understood. We explore the limits of mangrove vertical accretion to sustained periods of RSLR in the final stages of deglaciation. The timing of initiation and rate of mangrove vertical accretion were compared with independently modeled rates of RSLR for 78 locations. Mangrove forests expanded between 9800 and 7500 years ago, vertically accreting thick sequences of organic sediments at a rate principally driven by the rate of RSLR, representing an important carbon sink. We found it very likely (>90% probability) that mangroves were unable to initiate sustained accretion when RSLR rates exceeded 6.1 millimeters per year. This threshold is likely to be surpassed on tropical coastlines within 30 years under high-emissions scenarios.
We perform a constrained spectral fit analysis of the excess observed in the electron recoil energy spectrum by XENON1T with neutrino magnetic moment, charge radius, neutrino millicharge and new ...light vector and scalar mediators. Within limits allowed by other laboratory experiments we find that the excess can be explained in the range (2−4)×10−11μB for the magnetic moment, (2−6)×10−31 cm2 for the charge radius, (1.7−2.3)×10−12e for the millicharge and (10−100) keV masses of light mediators with couplings of 3.5×10−7 for vector/axial-vector, 1×10−6 and 4×10−6 for scalar and pseudo-scalar mediators respectively. Among all neutrino millicharge, magnetic moment and vector mediators fit better to the observed spectrum. We also derive constraints on all new physics parameters considered here.
Antifreeze proteins (AFPs) inhibit ice growth by adsorbing onto specific ice planes. Microbial AFPs show diverse antifreeze activity and ice plane specificity, while sharing a common molecular ...scaffold. To probe the molecular mechanisms responsible for AFP activity, we here characterized the antifreeze activity and crystal structure of TisAFP7 from the snow mold fungus Typhula ishikariensis. TisAFP7 exhibited intermediate activity, with the ability to bind the basal plane, compared with a hyperactive isoform TisAFP8 and a moderately active isoform TisAFP6. Analysis of the TisAFP7 crystal structure revealed a bound-water network arranged in a zigzag pattern on the surface of the protein's ice-binding site (IBS). While the three AFP isoforms shared the water network pattern, the network on TisAFP7 IBS was not extensive, which was likely related to its intermediate activity. Analysis of the TisAFP7 crystal structure also revealed the presence of additional water molecules that form a ring-like network surrounding the hydrophobic side chain of a crucial IBS phenylalanine, which might be responsible for the increased adsorption of AFP molecule onto the basal plane. Based on these observations, we propose that the extended water network and hydrophobic hydration at IBS together determine the TisAFP activity.
Techno-economic performance comparison of compact fluorescent lamps (CFL) with light emitting diodes (LED), electrode less fluorescent lamps (EEFL), fluorescent tubes, incandescent bulbs, ...photovoltaic (PV) and fiber optic lighting systems was carried out in view of worsening power and energy crisis in Pakistan. Literature survey showed 23W CFL, 21W EEFL, 18W fluorescent tube or 15W LED lamps emit almost same quantity of luminous flux (lumens) as a standard 100W incandescent lamp. All inclusive, operational costs of LED lamps were found 1.21, 1.62. 1.69, 6.46, 19.90 and 21.04 times lesser than fluorescent tubes, CFL, EEFL, incandescent bulbs, fiber optic solar lighting and PV systems, respectively. However, tubes, LED, CFL and EEFL lamps worsen electric power quality of low voltage networks due to high current harmonic distortions (THD) and poor power factors (PF). Fluorescent lamps emit UV and pollute environment by mercury and phosphors when broken or at end of their life cycle. Energy consumption, bio-effects, and environmental concerns prefer LED lamps over phosphor based lamps but power quality considerations prefer EEFL. CFL and EEFL manufacturers claim operating temperatures in range of −20°C<TCFL<60°C and −30°C<TCFL<50°C but CFL frequently damage in wet and damp locations. Costs of low THD and high PF CFL, EEFL and LED lamps may be five to ten times higher that high THD and low PF lamps. Choice of a lamp depends upon its current THD, PF, life span, energy consumption, efficiency, efficacy, color rendering index (CRI) and associated physical effects. This work proposes manufacturing and user level innovations to get rid of low PF problems. Keeping in view downside of phosphor based lamps our research concludes widespread adoption of LED lamps. Government and commercial buildings may consider full spectrum hybrid thermal photovoltaic and solar fiber optic illumination systems.
Multidrug-resistant (MDR) bacteria have become a severe threat to community wellbeing. Conventional antibiotics are getting progressively more ineffective as a consequence of resistance, making it ...imperative to realize improved antimicrobial options. In this review we emphasized the microorganisms primarily reported of being resistance, referred as ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacteriaceae) accentuating their capacity to "escape" from routine antimicrobial regimes. The upcoming antimicrobial agents showing great potential and can serve as alternative therapeutic options are discussed. We also provided succinct overview of two evolving technologies; specifically network pharmacology and functional genomics profiling. Furthermore, In vivo imaging techniques can provide novel targets and a real time tool for potential lead molecule assessment. The employment of such approaches at prelude of a drug development process, will enables more informed decisions on candidate drug selection and will maximize or predict therapeutic potential before clinical testing.
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