Abstract
Although testing is critical in industries, the general approaches of testing in engineering design are under-represented in academia. This research investigates the current state of testing ...based on design textbooks. The findings suggest there is no clear definition of testing. Testing appears in different design stages with adjacent concepts such as prototyping, experimentation, verification, and validation. The processes of testing and its role within engineering design are ambiguous. Recommendations to design educators are provided, and the limitations of the study are discussed.
Purpose
To compare nutrient-stimulated changes in superior mesenteric artery (SMA) blood flow, glucose absorption and glycaemia in individuals older than 65 years with, and without, critical illness.
...Methods
Following a 1-h ‘observation’ period (
t
0
–
t
60
), 0.9 % saline and glucose (1 kcal/ml) were infused directly into the small intestine at 2 ml/min between
t
60
–
t
120
, and
t
120
–
t
180
, respectively. SMA blood flow was measured using Doppler ultrasonography at
t
60
(fasting),
t
90
and
t
150
and is presented as raw values and nutrient-stimulated increment from baseline (Δ). Glucose absorption was evaluated using serum 3-
O
-methylglucose (3-OMG) concentrations during, and for 1 h after, the glucose infusion (i.e.
t
120
–
t
180
and
t
120
–
t
240
). Mean arterial pressure was recorded between
t
60
–
t
240
. Data are presented as median (25th, 75th percentile).
Results
Eleven mechanically ventilated critically ill patients age 75 (69, 79) years and nine healthy volunteers 70 (68, 77) years were studied. The magnitude of the nutrient-stimulated increase in SMA flow was markedly less in the critically ill when compared with healthy subjects Δ
t
150
: patients 115 (−138, 367) versus health 836 (618, 1,054) ml/min;
P
= 0.001. In patients, glucose absorption was reduced during, and for 1 h after, the glucose infusion when compared with health AUC
120–180
: 4.571 (2.591, 6.551) versus 11.307 (8.447, 14.167) mmol/l min;
P
< 0.001 and AUC
120–240
: 26.5 (17.7, 35.3) versus 40.6 (31.7, 49.4) mmol/l min;
P
= 0.031. A close relationship between the nutrient-stimulated increment in SMA flow and glucose absorption was evident (3-OMG AUC
120–180
and ∆SMA flow at
t
150
:
r
2
= 0.29;
P
< 0.05).
Conclusions
In critically ill patients aged >65 years, stimulation of SMA flow by small intestinal glucose infusion may be attenuated, which could account for the reduction in glucose absorption.
Design, fabrication, and characterization of monolithically integrated widely tunable all-optical wavelength converters in InP is reported. The devices are based on the SGDBR laser integrated with ...different MZI-SOA wavelength converters. Error-free wavelength conversion at 2.5 Gbps was demonstrated over 50 nm input and 22 nm output wavelength range. Static operation, extinction ratio enhancement, signal reamplification, dynamic range, and chirp properties were characterized as well.
BACKGROUND: The development of the mouse zygote following fertilization in vitro in a KSOM-type medium containing either l-glutamine or glycyl-l-glutamine has been examined, and compared with the ...development of mouse zygotes produced by natural fertilization. METHODS: Mouse IVF, embryo culture and embryo transfer. RESULTS: Fertilization rates, development to the blastocyst stage, implantation rate, gross fetal development and fetal body weight are not different in a KSOM-type medium containing either l-glutamine or glycyl-l-glutamine. No evidence of abnormal fetal development, such as exencephaly, was observed. The replacement of l-glutamine with glycyl-l-glutamine favoured the development of relatively more inner cell mass cells than trophectoderm cells, and reduced the numbers of pyknotic and fragmented nuclei in the blastocysts that developed in vitro. CONCLUSIONS: There is no evidence that the presence of glutamine in the medium used for IVF influences significantly the subsequent development of the zygote. Replacing glutamine with glycyl-l-glutamine may be advantageous.
The addition of amino acids to a modified simplex optimized medium (mKSOM) did not increase the percentage of blastocysts that develop from CF1 mouse ova fertilized in vitro. In contrast, the ...percentage of blastocysts that began to hatch and the number of cells in these blastocysts, particularly in the inner cell mass, was increased. The added amino acids also supported the development of a more organized extracellular matrix in the same blastocysts. The results suggest that zygotes produced in amino acid-supplemented mKSOM have a greater developmental potential, perhaps developing at a faster rate, than zygotes produced in mKSOM. This enhanced developmental potential may be caused by the alleviation of osmotic stress on the ova and zygotes by the amino acids that are osmolytes. The fertilization of human ova in vitro may benefit from the inclusion of free amino acids in the fertilizing medium. The availability of a medium that can be used to support both IVF and preimplantation development in the mouse is likely to benefit the recovery of mouse strains from cryopreserved spermatozoa.
