Quantifying the computational capability of a nanomagnetic reservoir computing platform with emergent magnetisation dynamics.

Devices based on arrays of interconnected magnetic nano-rings with emergent magnetization dynamics have recently been proposed for use in reservoir computing applications, but for them to be computationally useful it must be possible to optimise their dynamical responses. Here, we use a phenomenological model to demonstrate that such reservoirs can be optimised for classification tasks by tuning hyperparameters that control the scaling and input-rate of data into the system using rotating magnetic fields. We use task-independent metrics to assess the rings' computational capabilities at each set of these hyperparameters and show how these metrics correlate directly to performance in spoken and written digit recognition tasks. We then show that these metrics, and performance in tasks, can be further improved by expanding the reservoir's output to include multiple, concurrent measures of the ring arrays' magnetic states.

Measurement of the heat flux normalized spin Seebeck coefficient of thin films as a function of temperature.

The spin Seebeck effect (SSE) has generated interest in the thermoelectric and magnetic communities for potential high efficiency energy harvesting applications and spintronic communities as a source of pure spin current. Understanding the underlying mechanisms requires characterization of potential materials across a range of temperatures; however, for thin films, the default measurement of an applied temperature gradient (across the sample) has been shown to be compromised by the presence of thermal resistances. Here, we demonstrate a method to perform low temperature SSE measurements where, instead of monitoring the temperature gradient, the heat flux passing through the sample is measured using two calibrated heat flux sensors. This has the advantage of measuring the heat loss through the sample as well as providing a reliable method to normalize the SSE response of thin film samples. We demonstrate this method with an SiO2/Fe3O4/Pt sample where a semiconducting-insulating transition occurs at the Verwey transition, TV, of Fe3O4 and quantify the thermomagnetic response above and below TV.

CD66 and CD49f expressing cells are associated with distinct neoplastic phenotypes and progression in human cervical cancer.

BACKGROUND: In this study, building on our recent work identifying a subset of CD66+ve cells with distinctive tumourigenic properties in human cervical cancers, we examine patterns of expression and function of these cells; to generate insights into the process of metastasis. METHODS: Our broad approach in this study has been to compare the expression and function of two subsets marked by CD66 and CD49f. We use a combination of histopathology, immunostaining and flow cytometry, functional analysis of an established cervical cancer cell line and a retrospective analysis of a cohort of cervical cancer. RESULTS: We noted CD66 expression associated with clusters of cells which are spindle shaped, SMA+ve, podoplanin+ve, phalloidin high, fibronectin high, plakoglobin low, ki67-ve and CK10+ve at the migratory phase along with features of partial EMT. Further, TGFß1 a well known regulator of EMT, positively correlated with CD66 expression. The additional CD49f+ve subset at the leading invading front of migration was SMA-ve, phalloidin low, fibronectin low, plakoglobin high, Ki67+ve and CK14+ve. These data are consistent with a role for CD66 cells in metastatic invasion with a collective cell migration process co-opting the CD49f subset. Our retrospective analysis of a cohort is consistent with a role for CD66 in metastasis. However, the broad analysis of CD66, CD49f and TGFß1 expression with patterns of overall survival points to a possible protective effect particularly for local recurrences. Hence, future studies focussing on potential heterogeneity within the CD66 subset along with the possible role of isoforms and intra-cellular roles would be essential.

Modulation of CaV2.1 channels by neuronal calcium sensor-1 induces short-term synaptic facilitation.

Facilitation and inactivation of P/Q-type Ca2+ currents mediated by Ca2+/calmodulin binding to Ca(V)2.1 channels contribute to facilitation and rapid depression of synaptic transmission, respectively. Other calcium sensor proteins displace calmodulin from its binding site and differentially modulate P/Q-type Ca2 + currents, resulting in diverse patterns of short-term synaptic plasticity. Neuronal calcium sensor-1 (NCS-1, frequenin) has been shown to enhance synaptic facilitation, but the underlying mechanism is unclear. We report here that NCS-1 directly interacts with IQ-like motif and calmodulin-binding domain in the C-terminal domain of Ca(V)2.1 channel. NCS-1 reduces Ca2 +-dependent inactivation of P/Q-type Ca2+ current through interaction with the IQ-like motif and calmodulin-binding domain without affecting peak current or activation kinetics. Expression of NCS-1 in presynaptic superior cervical ganglion neurons has no effect on synaptic transmission, eliminating effects of this calcium sensor protein on endogenous N-type Ca2+ currents and the endogenous neurotransmitter release machinery. However, in superior cervical ganglion neurons expressing wild-type Ca(V)2.1 channels, co-expression of NCS-1 induces facilitation of synaptic transmission in response to paired pulses and trains of depolarizing stimuli, and this effect is lost in Ca(V)2.1 channels with mutations in the IQ-like motif and calmodulin-binding domain. These results reveal that NCS-1 directly modulates Ca(V)2.1 channels to induce short-term synaptic facilitation and further demonstrate that CaS proteins are crucial in fine-tuning short-term synaptic plasticity.

CD66+ cells in cervical precancers are partially differentiated progenitors with neoplastic traits.

