13 research outputs found
The Relationship Between Leaf Traits, Stomatal Conductance, and Assimilation Rates in New Zealand Native Plant Species: A Study Based on the University of Auckland Botanical Collection
No full textTerrestrial vascular plants rely on their foliage as their major photosynthetic surfaces. For a deeper comprehension of terrestrial ecosystem dynamics, nutrient cycles, responses to the current global climate change, and the evolutionary trajectories of foliage form and function, it is imperative that we measure and comprehend the relationships among the functional features of leaves. There is a consistent pattern of close interaction between leaf features across a wide variety of plant ecosystems. Very few studies have addressed this phenomenon in relation to the New Zealand flora. The current study was carried out to assess relationships between leaf and plant traits for specimens in the Auckland University botanical collection within the University grounds. Based on physiological parameters such as shade conditions and different leaf traits (e.g.: leaf size, leaf shape and plant size), twenty tree species were selected for the current study. Five trees per species were selected based on accessibility and availability. All the photosynthetic parameters (assimilation rate, stomatal conductance, water use efficiency) were taken from LI-6800 while other leaf and tree dimension data (tree height, trunk diameter, leaf length, leaf width and leaf thickness) were gathered from the literature. Regression analysis was used to assess relationships between the leaf and plant traits. The assimilation rate of tested tree species was ranged in between 0.396 μmol m⁻² s⁻¹ and 20.806 μmol m⁻² s⁻¹ while the stomatal conductance was in between 0.016 mol m⁻² s⁻¹ and 0.369 mol m⁻² s⁻¹. The instantaneous water use efficiency ranged from 6.701 to 736.83 over the study period. The analyzed results highlighted that; tree height was responsible for 15.75 % variation of assimilation rate while the trunk diameter accounts for 14.95 % variation of WUE in tested tree species. A major predictor of specific leaf area was leaf thickness, meaning that as leaf thickness increases, specific leaf area will decrease. The assimilation rate, stomatal conductance, and instantaneous water use efficiency were not strongly predicted by the majority of the leaf parameters taken into account in this study. Therefore, more research needs to be done to evaluate the other factors that might influence the previously listed leaf characteristics
The impacts of 3D radiative transfer effects on cloud radiative property simulations and retrievals
No full textThis paper presents a new method for representing the important effects of horizontal radiation transport through cloud sides in two-stream radiation schemes. Ordinarily, the radiative transfer equations are discretized separately for the clear and cloudy regions within each model level, but here terms are introduced that represent the exchange of radiation laterally between regions and the resulting coupled equations are solved for each layer. This approach may be taken with both the direct incoming shortwave radiation, which is governed by Beer’s law, and the diffuse shortwave and longwave radiation, governed by the two-stream equations. The rate of lateral exchange is determined by the area of cloud “edge.” The validity of the method is demonstrated by comparing with rigorous 3D radiative transfer calculations in the literature for two cloud types in which the 3D effect is strong, specifically cumulus and aircraft contrails. The 3D effect on shortwave cloud radiative forcing varies between around −25% and around +100%, depending on solar zenith angle. Even with an otherwise very simplistic representation of the cloud, the new scheme exhibits good agreement with the rigorous calculations in the shortwave, opening the way for efficient yet accurate representation of this important effect in climate models.This work is supported by the grant CyberTraining: DSE: Cross-Training of Researchers in Computing, Applied Mathematics and Atmospheric Sciences using Advanced Cyberinfrastructure Resources from the National Science Foundation (grant no. OAC–1730250). This grant also supported co-author Chamara Rajapakshe as graduate assistant. The hardware in the UMBC High Performance Computing Facility (HPCF) is supported by the U.S. National Science Foundation through the MRI program (grant nos. CNS– 0821258, CNS–1228778 , and OAC–1726023) and the SCREMS program (grant no. DMS–
0821311), with additional substantial support from the University of Maryland, Baltimore County (UMBC). See hpcf.umbc.edu for more information on HPCF and the projects using its resources.https://userpages.umbc.edu/~gobbert/papers/CT2018Team5.pd
The Pearly Gates: A collection of science fiction short stories
No full textWhen Saint Peter passes through the pearly gates, he is confronted with a profound dilemma. By the year 2100, Earth stands on the brink of extinction, and humanity as a whole seeks admission to heaven. However, in accordance with the admission criteria of heaven, every individual is entitled to enter, potentially overwhelming the heavenly supply chain. Can Saint Peter find a solution?To discover the answer and enjoy an additional 14 captivating short stories, delve into this book. While it falls under the umbrella of science fiction, it offers a unique twist. The author delves deep into the realm of science itself, moving beyond the familiar territories of aliens and time travel. This book is crafted to cater to both science enthusiasts and those less versed in scientific matters.Chamara Panakaduwa, a proud product of the University of Salford, the University of Bedfordshire, and Birmingham City University, presents this distinct creation for aficionados of science fiction as well as casual readers. The book's distinctive flavour is its infusion of the concept of sustainability, a personal favourite of the author
Participatory budgeting in a Sri Lankan urban council: A practice of power and domination
