The recent Arctic warm period OVERLAND, J. E.; WANG, M.; SALO, S.
Tellus. Series A, Dynamic meteorology and oceanography,
August 2008, Volume:
60, Issue:
4
Journal Article
Peer reviewed
ABSTRACT
Arctic winter, spring and autumn surface air temperature (SAT) anomalies and associated sea level pressure (SLP) fields have decidedly different spatial patterns at the beginning of the 21st ...century (2000–2007) compared to most of the 20th century; we suggest calling this recent interval the Arctic warm period. For example, spring melt date as measured at the North Pole Environmental Observatory (2002–2007) is 7 d earlier than the records from the Russian North Pole stations (1937–1987) and statistically different at the 0.05 level. The 20th century was dominated by the two main climate patterns, the Arctic Oscillation/Northern Annular Mode (AO/NAM) and the Pacific North American‐like (PNA*) pattern. The predominately zonal winds associated with the positive phases of these patterns contribute to warm anomalies in the Arctic primarily over their respective Eastern and Western Hemisphere land areas, as in 1989–1995 and 1977–1987. In contrast, SAT in winter (DJF) and spring (MAM) for 2000–2007 show an Arctic‐wide SAT anomaly of greater than +1.0°C and regional hot spots over the central Arctic of greater than +3.0°C. Unlike the AO and PNA*, anomalous geostrophic winds for 2000–2007 often tended to blow toward the central Arctic, a meridional wind circulation pattern. In spring 2000–2005, these winds were from the Bering Sea toward the North Pole, whereas in 2006–2007 they were mostly from the eastern Barents Sea. A meridional pattern was also seen in the late 1930s with anomalous winter (DJFM) SAT, at Spitzbergen, of greater than +4°C. Both periods suggest natural atmospheric advective contributions to the hot spots with regional loss of sea ice. Recent warm SAT anomalies in autumn are consistent with climate model projections in response to summer reductions in sea ice extent. The recent dramatic loss of Arctic sea ice appears to be due to a combination of a global warming signal and fortuitous phasing of intrinsic climate patterns.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
During the last decade, the southeastern Bering Sea shelf has undergone a warming of ∼3
°C that is closely associated with a marked decrease of sea ice over the area. This shift in the physical ...environment of the shelf can be attributed to a combination of mechanisms, including the presence over the eastern Bering Sea shelf of a relatively mild air mass during the winter, especially from 2000 to 2005; a shorter ice season caused by a later fall transition and/or an earlier spring transition; increased flow through Unimak Pass during winter, which introduces warm Gulf of Alaska water onto the southeastern shelf; and the feedback mechanism whereby warmer ocean temperatures during the summer delay the southward advection of sea ice during winter. While the relative importance of these four mechanisms is difficult to quantify, it is evident that for sea ice to form, cold arctic winds must cool the water column. Sea ice is then formed in the polynyas during periods of cold north winds, and this ice is advected southward over the eastern shelf. The other three mechanisms can modify ice formation and melt, and hence its extent. In combination, these four mechanisms have served to temporally and spatially limit ice during the 5-year period (2001–2005). Warming of the eastern Bering Sea shelf could have profound influences on the ecosystem of the Bering Sea—from modification of the timing of the spring phytoplankton bloom to the northward advance of subarctic species and the northward retreat of arctic species.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Chronic neuropathic pain is known to alter the primary motor cortex (M1) function. Less is known about the normal, physiological effects of experimental neurogenic pain on M1. The objective of this ...study is to determine how short-interval intracortical inhibition (SICI) is altered in the M1 representation area of a muscle exposed to experimental pain compared to SICI of another muscle not exposed to pain. The cortical representation areas of the right abductor pollicis brevis (APB) and biceps brachii (BB) muscles of 11 subjects were stimulated with a multi-locus transcranial magnetic stimulation device while the resulting motor-evoked potentials (MEPs) were recorded with electromyography. Single- and paired-pulse TMS was administered in seven conditions, including one with the right hand placed in cold water. The stimulation intensity for the conditioning pulses in the paired-pulse examination was 80% of the resting motor threshold (RMT) of the stimulated site and 120% of RMT for both the test and single pulses. The paired-pulse MEP amplitudes were normalized with the mean amplitude of the single-pulse MEPs of the same condition and muscle. SICI was compared between conditions. After the cold pain, the normalized paired-pulse MEP amplitudes decreased in APB, but not in BB, indicating that SICI was potentially increased only in the cortical area of the muscle subjected to pain. These data suggest that SICI is increased in the M1 representation area of a hand muscle shortly after exposure to pain has ended, which implies that short-lasting pain can alter the inhibitory balance in M1.
