Hybrid cascode feedforward compensation for nano-scale low-power ultra-area-efficient three-stage amplifiers

A modified frequency compensation technique is proposed for low-power area-efficient three-stage amplifiers driving medium to large capacitive loads. Coined hybrid cascode feedforward compensation (HCFC), the total compensation capacitor is divided and shared between two internal high-speed feedback loops instead of only one loop as is common in prior art. Detailed analysis of this technique shows significant improvement in terms of bandwidth and stability. This is verified for a 1.2-V amplifier driving a 500-pF capacitive load in 90-nm CMOS technology, where HCFC reduces the total capacitor size and improves the gain-bandwidth by at least 30% and 40% respectively, compared to the prevailing schemes.     

Nanofiltration for the separation of pharmaceuticals from nutrients in source-separated urine

The potential of nanofiltration for the separation of pharmaceutical and estrogenic compounds from salts in urine was investigated with the aim of producing a micropollutant-free nutrient solution that can be used as a fertilizer. A fresh urine solution and a synthetic solution of similar inorganic composition were tested at different pH values in order to investigate their separation behavior. These solutions were spiked with the micropollutants propranolol, ethinylestradiol, ibuprofen, diclofenac and carbamazepine. Among the membranes tested, NF270 showed the best performance with respect to the retention of micropollutants. The optimum retention of micropollutants was obtained at values of around pH 5. At this point, the retention of all micropollutants in non-hydrolysed urine was above 92%, while the corresponding value for the synthetic urine solution was above 73%. From the results, it can be concluded that the retention mechanism is determined by steric and electrostatic effects as well as by the partitioning of the micropollutants in the membrane. The nutrients urea and ammonia were well permeated, but phosphate and sulfate were almost completely retained. Nanofiltration can consequently be used to produce a permeate which contains most of the nitrogen and a greatly reduced proportion of micropollutants.     

Correlation of Immunological and Histopathological Features with Gene Expression-Based Classifiers in Colon Cancer Patients

The purpose of this study was to evaluate the association between four distinct histopathological features: (1) tumor infiltrating lymphocytes, (2) mucinous differentiation, (3) tumor-stroma ratio, plus (4) tumor budding and two gene expression-based classifiers—(1) consensus molecular subtypes (CMS) plus (2) colorectal cancer intrinsic subtypes (CRIS). All four histopathological features were retrospectively scored on hematoxylin and eosin sections of the most invasive part of the primary tumor in 218 stage II and III colon cancer patients from two independent cohorts (AMC-AJCC-90 and AC-ICAM). RNA-based CMS and CRIS assignments were independently obtained for all patients. Contingency tables were constructed and a χ2 test was used to test for statistical significance. Odds ratios with 95% confidence intervals were calculated. The presence of tumor infiltrating lymphocytes and a mucinous phenotype (>50% mucinous surface area) were strongly correlated with CMS1 (p < 0.001 and p = 0.008) and CRIS-A (p = 0.006 and p < 0.001). The presence of mucus (≥ 10%) was associated with CMS3: mucus was present in 64.1% of all CMS3 tumors (p < 0.001). Although a clear association between tumor-stroma ratio and CMS4 was established in this study (p = 0.006), still 32 out of 61 (52.5%) CMS4 tumors were scored as stroma-low, indicating that CMS4 tumors cannot be identified solely based on stromal content. Higher budding counts were seen in CMS4 and CRIS-B tumors (p = 0.045 and p = 0.046). No other associations of the measured parameters were seen for any of the other CRIS subtypes. Our analysis revealed clear associations between histopathologic features and CMS or CRIS subtypes. However, identification of distinct molecular subtypes solely based on histopathology proved to be infeasible. Combining both molecular and morphologic features could potentially improve patient stratification.     

The Interplay between Drivers of Erythropoiesis and Iron Homeostasis in Rare Hereditary Anemias: Tipping the Balance

Rare hereditary anemias (RHA) represent a group of disorders characterized by either impaired production of erythrocytes or decreased survival (i.e., hemolysis). In RHA, the regulation of iron metabolism and erythropoiesis is often disturbed, leading to iron overload or worsening of chronic anemia due to unavailability of iron for erythropoiesis. Whereas iron overload generally is a well-recognized complication in patients requiring regular blood transfusions, it is also a significant problem in a large proportion of patients with RHA that are not transfusion dependent. This indicates that RHA share disease-specific defects in erythroid development that are linked to intrinsic defects in iron metabolism. In this review, we discuss the key regulators involved in the interplay between iron and erythropoiesis and their importance in the spectrum of RHA.     

