597 research outputs found

    Occupational choice, number of entrepreneurs and output: theory and empirical evidence with Spanish data

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    This paper extends the (Lucas, Bell J Econ 9:508–523,1978) model of occupational choices by individuals with different skills, beyond the simple options of self-employment or wage-employment, by including a second choice for the self-employed. That is, an option to hire employees and so become self-employed with employees (SEWEs), or to be self-employed without employees (SEWNEs). We solve for the market equilibrium and examine the sensitivity of relative sizes of occupational groups, and of the level of productivity, to changes in the exogenous parameters. The results show that the positive (negative) association between number of SEWEs (SEWNEs) and productivity, observed in the Spanish data, can be explained, under certain conditions, as the result of cross-region and time differences in average skills. These findings point to the importance of distinguishing between SEWEs and SEWNEs in drawing valid conclusions concerning any link between entrepreneurship and economic development

    Variational Principle underlying Scale Invariant Social Systems

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    MaxEnt's variational principle, in conjunction with Shannon's logarithmic information measure, yields only exponential functional forms in straightforward fashion. In this communication we show how to overcome this limitation via the incorporation, into the variational process, of suitable dynamical information. As a consequence, we are able to formulate a somewhat generalized Shannonian Maximum Entropy approach which provides a unifying "thermodynamic-like" explanation for the scale-invariant phenomena observed in social contexts, as city-population distributions. We confirm the MaxEnt predictions by means of numerical experiments with random walkers, and compare them with some empirical data

    Outcomes and relevance of emergency percutaneous coronary angiography and intervention after resuscitated cardiac arrest: a retrospective study.

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    In patients resuscitated from cardiac arrest and displaying no ST-segment elevation on initial electrocardiogram (ECG), recent randomized trials indicated no benefits from early coronary angiography. How the results of such randomized studies apply to a real-world clinical context remains to be established. We retrospectively analyzed a clinical database including all patients 18 yo or older admitted to our tertiary University Hospital from January 2017 to August 2020 after successful resuscitation of out-of-Hospital (OHCA) or In-Hospital (IHCA) cardiac arrest of presumed cardiac origin, and undergoing immediate coronary angiography, regardless of the initial rhythm and post-resuscitation ECG. The primary outcome of the study was survival at day 90 after cardiac arrest. Demographic data, characteristics of cardiac arrest, duration of resuscitation, laboratory values at admission, angiographic data and revascularization status were collected. Comparisons were performed according to the initial ECG (ST-segment elevation or not), and between survivors and non-survivors. Variables associated with the primary outcome were evaluated by univariate and multivariate regression analyses. We analyzed 147 patients (130 OHCA and 17 IHCA), including 67 with STEMI and 80 without STEMI (No STEMI). Immediate revascularization was performed in 65/67 (97%) STEMI and 15/80 (19%) no STEMI. Day 90 survival was significantly higher in STEMI (48/67, 72%) than no STEMI (44/80, 55%). In the latter patients, survival was not influenced by the revascularization status. In univariate and multivariate analyses, lower age, a shockable rhythm, shorter durations of no flow and low flow, and a lower initial blood lactate were associated with survival in both STEMI and no STEMI. In contrast, metabolic abnormalities, including lower initial plasma sodium and higher potassium were significantly associated with mortality only in the subgroup of no STEMI patients. Our results, obtained in a real-world clinical setting, indicate that an immediate coronary angiography is not associated with any survival advantage in patients resuscitated from cardiac arrest of presumed cardiac etiology without ST-segment elevation on initial ECG. Furthermore, we found that some early metabolic abnormalities may be associated with mortality in this population, which should deserve further investigation

    The Truth, the Whole Truth, and Nothing but the Truth: A Pragmatic Guide to Assessing Empirical Evaluations

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    An unsound claim can misdirect a field, encouraging the pursuit of unworthy ideas and the abandonment of promising ideas. An inadequate description of a claim can make it difficult to reason about the claim, for example to determine whether the claim is sound. Many practitioners will acknowledge the threat of un- sound claims or inadequate descriptions of claims to their field. We believe that this situation is exacerbated and even encouraged by the lack of a systematic approach to exploring, exposing, and addressing the source of unsound claims and poor exposition. This paper proposes a framework that identifies three sins of reasoning that lead to unsound claims and two sins of exposition that lead to poorly described claims. Sins of exposition obfuscate the objective of determining whether or not a claim is sound, while sins of reasoning lead directly to unsound claims. Our framework provides practitioners with a principled way of critiquing the integrity of their own work and the work of others. We hope that this will help individuals conduct better science and encourage a cultural shift in our research community to identify and promulgate sound claims

    Energy Characterization of Garbage Collectors for Dynamic Applications on Embedded Systems