No full textDrawing on Bourdieu’s triad, i.e. field, habitus and capital, the paper aims at unfolding the practice of participatory budgeting (PB) in one Sri Lankan urban council, which we have referred to as the “Costal Urban Council (CUC)”, and in this process explores how such practice is framed and constrained by the structural and relational aspects of various forms of capital. The PB practice in the CUC has failed to achieve its fundamental objective—public participation in a manner of equality, justice, and transparency, or at least best partial success in some areas such as rates collection. We have demonstrated how PB has become a practice of power and domination rather than a means of fostering political emancipation in the CUC. The field-specific organisation of various forms of capital has allowed the chairman of the CUC to become dominant and take control of the whole budgeting process and PB, which is aimed at impeding such political practices, has become dominated by the same political dynamics. We argue that PB in the specific field of less-developed countries can have far greater effects than simply revitalising local democracy, including providing personal gains and potentially posing a threat to democracy
Beyond the genome: the role of functional markers in contemporary plant breeding
No full textFunctional markers (FMs) are derived from polymorphisms that confer phenotypic trait variation, making them powerful tools in plant breeding. Unlike random markers, for which trait associations are unknown, or at best established via linkage or quantitative trait locus (QTL) analysis, FMs are associated with causative polymorphisms, providing precise and reliable information for trait selection. Since the concept of FMs was first proposed in 2003, the emergence and adoption of technologies that were not available at the time have significantly advanced FM discovery and application by enhancing the ability to precisely identify causal variants underlying complex traits, which is a critical prerequisite for FM development. Novel technologies such as high-throughput sequencing, multi-omics, gene editing, and advanced computational tools have enabled the precise identification and functional validation of DNA polymorphisms associated with trait variation. FMs can be used in genomic selection (GS) and modern plant breeding programs by improving selection efficiency and accuracy. While FMs provide numerous benefits, challenges still remain regarding their stability and transferability, and innovative approaches to overcome these limitations are continually being explored. The role of FMs in plant breeding is expected to grow as functional annotation of genomes improves and technologies like genome editing become more accessible. These developments will enable breeders to effectively integrate FMs into breeding pipelines for accelerating genetic gains and addressing global agricultural challenges.This is published as Park T-C, Silva PC, Lübberstedt T and Scott MP (2025) Beyond the genome: the role of functional markers in contemporary plant breeding. Front. Plant Sci. 16:1637299. doi: 10.3389/fpls.2025.1637299The author(s) declare that financial support was received for the research and/or publication of this article. This research was supported in part by the U.S. Department of Agriculture, Agricultural Research Service (project number 5030-21000-073-000-D) and by grants from the USDA-NIFA-OREI program, award numbers 2020-51300-32180 and 2021-51300-34896
THE MARRIAGE OF SPECTROSCOPY AND DYNAMICS: CHIRPED-PULSE FOURIER-TRANSFORM MM-WAVE (CP-FT-MMW) SPECTROSCOPY IN PULSED UNIFORM SUPERSONIC FLOWS
No full textAuthor Institution: Department of Chemsitry, Wayne State University, Detroit, MI 48202; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139A new experimental scheme is presented that combines two powerful emerging technologies:~chirped-pulse Fourier-transform mm-Wave spectroscopy and pulsed uniform supersonic flows. It promises a nearly universal detection method that can deliver quantitative isomer, conformer, and vibrational level specific detection, characterization of unstable reaction products and intermediates, and perform unique spectroscopic, kinetics, and dynamics measurements. Chirped-pulse Fourier-transform microwave (CP-FTMW) spectroscopy, pioneered by Pate and coworkers, allows rapid acquisition of broadband microwave spectrum through advancements in waveform generation and oscilloscope technology. This revolutionary approach has successfully been adapted to higher frequencies by the Field group at MIT. Our new apparatus will exploit amplified chirped pulses in the range of 26-40 GHz, in combination with a pulsed uniform supersonic flow from a Laval nozzle. This nozzle source, pioneered by Rowe, Sims, and Smith for low temperature kinetics studies, produces thermalized reactants at high densities and low temperatures perfectly suitable for reaction dynamics experiments studied using the CP-mmW approach. This combination of techniques shall enhance the thousand-fold improvement in data acquisition rate achieved in the CP method by a further 2-3 orders of magnitude. A pulsed flow alleviates the challenges of continuous uniform flow, e.g.~large gas loads and reactant consumption rates. In contrast to other pulsed Laval systems currently in use, we will use a fast piezo valve and small chambers to achieve the desired pressures while minimizing the gas load, so that a 10 Hz repetition rate can be achieved with one turbomolecular pump. The proposed technique will be suitable for many diverse fields, including fundamental studies in spectroscopy and reaction dynamics, reaction kinetics, combustion, atmospheric chemistry, and astrochemistry. We expect a significant advancement in the ability to detect absolute populations of complex reaction products under near-nascent conditions, providing the powerful method of reaction dynamics with a universal spectroscopic probe capable of capturing the details of complex chemistry for specific product isomers and conformers
Mbembe, A. (2017). Crítica da razão Negra. Lisboa: Antígona.
