611 research outputs found
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Infrared absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison between experiment and theory
Experimentally and theoretically determined infrared spectra are reported for a series of straight-chain perfluorocarbons: C2F6, C3F8, C4F10, C5F12, C6F14, and C8F18. Theoretical spectra were determined using both density functional (DFT) and ab initio methods. Radiative efficiencies (REs) were determined using the method of Pinnock et al. (1995) and combined with atmospheric lifetimes from the literature to determine global warming potentials (GWPs). Theoretically determined absorption cross sections were within 10% of experimentally determined values. Despite being much less computationally expensive, DFT calculations were generally found to perform better than ab initio methods. There is a strong wavenumber dependence of radiative forcing in the region of the fundamental C-F vibration, and small differences in wavelength between band positions determined by theory and experiment have a significant impact on the REs. We apply an empirical correction to the theoretical spectra and then test this correction on a number of branched chain and cyclic perfluoroalkanes. We then compute absorption cross sections, REs, and GWPs for an additional set of perfluoroalkenes
Health-seeking behaviours of older black women living with non-communicable diseases in an urban township in South Africa
BACKGROUND: Various studies have shown that non-communicable diseases (NCDs) especially diabetes and
hypertension are prevalent among older women living in South African urban areas, placing a heavy burden on
the healthcare system. This study aimed to understand the health-seeking behaviour, healthcare practices and
prevalence of traditional herbal medicine (THM) use among older women self-reporting NCDs from the
Prospective Urban Rural Epidemiology study (PURE).
METHOD: A homogenous purposive sampling of PURE participants was used to recruit women who were
50 years or older (n = 250). Descriptive statistics were used to examine the number of NCDs reported by the
study sample, health seeking behaviour and practices as well as THM use. Logistic regression was also employed
to investigate possible associations between reported conditions and THM use or medical pluralism.
RESULTS: Within the study sample, 72 % self-reported an NCD. Of those with self-reported NCDs, 46 % had one,
and 54 % had two or more NCDs. Those with NCDs usually visited public clinics (80 %), relied on doctors (90 %)
and nurses (85 %) for health information, and mostly used conventional medicine (CM) to manage high blood
pressure (81 %). About 30 % of those with NCDs indicated using THM, of whom 29 (53 %) reported practicing
medical pluralism. Participants with dental problems (OR: 3.24, 95 % CI: 1.30–8.20), headaches (OR: 2.42, 95 % CI:
1.24–4.94), heart burn (OR: 2.30, 95 % CI: 1.18–4.48) and severe tiredness (OR: 2.05, 95 % CI: 1.08–3.99) were more
likely to use THM. Anxiety and allergies increased the likelihood to practise medical pluralism by five and 20 times,
respectively.
CONCLUSION: Self-reported NCD with co-morbidities was prevalent among the participants in the study. Most of the
study participants utilized state-owned clinics and hospitals for the management of their chronic conditions. THM use
was not very common. However, among those who used THM, medical pluralism was prevalent. Family history was the
most common reason for THM use, with many THM patrons utilizing these for treatment of a health condition. Older
black women with anxiety and allergies were more likely to practise medical pluralism
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Implementation of U.K. Earth system models for CMIP6
We describe the scientific and technical implementation of two models for a core set of
experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6).
The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the
Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to
HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data)
and initial conditions.We outline the scientific rationale and assumptions made in specifying these.
Notable details of the implementation include an ozone redistribution scheme for prescribed ozone
simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use
change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in
the simulation of background natural vegetation.We discuss the implications of these decisions for
interpretation of the simulation results. These simulations are expensive in terms of human and CPU
resources and will underpin many further experiments; we describe some of the technical steps taken to
ensure their scientific robustness and reproducibility
Groundwater resources in the Indo-Gangetic Basin : resilience to climate change and abstraction
Groundwater within the Indo‐Gangetic Basin (IGB) alluvial aquifer system forms one of the
world’s most important and heavily exploited reservoirs of freshwater. In this study we
have examined the groundwater system through the lens of its resilience to change – both
from the impact of climate change and increases in abstraction. This has led to the
development of a series of new maps for the IGB aquifer, building on existing datasets held
in Pakistan, India, Nepal and Bangladesh, a review of approximately 500 reports and papers,
and three targeted field studies on under‐researched topics within the region. The major
findings of the study are described below.
