218 research outputs found
Spectroscopic confirmation of a substantial population of luminous red galaxies at redshifts z ≳ 2
We confirm spectroscopically the existence of a population of galaxies at z greater than or similar to 2 with rest-frame optical colors similar to normal nearby galaxies. The galaxies were identified by their red near-infrared colors in deep images obtained with the Infrared Spectrometer and Array Camera on the Very Large Telescope of the field around the foreground cluster MS 1054-03. Redshifts of six galaxies with J(s)-K-s > 2.3 were measured from optical spectra obtained with the W. M. Keck telescope. Five out of six are in the range, demonstrating that the 2.43 = z = 3.52 J(s)-K-s color selection is quite efficient. The rest-frame ultraviolet spectra of confirmed z > 2 galaxies display a range of properties, with two galaxies showing emission lines characteristic of active galactic nuclei, two having Lyalpha in emission, and one showing interstellar absorption lines only. Their full spectral energy distributions are well described by constant star formation models with ages 1.4-2.6 Gyr, except for one galaxy whose colors indicate a dusty starburst. The confirmed z > 2 galaxies are very luminous: their K-s magnitudes are in the range 19.2-19.9, corresponding to rest-frame absolute V magnitudes from -24.8 to -23.2. Assuming that our bright spectroscopic sample is representative for the general population of J(s)-K-s selected objects, we find that the surface density of red z greater than or similar to 2 galaxies is approximate to0.9 arcmin(-2) to K-s = 21. The surface density is comparable to that of Lyman break-selected galaxies with K-s < 21, when corrections are made for the different redshift distributions of the two samples. Although there will be some overlap between the two populations, most "optical-break" galaxies are too faint in the rest-frame ultraviolet to be selected as Lyman break galaxies. The most straightforward interpretation is that star formation in typical optical-break galaxies started earlier than in typical Lyman break galaxies. Optical-break galaxies may be the oldest and most massive galaxies yet identified at, and they z 1 2 could evolve into early-type galaxies and bulges
Toward Industrial Private AI: A Two-Tier Framework for Data and Model Security
With the advances in 5G and IoT devices, industries are vastly adopting artificial intelligence (AI) techniques for improving classification and prediction-based services. However, the use of AI also raises concerns regarding data privacy and security that can be misused or leaked. Private AI was recently coined to address the data security issue by combining AI with encryption techniques, but existing studies have shown that model inversion attacks can be used to reverse engineer the images from model parameters. In this regard, we propose a federated learning and encryption-based private (FLEP) AI framework that provides two-tier security for data and model parameters in an Industrial IoT environment. We propose a three-layer encryption method for data security and provided a hypothetical method to secure the model parameters. Experimental results show that the proposed method achieves better encryption quality at the expense of slightly increased execution time. We also highlight several open issues and challenges regarding the FLEP AI framework's realization
Generic harvest control rules for European fisheries
In European fisheries, most stocks are overfished and many are below safe biological limits, resulting in a call from the European Commission for new long-term fisheries
management plans. Here, we propose a set of intuitive harvest control rules that are economically sound, compliant with international fishery agreements, based on
relevant international experiences, supportive of ecosystem-based fisheries management and compatible with the biology of the fish stocks. The rules are based on the
concept of maximum sustainable yield (MSY), with a precautionary target biomass that is 30% larger than that which produces MSY and with annual catches of 91%
MSY. Allowable catches decline steeply when stocks fall below MSY levels and are set to zero when stocks fall below half of MSY levels. We show that the proposed
rules could have prevented the collapse of the North Sea herring in the 1970s and that they can deal with strong cyclic variations in recruitment such as known for
blue whiting. Compared to the current system, these rules would lead to higher long-term catches from larger stocks at lower cost and with less adverse environmental impact
Surgical Reconstruction in Chronic Posterior Cruciate Ligament Injuries of the Knee
Introduction: This is a cross-sectional study to evaluate the outcome of posterior cruciate ligament reconstruction in chronic injuries using ipsilateral Bone-patella tendon-Bone graft in nine patients, between January 2000 and January 2003 at our institution. Methods: Eight male and one female patient; their ages ranged from 18 to 36 years old. The surgery was done at an average of 17.2 months (range from 3 and 40 months) post injury. All patients were followed up for a minimum of two years period. The assessment was done at twelve and twenty-four months using Lysholm knee score, IKDC knee examination evaluation score and arthrometric measurement with KT-2000. Results: The result showed only moderate success in restoration of ligament stability with 73.4% satisfactory objective results. However, the functional improvement and patient satisfaction is only 55%. The incidences of degenerative changes were 89% at the time of operation. Conclusion: Surgical reconstruction of chronic Posterior Cruciate Ligament restored satisfactory stability of the knee but the functional outcome was only moderate
Get Your Foes Fooled: Proximal Gradient Split Learning for Defense Against Model Inversion Attacks on IoMT Data