No full text[Excerto] Crítica da razão Negra, de Achile Mbembe, não é uma história das ideias, nem um exercício de sociologia histórica, embora se sirva da história “para propor um estilo de reflexão crítica acerca do mundo do nosso tempo” (p. 21). Logo na Introdução da obra, Achille Mbembe avisa que ela integra um processo que se encontra numa fase inicial e que se prende com a urgência em abrir a problemática da política da raça, do racismo e do colonialismo ao pensamento crítico, desclassificando o statu quo assente em predeterminações e estereótipos tendentes a dar “conforto” à lógica dominante. Por outras palavras, a necessidade em deixar para trás a ideia de verdade absoluta, a que, já em 1997, Stuart Hall chamara a atenção. E é disso que trata este livro, que tem um recorte teórico sublinhado, em que o autor discorre sobre o conceito de “negro”, sobre a evolução do pensamento europeu que lhe esteve na origem, sobre a colagem do selo àqueles que estão subalternizados (que apelida de “devir-negro do mundo”) e sobre os estratagemas destinados a ofuscar o próprio assunto. Neste livro, considera-se urgente a descolonização mental da Europa para combater o fenómeno do racismo global tecido pelo capitalismo selvagem, em que potencialmente todos poderão ser os novos “negros”.[Excerpt] Crítica da razão Negra [Critique of Black reason], by Achille Mbembe, is not a story about ideas, or an exercise in historical sociology, despite making use of history “to put forth a style of critical reflection about the world of our time” (p. 21). Straightaway in the work’s Introduction, Achille Mbembe lets the reader know that it’s included in a process that’s at a preliminary stage in connection with the urgency to open up the problem of racial policy, racism and colonialism to critical thinking, declassifying the status quo hinged on predeterminations and stereotypes tending to bring “comfort” to the predominant logic. In other words, the need to put behind the notion of absolute truth, which, as early as 1997, Stuart Hall called attention. And this is what this book is about, that it comprises an underscored theoretical clipping, where the author expounds on the concept of “black,” on the evolution of European thinking that was behind it, with regard to affixing the stamp on those that are subordinated (which he calls “black development” of the world) and regarding stratagems intended to overshadow the matter itself. This book deems it urgent to mentally decolonize Europe in order to fight the phenomenon of global racism forged by rampant capitalism, where potentially everyone could be the new “blacks”.(undefined)info:eu-repo/semantics/publishedVersio
Nietzsche and positivism: criticism of the moral and philosophy of knowledge.
No full textThe paper is basically divided into three moments; in the first of them, deals with the presentation of Nietzsche's critique of the so-called "absolute" principles of positivist moral philosophy, especially the philosopher's critique of altruism. It is also intended to present at this stage the way in which positivism has served to counteract and develop the Nietzschean perspective on the instinctual nature of values, insofar as it seeks to substantiate the idea which is not the philosopher's criticism of positivism a radical critique or a form of dogmatic anti-positivism. In a second moment, we try to analyze how Friedrich Nietzsche associates the theory of the positivist knowledge with the sensualism and the naive empiricism, opposing such gnosiological notions what can be considered its interpretive paradigm as what the philosopher called the perspectivism. In a third, we try to show how Jürgen Habermas in his work Knowledge and Interest can put Auguste Comte's positivism as one of the decisive influences of Nietzsche's perspectivism, associating the author with the spirituality born from the arguments elaborated by Hegel in his book , The phenomenology of the spirit and still to transcendentalism of Kantian inspiration.Sem bolsaO trabalho se divide basicamente em três momentos; no primeiro deles, trata da apresentação da crítica de Nietzsche aos ditos príncipios “absolutos” da filosofia moral positivista, especialmente da crítica do filósofo ao altruísmo. Pretende-se apresentar ainda nesta etapa, o modo com que o positivismo serviu a contraproposição e ao desenvolvimento da perspectiva nietzschiana acerca da natureza pulsional dos valores, na medida em que busca fundamentar a ideia a qual não se trata a crítica do filósofo ao positivismo, de uma crítica radical ou em um antipositivismo dogmático. Em um segundo momento, intenta-se analisar como Friedrich Nietzsche associa a teoria do conhecimento positivista ao sensualismo e ao empirismo ingênuo, contrapondo tais noções gnosiológicas tanto aquilo que pode ser considerado seu paradigma interpretativo quanto àquilo que o próprio filósofo chamara de perspectivismo. Em um terceiro momento, procuramos mostrar como Jürgen Habermas, em sua obra Conhecimento e Interesse pode colocar o positivismo de Auguste Comte como uma das influências decisivas do perspectivismo de Nietzsche, associando o autor à espiritualidade nascida a partir dos argumentos elaborados por Hegel em seu livro, A fenomenologia do espírito e ainda ao transcedentalismo de inspiração kantiana
Nietzsche and positivism: criticism of the moral and philosophy of knowledge.