The IGB groundwater system
1. The IGB alluvial aquifer system comprises a large volume of heterogeneous
unconsolidated sediment in a complex environmental setting. Annual rainfall varies
from 2000mm in the Bengal basin, and the
system is dissected by the major river systems of the Indus, Ganges and Brahmaputra.
The groundwater system has been modified by the introduction of large scale canal
irrigation schemes using water from the Indus and Ganges since the 19th and early 20th
centuries.
2. High yielding tubewells can be sustained in most parts of the alluvial aquifer system;
permeability is often in the range of 10 – 60 m/d and specific yield (the drainable
porosity) varies from 5 – 20%, making it highly productive.
3. High salinity and elevated arsenic concentrations exist in parts of the basin limiting the
usefulness of the groundwater resource. Saline water predominates in the Lower Indus,
and near to the coast in the Bengal Delta, and is also a major concern in the Middle
Ganges and Upper Ganges (covering much of the Punjab Region in Pakistan, southern
Punjab, Haryana and parts of Uttar Pradesh in India). Arsenic severely impacts the
development of shallow groundwater in the fluvial influenced deltaic area of the Bengal
Basin.
4. Recharge to the IGB aquifer system is substantial and dynamic, controlled by monsoonal
rainfall, leakage from canals, river infiltration and irrigation returns. Recharge from
rainfall can occur even with low annual rainfall (350 mm) and appears to dominate
where rainfall is higher (> 750 mm). Canal leakage is also highly significant and
constitutes the largest proportion of groundwater recharge in the drier parts of the
aquifer, partially mitigating the effects of abstraction on groundwater storage.
5. Deep groundwater (>150 m) in the Bengal basin has strategic value for water supply,
health and economic development. Excessive abstraction poses a greater threat to the
quality of this deep groundwater than climate change. Heavy pumping may induce the
downward migration of arsenic in parts of Bangladesh, and of saline water in coastal
regions, but field evidence and modelling both suggest that deep groundwater
abstraction for public water supply in southern Bangladesh is in general secure against
widespread ingress of arsenic and saline water for at least 100 years
Civilizational Values of the Armenian Society in Response to the Global Challenges of Human Civilization
At the present stage of world globalization processes, universal human values, consisting of a multitude of national values, are becoming especially important. The territory and population, the state and economy, social, public and cultural spheres of life are national values of the Armenians, and their preservation and development are the most important prerequisites for national security, both in their homeland and in the Diaspora. A particularly significant role in the permanent process of ensuring the necessary conditions for the national security of the Armenian people and Armenian statehood, in the most complicated and contradictory conditions of the globalization in the III millennium, is to be played by young people who constitute the active and creative core of nowadays society. The young generation, being the main heir to the centuries-old culture, is designed to preserve the values and traditions of the Armenian civilization and, thus, ensure the future path of the Armenian people in history
Reproductive aspects of the oceanic whitetip shark, Carcharhinus longimanus (Elasmobranchii: Carcharhinidae), in the equatorial and southwestern Atlantic Ocean
The present study sought to study the reproductive biology of the oceanic whitetip shark, Carcharhinus longimanus, in the equatorial and southwestern Atlantic Ocean. A total of 234 specimens were collected as bycatch during pelagic longline fisheries targeting tunas and swordfish, between December 2003 and December 2010. The fishing area was located between latitudes 10N and 35S and longitudes 3E and 40W. Of the 234 individuals sampled, 118 were females (with sizes ranging from 81 to 227 cm TL, total length) and 116 males (ranging from 80 to 242 cm TL). The reproductive stages of the females were classed as immature, mature, preovulatory and pregnant, while males were divided into immature, maturing and mature. The size at maturity for females was estimated at 170.0 cm TL, while that for males was between 170.0 and 190.0 cm TL. Ovarian fecundity ranged from 1 to 10 follicles and uterine fecundity from 1 to 10 embryos. The reproductive cycle of this species is most likely biennial, with parturition occurring once every two years.info:eu-repo/semantics/publishedVersio
