218 research outputs found
Concentration dependence of optical gain in Yb<sup>3+</sup>-doped potassium double tungstate channel waveguides
Etiology and outcome of hypoglycemia in young children: a retrospective cohort study
Objectives:
Hypoglycemia is one of the most common presenting complaints at a pediatric emergency department. There are many distinct causes of hypoglycemia, ranging from nutritional insufficiency to infectious origins to metabolic disorders. Full clinical assessment and appropriate investigations can help differentiate the cause of hypoglycemia with subsequent tailored management. All patients with hypoglycemia should have a full clinical assessment together with a hypoglycemia screen if appropriate. This clinical review aims to determine the investigation of hypoglycemia in young children (<6 years) and whether these patients received a subsequent diagnosis and adequate follow-up plans.
Material and Methods:
The laboratory database searched for all children from 0 to 6 years old, with hypoglycemia defined as plasma glucose (PG) <54.0 mg/dL (or <3.0 mmol/L) from 2013 to 2021 at the Royal Hospital of Children, Glasgow. Cases were reviewed for the biochemistry investigations to determine if they had hypoglycemia screening requested and/or performed the presenting complaint, clinical diagnosis, and subsequent follow-up arrangements.
Results:
Five hundred and one children were identified with hypoglycemia (PG <54.0 mg/dL) over a 9-year period. Of these patients, 28% (142/501) had a full hypoglycemia screen, 38% had a partial screen, and 34% (166/501) had no additional blood tests related to hypoglycemia screening other than a PG. The cause of hypoglycemia was identified in 15% (77/501), with gastroenteritis being the most common cause. Of those who were hypoglycemic, 48% (240/501) had an ongoing follow-up. Among those with severe hypoglycemia (PG ≤27.0 mg/dL) (86/501), causes were identified in 72% (62/86) and 63% (54/86) of this cohort which was followed up after the first presentation.
Conclusion:
Screening was not consistently performed for all patients presenting with hypoglycemia. A great portion of patients were not fully investigated or followed up. This could be a result of clinical judgment in the assessment of further investigation for hypoglycemia. However, moderate and severe hypoglycemia still require further investigations, which can potentially lead to long-term consequences if not managed appropriately
Pressure Dependence of Born Effective Charges, Dielectric Constant and Lattice Dynamics in SiC
The pressure dependence of the Born effective charge, dielectric constant and
zone-center LO and TO phonons have been determined for -SiC by a linear
response method based on the linearized augmented plane wave calculations
within the local density approximation. The Born effective charges are found to
increase nearly linearly with decreasing volume down to the smallest volume
studied, , corresponding to a pressure of about 0.8 Mbar. This
seems to be in contradiction with the conclusion of the turnover behavior
recently reported by Liu and Vohra [Phys.\ Rev.\ Lett.\ {\bf 72}, 4105 (1994)]
for -SiC. Reanalyzing their procedure to extract the pressure dependence of
the Born effective charges, we suggest that the turnover behavior they obtained
is due to approximations in the assumed pressure dependence of the dielectric
constant , the use of a singular set of experimental data
for the equation of state, and the uncertainty in measured phonon frequencies,
especially at high pressure.Comment: 25 pages, revtex, 5 postscript figures appended, to be published in
Phys. Rev.
Transfer of K-types on local theta lifts of characters and unitary lowest weight modules
In this paper we study representations of the indefinite orthogonal group
O(n,m) which are local theta lifts of one dimensional characters or unitary
lowest weight modules of the double covers of the symplectic groups. We apply
the transfer of K-types on these representations of O(n,m), and we study their
effects on the dual pair correspondences. These results provide examples that
the theta lifting is compatible with the transfer of K-types. Finally we will
use these results to study subquotients of some cohomologically induced
modules
Characterization of the functional domain of tissue inhibitor of metalloproteinases-2 (TIMP-2)
Structural gate decomposition for depth-optimal technology mapping in LUT-based FPGA designs
Adoption of Global Investment Performance Standards: Case of ASEAN
Research on voluntary compliance with accepted international standards has paid overwhelming attention to financial reporting standards, but not to investment performance standards. Previous research on the adoption of the Global Investment Performance Standards has overlooked the unique region of the Association of Southeast Asian Nations. Using 17 years (1999 to 2015) worth of data from all ten countries, which generates 170 country-year observations for each variable of the study, this paper evaluates whether, and how, social and economic pressures influence the adoption of GIPS in the region in the Institutional Theory lens. The results suggest that social pressure is more impactful than economic pressure on the adoption of GIPS. The findings have generated useful contributions and implications in this vein, and several future research directions have been identified.
Keywords: Global Investment Performance Standards (GIPS); ASEAN; investment profession; regional integration; voluntary adoption; sustainability reporting; Chartered Financial Analyst (CFA).
JEL classification: G11, G15, N95, P1
Precise Regulation of Gene Expression Dynamics Favors Complex Promoter Architectures
Promoters process signals through recruitment of transcription factors and RNA polymerase, and dynamic changes in promoter activity constitute a major noise source in gene expression. However, it is barely understood how complex promoter architectures determine key features of promoter dynamics. Here, we employ prototypical promoters of yeast ribosomal protein genes as well as simplified versions thereof to analyze the relations among promoter design, complexity, and function. These promoters combine the action of a general regulatory factor with that of specific transcription factors, a common motif of many eukaryotic promoters. By comprehensively analyzing stationary and dynamic promoter properties, this model-based approach enables us to pinpoint the structural characteristics underlying the observed behavior. Functional tradeoffs impose constraints on the promoter architecture of ribosomal protein genes. We find that a stable scaffold in the natural design results in low transcriptional noise and strong co-regulation of target genes in the presence of gene silencing. This configuration also exhibits superior shut-off properties, and it can serve as a tunable switch in living cells. Model validation with independent experimental data suggests that the models are sufficiently realistic. When combined, our results offer a mechanistic explanation for why specific factors are associated with low protein noise in vivo. Many of these findings hold for a broad range of model parameters and likely apply to other eukaryotic promoters of similar structure
Robust simplifications of multiscale biochemical networks
<p>Abstract</p> <p>Background</p> <p>Cellular processes such as metabolism, decision making in development and differentiation, signalling, etc., can be modeled as large networks of biochemical reactions. In order to understand the functioning of these systems, there is a strong need for general model reduction techniques allowing to simplify models without loosing their main properties. In systems biology we also need to compare models or to couple them as parts of larger models. In these situations reduction to a common level of complexity is needed.</p> <p>Results</p> <p>We propose a systematic treatment of model reduction of multiscale biochemical networks. First, we consider linear kinetic models, which appear as "pseudo-monomolecular" subsystems of multiscale nonlinear reaction networks. For such linear models, we propose a reduction algorithm which is based on a generalized theory of the limiting step that we have developed in <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. Second, for non-linear systems we develop an algorithm based on dominant solutions of quasi-stationarity equations. For oscillating systems, quasi-stationarity and averaging are combined to eliminate time scales much faster and much slower than the period of the oscillations. In all cases, we obtain robust simplifications and also identify the critical parameters of the model. The methods are demonstrated for simple examples and for a more complex model of NF-<it>κ</it>B pathway.</p> <p>Conclusion</p> <p>Our approach allows critical parameter identification and produces hierarchies of models. Hierarchical modeling is important in "middle-out" approaches when there is need to zoom in and out several levels of complexity. Critical parameter identification is an important issue in systems biology with potential applications to biological control and therapeutics. Our approach also deals naturally with the presence of multiple time scales, which is a general property of systems biology models.</p
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