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    Stepped care targeting psychological distress in head and neck and lung cancer patients: a randomized clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Psychological distress is common in cancer survivors. Although there is some evidence on effectiveness of psychosocial care in distressed cancer patients, referral rate is low. Lack of adequate screening instruments in oncology settings and insufficient availability of traditional models of psychosocial care are the main barriers. A stepped care approach has the potential to improve the efficiency of psychosocial care. The aim of the study described herein is to evaluate efficacy of a stepped care strategy targeting psychological distress in cancer survivors.</p> <p>Methods/design</p> <p>The study is designed as a randomized clinical trial with 2 treatment arms: a stepped care intervention programme versus care as usual. Patients treated for head and neck cancer (HNC) or lung cancer (LC) are screened for distress using OncoQuest, a computerized touchscreen system. After stratification for tumour (HNC vs. LC) and stage (stage I/II vs. III/IV), 176 distressed patients are randomly assigned to the intervention or control group. Patients in the intervention group will follow a stepped care model with 4 evidence based steps: 1. Watchful waiting, 2. Guided self-help via Internet or a booklet, 3. Problem Solving Treatment administered by a specialized nurse, and 4. Specialized psychological intervention or antidepressant medication. In the control group, patients receive care as usual which most often is a single interview or referral to specialized intervention. Primary outcome is the Hospital Anxiety and Depression Scale (HADS). Secondary outcome measures are a clinical level of depression or anxiety (CIDI), quality of life (EQ-5D, EORTC QLQ-C30, QLQ-HN35, QLQ-LC13), patient satisfaction with care (EORTC QLQ-PATSAT), and costs (health care utilization and work loss (TIC-P and PRODISQ modules)). Outcomes are evaluated before and after intervention and at 3, 6, 9 and 12 months after intervention.</p> <p>Discussion</p> <p>Stepped care is a system of delivering and monitoring treatments, such that effective, yet least resource-intensive, treatment is delivered to patients first. The main aim of a stepped care approach is to simplify the patient pathway, provide access to more patients and to improve patient well-being and cost reduction by directing, where appropriate, patients to low cost (self-)management before high cost specialist services.</p> <p>Trial registration</p> <p>NTR1868</p

    Analysis of the DNA adducts of phenyl glycidyl ether in a calf thymus DNA hydrolysate by capillary zone electrophoresis-electrospray mass spectrometry: evidence for phosphate alkylation

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    Calf thymus DNA was reacted irt vitro with phenyl glycidyl ether (PGE) and was hydrolysed enzymatically, to the 5'-monophosphate nucleotides using deoxyribonuclease I (DNA-ase I) and nuclease P1, The adducts were concentrated using solid phase extraction (SPE), on a polystyrene divinylbenzene copolymer in order to remove the unmodified nucleotides. The adducts could be identified using capillary zone electrophoresis-electrospray tandem mass spectrometry (CZE ES-MS/MS), using sample stacking. In addition to the base alkylated 2'-deoxynucleotides present in the DNA-hydrolysate, also phosphate alkylated 2'-deoxynucleotide adducts were identified for TMP and dAMP, An additional adduct, dUMP alkylated on the uridine moiety was found originating from the hydrolytic deamination of dCMP alkylated on N-3 Of the cytosine moiety, Enzymatic hydrolysis using nuclease P1 was incomplete as shown by the presence of dinucleotides alkylated on the base moiety, They were successfully hydrolysed to the corresponding 2'-deoxynucleotides by snake venom phosphodiesterase (SVP), Data are shown indicating that alkylations on the pyrimidine bases were more resistant to enzymatic hydrolysis with nuclease P1 than the purine alkylated products

    Statistical simulation: Adding efficiency to the computer designer's toolbox

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    Inclusion of Hermetia Illucens larvae or prepupae in an experimental extruded feed: process optimisation and impact on in vitro digestibility

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    This study investigated the effect of extrusion on digestibility of different blends containing Hermetia illucens (HI) larvae or prepupae. Five blends of HI larvae or prepupae and wheat flour, in a ratio of 25:75, with or without sunflower oil addition, have been formulated as follows: prepupae\u2009+\u2009wheat (no oil); prepupae\u2009+\u2009wheat (low oil); prepupae\u2009+\u2009wheat (medium oil); prepupae\u2009+\u2009wheat (high oil); larvae\u2009+\u2009wheat (no oil). Ether extract (EE) content in different blend was 31.5, 38.9, 46.3, 53.7 and 46.27\u2009g\u2009kg 121 on wet basis (wb), respectively. Blends were homogeneous for moisture (238.9\u2009g\u2009kg 121) and crude protein (112.6\u2009g\u2009kg 121 wb). Feed blends were extruded by a co-rotating, conical twin-screw mini extruder and net torque value (NTV) was recorded as indicator of extrudability. The best performing blend was furtherly tested at four barrel temperatures (60, 70, 80 and 90\u2009\ub0C). In vitro organic matter digestibility (OMD) and in vitro crude protein digestibility (CPD) were measured to evaluate the effect of extrusion process on nutritional value. Increasing the blend EE content up to 53.74\u2009g kg 121 wb, NTV was reduced by four times (<100 Ncm) compared to 31.5 and 38.9\u2009g kg 121 wb EE blends. The best performing mixture was larvae\u2009+\u2009wheat (no oil). Extrusion process increased OMD but not CPD compared to unextruded control, while different extrusion temperature did not affect OMD nor CPD. Concluding, extrusion can contribute to increase OMD in insect containing feed blends. EE content in the blends is a key variable that should be defined in the process
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