121 research outputs found
Recommended from our members
Meta-analysis reveals that pollinator functional diversity and abundance enhance crop pollination and yield
How insects promote crop pollination remains poorly understood in terms of the contribution of functional trait differences between species. We used meta-analyses to test for correlations between community abundance, species richness and functional trait metrics with oilseed rape yield, a globally important crop. While overall abundance is consistently important in predicting yield, functional divergence between species traits also showed a positive correlation. This result supports the complementarity hypothesis that pollination function is maintained by non-overlapping trait distributions. In artificially constructed communities (mesocosms), species richness is positively correlated with yield, although this effect is not seen under field conditions. As traits of the dominant species do not predict yield above that attributed to the effect of abundance alone, we find no evidence in support of the mass ratio hypothesis. Management practices increasing not just pollinator abundance, but also functional divergence, could benefit oilseed rape agriculture
Economics of beekeeping as pollination management practices adopted by farmers in Chitwan district of Nepal
The Diversity and Abundance of Small Arthropods in Onion, Allium cepa, Seed Crops, and their Potential Role in Pollination
Onion, Allium cepa L. (Asparagales: Amaryllidaceae), crop fields grown for seed production require arthropod pollination for adequate seed yield. Although many arthropod species visit A. cepa flowers, for most there is little information on their role as pollinators. Small flower visiting arthropods (body width < 3 mm) in particular are rarely assessed. A survey of eight flowering commercial A. cepa seed fields in the North and South Islands of New Zealand using window traps revealed that small arthropods were highly abundant among all except one field. Insects belonging to the orders Diptera and Thysanoptera were the most abundant and Hymenoptera, Collembola, Psocoptera, Hemiptera, and Coleoptera were also present. To test whether small arthropods might contribute to pollination, seed sets from umbels caged within 3 mm diameter mesh cages were compared with similarly caged, hand-pollinated umbels and uncaged umbels. Caged umbels that were not hand-pollinated set significantly fewer seeds (average eight seeds/umbel, n = 10) than caged hand-pollinated umbels (average 146 seeds/umbel) and uncaged umbels (average 481 seeds/umbel). Moreover, sticky traps placed on umbels within cages captured similar numbers of small arthropods as sticky traps placed on uncaged umbels, suggesting cages did not inhibit the movement of small arthropods to umbels. Therefore, despite the high abundance of small arthropods within fields, evidence to support their role as significant pollinators of commercial A. cepa seed crops was not found
Who Sets the Agenda? Analyzing Key Actors and Dynamics of Economic Diversification in Kazakhstan Throughout 2011–2016
This contribution attempts to answer the key question: Who sets the agenda for economic diversification in the context of Kazakhstan? This question remains critical in current scholarly debates. Although Kazakhstan, a young post-Soviet developing nation, has received fair scholarly attention with regard to the agenda setting stage of the policy cycle, the existing literature has yet failed to (1) empirically establish who actually sets the agenda for a certain policy issue and (2) employ the Internet research methods. This paper seeks to fill these gaps. The literature review of Kazakh-specific agenda setting publications suggests that among the major actors, the government tends to exert predominant influence, though other actors may also play a role, for example, media and academia. This research is driven by Internet penetration rate data and focuses on the period from January 2011 until December 2016. The findings lead to two key conclusions. First, think tanks seem to set the government agenda for economic diversification policy in Kazakhstan. Second, the government, while exhibiting the larger agenda setting magnitude vis-à-vis the other actors, shapes the subsequent debates as measured by the number of relevant references in media, think tanks, and academic publications. This research seeks to contribute to existing agenda setting theories in the Internet era by defining the most important actor(s), specifically in the Kazakh context based on longitudinal dynamics in attention
Dual FGF-2 and Intergrin α5β1 Signaling Mediate GRAF-Induced RhoA Inactivation in a Model of Breast Cancer Dormancy
Interactions with the bone marrow stroma regulate dormancy and survival of breast cancer micrometastases. In an in vitro model of dormancy in the bone marrow, we previously demonstrated that estrogen-dependent breast cancer cells are partially re-differentiated by FGF-2, re-express integrin α5β1 lost with malignant transformation and acquire an activated PI3K/Akt pathway. Ligation of integrin α5β1 by fibronectin and activation of the PI3K pathway both contribute to survival of these dormant cells. Here, we investigated mechanisms responsible for the dormant phenotype. Experiments demonstrate that integrin α5β1 controls de novo cytoskeletal rearrangements, cell spreading, focal adhesion kinase rearrangement to the cell perimeter and recruitment of a RhoA GAP known as GRAF. This results in the inactivation of RhoA, an effect which is necessary for the stabilization of cortical actin. Experiments also demonstrate that activation of the PI3K pathway by FGF-2 is independent of integrin α5β1 and is also required for cortical actin reorganization, GRAF membrane relocalization and RhoA inactivation. These data suggest that GRAF-mediated RhoA inactivation and consequent phenotypic changes of dormancy depend on dual signaling by FGF-2-initiated PI3K activation and through ligation of integrin α5β1 by fibronectin
Association between routine laboratory tests and long-term mortality among acutely admitted older medical patients: a cohort study
