403 research outputs found
The transfer of fibres in the carding machine
The problem of understanding the transfer of fibres between carding-machine surfaces is addressed by considering the movement of a single fibre in an airflow. The structure of the aerodynamic flow field predicts how and when fibres migrate between the different process surfaces. In the case of a revolving-flats carding machine the theory predicts a âstrongâ aerodynamic mechanism between taker-in and cylinder and a âweakâ mechanism between cylinder and removal cylinder resulting in effective transfer in the first case and a more limited transfer in the second
Interactions between liquid Sn-Bi based solders and contact metals for high temperature applications
Liquid solder interconnects are promising as an alternative
approach to conventional high melting point solder
interconnects for applications where the operating
temperature is likely to exceed 125°C. In order to ensure that
a liquid solder interconnect remains in contact with the
terminations on the component and the substrate, and that
electrical contact between them remains unbroken, there must
be some growth of an intermetallic compound (IMC) at the
interfaces between the solder and the contact metallizations.
However, given that IMC growth is generally much faster
when the solder is liquid, the growing IMC must act as a
strong diffusion barrier to suppress further IMC growth. This
paper presents preliminary studies of liquid-phase Sn-Bi
based solders that result in stable interfaces between the
solders and three common contact metallizations, consisting
of electroless Ni(P)/Au, of Cu and of Ti-W. Small quantities
(1 or 2 %) of an additional element, including Cr, Si, Zn, Ag,
Au, Al and Cu, have been alloyed with the eutectic Sn-Bi
composition to find an effective inhibitor additive that can
achieve a strong IMC diffusion barrier. IMCs and their
growth rates, as well as the consumption rates of the three
contact metallizations in contact with the molten solders, were
investigated. Storage temperatures of 200°C and 240°C were
used, with storage times ranging between two hours and one
month. Results to date show that suitable additives can
significantly reduce IMC growth rates for both the Ni(P)-Au
and Cu contact metallizations, while no appreciable IMC
growth is observed for Ti-W in contact with both the original
and the various alloyed Sn-Bi based solders. Based on the
current results, criteria to further assist the design of feasible
molten liquid solder â contact metallization systems have
been deduced
Câterminal variants of the P2X7 receptor are associated with prostate cancer progression and bone metastasis â evidence from clinical and preâclinical data
PRIMA1 mutation: A new cause of nocturnal frontal lobe epilepsy
Objective
Nocturnal frontal lobe epilepsy (NFLE) can be sporadic or autosomal dominant; some families have nicotinic acetylcholine receptor subunit mutations. We report a novel autosomal recessive phenotype in a single family and identify the causative gene.
Methods
Whole exome sequencing data was used to map the family, thereby narrowing exome search space, and then to identify the mutation.
Results
Linkage analysis using exome sequence data from two affected and two unaffected subjects showed homozygous linkage peaks on chromosomes 7, 8, 13, and 14 with maximum LOD scores between 1.5 and 1.93. Exome variant filtering under these peaks revealed that the affected siblings were homozygous for a novel splice site mutation (c.93+2T>C) in the PRIMA1 gene on chromosome 14. No additional PRIMA1 mutations were found in 300 other NFLE cases. The c.93+2T>C mutation was shown to lead to skipping of the first coding exon of the PRIMA1 mRNA using a minigene system.
Interpretation
PRIMA1 is a transmembrane protein that anchors acetylcholinesterase (AChE), an enzyme hydrolyzing acetycholine, to membrane rafts of neurons. PRiMA knockout mice have reduction of AChE and accumulation of acetylcholine at the synapse; our minigene analysis suggests that the c.93+2T>C mutation leads to knockout of PRIMA1. Mutations with gain of function effects in acetylcholine receptor subunits cause autosomal dominant NFLE. Thus, enhanced cholinergic responses are the likely cause of the severe NFLE and intellectual disability segregating in this family, representing the first recessive case to be reported and the first PRIMA1 mutation implicated in disease
"The extreme penalty of the law": mercy and the death penalty as aspects of state power in colonial Nyasaland, c. 1903-47
Open access article.Capital punishment was the pinnacle of the colonial judicial system and its use of state violence, but has previously been neglected as a topic of historical research in Africa. This article is based on the case files and legal records of over 800 capital trials â predominantly for murder â dating between 1900 and 1947. It outlines the functioning of the legal system in Nyasaland and the tensions between âviolenceâ and âhumanitarianismâ in the use and reform of the death penalty. Capital punishment was a political penalty as much as a judicial punishment, with both didactic and deterrent functions: it operated through mercy and the sparing of condemned lives as well as through executions. Mercy in Nyasaland was consistent with colonial political objectives and cultural values: it was decided not only on the facts of cases, but according to British conceptions of âjusticeâ, âorderâ, âcriminalityâ, and âAfricanâ behaviour. This article analyses the use of mercy in Nyasaland to provide a lens on the nature of colonial governance, and the tensions between African and colonial understandings of violence.Arts and Humanities Research Council (UK) and the Beit Fund, University of Oxfor
The management of diabetic ketoacidosis in children
The object of this review is to provide the definitions, frequency, risk factors, pathophysiology, diagnostic considerations, and management recommendations for diabetic ketoacidosis (DKA) in children and adolescents, and to convey current knowledge of the causes of permanent disability or mortality from complications of DKA or its management, particularly the most common complication, cerebral edema (CE). DKA frequency at the time of diagnosis of pediatric diabetes is 10%â70%, varying with the availability of healthcare and the incidence of type 1 diabetes (T1D) in the community. Recurrent DKA rates are also dependent on medical services and socioeconomic circumstances. Management should be in centers with experience and where vital signs, neurologic status, and biochemistry can be monitored with sufficient frequency to prevent complications or, in the case of CE, to intervene rapidly with mannitol or hypertonic saline infusion. Fluid infusion should precede insulin administration (0.1 U/kg/h) by 1â2 hours; an initial bolus of 10â20 mL/kg 0.9% saline is followed by 0.45% saline calculated to supply maintenance and replace 5%â10% dehydration. Potassium (K) must be replaced early and sufficiently. Bicarbonate administration is contraindicated. The prevention of DKA at onset of diabetes requires an informed community and high index of suspicion; prevention of recurrent DKA, which is almost always due to insulin omission, necessitates a committed team effort
Follow-up for screen-detected ductal carcinoma in situ: Results of a survey of UK centres participating in the Sloane project
Neuromatch Academy: a 3-week, online summer school in computational neuroscience
Neuromatch Academy (https://academy.neuromatch.io; (van Viegen et al., 2021)) was designed as an online summer school to cover the basics of computational neuroscience in three weeks. The materials cover dominant and emerging computational neuroscience tools, how they complement one another, and specifically focus on how they can help us to better understand how the brain functions. An original component of the materials is its focus on modeling choices, i.e. how do we choose the right approach, how do we build models, and how can we evaluate models to determine if they provide real (meaningful) insight. This meta-modeling component of the instructional materials asks what questions can be answered by different techniques, and how to apply them meaningfully to get insight about brain function
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