120 research outputs found
The TimeâMoney Trade-Off for Entrepreneurs: When to Hire the First Employee?
For many early-stage entrepreneurs, hiring the first employee is a critical step in the firmâs growth. Doing so often requires significant time and monetary investments. To understand the trade-offs involved in deciding when to hire the first employee and how hiring differs in entrepreneurial settings from more established firm settings, we present a simple growth model that depends on two critical inputs for revenue generation: the entrepreneurâs time and money. We show that without hiring, the entrepreneurâs time eventually becomes more valuable than money in contributing to the firmâs growth. In that context, the value of the employee is driven by how much relief he provides to the entrepreneur. We characterize the optimal timing of hiring in terms of the firmâs cash position and how the firm is affected if it requires an upfront fixed investment in time and/or money. We find that the upfront investment in time needed for hiring cannot be converted to an equivalent upfront investment in money and that mistiming hiring can be very costly, especially when these upfront investments are high
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Fish Passage Studies IV: Passage Options for Climbing Lamprey: If You Build It They Will Come
Putting âthe socialâ back into social policy
As a result of the dominant neo-liberal approach to economic and social policy in the United Kingdom over the last three and a half decades British society is becoming increasingly fragmented with, for the first time since the 1930s, a generation of people set to experience worse living standards than their parents. With the marginalisation of the collectivist and humanitarian aims of the post-war welfare settlement and promotion of a strongly individualistic culture and politics, it is necessary to reconsider what âthe socialâ means and why it is important for societal progress. First, this chapter considers what âthe socialâ has meant for social policy in the post-war welfare state period. Second, the chapter examines how âthe socialâ aspect of policy has been downgraded over the last three and a half decades by the dominant neo-liberal approach. This has been achieved by a combination of policy change, the biased mobilisations of public discourse, and increasing individualisation and disempowerment experienced by citizens. Third, an alternative âsocial qualityâ approach is proposed, which seeks to put âthe socialâ back into both social and economic policy. This alternative model, which focuses on humans as social beings and collective solutions to social problems, provides an as yet incomplete, but promising basis on which to oppose neoliberal policy and promote an alternative vision for social policy in the 21st century
Bicarbonate-based Purge Solution As A Bleeding Reduction Strategy in Patients on Impella Support
Study: The Impella Catheters require a heparin-containing purge solution to maintain proper pump function by reducing the risk of biomaterial deposition in the purge gaps. A bicarbonate-based purge solution (BBPS) has been proposed as an alternative to a heparin-based purge solution. We review performance in patients supported to date with a BBPS (heparin-induced thrombocytopenia patients were excluded from this analysis). Methods: This review includes patients (n=26) supported using sodium bicarbonate (25 mEq/1L of D5W) in the purge from September 2020 to February 2021. These patients were supported with BBPS post-operatively where heparin in the purge was not desired or were transitioned to BBPS because of bleeding issues. Case data were collected from an internal database to develop the clinical narrative and cross-referenced against Impella Controller data logs to assess purge trends and pump function. Results: All pumps were switched to BBPS in the purge if not started with BBPS (Figure 1A). The average time to initiating BBPS was 1.6 days (excluding n=3 outliers where time to switching was \u3e15 days). The average duration of support with BBPS was 5 days and a maximum duration of 22 days (Figure 1B). Figure 1C shows clinical indications for use. Purge pressure and purge flow remained stable while on BBPS (Figure 1D). In conclusion, this preliminary experience suggests the feasibility of using BBPS to maintain purge patency, ensure pump motor reliability, reduce bleeding risk, and simplify anticoagulation management. Use of a BBPS may be a safe and effective alternative to heparin in the purge for patients in which heparin is contraindicated or not feasible. More patient experience and analysis are needed to evaluate how bicarbonate compares to heparin in the purge for all patients
Bicarbonate Purge Solution to Support Impella Devices for Patients with Clinically Suspected or Confirmed Heparin-induced Thrombocytopenia
Study: The Impella catheter is a transvalvular, micro-axial left ventricular assist device that provides temporary mechanical circulatory support and requires a heparin-containing purge solution to reduce the risk of biomaterial deposition in the purge gaps and also maintain proper pump function. For patients with suspected or confirmed heparin-induced thrombocytopenia (HIT), direct thrombin inhibitors (DTI) have been proposed as an alternative to heparin in the purge, but have been associated with pump failure requiring temporary tPA in the purge solution to normalize pump function. In this report, we review HIT patients supported with a sodium bicarbonate-based purge solution (BBPS).
Methods: Patients with suspected or confirmed HIT on Impella support using sodium bicarbonate (25 mEq in 1L D5W solution) in the purge from September 2020 to January 2021 were reviewed. Case data were obtained from Impella Quality (IQ) database for those supported with a BBPS and clinically suspected or confirmed HIT. Purge pressures and purge flows were evaluated from the Automated Impella Controller (AIC).
Results: Ten patients were supported with a BBPS during this period. Impella support was begun either with no anticoagulant (n=5), DTI (n=2), or heparin (n=3) and then switched to BBPS. Impella run time using a BBPS ranged from 1-14 days; five pumps had a run time with a BBPS \u3e 10 days (Figure 1). Systemic DTI use was used in five cases along with a BBPS. No purge pathway thrombosis or bleeding events were observed, along with no changes in purge flow or purge pressures observed.