Myocardial ischemia – reperfusion injury Salo, S. V.; Shumakov, V. O.; Shpak, S. S. ...
Zaporozhskiĭ medit͡s︡inskiĭ zhurnal,
10/2023, Volume:
25, Issue:
5
Journal Article
Peer reviewed
Open access
Aim. To summarize and broaden the idea about mechanisms of acute coronary insufficiency development and pathophysiological features of myocardial reperfusion injury.
Today, in the event of acute ...coronary syndrome, according to the latest recommendations for myocardial revascularization, percutaneous coronary intervention should be performed to determine the anatomy of coronary artery lesions and further percutaneous therapy. But in some patients, after blood flow restoration, reperfusion injury occurs, which is primarily related to the duration of ischemia, infarct size, and the myocardial resistance to ischemia.
Treatment of myocardial infarction, like any treatment method, has evolved. In the 60s of the previous century, it included morphine, oxygen, warfarin and bed rest for 4–6 weeks. Then, during the 70s, it consisted of morphine, oxygen, lidocaine, warfarin, bed rest for 2–3 weeks and possibly coronary angiography for the further bypass surgery. The late 1970s saw the rapid progress in thrombolysis, first intravenous and then intracoronary. And starting in the early 1980s, since G. Hartzler performed the first balloon angioplasty for acute coronary artery occlusion, the stage of mechanical myocardial reperfusion has come. At the same time, knowledge about the pathophysiology of acute coronary ischemia was deepened. The World Health Organization developed ECG criteria for acute myocardial infarction using population-based studies in the 1950s–1970s, and additional four normative European regulations since then were issued defining concepts, key points of diagnosis and possible complications of myocardial infarction.
Conclusions. The development of myocardial ischemic-reperfusion injury is a staged process that has a complex pathogenesis, its own clinical manifestations, and an association with more negative long-term outcomes of myocardial infarction treatment. Its main components are myocardial swelling involving cardiomyocytes, endotheliocytes, and the interstitial space; downregulation of cytoskeleton and disruption of sarcolemma integrity; increased vascular wall permeability; spasm of arterioles; intravascular accumulation of platelets and leukocytes, and the resultant the most severe form of myocardial damage is intramyocardial hemorrhage. Clinically, this is manifested by the no-reflow phenomenon following percutaneous coronary intervention.
Winter Water Properties and the Chukchi Polynya Ladd, C.; Mordy, C. W.; Salo, S. A. ...
Journal of geophysical research. Oceans,
August 2016, 2016-08-00, 20160801, Volume:
121, Issue:
8
Journal Article
Peer reviewed
Water properties from moored measurements (2010–2015) near Icy Cape on the eastern Chukchi shelf have been examined in relation to satellite observations of ice cover. Atlantic Water (AW), with ...temperature >−1°C and salinity >33.6, has been observed to upwell from deeper than 200 m in the Arctic Basin onto the Chukchi Shelf via Barrow Canyon. Most previous observations of AW on the Chukchi shelf have been in or near Barrow Canyon; observations of AW farther onto the shelf are rare. Despite mooring location on the shelf ∼225 km from the head of Barrow Canyon, five AW events have been observed at mooring C1 (70.8°N, 163.2°W) in 4 years of data. All but one of the events occurred under openings in the sea‐ice cover (either a polynya or the ice edge). No events were observed during the winter of 2011/2012, a year with little polynya activity in the region. In addition to changes in temperature and salinity, the AW events are typically associated with southwestward winds and currents, changes in sea‐ice cover, and increased nutrient concentrations in the bottom water. Estimates of heat content associated with the AW events suggest that the Chukchi Polynya can often be classified as a hybrid sensible heat/wind‐driven polynya.