Supernova (SN) H0pe was discovered as a new transient in
James Webb
Space Telescope (JWST) NIRCam images of the galaxy cluster
PLCK G165.7+67.0
taken as part of the Prime Extragalactic Areas for ...Reionization and Lensing Science (PEARLS) JWST GTO program (ID 1176) on 2023 March 30. The transient is a compact source associated with a background galaxy that is stretched and triply imaged by the strong gravitational lensing of the cluster. This paper reports spectra in the 950–1370 nm observer frame of two of the galaxy images obtained with Large Binocular Telescope (LBT) Utility Camera in the Infrared (LUCI) in long-slit mode two weeks after the JWST observations. The individual and average spectra show the O
II
λλ
3727,3730 doublet and the Balmer and 4000 Å breaks at redshift
z
= 1.783 ± 0.002. The code investigating galaxy emission (CIGALE) best-fit model of the spectral energy distribution indicates that the host galaxy of SN H0pe is massive (
M
star
≃ 6 × 10
10
M
⊙
after correcting for a magnification factor
μ
∼ 7) with a predominantly intermediate-age (∼2 Gyr) stellar population, moderate extinction, and a magnification-corrected star formation rate ≃13
M
⊙
yr
−1
, consistent with being below the main sequence of star formation. These properties suggest that H0pe might be a type Ia SN. Additional observations of SN H0pe and its host recently carried out with JWST (JWST-DD-4446; PI: B. Frye) will be able to both determine the SN classification and confirm its association with the galaxy analyzed in this work.
Abstract Background context The evidence-based clinical guideline on the diagnosis and treatment of degenerative lumbar spinal stenosis by the North American Spine Society (NASS) provides ...evidence-based recommendations to address key clinical questions surrounding the diagnosis and treatment of degenerative lumbar spinal stenosis. The guideline is intended to reflect contemporary treatment concepts for symptomatic degenerative lumbar spinal stenosis as reflected in the highest quality clinical literature available on this subject as of July 2010. The goals of the guideline recommendations are to assist in delivering optimum efficacious treatment and functional recovery from this spinal disorder. Purpose Provide an evidence-based educational tool to assist spine care providers in improving quality and efficiency of care delivered to patients with degenerative lumbar spinal stenosis. Study design Systematic review and evidence-based clinical guideline. Methods This report is from the Degenerative Lumbar Spinal Stenosis Work Group of the NASS's Evidence-Based Clinical Guideline Development Committee. The work group consisted of multidisciplinary spine care specialists trained in the principles of evidence-based analysis. The original guideline, published in 2006, was carefully reviewed. A literature search addressing each question and using a specific search protocol was performed on English language references found in MEDLINE, EMBASE (Drugs and Pharmacology), and four additional, evidence-based, databases to identify articles published since the search performed for the original guideline. The relevant literature was then independently rated by a minimum of three physician reviewers using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final recommendations to answer each clinical question were arrived at via work group discussion, and grades were assigned to the recommendations using standardized grades of recommendation. In the absence of Levels I to IV evidence, work group consensus statements have been developed using a modified nominal group technique, and these statements are clearly identified as such in the guideline. Results Sixteen key clinical questions were assessed, addressing issues of natural history, diagnosis, and treatment of degenerative lumbar spinal stenosis. The answers are summarized in this document. The respective recommendations were graded by the strength of the supporting literature that was stratified by levels of evidence. Conclusions A clinical guideline for degenerative lumbar spinal stenosis has been updated using the techniques of evidence-based medicine and using the best available clinical evidence to aid both practitioners and patients involved with the care of this condition. The entire guideline document, including the evidentiary tables, suggestions for future research, and all references, will be available electronically at the NASS Web site ( www.spine.org ) and will remain updated on a timely schedule.
We report on the successful science verification phase of a new observing mode at the Keck Interferometer, which provides a line-spread function width and sampling of 150 km s{sup -1} at the K'-band, ...at a current limiting magnitude of K' {approx} 7 mag with a spatial resolution of {lambda} / 2 B {approx} 2.7 mas and a measured differential phase stability of unprecedented precision (3 mrad at K = 5 mag, which represents 3 {mu} as on the sky or a centroiding precision of 10{sup -3}). The scientific potential of this mode is demonstrated by the presented observations of the circumstellar disk of the evolved Be-star 48 Lib. In addition to indirect methods such as multi-wavelength spectroscopy and polarimetry, the spectro-interferometric astrometry described here provides a new tool to directly constrain the radial density structure in the disk. For the first time, we resolve several Pfund emission lines, in addition to Br {gamma}, in a single interferometric spectrum, with adequate spatial and spectral resolution and precision to analyze the radial disk structure in 48 Lib. The data suggest that the continuum and Pf-emission originates in significantly more compact regions, inside the Br {gamma}-emission zone. Thus, spectro-interferometric astrometry opens the opportunity to directly connect the different observed line profiles of Br {gamma} and Pfund in the total and correlated flux to different disk radii. The gravitational potential of a rotationally flattened Be star is expected to induce a one-armed density perturbation in the circumstellar disk. Such a slowly rotating disk oscillation has been used to explain the well-known periodic V/R spectral profile variability in these stars, as well as the observed V/R cycle phase shifts between different disk emission lines. The differential line properties and linear constraints set by our data are consistent with theoretical models and lend direct support to the existence of a radius-dependent disk density perturbation. The data also show decreasing gas rotation velocities at increasing stellocentric radii as expected for Keplerian disk rotation, assumed by those models.