BACKGROUND: Older people have the highest incidence of acute medical admissions. Old age and acute hospital admissions are associated with a high risk of adverse health outcomes after discharge, such as reduced physical performance, readmissions and mortality. Hospitalisations in this population are often by acute admission and through the emergency department. This, along with the rapidly increasing proportion of older people, warrants the need for clinically feasible tools that can systematically assess vulnerability in older medical patients upon acute hospital admission. These are essential for prioritising treatment during hospitalisation and after discharge. Here we explore whether an abbreviated form of the FI-Lab frailty index, calculated as the number of admission laboratory test results outside of the reference interval (FI-OutRef) was associated with long term mortality among acutely admitted older medical patients. Secondly, we investigate other markers of aging (age, total number of chronic diagnoses, new chronic diagnoses, and new acute admissions) and their associations with long-term mortality. METHODS: A cohort study of acutely admitted medical patients aged 65 or older. Survival time within a 3 years post-discharge follow up period was used as the outcome. The associations between the markers and survival time were investigated by Cox regression analyses. For analyses, all markers were grouped by quartiles. RESULTS: A total of 4,005 patients were included. Among the 3,172 patients without a cancer diagnosis, mortality within 3 years was 39.9%. Univariate and multiple regression analyses for each marker showed that all were significantly associated with post-discharge survival. The changes between the estimates for the FI-OutRef quartiles in the univariate- and the multiple analyses were negligible. Among all the markers investigated, FI-OutRef had the highest hazard ratio of the fourth quartile versus the first quartile: 3.45 (95% CI: 2.83-s4.22, P < 0.001). CONCLUSION: Among acutely admitted older medical patients, FI-OutRef was strongly associated with long-term mortality. This association was independent of age, sex, and number of chronic diagnoses, new chronic diagnoses, and new acute admissions. Hence FI-OutRef could be a biomarker of advancement of aging within the acute care setting. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12877-017-0434-3) contains supplementary material, which is available to authorized users
Prolonged oral cannabinoid administration prevents neuroinflammation, lowers β-amyloid levels and improves cognitive performance in Tg APP 2576 mice
Background: Alzheimer’s disease (AD) brain shows an ongoing inflammatory condition and non-steroidal antiinflammatories
diminish the risk of suffering the neurologic disease. Cannabinoids are neuroprotective and antiinflammatory
agents with therapeutic potential.
Methods: We have studied the effects of prolonged oral administration of transgenic amyloid precursor protein
(APP) mice with two pharmacologically different cannabinoids (WIN 55,212-2 and JWH-133, 0.2 mg/kg/day in the
drinking water during 4 months) on inflammatory and cognitive parameters, and on 18F-fluoro-deoxyglucose
(18FDG) uptake by positron emission tomography (PET).
Results: Novel object recognition was significantly reduced in 11 month old Tg APP mice and 4 month
administration of JWH was able to normalize this cognitive deficit, although WIN was ineffective. Wild type mice
cognitive performance was unaltered by cannabinoid administration. Tg APP mice showed decreased 18FDG
uptake in hippocampus and cortical regions, which was counteracted by oral JWH treatment. Hippocampal GFAP
immunoreactivity and cortical protein expression was unaffected by genotype or treatment. In contrast, the density
of Iba1 positive microglia was increased in Tg APP mice, and normalized following JWH chronic treatment. Both
cannabinoids were effective at reducing the enhancement of COX-2 protein levels and TNF-a mRNA expression
found in the AD model. Increased cortical b-amyloid (Ab) levels were significantly reduced in the mouse model by
both cannabinoids. Noteworthy both cannabinoids enhanced Ab transport across choroid plexus cells in vitro.
Conclusions: In summary we have shown that chronically administered cannabinoid showed marked beneficial
effects concomitant with inflammation reduction and increased Ab clearanceThis work was supported by the Spanish Ministry of Science and
Technology (SAF 2005-02845 to M.L.C). A.M.M-M. was recipient a fellowship
from the Ministry of Education and Scienc
Alterations to Melanocortinergic, GABAergic and Cannabinoid Neurotransmission Associated with Olanzapine-Induced Weight Gain
Background/Aim: Second generation antipsychotics (SGAs) are used to treat schizophrenia but can cause serious metabolic side-effects, such as obesity and diabetes. This study examined the effects of low to high doses of olanzapine on appetite/ metabolic regulatory signals in the hypothalamus and brainstem to elucidate the mechanisms underlying olanzapineinduced obesity. Methodology/Results: Levels of pro-opiomelanocortin (POMC), neuropeptide Y (NPY) and glutamic acid decarboxylase (GAD65, enzyme for GABA synthesis) mRNA expression, and cannabinoid CB1 receptor (CB1R) binding density (using [ 3 H]SR-141716A) were examined in the arcuate nucleus (Arc) and dorsal vagal complex (DVC) of female Sprague Dawley rats following 0.25, 0.5, 1.0 or 2.0 mg/kg olanzapine or vehicle (36/day, 14-days). Consistent with its weight gain liability, olanzapine significantly decreased anorexigenic POMC and increased orexigenic NPY mRNA expression in a dose-sensitive manner in the Arc. GAD65 mRNA expression increased and CB1R binding density decreased in the Arc and DVC. Alterations to neurotransmission signals in the brain significantly correlated with body weight and adiposity. The minimum dosage threshold required to induce weight gain in the rat was 0.5 mg/kg olanzapine. Conclusions: Olanzapine-induced weight gain is associated with reduced appetite-inhibiting POMC and increased NPY. This study also supports a role for the CB1R and GABA in the mechanisms underlying weight gain side-effects, possibly b
- …
