Friday, January 31, 2025
Home Blog Page 1094

Why the gender gap in physics has been stable for more than a century

0
Why the gender gap in physics has been stable for more than a century


The gender gap in physics has been stable for more than a century. Here's why
a)Two existing nodes with their ego networks (grayed out) that belong to different groups, indicated by different colors (red and blue). The size of a node indicates its Π, or how attractive it is. b) New nodes arrive and attach to the existing nodes based on their attractiveness Π. For simplicity, each new node only attaches to one existing node. c) Inferring the labels of the new nodes using the mixing values in H. The mixing matrix H used in the figure is only for illustrative purposes and does not represent real data. Credit: Complexity Science Hub

As a physicist and data scientist with a keen interest in gender inequality, Fariba Karimi was amazed to discover that the gender gap in physics has remained almost unchanged since 1900. As the citation and coauthorship networks in physics expand, women still make up a small proportion—and the gaps between male and female are getting larger in terms of absolute numbers.

“With roughly the same number of men and women in the world, we should expect this gap to close in an equal society. But what we see in reality is a persistent gap in physics over time,” says Karimi, from the Complexity Science Hub.

“This gap was puzzling me. Why is this happening and when will this gap close?,” adds Karimi, also a professor at Graz University of Technology. Together with computer scientist Jun Sun, from the Leibniz Institute for the Social Sciences, Karimi decided to investigate why these inequities persist.

In a paper, titled “Emergence of group size disparity in growing networks with adoption,” published in Communications Physics, Karimi and Sun introduce a model that combines two key mechanisms—generalized preferential attachment and asymmetric mixing—to explain the enduring disparities observed in academic networks.

First, a look at real-world dynamics

Initially, the researchers constructed and examined the growing networks of citation and coauthorship in the American Physical Society (APS) publications. The APS dataset includes more than 668,000 papers published in APS journals between 1893 and 2020 and more than 8,5 million citations.

They observed that the ratios of male- to female-led papers, as well as male to female researchers, remain considerably high for decades, reflecting systematic disparities that can be associated to historical barriers of entry and social preferences.

“I was fascinated to see more and more female physicists, and more female-led papers in the field, which is good because we had a really large disparity before,” says Sun. “On the other hand, the gap in terms of absolute numbers was getting larger.”

Who takes in the newcomer?

Karimi and Sun decided to investigate these empirical findings further to uncover the reasons behind these disparities. “In real systems, it’s not as simple as someone coming and connecting to others in a network. Especially in systems like academia, it is also a matter of who takes in the newcomer and adopts him or her into their personal network. In our new model, we wanted to consider this adoption process,” explains Karimi.

“We combined two existing models into one,” adds Karimi. In the novel model, asymmetric mixing is the fundamental mechanism of adoption, as it reflects homophily, or the tendency that people who are alike act alike, that “birds of a feather naturally flock together.” A generalized preferential attachment growth mechanism is also incorporated into the model, where popular or established members attract more connections.

“We were able to replicate real-world dynamics with our model,” explains Karimi. Their model demonstrated, as the real-world data, the persistence of gender imbalances in citation and coauthorship trends.

“Our model shows that, if we continue collaborating and citing fellow physicists this way, this gap will remain as it is,” says Karimi.

“The novelty here is that we do not assume that the increase in women is an endogenous factor, but rather an emergent property of a time-dependent growing system. This explains why the gap persists,” explains Karimi.

What-if scenarios

“Our model shows that this slow arrival of women in physics is also related to biases that emerge when one decides to collaborate with a new person. Having an understanding of this mechanism allows us to discuss what-if scenarios,” adds the physicist.

“Theoretically, we could adjust the probability of adoption so that the number of women arriving will speed up and compensate, and they will have a similar adoption experience as men,” said Karimi. “If we don’t take these interventions soon, this gap will not close very easily because of this adoption process. It’s not just about having more women, but also about how they are integrating into networks.”

Implications for academia and beyond

While the study focuses on academic networks, its implications extend beyond academia. According to Karimi, the same network dynamics could also apply to various sectors, including corporate boards and managerial hiring practices, where biases and preferences can shape long-term growth and group representation.

Understanding the mechanisms behind these disparities could allow policymakers, organizations, and academic institutions to design interventions that promote more inclusive and equitable environments.

Creating opportunities for junior women and senior men to collaborate more is one way to promote collaboration equity, suggests Karimi.

“In the model, closing the gap is easily achieved by adjusting a couple of parameters. However, in reality such interventions are much more challenging, such as by giving female researchers more opportunities for funding, as well as promotion,” says Sun.