Abstract
Synopsis
Archerfishes (Toxotidae) are variously found in the fresh- and brackish-water environments of Asia Pacific and are well known for their ability to shoot water at terrestrial prey. ...These shots of water are intended to strike their prey and cause it to fall into the water for capture and consumption. While this behavior is well known, there are competing hypotheses (blowpipe vs. pressure tank hypothesis) of how archerfishes shoot and which oral structures are involved. Current understanding of archerfish shooting structures is largely based on two species, Toxotes chatareus and T. jaculatrix. We do not know if all archerfishes possess the same oral structures to shoot water, if anatomical variation is present within these oral structures, or how these features have evolved. Additionally, there is little information on the evolution of the Toxotidae as a whole, with all previous systematic works focusing on the interrelationships of the family. We first investigate the limits of archerfish species using new and previously published genetic data. Our analyses highlight that the current taxonomy of archerfishes does not conform to the relationships we recover. Toxotes mekongensis and T. siamensis are placed in the synonymy of T. chatareus, Toxotes carpentariensis is recognized as a species and removed from the synonymy of T. chatareus, and the genus Protoxotes is recognized for T. lorentzi based on the results of our analyses. We then take an integrative approach, using a combined analysis of discrete hard- and soft-tissue morphological characters with genetic data, to construct a phylogeny of the Toxotidae. Using the resulting phylogenetic hypothesis, we then characterize the evolutionary history and anatomical variation within the archerfishes. We discuss variation in the oral structures and the evolution of the mechanism with respect to the interrelationships of archerfishes, and find that the oral structures of archerfishes support the blowpipe hypothesis but soft-tissue oral structures may also play a role in shooting. Finally, by comparing the morphology of archerfishes to their sister group, we find that the Leptobramidae has relevant shooting features in the oral cavity, suggesting that some components of the archerfish shooting mechanism are examples of co-opted or exapted traits.
Sinopsis (Malay)
Pelbagai jenis Ikan Sumpit (Toxotidae) dapat dijumpai di persekitaran air tawar dan payau di Asia Pasifik dan mereka terkenal dengan kebolehan mereka menembak air ke arah mangsa di darat. Tembakan air ini bertujuan untuk menyerang mangsa mereka dan menyebabkan mereka jatuh ke dalam air untuk ditangkap dan dimakan. Walaupun tingkah laku ini diketahui umum, terdapat hipotesis yang bersaing (hipotesis sumpitan vs. tangki tekanan) tentang cara ikan sumpit menembak dan struktur mulut yang terlibat. Pemahaman semasa tentang struktur menembak ikan sumpit adalah sebahagian besarnya berdasarkan dua spesies, Toxotes chatareus dan T. jaculatrix. Kami tidak pasti sama ada semua ikan sumpit mempunyai struktur mulut yang sama untuk menembak air, jika variasi anatomi terdapat dalam struktur mulut ini, atau bagaimana ciri-ciri ini telah berkembang. Tambahan pula, terdapat sedikit maklumat tentang evolusi Toxotidae secara keseluruhan, dengan semua penyelidikan sistematik sebelum ini memfokuskan pada hubungan saling keluarga. Kami pada mulanya mengkaji had spesies ikan sumpit ini menggunakan data genetik baharu dan yang diterbitkan sebelum ini. Analisis kami menunjukkan bahawa taksonomi semasa ikan sumpit tidak mematuhi hubungan yang kami perolehi. Toxotes mekongensis dan T. siamensis diletakkan bersama kesinoniman T. chatareus, Toxotes carpentariensis yang diiktiraf sebagai satu spesies dan dikeluarkan daripada kesinoniman T. chatareus, dan genus Protoxotes yang diiktiraf untuk T. lorentzi adalah berdasarkan hasil analisis kami. Kemudian kami mengambil pendekatan integratif, menggunakan analisis gabungan karakter morfologi tisu keras dan lembut diskret dengan data genetik, untuk membina filogeni Toxotidae. Menggunakan hipotesis filogenetik yang terhasil, kami kemudian mencirikan sejarah evolusi dan variasi anatomi dalam ikan sumpit. Kami membincangkan variasi dalam struktur mulut dan evolusi mekanisme berkenaan yang berkaitan dengan ikan sumpit, dan mendapati bahawa struktur mulut ikan sumpit menyokong hipotesis sumpitan tetapi struktur mulut tisu lembut juga mungkin memainkan peranan dalam cara menembak. Akhir sekali, dengan membandingkan morfologi ikan sumpit kepada kumpulan saudara mereka, kami mendapati bahawa Leptobramidae mempunyai ciri penangkapan yang relevan dalam rongga mulut mereka, menunjukkan bahawa beberapa komponen mekanisme penangkapan ikan sumpit merupakan contoh ciri-ciri yang diikut-sertakan atau diguna semula.
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