Realizing spin-Hamiltonians in nanoscale active photonic lattices

Spin models arise in the microscopic description of magnetic materials and have been recently used to map certain classes of optimization problems involving large degrees of freedom. In this regard, various optical implementations of such Hamiltonians have been demonstrated to quickly converge to the global minimum in the energy landscape. Yet, so far, an integrated nanophotonic platform capable of emulating complex magnetic materials is still missing. Here, we show that the cooperative interplay among vectorial electromagnetic modes in coupled metallic nanolasers can be utilized to implement certain types of spin Hamiltonians. Depending on the topology/geometry of the arrays, these structures can be governed by a classical XY Hamiltonian that exhibits ferromagnetic and antiferromagnetic couplings, as well as geometrical frustration. Our results pave the way towards a scalable nanophotonic platform to study spin exchange interactions and could address a variety of optimization problems

Are Patents Impeding Medical Care and Innovation?

This month's debate examines whether the current patent system is crucial for stimulating health research or whether it is stifling biomedical research and impeding medical care. Background to the debate: Pharmaceutical and medical device manufacturers argue that the current patent system is crucial for stimulating research and development (R&D), leading to new products that improve medical care. The financial return on their investments that is afforded by patent protection, they claim, is an incentive toward innovation and reinvestment into further R&D. But this view has been challenged in recent years. Many commentators argue that patents are stifling biomedical research, for example by preventing researchers from accessing patented materials or methods they need for their studies. Patents have also been blamed for impeding medical care by raising prices of essential medicines, such as antiretroviral drugs, in poor countries. This debate examines whether and how patents are impeding health care and innovation

PRIVACY DASHBOARD

A computing device may display a graphical user interface (GUI) of a privacy dashboard showing permission usage of sensor data (e.g., location, microphone, camera, etc.) and content provider data (e.g., files, media, contacts, calendar, short message service (SMS), call log, etc.) by applications for a given time period (e.g., the past 24 hours, the past 7 days, etc.). The privacy dashboard may include graphs, lists, and other visual indicators for displaying information about the permission usage per sensor and/or per application in a clear, concise, and comprehensible way. In the privacy dashboard, the computing device may include certain types of privacy information, such as sensor data usage, within the initial screen while omitting other types of privacy information, such as content provider data usage, from the initial screen. The computing device may display information about other types of privacy information in response to a user input (e.g., touch input). In some examples, the privacy dashboard may enable a user to see detailed information about permission usage of an application and manage permissions for each application via the privacy dashboard. As such, the privacy dashboard may improve user awareness and comprehension of data access by increasing transparency with respect to permission usage by applications

Realizing spin-Hamiltonians in nanoscale active photonic lattices

Spin models arise in the microscopic description of magnetic materials and have been recently used to map certain classes of optimization problems involving large degrees of freedom. In this regard, various optical implementations of such Hamiltonians have been demonstrated to quickly converge to the global minimum in the energy landscape. Yet, so far, an integrated nanophotonic platform capable of emulating complex magnetic materials is still missing. Here, we show that the cooperative interplay among vectorial electromagnetic modes in coupled metallic nanolasers can be utilized to implement certain types of spin Hamiltonians. Depending on the topology/geometry of the arrays, these structures can be governed by a classical XY Hamiltonian that exhibits ferromagnetic and antiferromagnetic couplings, as well as geometrical frustration. Our results pave the way towards a scalable nanophotonic platform to study spin exchange interactions and could address a variety of optimization problems

Realizing Spin-Hamiltonians in Nanolaser Lattices

We demonstrate both theoretically and experimentally that coupled metallic nanolasers can be used to emulate spin-Hamiltonians. Depending on the geometry of the array, we observe ferromagnetic and antiferromagnetic behaviors, as well as geometric frustration

Adnexal torsion in a heterotopic pregnancy: a rare clinical entity with diagnostic dilemma

Adnexal torsion is an uncommon cause of surgical emergency during pregnancy. Its incidence is 1 in 5000 pregnancies, occurring more frequently in the first trimester after ovarian hyper stimulation. Heterotopic pregnancy is also a rare entity and cause pain abdomen but without the classical symptom of bleeding per vaginum. Heterotopic pregnancy with adnexal torsion is extremely rare but increases the case fatality rate. Hence the differential diagnosis of pain abdomen during early pregnancy both may be considered and it should not be forgotten that adnexal torsion may occur in absence of ovarian cyst. We report a case of adnexal torsion that was successfully managed by laparoscopy followed by laparotomy during pregnancy and diagnosed as a heterotopic pregnancy after getting the histopathological report. A 24-year-old G2P1 admitted to LR of SCBMCH at 4 weeks of GA with severe left abdominal pain and nausea for one day. Her vitals were stable. There was tenderness on the left iliac fossa with cervical motion tenderness and left POD fullness and tenderness, TAS visualized a foetus in utero with GA of 7 weeks and a hyperechoic mass of 6 x 6 cm on left side. Laparotomy done as the mass was gangrenous, enlarged and haemorhagic. Total salpingo oophorectomy of left side was done. Postoperative period was uneventful and managed with progesterone to continue the pregnancy. Histopathology report confirmed heterotopic pregnancy. This case suggests that clinicians should suspect both heterotopic pregnancy and adnexal torsion while evaluating pregnant patients with pain abdomen

Correlation of Clinical Examination, MRI and Arthroscopy Findings in Menisco-Cruciate Injuries of the Knee: A Prospective Diagnostic Study

Background: The aim of this study was to examine the correlation of the clinical examination, MRI and arthroscopic findings in cruciate ligaments and meniscal injuries of knee and to evaluate the accuracy of clinical examination and MRI with the gold standard arthroscopy. Methods: A prospective diagnostic double-blind study was conducted on 104 consecutive patients admitted to the outdoor/casualty with trauma to the knee complaining of knee pain/locking/ instability, from August 2012 to June 2014. All the patients were subjected to clinical examination, MRI scanning and diagnostic arthroscopy. Variables like sensitivity, specificity, positive predictive value, negative predictive value and accuracy of clinical examination and MRI against arthroscopy were evaluated. Results: The sensitivity, specificity and accuracy of clinical examination for anterior cruciate ligament tears were 94.7%, 71.4% and 88.5% and for MRI were 94.7%, 78.6% and 90.4%, respectively; for posterior cruciate ligament tears 100%, 100% and 100% for clinical examination and for MRI 80%, 97.9% and 96.2%, respectively. These values for medial meniscus tears were 76.5%, 68.6% and 71.2% for clinical examination and 88.2%, 62.8% and 71.2% respectively for MRI. For lateral meniscus tears, 40%, 94.6% and 78.8% for clinical examination and 46.7%, 89.2% and 76.9% respectively for MRI. Conclusions: A skillfully performed clinical examination establishes a diagnosis on which an arthroscopic procedure can be planned, reserving MRI scans for patients where the clinical examination fails to establish a diagnosis or cannot be performed. Decision to use MRI should be based on the criteria that it would confirm, expand the diagnosis or change diagnosis in such a way that alters the proposed treatment