Contribution of an alveolar cell of origin to the high-grade malignant phenotype of pregnancy-associated breast cancer.

Pregnancy-associated breast cancers (PABCs) are tumors diagnosed during pregnancy or up to 5 years following parturition, and are usually high-grade, connective tissue-rich, and estrogen receptor (ER)/progesterone receptor-negative. Little is known about the cellular origin of PABCs or the mechanisms by which PABCs are initiated. Using the RCAS retrovirus to deliver the ErbB2 oncogene into the mammary epithelium of our previously reported MMTV-tva transgenic mice, we detected high-grade, poorly differentiated, stroma-rich and ER-negative tumors during pregnancy and lactation. These high-grade and stroma-rich tumors were less frequent in involuted mice or in age-matched nulliparous mice. More importantly, by generating a WAP-tva transgenic line for expression of ErbB2 selectively in WAP(+) mammary alveolar cells, we found that tumors had similar morphological phenotypes (high grade, poorly differentiated, stroma-rich and ER-negative), irrespective of the time since pregnancy and even in the absence of pregnancy. These data suggest that PABCs arise preferentially from an alveolar cell population that expands during pregnancy and lactation. This somatic mouse model may also be useful for preclinical testing of new prophylactic and therapeutic strategies against PABC

Estimating the size of the cosmic-ray halo using particle distribution moments

Context: Particle transport in many astrophysical problems can be described either by the Fokker–Planck equation or by an equivalent system of stochastic differential equations. Aims: It is shown that the latter method can be applied to the problem of defining the size of the cosmic-ray galactic halo. Methods: Analytical expressions for the leading moments of the pitch-angle distribution of relativistic particles are determined. Particle scattering and escape are analyzed in terms of the moments. Results: In the case of an anisotropic distribution, the first moment leads to an expression for the halo size, identified with the particle escape from the region of strong scattering. Previous studies are generalized by analyzing the case of a strictly isotropic initial distribution. A new expression for the variance of the distribution is derived, which illustrates the anisotropization of the distribution. Conclusions: Stochastic calculus tools allow one to analyze physically motivated forms for the scattering rate, so that a detailed realistic model can be developed

A survey of current trends and suggested future directions in coral transplantation for reef restoration

Coral transplantation has been used in reef restoration for several decades, but information on the type of projects, their scope, scale, and success is mostly limited to published scientific studies and technical reports. Many practitioners do not have the capacity to share their progress in peer-reviewed literature, yet likely have a wealth of information to share on how to improve the efficiency of transplantation efforts. In order to incorporate non-published data on coral transplantation projects and gain an overview of the general features of these projects, we conducted an initial systematic online survey of projects run by various practitioners. Surveyed projects (n = 50) covered most of the tropical belt and ranged in size from a few hundred transplanted corals to >5000 transplants. The most frequent source of coral fragments were corals already broken from some previous impact (“corals of opportunity”; 58% of projects), followed by fragments stored in different types of aquaculture systems (42% of projects). The use of sexual reproduction was very limited. Fast-growing, branching corals were used in 96% of projects, being by far the most common transplanted growth form. About half of the projects mentioned undertaking maintenance of the transplantation plots. The majority of projects undertook subsequent monitoring (80%), yet the available data indicates that duration of monitoring efforts was not adequate to evaluate long-term success. The findings underline that while some general principles for successful coral restoration projects are reasonably well established, others need to be mainstreamed better in order to improve the effectiveness of coral transplantation for reef restoration. This relates in particular to sustainable funding, adequate site assessment, and long-term monitoring using established protocols. Additional information is needed to better understand and address potential challenges with regards to the sourcing of transplants and use of slow-growing species. A better integration of practitioners is necessary to improve the understanding of coral transplantation effectiveness. The results underline a need to develop and use monitoring protocols that allow gauging and comparing the effectiveness of coral transplantation among various projects, as well as for accessible platform(s) to allow the exchange of experiences made in different projects. Regular surveys of restoration projects are recommended to collate and share information among practitioners. We provide a number of recommendations for items to include in future surveys

Global navigation satellite system (GNSS): a utility for sustainable development in Ghana

The rapid spread of modern information and communication technologies (ICT) is dependent on the unprecedented increase in information relating to our natural, economic and social environment, and for Ghana and Africa to be in tune with the current trends in ICT, spatial information and methods to acquire them should be our priority. GNSS is therefore the obvious choice. This technology has an enormous potential to contribute to the management of environment, natural disasters, provide food security, emergency response, improve the efficiency in surveying and mapping. Land, water and air navigation will undergo a dramatic improvement with the application of GNSS. This is just to mention a few of the expected benefits. This paper focuses on the benefits to be derived by Ghana as a developing country and Africa in general from the introduction of a functional Multipurpose Global Navigation Satellite System. It specifically highlights the needed basic infrastructure for setting up a Continuously Operating reference System and the need for acquiring the necessary infrastructure to utilize the European Satellite-Based Augmentation System (SBAS), EGNOS. Areas of probable application and benefits have been outlined and the necessary considerations for a successful implementation and its sustenance have been suggested. It looks at how this space technology can support our sustainable development as developing nations.Journal of Science and Technology (Ghana) Vol. 27 (2) 2007: pp. 130-13

Evaluating surgical skills from kinematic data using convolutional neural networks

