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Radiatively driven convection in ice-covered lakes: Observations, scaling, and a mixed layer model

Penetrative convection is discussed where the instability is driven by radiative heating of water below the temperature of maximum density. Convection of this type occurs in ice-covered freshwater lakes in late spring, when the snow cover vanishes and solar radiation is absorbed beneath the ice cover. The vertical temperature structure, bulk mixed layer scaling, and mixed layer deepening are exami

Transcriptional dynamics of the embryonic stem cell switch

Recent ChIP experiments of human and mouse embryonic stem cells have elucidated the architecture of the transcriptional regulatory circuitry responsible for cell determination, which involves the transcription factors OCT4, SOX2, and NANOG. In addition to regulating each other through feedback loops, these genes also regulate downstream target genes involved in the maintenance and differentiation

CYP gene polymorphisms and early menarche

Early age at menarche is a risk factor for breast cancer. A previous study reported a significant positive association between the CYP3A4*1B variant allele and early puberty. We investigated whether polymorphisms of the CYP3A4, CYP17, CYP1B1, and CYP1A2 genes predict the age at onset of menarche. Five hundred eighty-three nulliparous women between ages 17 and 35, of various ethnic backgrounds, com

Investigation of the bond strength between the photo-sensitive polymer SU-8 and gold

We present the results from a thorough investigation of the bond strength between the photo-polymer SU-8 and Au. The data were obtained by pull-test experiments, below the glass transition temperature of the polymer. The different aspects that we investigated were: (i) the effect of using different adhesion promoters between the SU-8 and Au; (ii) the influence of the processing sequence, keeping e

First human transplantation of a nonacceptable donor lung after reconditioning ex vivo.

Purpose. This article describes an ex vivo method to recondition and transplant rejected donor lungs. Description. A 19-year-old man was brain dead after a traffic accident. A roentgenogram showed bilateral lung contusion. He had ongoing intratracheal bleeding. After optimizing ventilator treatment and suctioning the airways, PaO2 was 9 kPa (67.5 mm Hg) on FiO(2) = 0.7. The lungs were rejected by

Efficacy and safety of fixed low-dose dalteparin in preventing venous thromboembolism among obese or elderly hospitalized patients - A subgroup analysis of the PREVENT Trial

Background: We were concerned that a fixed rather than a weight-based dosing regimen of dalteparin sodium to prevent venous thromboembolism. (VTE) might result in decreased efficacy in obese patients and decreased safety in elderly patients. Methods: We retrospectively performed subgroup analyses using the database from the Prospective Evaluation of Dalteparin Efficacy for Prevention of VTE in Imm

Leukotriene A4 Hydrolase, Insights into the Molecular Evolution by Homology Modeling and Mutational Analysis of Enzyme from Saccharomyces cerevisiae

Mammalian leukotriene A4 (LTA4) hydrolase is a bifunctional zinc metalloenzyme possessing an Arg/Ala aminopeptidase and an epoxide hydrolase activity, which converts LTA4 into the chemoattractant LTB4. We have previously cloned an LTA4 hydrolase from Saccharomyces cerevisiae with a primitive epoxide hydrolase activity and a Leu aminopeptidase activity, which is stimulated by LTA4. Here we used a m

Chiral and achiral phosphine derivatives of alkylidyne tricobalt carbonyl clusters as catalyst precursors for (asymmetric) inter- and intramolecular Pauson-Khand reactions.

Phosphine derivatives of alkylidyne tricobalt carbonyl clusters have been tested as catalysts/catalyst precursors in intermolecular and (asymmetric) intramolecular Pauson-Khand reactions. A number of new phosphine derivatives of the tricobalt alkylidyne clusters [Co(3)(mu(3)-CR)(CO)(9)] (R = H, CO(2)Et) were prepared and characterised. The clusters [Co(3)(mu(3)-CR)(CO)(9-x)(PR'(3))(x)] (PR'(3) = a

Polymer recycling in aqueous two-phase extractions using thermoseparating ethylene oxide-propylene oxide copolymers

This is a study on the recovery and recycling of copolymer in aqueous two-phase systems containing random copolymers of ethylene oxide (EO) and propylene oxide (PO). The random copolymers separate from water solution when heated above the lower critical solution temperature (LCST). The primary phase systems were composed of EOPO copolymer and hydroxypropyl or hydroxyethyl starch. After phase separ

MAGIC-HAND: A bottle and jar opening machine for people with severe disabilities

This paper describes the development of a prototype product named MAGIC-HAND that has been developed to open bottles, jars and packages that require a twisting action. Its intended users are people with severe disabilities, who are not capable of using the current range of package opening tools. MAGIC-HAND is a kitchen accessory device that fits into standard kitchen furniture. The machine uses no

Radioimmunoassay of beta-microseminoprotein, a prostatic-secreted protein present in sera of both men and women

We describe a simple radioimmunoassay of beta-microseminoprotein, one of the three most abundant secretory proteins of the prostate gland. The detection limit of the assay is 1 microgram/L, and its precision, expressed as the total coefficient of variation, is less than 10% for values between 10 and 150 micrograms/L. Using this assay, we found that beta-microseminoprotein immunoreactivity was pres

Changes in soil properties following conversion of Acacia senegal plantation to other land management systems in North Kordofan State, Sudan

Changes in soil texture, bulk density, pH, concentrations and stocks of OC, N, P and K before and after conversion of a 6-year-old Acacia senegal plantation to other land management systems (LMS) were investigated, after three cropping seasons, in the drylands of western Sudan. LMS included pure and intercropped sorghum (PS), roselle (PR) and grasses (PC) with A. senegal at high and low-tree densi

Improved spectral relaxation methods for binary quadratic optimization problems

in this paper, we introduce two new methods for solving binary quadratic problems. While spectral relaxation methods have been the workhorse subroutine for a wide variety of computer vision problems-segmentation, clustering, subgraph matching to name a few-it has recently been challenged by semidefinite programming (SDP) relaxations. In fact, it can be shown that SDP relaxations produce better low

Yolk androgens and the development of avian immunity: an experiment in jackdaws (Corvus monedula).

Maternally derived androgens have been shown to influence offspring phenotype in various ways. In birds, the benefits of prenatal androgen exposure, such as increased competitiveness and accelerated growth in nestlings, have been suggested to be balanced by costs, such as reduced immune function. In this study, we used an integrative approach to examine the influence of yolk androgens on the devel