Cervical cancers, a malignancy associated with oncogenic papilloma viruses, remain a major disease burden in the absence of effective implementation of preventive strategies. CD66(+) cells have previously been identified as a tumor-propagating subset in cervical cancers. We investigated the existence, differentiation state, and neoplastic potential of CD66(+) cells in a precancer cell line harboring HPV31b episomes. The gene expression profile of CD66(high) cells overlaps with differentiated keratinocytes, neoplastic mesenchymal transition, cells of the squamocolumnar junction, and cervical cancer cell line-derived spheroids. There is elevated expression of DNMT1, Notch1, and the viral gene product E1⁁E4 in CD66(high) cells. Thus, CD66(high) cells, in the absence of differentiating signals, express higher levels of key regulators of keratinocytes stemness, differentiation, and the viral life cycle, respectively. We also find a striking association of neoplastic traits, including migration, invasion, and colony formation, in soft agar with CD66(high) cells. These properties and a distinct G2-M-enriched cell-cycle profile are conserved in cells from cervical cancers. Principally, using a precancerous cell line, we propose that CD66(high) cells have an intermediate differentiation state, with a cellular milieu connected with both viral replication and neoplastic potential, and validate some key features in precancer lesions. Such pathophysiologically relevant systems for defining cellular changes in the early phases of the disease process provide both mechanistic insight and potential therapeutic strategies. Collectively, our data provide a rationale for exploring novel therapeutic targets in CD66(+) subsets during cancer progression.

Ca2+-independent activation of Ca2+/calmodulin-dependent protein kinase II bound to the C-terminal domain of CaV2.1 calcium channels.

Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) forms a major component of the postsynaptic density where its functions in synaptic plasticity are well established, but its presynaptic actions are poorly defined. Here we show that CaMKII binds directly to the C-terminal domain of Ca(V)2.1 channels. Binding is enhanced by autophosphorylation, and the kinase-channel signaling complex persists after dephosphorylation and removal of the Ca(2+)/CaM stimulus. Autophosphorylated CaMKII can bind the Ca(V)2.1 channel and synapsin-1 simultaneously. CaMKII binding to Ca(V)2.1 channels induces Ca(2+)-independent activity of the kinase, which phosphorylates the enzyme itself as well as the neuronal substrate synapsin-1. Facilitation and inactivation of Ca(V)2.1 channels by binding of Ca(2+)/CaM mediates short term synaptic plasticity in transfected superior cervical ganglion neurons, and these regulatory effects are prevented by a competing peptide and the endogenous brain inhibitor CaMKIIN, which blocks binding of CaMKII to Ca(V)2.1 channels. These results define the functional properties of a signaling complex of CaMKII and Ca(V)2.1 channels in which both binding partners are persistently activated by their association, and they further suggest that this complex is important in presynaptic terminals in regulating protein phosphorylation and short term synaptic plasticity.

Synthesis and antibacterial activity of a novel series of 2,3-diaryl-substituted-imidazo(2,1-b)-benzothiazole derivatives.

Benzothiazole and imidazole compounds are extensively studied heterocyclics due to their wide spectrum of bioactivities. Among them, the imidazo(2,1-b)-benzothiazole derivatives are pharmacologically important because of their immunostimulant, anti-inflammatory, antifungal, antimicrobial, antitumor, and other activities. In the present research work, a novel series of 2,3-diaryl-substituted imidazo(2,1-b)-benzothiazoles 13a-o have been synthesized by reaction of substituted 2-aminobenzothiazoles 1-8 and an appropriately substituted alpha-bromo-1-(4''-substituted)-phenyl-2-(4'-substituted)-phenyl-1-ethanones 9-12 in the presence of anhydrous acetonitrile. They were characterized by physicochemical, elemental, and spectral (IR, (1)H-NMR, and Mass) data. All the synthesized compounds were screened for their in-vitro antibacterial activity against Gram-positive, Gram-negative bacteria. The investigation of antibacterial screening data revealed that most of the compounds tested have demonstrated congruent activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa as compared with the standard ampicillin. Among the series, compounds 13d, 13h, and 13m exhibited excellent an antibacterial activity profile as compared with the standard. In summary, preliminary results indicate that some of the newly synthesized title compounds exhibited promising antibacterial activities and they warrant more consideration as prospective antimicrobials.

Safety and efficacy of the M2A patency capsule for diagnosis of critical intestinal patency: results of a prospective clinical trial.