More information:
Jun Sun et al, Emergence of group size disparity in growing networks with adoption, Communications Physics (2024). DOI: 10.1038/s42005-024-01799-z

Citation:
Why the gender gap in physics has been stable for more than a century (2024, September 26)
retrieved 26 September 2024
from https://phys.org/news/2024-09-gender-gap-physics-stable-century.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

How the US government can stop ‘churches’ from getting treated like real churches by the IRS

0
How the US government can stop ‘churches’ from getting treated like real churches by the IRS


church
Credit: Unsplash/CC0 Public Domain

The Family Research Council is a conservative advocacy group with a “biblical worldview.” While it has a church ministries department that works with churches from several evangelical Christian denominations that share its perspectives, it does not represent a single denomination. Although its activities are primarily focused on policy, advocacy, government lobbying and public communication, the Internal Revenue Service granted the council’s application to be treated as “an association of churches” in 2020.

Concerned that the IRS had erred in allowing the council and similar groups to be designated churches or associations of churches, Democratic members of the House of Representatives sent the Treasury secretary and the IRS commissioner letters in 2022 and 2024 expressing alarm. The House Democrats pointed to what appeared to be “abuse” of the tax code and asked the IRS to “determine whether existing guidance is sufficient to prevent abuse and what resources or Congressional actions are needed.”

As a professor of nonprofit law, I believe some groups that aren’t churches or associations of churches want to be designated that way to avoid the scrutiny being a charitable organization otherwise requires. At the same time, some other groups that should qualify as churches may have difficulty doing so because of the IRS’ outdated test for that status.

Together with my colleague Ellen P. Aprill, I recently published a paper outlining two main arguments in favor of revising the federal government’s definitions of churches as they pertain to tax law.

No 990s means less scrutiny

All charitable nonprofits, including churches, get the same basic benefits under federal tax law. This means they don’t have to pay taxes on their revenue and that donors can deduct the value of their gifts from their taxable income—as long as they itemize deductions on their tax return.

Unlike other tax-exempt charities, churches don’t have to file 990 forms. That means the public does not have access to churches’ staff pay, board membership and funding details, which are in this publicly available tax form that all other charities must complete every year. The availability of 990 forms enhances the transparency and accountability of the nonprofit sector.

And churches and associations of churches are unlikely to get audited by the IRS. Federal law requires that a senior IRS official “reasonably believes” the church or association has violated federal tax rules before beginning an investigation. This means that an official must have reason to believe the organization has violated federal tax law before obtaining any information from the organization.

This standard is higher than what’s needed before an audit can begin for all other tax-exempt organizations and indeed all taxpayers. For everyone else, the IRS is free to begin an examination based only on a suspicion of a violation or even based on random selection.

Also, unlike other tax-exempt charities, churches and church associations are automatically eligible for their tax-exempt status. They don’t have to apply for it.

Why churches get special treatment

Congress has passed laws granting churches and what it calls “integrated auxiliaries” and “conventions or associations of churches” special protections because the First Amendment to the U.S. Constitution protects religious freedom.

Churches include houses of worship ranging in size from a handful of parishioners to megachurches with 10,000 or more people attending weekly services. Houses of worship of all faiths, including synagogues, mosques and temples, count as churches, according to the IRS.

Integrated auxiliaries are church schools and other organizations affiliated with churches or conventions and primarily supported by internal church sources, as opposed to by the public or government.

Conventions or associations of churches are organizations that have houses of worship from either a single denomination or from multiple denominations as their members. Most denominational bodies, such as the executive committee of the Southern Baptist Convention and the U.S. Conference of Catholic Bishops, are likely conventions or associations of churches, although the IRS does not publish a list of such entities.

Not every religious nonprofit belongs in one of these categories.

For example, the University of Notre Dame, where I teach law students and conduct legal research, and World Vision, a global humanitarian group, are both religious organizations that do not fall into any of these categories. This makes sense, because Notre Dame and World Vision are primarily engaged in activities other than fostering a religious congregation or coordinating the activities of churches within a single denomination.

The IRS has long relied on a 14-factor test to distinguish churches from other religious nonprofits. Examples of those factors include having ordained ministers, a formal doctrine, a distinct membership and a regular congregation attending religious services.

It’s not necessary for all the factors to apply to pass this test.

Yet for almost as long, courts have been uncomfortable with this test because it draws heavily on the traditional characteristics of Protestant Christian churches, as the U.S. Court of Federal Claims explained in a 2009 ruling. This system therefore may be a poor fit for houses of worship of other faiths, especially given the increasing diversity of faith communities.