Medial Prefrontal Cortex to Nucleus Reuniens Circuit Is Critical for Performance in an Operant Delayed Nonmatch to Position Task
Working memory refers to the temporary retention of a small amount of information used in the execution of a cognitive task. The prefrontal cortex and its connections with thalamic subregions are thought to mediate specific aspects of working memory, including engaging with the hippocampus to mediate memory retrieval. We used an operant delayed-non match to position task, which does not require the hippocampus, to determine roles of the rodent medial prefrontal cortex (mPFC), the nucleus reuniens thalamic region (RE), and their connection. We found that transient inactivation of the mPFC and RE using the GABA-A agonist muscimol led to a delay-independent reduction in behavioral performance in the delayed non-match to position paradigm. We used a chemogenetic approach to determine the directionality of the necessary circuitry for behavioral performance reliant on working memory. Specifically, when we targeted mPFC neurons that project to the RE (mPFC-RE) we found a delay-independent reduction in the delayed non-match to position task, but not when we targeted RE neurons that project to the mPFC (RE-mPFC). Our results suggest a broader role for the mPFC-RE circuit in mediating working memory beyond the connection with the hippocampus
The Role of Corticothalamic Projections (Prelimbic Cortex to Nucleus Reuniens) in Working Memory
Working memory (WM) is the ability to store information for short periods of time and is used to execute tasks
WM has been understood to work via the medial prefrontal cortex (mPFC) and dorsal hippocampus (dHPC), but they do not directly project to each other
The nucleus reuniens of the thalamus (Re) is a “middle man” between the mPFC and dHPC
There are projections between the prelimbic cortex (PrL) and Re that may be used during WM
To test the connection of the PrL to Re, a delayed nonmatch to position (DNMTP) task was performe
Principles of protein targeting to the nucleolus
© 2015 The Author(s). Published with license by Taylor & Francis Group, LLC© Robert M Martin, Gohar Ter-Avetisyan, Henry D Herce, Anne K Ludwig, Gisela Lättig-Tünnemann, and M Cristina Cardoso
This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The moral rights of the named author(s) have been asserted.The nucleolus is the hallmark of nuclear compartmentalization and has been shown to exert multiple roles in cellular metabolism besides its main function as the place of rRNA synthesis and assembly of ribosomes. Nucleolar proteins dynamically localize and accumulate in this nuclear compartment relative to the surrounding nucleoplasm. In this study, we have assessed the molecular requirements that are necessary and sufficient for the localization and accumulation of peptides and proteins inside the nucleoli of living cells. The data showed that positively charged peptide entities composed of arginines alone and with an isoelectric point at and above 12.6 are necessary and sufficient for mediating significant nucleolar accumulation. A threshold of 6 arginines is necessary for peptides to accumulate in nucleoli, but already 4 arginines are sufficient when fused within 15 amino acid residues of a nuclear localization signal of a protein. Using a pH sensitive dye, we found that the nucleolar compartment is particularly acidic when compared to the surrounding nucleoplasm and, hence, provides the ideal electrochemical environment to bind poly-arginine containing proteins. In fact, we found that oligo-arginine peptides and GFP fusions bind RNA in vitro. Consistent with RNA being the main binding partner for arginines in the nucleolus, we found that the same principles apply to cells from insects to man, indicating that this mechanism is highly conserved throughout evolution.RMM was supported by a post-doctoral grant from Fundação para a Ciência e Tecnologia, Portugal (SFRH-BPD-66611–2009). This work was supported by grants of the German Research Council (DFG CA198/3) to MCC.info:eu-repo/semantics/publishedVersio
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