BACKGROUND AND AIM: The presence of a critical intestinal stricture is a contraindication for conventional capsule endoscopy for the risk of impaction. Prior assessment of intestinal patency can substantially minimize this risk. The aim of the present study was to assess the safety and efficacy of the M2A patency capsule (PC) for verification of intestinal strictures. METHODS: The M2A PC consists of a biodegradable body surrounding a small radiofrequency identification (RFID) tag. This capsule was administered to patients with known or suspected intestinal strictures. Patency was verified if the capsule was excreted intact. The capsule disintegrated into small fragments and only the RFID tag was excreted if retained at the stricture beyond a stipulated time. The patency scanner was used to detect the RFID tag externally. The M2A video capsule (VC) was administered to patients who excreted the intact capsule. RESULTS: Twenty-six patients with known or suspected intestinal strictures were administered the M2A PC. This included 16 (61%) patients with tuberculosis, eight (31%) with Crohn's disease, and one each of postoperative and malignant strictures. Eight capsules were excreted intact within 72 h and two at 109 and 110 h. Fifteen capsules disintegrated in the G(I) tract and one capsule was removed during surgery. No PC-related complications were noted. Six of the eight patients who tested positive for patency were tested with the regular M2A VC with normal excretion. CONCLUSION: The M2A PC is a reliable indicator of functional patency in suspected or even known cases of intestinal stricture. It could be used prior to conventional capsule endoscopy to predict and minimize the risk of impaction.

Impact of reducing duodenobiliary reflux on biliary stent patency: an in vitro evaluation and a prospective randomized clinical trial that used a biliary stent with an antireflux valve.

BACKGROUND: The mechanisms leading to occlusion of plastic biliary stents (PBS) are not known. OBJECTIVE: To evaluate the impact of reducing duodenobiliary reflux on stent patency rate. DESIGN: A newly designed antireflux PBS (AR-PBS) was tested in vitro by using ox bile. A prospective randomized trial in human beings was conducted. SETTING: Tertiary medical center. PATIENTS: Patients with malignant bile-duct strictures were studied. INTERVENTIONS: A PBS or an AR-PBS stent was placed by using standard techniques, and the patients were followed at regular intervals. Patients presenting with stent occlusion underwent re-stent placement with either a PBS or a metal stent. MAIN OUTCOME MEASUREMENTS: In vitro: resistance to retrograde flow and comparison of the basal and peak antegrade flow pressures between the 2 stents. In vivo: stent patency rates, complications, and the efficacy of the stents in improving the liver test. RESULTS: The AR-PBS stent could withstand a retrograde pressure gradient of >320 mm Hg compared with <1 mm Hg for the PBS. Secondary to the siphon effect of the valve, the antegrade flow resistance offered by the AR-PBS was on the negative side for all flow rates compared with PBS (P < .001). The median patency of the AR-PBS in human studies was 145 days (range, 52-252 days) compared with 101 days (range, 41-210 days) for the PBS (P = .002). Both stents were equally effective in improving the liver test, and complication rates were similar in the 2 groups. LIMITATIONS: The occluded stents were not examined microscopically. CONCLUSIONS: The antireflux biliary stent remains patent for a longer time and hence duodenobiliary reflux may be contributing to stent occlusion.

A comparison between quarter, partial and total laser assisted hatching in selected infertility patients.

BACKGROUND: The object of this study was to evaluate the efficacy of laser assisted hatching (LAH) of embryos on implantation and pregnancy rates of a selected group of infertility patients. METHODS: A total of 322 cycles using LAH was undertaken in our Centre between June 1998 and September 1999. Patients were offered LAH if they fell in either one or more of the following categories: (i) Patients over 37 years of age undergoing either IVF or intracytoplasmic sperm injection (ICSI) treatment cycles; (ii) patients with more than 2 previous treatment cycle failures; (iii) patients undergoing frozen embryo replacement cycles and (iv) women who were considered to be poor responders. The initial results of totally breaching the zona pellucida (total LAH; group 1) did not meet with our expectations. We subsequently modified the technique to thinning one area of the zona pellucida (partial LAH; group 2) and this thinned area was then extended to a quarter segment (quarter LAH; group 3). RESULTS: In group 1, the pregnancy rate was 14.6% with a clinical pregnancy rate of 5.2%. In group 2 the pregnancy rate was 20.9% with a clinical pregnancy rate of 18% and for patients in group 3 the pregnancy rate was 29.0% with a clinical pregnancy rate of 22.1%. CONCLUSIONS: Overall there was firm statistical evidence that the pregnancy and clinical pregnancy rates arising from quarter LAH were higher in comparison with partial and total LAH.

Gestational surrogacy: a feasible option for patients with Rokitansky syndrome.

Rokitansky syndrome is a developmental defect characterized by agenesis of the uterus and vagina but normal gonads and secondary sexual characters. It is not commonly transmitted as a dominant genetic trait. Surrogacy, which is legally and ethically accepted in the UK and other countries, has made it possible for the patients with this syndrome to have their own genetic children. Six patients with Rokitansky syndrome underwent 11 ovarian stimulation cycles that resulted in 11 fresh and three frozen embryo transfer procedures into six prospective surrogate mothers. Both commissioning and surrogate couples were properly screened and counselled and their treatment was approved by the clinic internal review committee (ethics committee). The treatment cycles resulted in six clinical pregnancies (42.9% pregnancy rate per embryo transfer and 54.5% per oocyte retrieval) and three live births (21. 4% per embryo transfer, 27.3% per retrieval and 50% per patient). Gestational surrogacy is a viable treatment for patients with Rokitansky syndrome. Such patients should be well informed and supported to be able to have a family using their own genetic gametes.