Development of the yeast flora of whole-crop maize during ensiling and during subsequent aerobiosis

The fresh maize plant was inhabited by non-fermenting basidiomycetous yeast species, viz. Candida ingeniosa, Cryptococcus laurentii, Sporobolomyces roseus, Sporidiobolus salmonicolor and Rhodotorula rubra. These species had vanished after 2 days of anaerobiosis in a laboratory-scale silo. After this time, ascomycetous species tolerant to acetic acid were isolated. Successively Candida holmii, C. milleri, C. krusei, C. lambica, C. famata, Geotrichum candidum and Hansenula anomala were encountered. Except for C. famata and G. candidum these yeasts vigorously ferment glucose. Total yeast counts were 10⁷ g^?1 during the first 2 weeks and gradually decreased to about 10⁵ g^?1 after 4 months. This shows that anaerobic silage provides an adverse environment for yeasts. Exposure of maize silage to air resulted in complete consumption of lactic and acetic acids within 5 days. This was due to growth of C. hoimii, C. lambica and C. milled. The physiologically similar yeast species C. holmii and C. milled were both abundant from the early stage of the fermentation and during aerobiosis. However, C. milled predominated in the first 2 weeks of anaerobiosis. The less frequently occurring yeast species C. famata, G. candidum and H. anomala assimilated lactic acid and ethanol as well as minor products of bacterial sugar fermentation such as acetoin and butan-2,3-diol but not diacetyl.     

Design principles for low-voltage low-power analog integrated circuits

In this paper it is argued that there are good reasons to choose current as the information-carrying quantity in the case of low-voltage low-power design constraints. This paper focuses on the influence of the transfer quality on that choice. To obtain power-efficient transfer quality, indirect feedback is shown to be a good alternative to traditional feedback techniques.     

A transistor-only switched current sigma-delta A/D converter for aCMOS speech CODEC

This paper describes the design and measurement results of a 1-b A/D converter based on a transistor-only switched current (SI) second-order sigma-delta modulator. The 1-b A/D converter was simulated and processed in ES2 1.5 μm CMOS technology. The second-order filter is based on class AB switched current-integrators. The analog current memory cells in the integrator are optimized for linear operation with a strong class AB overlap region to avoid class B operation and cross-over distortion. Measurement results on the first silicon performing 11-b resolution show that this circuit technique is promising for speech CODEC A/D conversion     

Cost-sensitive ensemble learning: a unifying framework

Data Mining and Knowledge Discovery - Over the years, a plethora of cost-sensitive methods have been proposed for learning on data when different types of misclassification errors incur different...     

PERSIST: Policy-Based Data Management Middleware for Multi-Tenant SaaS Leveraging Federated Cloud Storage

NoSQL data stores are often combined to address different requirements within the same application. The implication of this trend is particularly important and relevant in the context of multi-tenant SaaS applications where tenants commonly have different storage- and privacy-related requirements and thus they desire to customize the storage setup according to their specific needs. Consequently, application developers are increasingly combining storage resources: on-premise and public cloud resources in a hybrid cloud setup, different external public cloud storage resources and providers in a federated cloud storage setup, etc. The consequences of these trends are twofold: (i) application developers and SaaS providers have to deal with heterogeneous technologies, different APIs, and implement complex storage logic (to address different requirements of tenants), all within the application layer; and (ii) storage architectures have become less rigid, and techniques are required to flexibly change the storage configuration of running applications, up to the level of individual service requests. To address these challenges, we present PERSIST, a middleware architecture that (i) externalizes the complexity of a federated cloud storage architecture and the complex storage logic from the SaaS application to storage policies, allows tenants to enforce different storage- and privacy-related requirements at a fine-grained level; and (ii) supports the dynamic (re)configurability of the underlying federated cloud storage architecture. Application-specific policies can be customized by individual tenants at run time, and PERSIST offers support for run-time cross-provider polyglot persistence and the confidentiality of sensitive data through encryption. We have validated PERSIST in a working prototype implementation. Our extensive evaluation efforts show (i) the accomplished reduction in the required development effort to support complex storage policies, (ii) the reduction in cost/effort to change the data storage architecture itself, and finally (iii) the acceptability of the performance overhead (around 6% for insert, and 2% for read, update and delete transactions).