Search results for "NORTHERN"

Ruiša pūķgalve Latvijas Universitātes Muzeja herbārijā

2020

Par Gada augu 2020 tika izvēlēts Latvijas aizsargājamais augs ruiša pūķgalve, ko Latvijā pirmo reizi atradis dabaspētnieks Eduards Lēmanis (1841 – 1902) 1883. gadā Antonopolē. Tas kopā ar citiem ruiša pūķgalves herbārija paraugiem glabājas Latvijas Universitātes Muzeja Botānikas un mikoloģijas kolekcijās. Tie ir gan Latvijā, gan Igaunijā ievākti eksemplāri laika posmā no 1848. līdz 1977. gadam.

Dracocephalum ruyschiana L. (pie Prensas (Antonopole))

1883

Nordischer Drachenkopf: Heidekieferwald bei Presna (Antonopol); Lichte Waldhange bei Nummern (1888.10.07.) /// Ruiša pūķgalve; Atradne: viršu priežu mežs pie Prensas (Antonopole); gaiša meža nogāze pie Numernes. /// Northern Dragon-head, deposit: heather pine forest near Prensa (Antonopole); a bright forest slope near Numerne. [Attēls no LU Muzeja kolekcijas Herbarium Latvicum (RIG II); (BOT1029_21)]

Dexamethasone modulates α2-macroglobulin and apolipoprotein E gene expression in cultured rat liver fat-storing (Ito) cells

1991

Fat-storing (Ito) cells are perisinusoidal liver cells thought to play a central role in vitamin A metabolism and fibrogenesis. Glucocorticoids have been shown to be beneficial in the treatment of certain types of liver diseases by delaying the development of cirrhosis. To study the regulatory effects of dexamethasone on Ito cell gene expression, Ito cells were isolated from normal rat liver and primary cultures were established. The effect of dexamethasone on the synthesis of α2-macroglobulin, apolipoprotein E, fibronectin and actin was examined. Protein synthesis was studied both at the protein level and at the RNA level by means of biosynthetic labeling, immunoprecipitation followed by s…

Transitions in Herd Management of Semi-Domesticated Reindeer in Northern Finland

2008

In northern Finland, reindeer-herd management has experienced two major transitions: extensification of intensive herding, and development of supplementary/corral feeding in winter. The transitions were studied in six herding associations in different parts of the Finnish reindeer management area. It was suggested that intensive herding turns into more extensive forms as the reasons for intensive herding (predation, reindeer disappearing to foreign areas, protection of agricultural fields) gradually ceased to exist. The results of the study, based on interviews of elderly reindeer herders, were variable. In the three southern areas intensive herding changed to the free ranging system at the…

A 45-year sub-annual reconstruction of seawater temperature in the Bay of Brest, France, using the shell oxygen isotope composition of the bivalve Gl…

2020

A reconstruction of sea surface temperature (SST) spanning 45 years (1966–2011) was developed from δ18O obtained from the aragonitic shells of Glycymeris glycymeris, collected from the Bay of Brest, France. Bivalve sampling was undertaken monthly between 2014 and 2015 using a dredge. In total, 401 live specimens and 243 articulated paired valves from dead specimens were collected, of which 24 individuals were used to reconstruct SST. Temperatures determined using the palaeotemperature equation of Royer et al. compared well with observed SST during the growing season between 1998 and 2010 (Pearson’s correlation: p = 0.002, r = 0.760). Furthermore, a significant negative correlation was foun…

2017

Ranking among the largest volcanic eruptions of the Common Era (CE), the ‘Millennium Eruption’ of Changbaishan produced a widely-dispersed tephra layer (known as the B-Tm ash), which represents an important tie point for palaeoenvironmental studies in East Asia. Hitherto, there has been no consensus on its age, with estimates spanning at least the tenth century CE. Here, we identify the cosmogenic radiocarbon signal of 775 CE in a subfossil larch engulfed and killed by pyroclastic currents emplaced during the initial rhyolitic phase of the explosive eruption. Combined with glaciochemical evidence from Greenland, this enables us to date the eruption to late 946 CE. This secure date rules out…

Pullneyocoris dentatus gen. et sp. nov. (Hemiptera: Pentatomoidea: Cydnidae), the third representative of the subfamily Amnestinae from mid-Cretaceou…

2020

Abstract A new genus and species of burrower bug, Pullneyocoris dentatus gen. et sp. nov. (Hemiptera: Cydnidae: Amnestinae), is described from amber of northern Myanmar. It is the third representative of this family known from Burmese amber, and besides its autapomorphies, it presents a mixture of characters relevant to the extant Parachilocoris Horvath, 1919 and Pullneya Horvath, 1919. A comparison of this new genus to the two genera already described from the burmite, i.e. Chilamnestocoris Lis J.A., Lis. B. & Heiss, 2018, and Punctacorona Wang, Du, Yao & Ren, 2019 is also provided.

Galactic Cosmic-Ray Anisotropy in the Northern hemisphere from the ARGO-YBJ Experiment during 2008-2012

2018

This paper reports on the observation of the sidereal large-scale anisotropy of cosmic rays using data collected by the ARGO-YBJ experiment over 5 years (2008-2012). This analysis extends previous work limited to the period from 2008 January to 2009 December, near the minimum of solar activity between cycles 23 and 24. With the new data sample, the period of solar cycle 24 from near minimum to maximum is investigated. A new method is used to improve the energy reconstruction, allowing us to cover a much wider energy range, from 4 to 520 TeV. Below 100 TeV, the anisotropy is dominated by two wide regions, the so-called “tail-in” and “loss-cone” features. At higher energies, a dramatic change…

Computation of anthropogenic sulphate aerosol forcing using radiative perturbation theory

1994

The radiative forcing of the climate by anthropogenic aerosols has been a matter of some concern for many years now, especially in the northern hemisphere. Recently in these pages, Charlson et al. attempted to quantify this forcing. However, that calculation involved relatively crude optical and radiative transfer models. In this paper, we use a far more detailed sulphate optical model, and employ radiative perturbation theory (a technique ideally suited to answering questions of this sort) to repeat this radiation calculation. We obtain results which are similar to Charlson et al., provided that proper allowance is made for the effects of humidity. DOI: 10.1034/j.1600-0889.1994.00003.x

The future of paleoclimate

2021

Our understanding of natural climate variability rapidly declines over the Common Era (CE) as the pre-instrumental temperature amplitude differs substantially among large-scale reconstructions. Highlighting such differences and emphasizing paleoclimatic findings is crucial for placing anthropogenic climate change in a long-term context. We argue that more proxy records are needed to accurately reconstruct first millennium CE temperature variability and value regional studies producing such data.