The need for automatic surgical skills assessment is increasing, especially because manual feedback from senior surgeons observing junior surgeons is prone to subjectivity and time consuming. Thus, automating surgical skills evaluation is a very important step towards improving surgical practice. In this paper, we designed a Convolutional Neural Network (CNN) to evaluate surgeon skills by extracting patterns in the surgeon motions performed in robotic surgery. The proposed method is validated on the JIGSAWS dataset and achieved very competitive results with 100% accuracy on the suturing and needle passing tasks. While we leveraged from the CNNs efficiency, we also managed to mitigate its black-box effect using class activation map. This feature allows our method to automatically highlight which parts of the surgical task influenced the skill prediction and can be used to explain the classification and to provide personalized feedback to the trainee.Comment: Accepted at MICCAI 201

Direct evaluation of pure graph state entanglement

We address the question of quantifying entanglement in pure graph states. Evaluation of multipartite entanglement measures is extremely hard for most pure quantum states. In this paper we demonstrate how solving one problem in graph theory, namely the identification of maximum independent set, allows us to evaluate three multipartite entanglement measures for pure graph states. We construct the minimal linear decomposition into product states for a large group of pure graph states, allowing us to evaluate the Schmidt measure. Furthermore we show that computation of distance-like measures such as relative entropy of entanglement and geometric measure becomes tractable for these states by explicit construction of closest separable and closest product states respectively. We show how these separable states can be described using stabiliser formalism as well as PEPs-like construction. Finally we discuss the way in which introducing noise to the system can optimally destroy entanglement.Comment: 23 pages, 9 figure

Myanmar Climate-Smart Agriculture Strategy

Myanmar has committed to apply CSA to contribute to regional food security and environmental protection during the 24th ASEAN Summit on May 10, 2014. The Myanmar CSA strategy encompasses the development of technical, policy and investment conditions to achieve a sustainable agricultural development for food security and nutrition through climate-resilient and sustainable agriculture. Myanmar’s CSA strategy aims to be socially, culturally and politically appropriate, environment-friendly and economically feasible to promote and attain sustainable agriculture, food security and nutrition, agricultural development and climate change adaptation and mitigation. Myanmar’s CSA strategy also aims to provide context and analysis for addressing agriculture in international climate negotiations to better inform climate negotiators and other stakeholders by identifying options and unpacking issues of interest

Mode-resolved reciprocal space mapping of electron-phonon interaction in the Weyl semimetal candidate Td-WTe2_2

The selective excitation of coherent phonons provides unique capabilities to control fundamental properties of quantum materials on ultrafast time scales. For instance, in the presence of strong electron-phonon coupling, the electronic band structure can become substantially modulated. Recently, it was predicted that by this means even topologically protected states of matter can be manipulated and, ultimately, be destroyed: For the layered transition metal dichalcogenide Td-WTe$_2$, pairs of Weyl points are expected to annihilate as an interlayer shear mode drives the crystalline structure towards a centrosymmetric phase. By monitoring the changes in the electronic structure of Td-WTe$_2$ with femtosecond resolution, we provide here direct experimental evidence that the coherent excitation of the shear mode acts on the electronic states near the Weyl points. Band structure data in comparison with our results imply, furthermore, the periodic reduction in the spin splitting of bands near the Fermi energy, a distinct electronic signature of the non-centrosymmetric Td ground state of WTe$_2$. The comparison with higher-frequency coherent phonon modes finally proves the shear mode-selectivity of the observed changes in the electronic structure. Our real-time observations reveal direct experimental insights into electronic processes that are of vital importance for a coherent phonon-induced topological phase transition in Td-WTe$_2$.Comment: 28 pages, 17 figure

Cell culture–based production of defective interfering influenza A virus particles in perfusion mode using an alternating tangential flow filtration system

Respiratory diseases including influenza A virus (IAV) infections represent a major threat to human health. While the development of a vaccine requires a lot of time, a fast countermeasure could be the use of defective interfering particles (DIPs) for antiviral therapy. IAV DIPs are usually characterized by a large internal deletion in one viral RNA segment. Consequentially, DIPs can only propagate in presence of infectious standard viruses (STVs), compensating the missing gene function. Here, they interfere with and suppress the STV replication and might act “universally” against many IAV subtypes. We recently reported a production system for purely clonal DIPs utilizing genetically modified cells. In the present study, we established an automated perfusion process for production of a DIP, called DI244, using an alternating tangential flow filtration (ATF) system for cell retention. Viable cell concentrations and DIP titers more than 10 times higher than for a previously reported batch cultivation were observed. Furthermore, we investigated a novel tubular cell retention device for its potential for continuous virus harvesting into the permeate. Very comparable performances to typically used hollow fiber membranes were found during the cell growth phase. During the virus replication phase, the tubular membrane, in contrast to the hollow fiber membrane, allowed 100% of the produced virus particles to pass through. To our knowledge, this is the first time a continuous virus harvest was shown for a membrane-based perfusion process. Overall, the process established offers interesting possibilities for advanced process integration strategies for next-generation virus particle and virus vector manufacturing. Key points • An automated perfusion process for production of IAV DIPs was established. • DIP titers of 7.40E + 9 plaque forming units per mL were reached. • A novel tubular cell retention device enabled continuous virus harvesting. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00253-021-11561-y