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•Long- term trends in fog occurrence at 12 Czech sites in 1961–2018 analysed using GAM.•Non-linear behaviour for both year-to-year trends and annual seasonality confirmed.•Significant ...decreasing trends detected though pattern differed among individual sites.•Significant seasonality in fog occurrence though pattern differed among individual sites.•Fog’s seasonal profile at some sites has deformed substantially over the long term.
Fog is a very important and complex atmospheric phenomenon of the utmost importance for the environment and for human society. For practical reasons, fog occurrence is observed regularly at meteorological stations worldwide. Decreasing trends in fog frequency reported from numerous regions have been often associated with either decreasing pollution or climate change, including increasing temperature and changes in atmospheric circulation.
We have examined the data on fog occurrence from twelve Czech sites representing different environments (urban, rural, mountain), geographical areas, and altitudes across the country. For our analysis we used long-term records from the time period of 1961–2018, covering both the ambient air’s heavily polluted periods of the 1970s and 1980s and the cleaner period, following the adoption of new, more stringent legislation and effective countermeasures after the 1990s. We applied a generalised additive model (GAM) framework as a flexible, semiparametric regression approach to address nonlinear trend shapes in a formalised and unified way. In particular, we employed a penalised spline approach with cross-validated penalty coefficient estimation.
Our study confirmed non-linear behaviour for both year-to-year trends and annual seasonality. Our results showed further that over the analysed, almost sixty-year period, fog occurrence has decreased significantly at all the examined sites, though the pattern of the long-term change differed among individual sites. Moreover, we have found significant seasonality in fog occurrence, though it is different at individual sites. Furthermore, apart from the overall annual fog probability change over the years, at some sites the fog’s seasonal profile has also deformed substantially over the long term.
ABSTRACT
We present highly resolved and sensitive imaging of the five nearby massive spiral galaxies (with rotation velocities $\rm \gt 300\, km\, s^{-1}$) observed by the UltraViolet Imaging ...Telescope onboard India’s multiwavelength astronomy satellite ASTROSAT, along with other archival observations. These massive spirals show a far-ultraviolet star formation rate in the range of ∼ 1.4 – 13.7 ${\rm M}_{\odot } \, \mathrm{yr}^{-1}$ and fall in the ‘Green Valley’ region with a specific star formation rate within ∼ 10−11.5 – 10−10.5 yr−1. Moreover, the mean star formation rate density of the highly resolved star-forming clumps of these objects is in the range 0.011 – 0.098 ${\rm M}_{\odot }\, \mathrm{ yr}^{-1}\, \mathrm{kpc}^{-2}$, signifying localized star formation. From the spectral energy distributions, under the assumption of a delayed star formation model, we show that the star formation of these objects had peaked in the period of ∼ 0.8 – 2.8 Gyr after the ‘Big Bang’ and the object that has experienced the peak sooner after the ‘Big Bang’ show relatively less star-forming activity at z ∼ 0 and falls below the main-sequence relation for a stellar content of $\rm \gtrsim 10^{11} \, {\rm M}_{\odot }$. We also show that these objects accumulated much of their stellar mass in the early period of evolution with ∼ 31 – 42 per cent of the total stellar mass obtained in a time of (1/16) – (1/5)th the age of the Universe. We estimate that these massive objects convert their halo baryons into stars with efficiencies falling between ∼ 7 and 31 per cent.
Yemen is the dark horse of the Middle East. Every so often it enters the headlines for one alarming reason or another-links with al-Qaeda, kidnapped Westerners, explosive population growth-then sinks ...into obscurity again. But, as Victoria Clark argues in this riveting book, we ignore Yemen at our peril. The poorest state in the Arab world, it is still dominated by its tribal makeup and has become a perfect breeding ground for insurgent and terrorist movements.
Clark returns to the country where she was born to discover a perilously fragile state that deserves more of our understanding and attention. On a series of visits to Yemen between 2004 and 2009, she meets politicians, influential tribesmen, oil workers and jihadists as well as ordinary Yemenis. Untangling Yemen's history before examining the country's role in both al-Qaeda and the wider jihadist movement today, Clark presents a lively, clear, and up-to-date account of a little-known state whose chronic instability is increasingly engaging the general reader.
Luminous X-ray gas coronae in the dark matter halos of massive spiral galaxies are a fundamental prediction of structure formation models, yet only a few such coronae have been detected so far. In ...this paper, we study the hot X-ray coronae beyond the optical disks of two "normal" massive spirals, NGC 1961 and NGC 6753. Based on XMM-Newton X-ray observations, hot gaseous emission is detected to ~60 kpc-well beyond their optical radii. The hot gas has a best-fit temperature of kT ~ 0.6 keV and an abundance of ~0.1 Solar, and exhibits a fairly uniform distribution, suggesting that the quasi-static gas resides in hydrostatic equilibrium in the potential well of the galaxies. To this end, the observations are confronted with the moving mesh code arepo and the smoothed particle hydrodynamics code gadget. With the further advance of numerical models, the present observations will be essential in constraining the feedback effects in structure formation simulations.
In this courageous and captivating autobiography, Mór vividly captures his early experiences of dissociation from his true existence - a common reaction by children suffering from repeated abuse. The ...path towards discovering his true identity and accepting himself takes him on a spiritual pilgrimage ending in the revelation of love and acceptance.
Invasive Cronobacter infections among infants are associated with severe neurologic disabilities and death. Early Cronobacter reports typically featured hospitalized and preterm infants and ...recognized contaminated powdered infant formula (PIF) as a transmission vehicle. To clarify recent epidemiology, we reviewed all cases of bloodstream infection or meningitis among infants that were reported to the Centers for Disease Control and Prevention and in the literature (1961–2018; n = 183). Most infants were neonates (100/150 67%); 38% (42/112) died, and 79% (81/102) had reported recent PIF consumption. In the final quarter of the study period (2004–2018), case counts were significantly higher (global average 8.7 cases/year); among US cases, significantly higher proportions occurred among full-term (56% 27/48) and nonhospitalized (78% 42/54) infants. PIF contamination, most commonly from opened containers, was identified in 30% (21/71) of investigations. Our findings reaffirm the need to promote safer alternatives for infant feeding, particularly among neonates.
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