7,389 research outputs found
TQM and labour productivity in Jordanian industrial companies
Reports on research to determine the degree of application of total quality management (TQM) philosophy and practices in industrial corporations in Jordan. Uses primary and secondary empirical data to examine the link between TQM and labour productivity. Survey responses were classified into two groups: high-TQM implementation and low-TQM implementation. Found that mean labour productivity measurements for high-TQM companies were significantly higher than for low-TQM companies over the period 1993-1998. Also, mean growth rates of labour productivity measurements for companies with high-level TQM were higher than for those with low-level TQM during this period. Regression analysis demonstrated a statistically significant positive relationship between TQM and labour productivity
The application of deep eutectic solvent ionic liquids for environmentally-friendly dissolution and recovery of precious metals
publisher: Elsevier articletitle: The application of deep eutectic solvent ionic liquids for environmentally-friendly dissolution and recovery of precious metals journaltitle: Minerals Engineering articlelink: http://dx.doi.org/10.1016/j.mineng.2015.09.026 content_type: article copyright: Copyright © 2015 The Authors. Published by Elsevier Ltd.© 2015 Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
General Relativistic Mean Field Theory for Rotating Nuclei
We formulate a general relativistic mean field theory for rotating nuclei
starting from the special relativistic model Lagrangian. The
tetrad formalism is adopted to generalize the model to the accelerated frame.Comment: 13 pages, REVTeX, no figures, submitted to Phys. Rev. Lett., the word
`curved' is replaced by `non-inertial' or `accelerated' in several places to
clarify the physical situation interested, some references are added, more
detail discussions are given with omitting some redundant sentence
Enhanced electron-phonon coupling in graphene with periodically distorted lattice
Electron-phonon coupling directly determines the stability of cooperative
order in solids, including superconductivity, charge and spin density waves.
Therefore, the ability to enhance or reduce electron-phonon coupling by optical
driving may open up new possibilities to steer materials' functionalities,
potentially at high speeds. Here we explore the response of bilayer graphene to
dynamical modulation of the lattice, achieved by driving optically-active
in-plane bond stretching vibrations with femtosecond mid-infrared pulses. The
driven state is studied by two different ultrafast spectroscopic techniques.
Firstly, TeraHertz time-domain spectroscopy reveals that the Drude scattering
rate decreases upon driving. Secondly, the relaxation rate of hot
quasi-particles, as measured by time- and angle-resolved photoemission
spectroscopy, increases. These two independent observations are quantitatively
consistent with one another and can be explained by a transient three-fold
enhancement of the electron-phonon coupling constant. The findings reported
here provide useful perspective for related experiments, which reported the
enhancement of superconductivity in alkali-doped fullerites when a similar
phonon mode was driven.Comment: 12 pages, 4 figure
Valsalva retinopathy in pregnancy: a case report
<p>Abstract</p> <p>Introduction</p> <p>Valsalva retinopathy is a unilateral or bilateral condition that occurs when increased intra-thoracic or intra-abdominal pressure transmitted to the eye causes a sharp rise in the intra-ocular venous pressure, and rupture of superficial retinal capillaries. The patient often gives a history of a recent strenuous physical act, which could have increased the intra-thoracic pressure. Pregnancy is known to be a risk factor for Valsalva retinopathy.</p> <p>Case presentation</p> <p>A 23-year-old woman in her seventh month of pregnancy presented with a history of decreased vision in her left eye of one-week duration. Examination of the affected eye showed best corrected visual acuity of 20/50, and fundus examination revealed a pre-retinal hemorrhage located in the macula. Based on clinical findings, the diagnosis of Valsalva retinopathy was made.</p> <p>Conclusion</p> <p>Retinal hemorrhages can be generated by Valsalva maneuvers. Pregnancy is a known risk factor for Valsalva retinopathy; however, the diagnosis should be made only after excluding other causes of retinal hemorrhages. It is a self-limited event. We report a case of Valsalva retinopathy complicating normal pregnancy and confirm that, to date, there is no evidence to indicate that there is a risk of recurrence following spontaneous vaginal delivery.</p
Preliminary observations on the usefulness of hinge structures for identification of bivalve larvae
Difficulties associated with discrimination of bivalve larvae isolated from plankton samples have long hampered both applied and basic research efforts in estuarine and open coastal marine environments. The vast majority of practical barriers to identification of larval bivalves may be eliminated through routine optical microscopic examination of the hinge apparatus of disarticulated larval shells. Representative micrographs of various ontogenetic stages of larval hinge development are presented for 12 genera (Mytilus, Geukensia, Crassostrea, Placopecten. Argopecten. Mya, Spisula, Mulinia, Ensis, Arca, Arctica. and Mercenaria) from 9 bivalve superfamilies (Mytilacea, Ostreacea. Pectinacea, Myacea, Mactracea. Solenacea, Arcacea, Arcticacea. and Veneracea). The larval hinge apparatus (provinculum). by itself is generally useful for superfamilial separation. When coupled with a consideration of gross shell shape, detailed examination of hinge line structures often permits generic or even specific, identification. A format is suggested for organization of qualitative morphological life history data that will provide an adeqate basis for comparison of the larval stages of various species of bivalves
Development and assessment of a clinical calculator for estimating the likelihood of recurrence and survival among patients with locally advanced rectal cancer treated with chemotherapy, radiotherapy, and surgery
Importance: Predicting outcomes in patients receiving neoadjuvant therapy for rectal cancer is challenging because of tumor downstaging. Validated clinical calculators that can estimate recurrence-free survival (RFS) and overall survival (OS) among patients with rectal cancer who have received multimodal therapy are needed.