Key Points
Upwelled Atlantic Water is observed on the Chukchi Shelf, far from Barrow Canyon
Atlantic Water is often associated with the Chukchi Polynya
Chukchi Polynya can often be classified as a hybrid sensible heat/wind‐driven polynya
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The combination of transcranial magnetic stimulation (TMS) and electroencephalography (EEG) is commonly applied for studying the effective connectivity of neuronal circuits. The stimulation excites ...neurons, and the resulting TMS-evoked potentials (TEPs) are recorded with EEG. A serious obstacle in this method is the generation of large muscle artifacts from scalp muscles, especially when frontolateral and temporoparietal, such as speech, areas are stimulated. Here, TMS–EEG data were processed with the signal-space projection and source-informed reconstruction (SSP–SIR) artifact-removal methods to suppress these artifacts. SSP–SIR suppressed muscle artifacts according to the difference in frequency contents of neuronal signals and muscle activity. The effectiveness of SSP–SIR in rejecting muscle artifacts and the degree of excessive attenuation of brain EEG signals were investigated by comparing the processed versions of the recorded TMS–EEG data with simulated data. The calculated individual lead-field matrix describing how the brain signals spread on the cortex were used as simulated data. We conclude that SSP–SIR was effective in suppressing artifacts also when frontolateral and temporoparietal cortical sites were stimulated, but it may have suppressed also the brain signals near the stimulation site. Effective connectivity originating from the speech-related areas may be studied even when speech areas are stimulated at least on the contralateral hemisphere where the signals were not suppressed that much.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The manifestations of cartilage‐hair hypoplasia (CHH), a metaphyseal chondrodysplasia caused by
RMRP
mutations, include short stature, hypoplastic hair, immunodeficiency and increased risk of ...malignancies. Clinical features show significant variability. We report a patient with normal height until age 12.5 years (−1.6 SDS at 11 years) who was diagnosed with CHH at 14 years.
RMRP
sequencing revealed compound heterozygosity for g.70A>G mutation and a 10‐nucleotide duplication at position −13 (TACTCTGTGA). Through the Finnish Skeletal Dysplasia Register, we identified 3 additional patients with identical genotype. Two of them also showed unusually mild growth failure (height SDS −1.6 at 14 years and −3.0 at 12 years, respectively). Three of the 4 patients suffered from recurrent infections; 1 developed progressive bronchiectasis and another died from aggressive lymphoma. Our findings expand the phenotypic variability in CHH to include normal childhood height. The milder growth retardation related to this particular genotype was not associated with less severe extra‐skeletal manifestations, emphasizing the need for careful follow‐up also in CHH patients with mild‐skeletal manifestations.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
As tautomerism and ionization may significantly change the interaction possibilities between a ligand and a target protein, these phenomena could have an effect on structure-based virtual screening. ...Tautomeric- and protonation-state enumeration ensures that the state with optimal interaction possibilities is included in the screening process, as the predicted state may not always be the optimal binder. However, there is very little information published if tautomer and protomer enumeration actually improves the enrichment of active molecules compared to the alternative of using a predicted form of each molecule. In this study, a retrospective virtual screening was performed using AutoDock on 19 drug targets with a publicly available data set. It is proposed that tautomer and protomer prediction can significantly save computing resources and can yield similar results to enumeration.
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IJS, KILJ, NUK, PNG, UL, UM
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