Niche Shifts: The Primary Driver of Novelty within Angiosperm Genera

2005 ◽  
Vol 30 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Donald A. Levin
Keyword(s):  
2006 ◽  
Vol 16 (3) ◽  
pp. 408-412 ◽  
Author(s):  
Nicolas Tremblay ◽  
Carl Bélec

Weather is the primary driver of both plant growth and soil conditions. As a consequence of unpredictable weather effects on crop requirements, more inputs are being applied as an insurance policy. Best management practices (BMPs) are therefore about using minimal input for maximal return in a context of unpredictable weather events. This paper proposes a set of complementary actions and tools as BMP for nitrogen (N) fertilization of vegetable crops: 1) planning from an N budget, 2) reference plot establishment, and 3) crop sensing prior to in-season N application based on a saturation index related to N requirement.


2021 ◽  
pp. 193229682110289
Author(s):  
Evan Olawsky ◽  
Yuan Zhang ◽  
Lynn E Eberly ◽  
Erika S Helgeson ◽  
Lisa S Chow

Background: With the development of continuous glucose monitoring systems (CGMS), detailed glycemic data are now available for analysis. Yet analysis of this data-rich information can be formidable. The power of CGMS-derived data lies in its characterization of glycemic variability. In contrast, many standard glycemic measures like hemoglobin A1c (HbA1c) and self-monitored blood glucose inadequately describe glycemic variability and run the risk of bias toward overreporting hyperglycemia. Methods that adjust for this bias are often overlooked in clinical research due to difficulty of computation and lack of accessible analysis tools. Methods: In response, we have developed a new R package rGV, which calculates a suite of 16 glycemic variability metrics when provided a single individual’s CGM data. rGV is versatile and robust; it is capable of handling data of many formats from many sensor types. We also created a companion R Shiny web app that provides these glycemic variability analysis tools without prior knowledge of R coding. We analyzed the statistical reliability of all the glycemic variability metrics included in rGV and illustrate the clinical utility of rGV by analyzing CGM data from three studies. Results: In subjects without diabetes, greater glycemic variability was associated with higher HbA1c values. In patients with type 2 diabetes mellitus (T2DM), we found that high glucose is the primary driver of glycemic variability. In patients with type 1 diabetes (T1DM), we found that naltrexone use may potentially reduce glycemic variability. Conclusions: We present a new R package and accompanying web app to facilitate quick and easy computation of a suite of glycemic variability metrics.


Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 601
Author(s):  
Keith Mayl ◽  
Christopher E. Shaw ◽  
Youn-Bok Lee

A hexanucleotide repeat expansion mutation in the first intron of C9orf72 is the most common known genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Since the discovery in 2011, numerous pathogenic mechanisms, including both loss and gain of function, have been proposed. The body of work overall suggests that toxic gain of function arising from bidirectionally transcribed repeat RNA is likely to be the primary driver of disease. In this review, we outline the key pathogenic mechanisms that have been proposed to date and discuss some of the novel therapeutic approaches currently in development.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ozan Isler ◽  
Simon Gächter ◽  
A. John Maule ◽  
Chris Starmer

AbstractHumans frequently cooperate for collective benefit, even in one-shot social dilemmas. This provides a challenge for theories of cooperation. Two views focus on intuitions but offer conflicting explanations. The Social Heuristics Hypothesis argues that people with selfish preferences rely on cooperative intuitions and predicts that deliberation reduces cooperation. The Self-Control Account emphasizes control over selfish intuitions and is consistent with strong reciprocity—a preference for conditional cooperation in one-shot dilemmas. Here, we reconcile these explanations with each other as well as with strong reciprocity. We study one-shot cooperation across two main dilemma contexts, provision and maintenance, and show that cooperation is higher in provision than maintenance. Using time-limit manipulations, we experimentally study the cognitive processes underlying this robust result. Supporting the Self-Control Account, people are intuitively selfish in maintenance, with deliberation increasing cooperation. In contrast, consistent with the Social Heuristics Hypothesis, deliberation tends to increase the likelihood of free-riding in provision. Contextual differences between maintenance and provision are observed across additional measures: reaction time patterns of cooperation; social dilemma understanding; perceptions of social appropriateness; beliefs about others’ cooperation; and cooperation preferences. Despite these dilemma-specific asymmetries, we show that preferences, coupled with beliefs, successfully predict the high levels of cooperation in both maintenance and provision dilemmas. While the effects of intuitions are context-dependent and small, the widespread preference for strong reciprocity is the primary driver of one-shot cooperation. We advance the Contextualised Strong Reciprocity account as a unifying framework and consider its implications for research and policy.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjun Zhang ◽  
Feng Jiang ◽  
Malte F. Stuecker ◽  
Fei-Fei Jin ◽  
Axel Timmermann