These courts have instead adopted an “associational test.” It focuses on whether the organization’s congregants hold religious services on a regular basis and gather in person on other occasions.

With the growth of virtual and televised religious services, an update of this test is overdue.

Proposed solutions

Aprill and I recommend that the IRS change its definition for churches to the associational one adopted by some courts in rulings as early as 1980. As the U.S. Court of Federal Claims explained in that 2009 ruling, this test focuses on whether a body of believers assembles regularly to worship. Given technological advances, the IRS should also make it clear that this test can be satisfied through remote participation in religious services using interactive, teleconferencing apps such as Zoom.

This definition would also be better suited for congregations of all faiths because some faiths do not prioritize many of the factors included in the IRS test, such as having a formal code of doctrine or requiring members to not be associated with other houses of worship or faiths. And it would better reflect how some Americans participate in religious services today.

We recommend that the IRS revisit its test for being a church and that Congress pass a law that would change the definition of church associations. The new law could limit associations of churches to organizations that represent a single denomination, as Congress likely initially intended.

This latter change would make it harder for religious organizations that are primarily involved in bringing churches from multiple faiths together to engage in advocacy or other activities to obtain this status and the lack of transparency and accountability that come with it. We believe Congress, not the IRS, should make this change because of the potential political tensions that narrowing the definition could create.

We don’t think the changes would impinge upon the special role that churches have in our society. Indeed, the revised test for qualifying as a church would better fit with both the increasing variety of faiths in our country and technological advancements.

Provided by
The Conversation


This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

Citation:
How the US government can stop ‘churches’ from getting treated like real churches by the IRS (2024, September 26)
retrieved 26 September 2024
from https://phys.org/news/2024-09-churches-real-irs.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

New method enables noninvasive plant magnetic resonance imaging

0
New method enables noninvasive plant magnetic resonance imaging


A milestone in plant magnetic resonance imaging
Metabolite imaging using CEST and CSI in developing pea seeds. Credit: Science Advances (2024). DOI: 10.1126/sciadv.adq4424

The “omics” technologies—genomics, transcriptomics, proteomics, and metabolomics—are at the forefront of discovery in modern plant science and systems biology. In contrast to the rather static genome, however, the metabolome and the products measured in it are very dynamic. In science, metabolome refers to the totality of all small molecules, also known as metabolites, in a biological cell, tissue or organism. Their concentration generally fluctuates greatly, both spatially and temporally.

In the biomedical field, one of the most powerful technological platforms allowing for in vivo metabolic diagnostic and functional studies is nuclear magnetic resonance (NMR) imaging or magnetic resonance imaging (MRI). In plant science, a similar perspective has been desired but not explored.

A new method for plant research

This method could now be provided by a development by scientists at Julius-Maximilians-Universität Würzburg (JMU) and the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK). Chemical exchange saturation transfer (CEST) is a new method for plant MRI. This method enables noninvasive access to the metabolism of sugars and amino acids in complex sink organs (seeds, fruits, taproots, and tubers) of major crops (maize, barley, pea, potato, sugar beet, and sugarcane).

Peter M. Jakob, Professor of Experimental Magnetic Resonance Imaging at the JMU, and Dr. Ljudmilla Borisjuk, head of the Assimilate Allocation and NMR working group at the IPK, are responsible for this. The group presents the results of their study in the latest issue of the journal Science Advances.

How CEST works

“Common H NMR imaging of biological tissue, for example, relies on signals primarily originating from water or lipid protons,” explains Jakob, discussing the background of the research project. As the concentration of metabolite protons is at least three orders of magnitude lower than that of water, the in vivo detection of metabolites requires effective suppression of the water signal.

Chemical exchange saturation transfer (CEST), an approach used in the biomedical field, could offer a solution. In CEST, magnetization is transferred from other molecules to water molecules so that the saturation effect (i.e., signal reduction) that was originally on the targeted species can be observed on water instead.

“In that way, CEST enables the detection of various metabolites based on their ability to exchange protons with water, thereby providing an additional MRI contrast,” says Simon Mayer, first author of the study and researcher at IPK Leibniz Institute. “Because of its high signal detection sensitivity and low susceptibility to magnetic field inhomogeneities, CEST analyzes heterogeneous botanical samples inaccessible to conventional magnetic resonance spectroscopy.”