Objective: To develop and validate clinical calculators providing estimates of rectal cancer recurrence and survival that are better for individualized decision-making than the American Joint Committee on Cancer (AJCC) staging system or the neoadjuvant rectal (NAR) score.
Design, Setting, and Participants: This prognostic study developed risk models, graphically represented as nomograms, for patients with incomplete pathological response using Cox proportional hazards and multivariable regression analyses with restricted cubic splines. Because patients with complete pathological response to neoadjuvant therapy had uniformly favorable outcomes, their predictions were obtained separately. The study included 1400 patients with stage II or III rectal cancer who received treatment with chemotherapy, radiotherapy, and surgery at 2 comprehensive cancer centers (Memorial Sloan Kettering [MSK] Cancer Center and Siteman Cancer Center [SCC]) between January 1, 1998, and December 31, 2017. Patients from the MSK cohort received chemoradiation, surgery, and adjuvant chemotherapy from January 1, 1998, to December 31, 2014; these patients were randomly assigned to either a model training group or an internal validation group. Models were externally validated using data from the SCC cohort, who received either chemoradiation, surgery, and adjuvant chemotherapy (chemoradiotherapy group) or short-course radiotherapy, consolidation chemotherapy, and surgery (total neoadjuvant therapy with short-course radiotherapy group) from January 1, 2009, to December 31, 2017. Data were analyzed from March 1, 2020, to January 10, 2021.
Exposures: Chemotherapy, radiotherapy, chemoradiotherapy, and surgery.
Main Outcomes and Measures: Recurrence-free survival and OS were the outcome measures, and the discriminatory performance of the clinical calculators was measured with concordance index and calibration plots. The ability of the clinical calculators to predict RFS and OS was compared with that of the AJCC staging system and the NAR score. The models for RFS and OS among patients with incomplete pathological response included postoperative pathological tumor category, number of positive lymph nodes, tumor distance from anal verge, and large- and small-vessel venous and perineural invasion; age was included in the risk model for OS. The final clinical calculators provided RFS and OS estimates derived from Kaplan-Meier curves for patients with complete pathological response and from risk models for patients with incomplete pathological response.
Results: Among 1400 total patients with locally advanced rectal cancer, the median age was 57.8 years (range, 18.0-91.9 years), and 863 patients (61.6%) were male, with tumors at a median distance of 6.7 cm (range, 0-15.0 cm) from the anal verge. The MSK cohort comprised 1069 patients; of those, 710 were assigned to the model training group and 359 were assigned to the internal validation group. The SCC cohort comprised 331 patients; of those, 200 were assigned to the chemoradiotherapy group and 131 were assigned to the total neoadjuvant therapy with short-course radiotherapy group. The concordance indices in the MSK validation data set were 0.70 (95% CI, 0.65-0.76) for RFS and 0.73 (95% CI, 0.65-0.80) for OS. In the external SCC data set, the concordance indices in the chemoradiotherapy group were 0.71 (95% CI, 0.62-0.81) for RFS and 0.72 (95% CI, 0.59-0.85) for OS; the concordance indices in the total neoadjuvant therapy with short-course radiotherapy group were 0.62 (95% CI, 0.49-0.75) for RFS and 0.67 (95% CI, 0.46-0.84) for OS. Calibration plots confirmed good agreement between predicted and observed events. These results compared favorably with predictions based on the AJCC staging system (concordance indices for MSK validation: RFS = 0.69 [95% CI, 0.64-0.74]; OS = 0.67 [95% CI, 0.58-0.75]) and the NAR score (concordance indices for MSK validation: RFS = 0.56 [95% CI, 0.50-0.63]; OS = 0.56 [95% CI, 0.46-0.66]). Furthermore, the clinical calculators provided more individualized outcome estimates compared with the categorical schemas (eg, estimated RFS for patients with AJCC stage IIIB disease ranged from 7% to 68%).
Conclusions and Relevance: In this prognostic study, clinical calculators were developed and validated; these calculators provided more individualized estimates of the likelihood of RFS and OS than the AJCC staging system or the NAR score among patients with rectal cancer who received multimodal treatment. The calculators were easy to use and applicable to both short- and long-course radiotherapy regimens, and they may be used to inform surveillance strategies and facilitate future clinical trials and statistical power calculations
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