No full textThe paper is basically divided into three moments; in the first of them, deals with the presentation of Nietzsche's critique of the so-called "absolute" principles of positivist moral philosophy, especially the philosopher's critique of altruism. It is also intended to present at this stage the way in which positivism has served to counteract and develop the Nietzschean perspective on the instinctual nature of values, insofar as it seeks to substantiate the idea which is not the philosopher's criticism of positivism a radical critique or a form of dogmatic anti-positivism. In a second moment, we try to analyze how Friedrich Nietzsche associates the theory of the positivist knowledge with the sensualism and the naive empiricism, opposing such gnosiological notions what can be considered its interpretive paradigm as what the philosopher called the perspectivism. In a third, we try to show how Jürgen Habermas in his work Knowledge and Interest can put Auguste Comte's positivism as one of the decisive influences of Nietzsche's perspectivism, associating the author with the spirituality born from the arguments elaborated by Hegel in his book , The phenomenology of the spirit and still to transcendentalism of Kantian inspiration.Sem bolsaO trabalho se divide basicamente em três momentos; no primeiro deles, trata da apresentação da crítica de Nietzsche aos ditos príncipios “absolutos” da filosofia moral positivista, especialmente da crítica do filósofo ao altruísmo. Pretende-se apresentar ainda nesta etapa, o modo com que o positivismo serviu a contraproposição e ao desenvolvimento da perspectiva nietzschiana acerca da natureza pulsional dos valores, na medida em que busca fundamentar a ideia a qual não se trata a crítica do filósofo ao positivismo, de uma crítica radical ou em um antipositivismo dogmático. Em um segundo momento, intenta-se analisar como Friedrich Nietzsche associa a teoria do conhecimento positivista ao sensualismo e ao empirismo ingênuo, contrapondo tais noções gnosiológicas tanto aquilo que pode ser considerado seu paradigma interpretativo quanto àquilo que o próprio filósofo chamara de perspectivismo. Em um terceiro momento, procuramos mostrar como Jürgen Habermas, em sua obra Conhecimento e Interesse pode colocar o positivismo de Auguste Comte como uma das influências decisivas do perspectivismo de Nietzsche, associando o autor à espiritualidade nascida a partir dos argumentos elaborados por Hegel em seu livro, A fenomenologia do espírito e ainda ao transcedentalismo de inspiração kantiana
Multiplexed characterization of complex gas-phase mixtures combining chirped-pulse Fourier transform microwave spectroscopy and VUV photoionization time-of-flight mass spectrometry
No full textInternational audienceWe report details of the design and operation of a single apparatus that combines Chirped-Pulse Fourier Transform Microwave (CP-FTMW) spectroscopy with vacuum ultraviolet (VUV) photoionization Time-of-Flight Mass Spectrometry (TOFMS). The supersonic expansion used for cooling samples is interrogated first by passing through the region between two microwave horns capable of broadband excitation and detection in the 2-18 GHz frequency region of the microwave. After passing through this region, the expansion is skimmed to form a molecular beam, before being probed with 118 nm (10.5 eV) single-photon VUV photoionization in a linear time-of-flight mass spectrometer. The two detection schemes are powerfully complementary to one another. CP-FTMW detects all components with significant permanent dipole moments. Rotational transitions provide high-resolution structural data. VUV TOFMS provides a gentle and general method for ionizing all components of a gas phase mixture with ionization thresholds below 10.5 eV, providing their molecular formulae. The advantages, complementarity, and limitations of the combined methods are illustrated through results on two gas-phase mixtures made up of (i) three furanic compounds, two of which are structural isomers of one another, and (ii) the effluent from a flash pyrolysis source with o-guaiacol as the precursor. © 2018 Author(s)