The results are encouraging. “Our studies demonstrate that CEST is a powerful MRI approach that facilitates in vivo metabolic analysis in plants, allowing microscopic resolution and dynamic assessment of sugar and amino acid distribution despite the magnetic heterogeneity of the samples. Its application to various crops demonstrates that CEST is a species-, variety-, and organ-agnostic approach to noninvasively visualizing metabolites without the need for prior labeling or sample processing,” explains Dr. Borisjuk.

The research team showed metabolite dynamics in growing seeds, which is impossible using conventional techniques. Breeders highly seek knowledge of the spatiotemporal dynamics of sugars and amino acids in sink organs. Their distribution influences mass transport and metabolism in many ways; this knowledge ultimately flows into crop improvement.

Insights into the metabolism of living plants

CEST offers unprecedented opportunities for monitoring dynamic changes in metabolites in living plants. It is particularly important for a deeper understanding of trait formation and supporting breeding research by in vivo testing metabolic responses to genetic engineering and/or developmental alterations.

“Visualization of metabolite dynamics in living plants is a desired tool to bridge structural and metabolic interactions in plant responses to ever-changing environments. Thus, introducing CEST, which visualizes internal tissue structure and metabolite dynamics while avoiding tracers using only one technological platform, MRI, is an important milestone toward this goal.”

More information:
Simon Mayer et al, Metabolic imaging in living plants: A promising field for chemical exchange saturation transfer (CEST) MRI, Science Advances (2024). DOI: 10.1126/sciadv.adq4424

Citation:
New method enables noninvasive plant magnetic resonance imaging (2024, September 26)
retrieved 26 September 2024
from https://phys.org/news/2024-09-method-enables-noninvasive-magnetic-resonance.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

The unexpected role of magnetic microbes in deep-sea mining

0
The unexpected role of magnetic microbes in deep-sea mining


The unexpected role of magnetic microbes in deep-sea mining
The growth of polymetallic nodules provides a low-oxygen, organic-rich microenvironment suitable for magnetotactic bacteria. Credit: Yan Liu

Polymetallic nodules are potato-sized formations on the ocean floor that are rich in minerals such as nickel, cobalt, and manganese. Their concentration of rare, economically important minerals has made the nodules the focus of controversial deep-sea mining enterprises.

There are several hypotheses as to how the nodules grow, but most agree that they form as metallic components in seawater slowly precipitate onto the seafloor. Several studies suggest that microorganisms play a role in nodule growth as well. The nodules tend to contain biogenic magnetite—the fossil remains of magnetotactic bacteria, which have magnetic organelles that act like tiny compass needles.

In a study published in the Journal of Geophysical Research: Solid Earth, researchers have examined the relationship between bacteria abundance and polymetallic nodule distribution in the Clarion-Clipperton Fracture Zone (CCFZ), an environmental management area south of Hawaii managed by the International Seabed Authority. The CCFZ could be an economically vital region for the burgeoning deep-sea mining exploration industry.

The authors analyzed seafloor sediments collected during a research cruise in 2013. They used a vibrating sample magnetometer to determine magnetic properties, electron microscopes to identify minerals based on electron diffraction, and spectroscopy techniques (which test how materials absorb and emit light and other radiation) to test for rare earth elements.

The results revealed three distinct origins of magnetic minerals in the samples: windborne dust, volcanoes, and bacteria. Windborne sediments were likely transported into the region by midlatitude westerlies and northeasterly trade winds, as indicated by decreasing magnetite concentrations from north to south and from east to west in the CCFZ. Volcanic magnetite resulted from the Antarctic Bottom Water’s erosion of the Line Islands and Hawaiian chain.

The highest abundance of biogenic magnetite, the type associated with bacteria, coincided with the highest densities of polymetallic nodules in the CCFZ. The findings led the authors to hypothesize that the nodules produce carbon-rich, low-oxygen microenvironments that both support bacteria and encourage the biomineralization of magnetite nanocrystals. In turn, the bacteria help to foster the growth of the nodules.

The results offer new insights into the formation of polymetallic nodules and the ecological distribution of magnetotactic bacteria, with implications for potential deep-sea exploration.

More information:
Yan Liu et al, Insights Into a Correlation Between Magnetotactic Bacteria and Polymetallic Nodule Distribution in the Eastern Central Pacific Ocean, Journal of Geophysical Research: Solid Earth (2024). DOI: 10.1029/2024JB029062

This story is republished courtesy of Eos, hosted by the American Geophysical Union. Read the original story here.