AbstractThe El Niño-Southern Oscillation (ENSO), the primary driver of year-to-year global climate variability, is known to influence the North Tropical Atlantic (NTA) sea surface temperature (SST), especially during boreal spring season. Focusing on statistical lead-lag relationships, previous studies have proposed that interannual NTA SST variability can also feed back on ENSO in a predictable manner. However, these studies did not properly account for ENSO’s autocorrelation and the fact that the SST in the Atlantic and Pacific, as well as their interaction are seasonally modulated. This can lead to misinterpretations of causality and the spurious identification of Atlantic precursors for ENSO. Revisiting this issue under consideration of seasonality, time-varying ENSO frequency, and greenhouse warming, we demonstrate that the cross-correlation characteristics between NTA SST and ENSO, are consistent with a one-way Pacific to Atlantic forcing, even though the interpretation of lead-lag relationships may suggest otherwise.


Ecology ◽  
2015 ◽  
Vol 96 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Patrick Grof-Tisza ◽  
Marcel Holyoak ◽  
Edward Antell ◽  
Richard Karban

2013 ◽  
Vol 210 (12) ◽  
pp. 2553-2567 ◽  
Author(s):  
Christine D. Pozniak ◽  
Arundhati Sengupta Ghosh ◽  
Alvin Gogineni ◽  
Jesse E. Hanson ◽  
Seung-Hye Lee ◽  
...  

Excessive glutamate signaling is thought to underlie neurodegeneration in multiple contexts, yet the pro-degenerative signaling pathways downstream of glutamate receptor activation are not well defined. We show that dual leucine zipper kinase (DLK) is essential for excitotoxicity-induced degeneration of neurons in vivo. In mature neurons, DLK is present in the synapse and interacts with multiple known postsynaptic density proteins including the scaffolding protein PSD-95. To examine DLK function in the adult, DLK-inducible knockout mice were generated through Tamoxifen-induced activation of Cre-ERT in mice containing a floxed DLK allele, which circumvents the neonatal lethality associated with germline deletion. DLK-inducible knockouts displayed a modest increase in basal synaptic transmission but had an attenuation of the JNK/c-Jun stress response pathway activation and significantly reduced neuronal degeneration after kainic acid–induced seizures. Together, these data demonstrate that DLK is a critical upstream regulator of JNK-mediated neurodegeneration downstream of glutamate receptor hyper-activation and represents an attractive target for the treatment of indications where excitotoxicity is a primary driver of neuronal loss.


2021 ◽  
Author(s):  
Mark Blagrove ◽  
Julia Lockheart

There are many theories of the function of dreams, such as memory consolidation, emotion processing, threat simulation and social simulation. In general, such theories hold that the function of dreams occurs within sleep; occurs for unrecalled dreams as well as for dream that are recalled on awakening; and that conscious recall of dreams is not necessary for their function to occur. In contrast, we propose that dreams have an effect of enhancing empathy and group bonding when dreams are shared and discussed with others. We propose also that this effect would have occurred in history and pre-history and, as it would have enhanced the cohesiveness and mutual understanding of group members, the fictional and engaging characteristics of dream content would have been selected for during human social evolution, interacting with cultural practices of dream-sharing. Such dream-sharing may have taken advantage of the long REM periods that occur for biological reasons near the end of the night. Dream-production and dream-sharing may have developed alongside story-telling, utilising common neural mechanisms. Dream-sharing hence would have contributed to Human Self-Domestication, held by many researchers to be the primary driver of the evolution of human prosociality, tolerance and reduced intragroup emotional reactivity. We note that within-sleep theories of dream function rely on correlational rather than experimental findings, and have as yet untested and speculative mechanisms, whereas post-sleep effects of dream-sharing are easily testable and have mechanisms congruent with the social processes proposed by the theory of Human Self-Domestication.


2021 ◽  
Vol 31 (19) ◽  
pp. R1252-R1266
Author(s):  
Olivia K. Bates ◽  
Cleo Bertelsmeier

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