In conclusion, preliminary experience suggests the use of BBPS in the setting suspected or confirmed HIT patients supported with an Impella is safe and effective and may provide a useful therapeutic option for heparin intolerant patients. Future work should investigate mechanisms and purge reliability of BBPS in this setting
How the AIS can Improve its Contributions to the UNâs Sustainability Development Goals: Towards A Framework for Scaling Collaborations and Evaluating Impact
In June, 2019, the Association for Information Systems (AIS) adopted a new approach to addressing global sustainability issues by establishing the AIS Sustainability Task Force (AIS STF). This initiative focuses on building on the outcomes from the United Nations (UN) Millennium Development Goals (MDG, 2000-2015) and applying them to address the challenges associated with the UN Sustainable Development Goals (SDG, 2016-2030). In this paper, we review the challenges and outcomes from the UN sustainability programs with their potential relevance to IS in general and the AIS in particular to inform and assist increased efforts to achieve the global sustainability goals. The initial event, the AIS Sustainability Summit held at ICIS 2019, provided a forum for AIS groups and communities to share their current interests, plans, activities, and experiences relevant to the MDG and SDG. The event primarily focused on facilitating opportunities to scale the AISâs sustainability activities through multi-disciplinary collaboration across the AIS and its communities. Members from four AIS special interest groups and the STFâs Education Workgroup presented exemplary projects at the summit that demonstrated how one can apply applied IS and research capabilities to address sustainability challenges. The sustainability summitâs also explored opportunities to achieve positive impact in addressing the SDGâs global challenges through applying AIS membersâ knowledge, skills, and capabilities in relevant ways in collaboration with suitable organizations outside the AIS. Potential organizations include business, government, societal groups, and UN bodies. We presented and discussed the AIS STFâs aims, plans, outcomes, and impact. By analyzing details and options for cross-organizational collaboration, the representatives of organizations at the sustainability summit developed a proposed framework for scaling contributions and evaluating impact. Finally, they drew conclusions about the proposed activities, approaches, and framework for the AIS to improve the scope and scale of its contributions in addressing the SDG. Critically, the AIS needs to ensure that its proposed activities, contributions, and impact are examined by an internationally recognized independent process. We propose a model for the AIS to realize this requirement for evaluation in 2021
Energy spread of ultracold electron bunches extracted from a laser cooled gas
Ultrashort and ultracold electron bunches created by near-threshold
femtosecond photoionization of a laser-cooled gas hold great promise for
single-shot ultrafast diffraction experiments. In previous publications the
transverse beam quality and the bunch length have been determined. Here the
longitudinal energy spread of the generated bunches is measured for the first
time, using a specially developed Wien filter. The Wien filter has been
calibrated by determining the average deflection of the electron bunch as a
function of magnetic field. The measured relative energy spread
agrees well with the theoretical model
which states that it is governed by the width of the ionization laser and the
acceleration length
The quasar fraction in low-frequency selected complete samples and implications for unified schemes
Low-frequency radio surveys are ideal for selecting orientation-independent
samples of extragalactic sources because the sample members are selected by
virtue of their isotropic steep-spectrum extended emission. We use the new 7C
Redshift Survey along with the brighter 3CRR and 6C samples to investigate the
fraction of objects with observed broad emission lines - the `quasar fraction'
- as a function of redshift and of radio and narrow emission line luminosity.
We find that the quasar fraction is more strongly dependent upon luminosity
(both narrow line and radio) than it is on redshift. Above a narrow [OII]
emission line luminosity of log L_[OII] > 35 W (or radio luminosity log L_151 >
26.5 W/Hz/sr), the quasar fraction is virtually independent of redshift and
luminosity; this is consistent with a simple unified scheme with an obscuring
torus with a half-opening angle theta_trans approx 53 degrees. For objects with
less luminous narrow lines, the quasar fraction is lower. We show that this is
not due to the difficulty of detecting lower-luminosity broad emission lines in
a less luminous, but otherwise similar, quasar population. We discuss evidence
which supports at least two probable physical causes for the drop in quasar
fraction at low luminosity: (i) a gradual decrease in theta_trans and/or a
gradual increase in the fraction of lightly-reddened (0 < A(V) < 5)
lines-of-sight with decreasing quasar luminosity; and (ii) the emergence of a
distinct second population of low luminosity radio sources which, like M87,
lack a well-fed quasar nucleus and may well lack a thick obscuring torus.Comment: 10 pages, 4 figures, accepted for publication in MNRA
Chemical Entities of Biological Interest: an update
Chemical Entities of Biological Interest (ChEBI) is a freely available dictionary of molecular entities focused on âsmallâ chemical compounds. The molecular entities in question are either natural products or synthetic products used to intervene in the processes of living organisms. Genome-encoded macromolecules (nucleic acids, proteins and peptides derived from proteins by cleavage) are not as a rule included in ChEBI. In addition to molecular entities, ChEBI contains groups (parts of molecular entities) and classes of entities. ChEBI includes an ontological classification, whereby the relationships between molecular entities or classes of entities and their parents and/or children are specified. ChEBI is available online at http://www.ebi.ac.uk/chebi/. This article reports on new features in ChEBI since the last NAR report in 2007, including substructure and similarity searching, a submission tool for authoring of ChEBI datasets by the community and a 30-fold increase in the number of chemical structures stored in ChEBI
Expressions 1998-1999
https://openspace.dmacc.edu/expressions/1018/thumbnail.jp
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