The past decade has seen a rapid adoption of Artificial Intelligence (AI), specifically the deep learning networks, in Internet of Medical Things (IoMT) ecosystem. However, it has been shown recently that the deep learning networks can be exploited by adversarial attacks that not only make IoMT vulnerable to the data theft but also to the manipulation of medical diagnosis. The existing studies consider adding noise to the raw IoMT data or model parameters which not only reduces the overall performance concerning medical inferences but also is ineffective to the likes of deep leakage from gradients method. In this work, we propose proximal gradient split learning (PSGL) method for defense against the model inversion attacks. The proposed method intentionally attacks the IoMT data when undergoing the deep neural network training process at client side. We propose the use of proximal gradient method to recover gradient maps and a decision-level fusion strategy to improve the recognition performance. Extensive analysis show that the PGSL not only provides effective defense mechanism against the model inversion attacks but also helps in improving the recognition performance on publicly available datasets. We report 14.0 % , 17.9 % , and 36.9 % gains in accuracy over reconstructed and adversarial attacked images, respectively
Stream-Based Authentication Strategy Using IoT Sensor Data in Multi-homing Sub-aqueous Big Data Network
Big data analytics has addressed many in-place and remote network issues in a sub-aqueous distributed computing environment. Recently, a new phenomenon is introduced in the data analytics clusters that focus on multi-homing network connectivity procedures among off-ground multiple nodes of the large-scale on-running wireless industrial applications. In this way, the clusters perform multi-layer cross-connected task processing among various networks simultaneously and perform stream based data block placement over multiple nodes in a sequential order. This satisfies the procedural performance of the cluster; however, security remains an open issue in it because of unavailability of inter-network data block processing authorization. In this paper, we propose a stream based authentication mechanism, that specifically addresses security concerns of multi-homing sub-aqueous big data networks and presents a key authorization infrastructure that performs a proper handing taking among multiple off-ground Datanodes before an inter-network data block exchange. The simulation results depict that our approach increases multi-homing network compatibility and reliability while processing a data block in the sub-aqueous distributed computing environment
Activation of WNT and BMP signaling in adult human articular cartilage following mechanical injury
Acute full thickness joint surface defects can undergo repair, which involves tissue patterning and endochondral bone formation. Molecular signals regulating this process may contribute to the repair outcome, chronic evolution and, eventually, the onset of osteoarthritis. We tested the hypothesis that mechanical injury modulates morphogenetic pathways in adult human articular cartilage explants. Adjacent articular cartilage explants were obtained from preserved areas of the femoral condyles of patients undergoing arthroplasty for osteoarthritis, or from a normal joint of a patient undergoing lower limb amputation. Paired explants were individually maintained in explant culture. From each pair, one explant was mechanically injured and the other left uninjured as a control. Cultures were terminated at different time points for histochemistry, immunohistochemistry and gene expression analysis by reverse transcription real time PCR. Bone morphogenetic protein 2 (BMP-2) mRNA was upregulated in the injured explants. We detected phosphorylation of SMAD-1 and SMAD-5, consistent with activation of the bone morphogenetic protein (BMP) pathway. FRZB-1 mRNA was downregulated in the injured explants, suggesting de-repression of WNT signaling. Accordingly, expression of the canonical WNT target genes Axin-2 and c-JUN was upregulated in the injured explants. Activation of the canonical WNT signaling pathway by LiCl treatment induced upregulation of COL2A1 and Aggrecan mRNA, suggesting an anabolic effect. Phosphorylation of SMAD-1/-5 and downregulation of FRZB were confirmed in vivo in a mouse model of joint surface injury. Taken together, these data show modulation of the BMP and WNT pathways following mechanical injury in vitro and in vivo, which may play a role in the reparative response of the joint surface. These pathways may, therefore, represent potential targets in protocols of biological joint surface defect repai
Cross-calibration of CO- versus dust-based gas masses and assessment of the dynamical mass budget in Herschel-SDSS Stripe82 galaxies
We present a cross-calibration of CO- and dust-based molecular gas masses at z ≤ 0.2. Our results are based on a survey with the IRAM 30-m telescope collecting CO(1–0) measurements of 78 massive (logM⋆/M⊙> 10) galaxies with known gas-phase metallicities and with IR photometric coverage from Wide-field Infrared Survey Explorer(WISE; 22 μm) and Herschel Spectral and Photometric Imaging Receiver (SPIRE; 250, 350, 500μm). We find a tight relation (∼0.17 dex scatter) between the gas masses inferred from CO and dust continuum emission, with a minor systematic offset of 0.05 dex. The two methods can be brought into agreement by applying a metallicity-dependent adjustment factor (∼0.13 dex scatter). We illustrate that the observed offset is consistent with a scenario in which dust traces not only molecular gas but also part of the HI reservoir, residing in the H2-dominated region of the galaxy. Observations of the CO(2–1) to CO(1–0) line ratio for two-thirds of the sample indicate a narrow range in excitation properties, with a median ratio of luminosities ⟨R21⟩ ∼ 0.64. Finally, we find dynamical mass constraints from spectral line profile fitting to agree well with the anticipated mass budget enclosed within an effective radius, once all mass components (stars, gas, and dark matter) are accounted for
- …