Citation:
The unexpected role of magnetic microbes in deep-sea mining (2024, September 26)
retrieved 26 September 2024
from https://phys.org/news/2024-09-unexpected-role-magnetic-microbes-deep.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Hydrogen is touted as a climate solution, but can it be good business?

0
Hydrogen is touted as a climate solution, but can it be good business?


Hydrogen is touted as a climate solution, but can it be good business?
Initial world demand for hydrogen. Credit: Journal of Environmental Economics and Management (2024). DOI: 10.1016/j.jeem.2024.103035

Hydrogen is often seen as a key element in the global energy transition, offering a cleaner alternative to fossil fuels—in particular for difficult-to-decarbonize sectors such as heavy-duty transportation and steel and cement manufacturing. But turning hydrogen into a globally traded commodity requires more than just production.

According to new research from UBC Sauder School of Business, hydrogen‘s commercial success hinges critically on innovation, strategic government policies, and long-term contracts to ensure cost-effective production and scalable trade.

The work is published in the Journal of Environmental Economics and Management.

The study developed an international trade model to examine factors that would make hydrogen producers competitive on the global scale, such as transportation costs, government policies and technological advances.

“Hydrogen has tremendous potential to reshape energy markets,” said Dr. Werner Antweiler, associate professor at the UBC Sauder School of Business and co-author of the study. “But making it profitable requires coordinated efforts across governments, industries and markets to reduce costs and build the infrastructure for trade.”

Lowering production costs

Hydrogen’s commercial viability depends heavily on reducing production costs, particularly for green hydrogen, which is produced from renewable energy sources like wind and solar. While green hydrogen is the cleanest option, it’s currently the most expensive compared to blue hydrogen (produced from natural gas with carbon capture) and turquoise hydrogen (produced by splitting methane).

“We’re seeing progress with cheaper solar power, but we also need breakthroughs in electrolyzers to make green hydrogen viable at scale,” said Dr. Antweiler.

Government policies: Innovation and building hydrogen infrastructure

Transportation is another major challenge. Hydrogen is costly to move.

“Hydrogen can be transported in two ways: using converted natural gas pipelines or liquefying it, either by cooling it like natural gas or converting it into ammonia for shipment by tanker,” said Dr. Antweiler.

Instead of just subsidizing production, governments will need to invest in infrastructure—pipelines, export terminals and storage facilities—to support cost-effective hydrogen trade.

“Hydrogen producers want to focus on production, not building export facilities. There’s a lot of development needed outside the hydrogen industry itself,” noted Dr. Antweiler.

Government policies would also need to prioritize innovation. Countries investing in research and development for cheaper electrolyzers or methane pyrolysis for turquoise hydrogen will gain a competitive edge in the emerging market.

“Innovation is the real game-changer. There’s significant potential for hydrogen to transition from locally interesting to globally traded as these technologies develop,” said Dr. Antweiler.

Long-term contracts: Ensuring market stability

A key finding was the importance of long-term contracts in the hydrogen market, where capital-intensive production plants require long-term certainty. These contracts stabilize prices and ensure reliable demand, providing security for both producers and buyers.

“Hydrogen won’t operate like the spot market for oil and gas,” said Dr. Antweiler. “Developers need guarantees of customers for years to come, which is why long-term contracts are crucial.”

However, these contracts also carry risks. A country might commit to blue hydrogen today, only to find that green hydrogen becomes cheaper later. Balancing stability with flexibility will be key to the hydrogen market’s long-term success.

A two-way trade future: Exporting and importing hydrogen

The study found that hydrogen trade is likely to involve both exporting and importing, unlike oil markets where countries typically do one or the other. Many countries have the potential to produce hydrogen with renewable energy, while the supply of fossil fuels is concentrated in a handful of large producer countries.

“Hydrogen trade could evolve into a system where countries both buy and sell,” explained Dr. Antweiler. “As demand increases, nations will need to secure supply from multiple sources, making hydrogen a flexible, globally traded commodity.”

Dr. Antweiler noted that major energy companies in Europe and the Middle East are already investing billions in hydrogen infrastructure as they prepare for a future where hydrogen plays a central role in energy markets beyond fossil fuels.

More information:
Werner Antweiler et al, The emerging international trade in hydrogen: Environmental policies, innovation, and trade dynamics, Journal of Environmental Economics and Management (2024). DOI: 10.1016/j.jeem.2024.103035

Citation:
Hydrogen is touted as a climate solution, but can it be good business? (2024, September 26)
retrieved 26 September 2024
from https://techxplore.com/news/2024-09-hydrogen-touted-climate-solution-good.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link