1,349 research outputs found
Is Strategy Different for Very Small and New Firms?
In this paper, we argue that much of the small business strategic management literature has drawn too heavily from work done on large, established firms. We build upon the notions of the liabilities of smallness and newness to discuss how microenterprises and very new firms are different in regards to their strategic analysis, strategic content, strategic resources, and strategic processes. We note that there are a number of important and non-obvious questions that need to be asked that have implications for the most common firms in the world, those that are very small
High-Brightness Beams from a Light Source Injector: The Advanced Photon Source Low-Energy Undulator Test Line Linac
The use of existing linacs, and in particular light source injectors, for free-electron laser (FEL) experiments is becoming more common due to the desire to test FELs at ever shorter wavelengths. The high-brightness, high-current beams required by high-gain FELs impose technical specifications that most existing linacs were not designed to meet. Moreover, the need for specialized diagnostics, especially shot-to-shot data acquisition, demands substantial modification and upgrade of conventional linacs. Improvements have been made to the Advanced Photon Source (APS) injector linac in order to produce and characterize high-brightness beams. Specifically, effort has been directed at generating beams suitable for use in the low-energy undulator test line (LEUTL) FEL in support of fourth-generation light source research. The enhancements to the linac technical and diagnostic capabilities that allowed for self-amplified spontaneous emission (SASE) operation of the FEL at 530 nm are described. Recent results, including details on technical systems improvements and electron beam measurement techniques, will be discussed. The linac is capable of accelerating beams to over 650 MeV. The nominal FEL beam parameters used are as follows: 217 MeV energy; 0.1-0.2% rms energy spread; 4-8 um normalized rms emittance; 80-120 A peak current from a 0.2-0.7 nC charge at a 2-7 ps FWHM bunch
A new bond fluctuation method for a polymer undergoing gel electrophoresis
We present a new computational methodology for the investigation of gel
electrophoresis of polyelectrolytes. We have developed the method initially to
incorporate sliding motion of tight parts of a polymer pulled by an electric
field into the bond fluctuation method (BFM). Such motion due to tensile force
over distances much larger than the persistent length is realized by non-local
movement of a slack monomer at an either end of the tight part. The latter
movement is introduced stochastically. This new BFM overcomes the well-known
difficulty in the conventional BFM that polymers are trapped by gel fibers in
relatively large fields. At the same time it also reproduces properly
equilibrium properties of a polymer in a vanishing filed limit. The new BFM
thus turns out an efficient computational method to study gel electrophoresis
in a wide range of the electric field strength.Comment: 15 pages, 11 figure
A dataset of hourly sea surface temperature from drifting buoys
A dataset of sea surface temperature (SST) estimates is generated from the temperature observations of surface drifting buoys of NOAAâs Global Drifter Program. Estimates of SST at regular hourly time steps along drifter trajectories are obtained by fitting to observations a mathematical model representing simultaneously SST diurnal variability with three harmonics of the daily frequency, and SST low-frequency variability with a first degree polynomial. Subsequent estimates of non-diurnal SST, diurnal SST anomalies, and total SST as their sum, are provided with their respective standard uncertainties. This Lagrangian SST dataset has been developed to match the existing and on-going hourly dataset of position and velocity from the Global Drifter Program
Gel-Electrophoresis and Diffusion of Ring-Shaped DNA
A model for the motion of ring-shaped DNA in a gel is introduced and studied
by numerical simulations and a mean-field approximation. The ring motion is
mediated by finger-shaped loops (hernias) that move in an amoeba-like fashion
around the gel obstructions. This constitutes an extension of previous
reptation tube treatments. It is shown that tension is essential for describing
the dynamics in the presence of hernias. It is included in the model as long
range interactions over stretched DNA regions. The mobility of ring-shaped DNA
is found to saturate much as in the well-studied case of linear DNA.
Experiments in polymer gels, however, show that the mobility drops
exponentially with the DNA ring size. This is commonly attributed to
dangling-ends in the gel that can impale the ring. The predictions of the
present model are expected to apply to artificial 2D obstacle arrays (W.D.
Volkmuth, R.H. Austin, Nature 358,600 (1992)) which have no dangling-ends. In
the zero-field case an exact solution of the model steady-state is obtained,
and quantities such as the average ring size are calculated. An approximate
treatment of the ring dynamics is given, and the diffusion coefficient is
derived. The model is also discussed in the context of spontaneous symmetry
breaking in one dimension.Comment: 8 figures, LaTeX, Phys. Rev. E - in pres
Pain Control: Opioid vs. Nonopioid Analgesia During the Immediate Postoperative Period
Background Opioid analgesia has become the mainstay for acute pain management in the postoperative setting. However, the use of opioid medications comes with significant risks and side effects. Due to increasing numbers of prescriptions to those with chronic pain, opioid medications have become more expensive while becoming less effective due to the buildup of patient tolerance. The idea of opioid-free analgesic techniques has rarely been breached in many hospitals. Emerging research has shown that opioid-sparing approaches have resulted in lower reported pain scores across the board, as well as significant cost reductions to hospitals and insurance agencies. In addition to providing adequate pain relief, the predicted cost burden of an opioid-free or opioid-sparing approach is significantly less than traditional methods.
Methods The following groups were considered in our inclusion criteria: those who speak the English language, all races and ethnicities, male or female, home medications, those who are at least 18 years of age and able to provide written informed consent, those undergoing inpatient or same-day surgical procedures. In addition, our scoping review includes the following exclusion criteria: those who are non-English speaking, those who are less than 18 years of age, those who are not undergoing surgical procedures while admitted, those who are unable to provide numeric pain score due to clinical status, those who are unable to provide written informed consent, and those who decline participation in the study. Data was extracted by one reviewer and verified by the remaining two group members. Extraction was divided as equally as possible among the 11 listed references. Discrepancies in data extraction were discussed between the article reviewer, project editor, and group leader.
Results We identified nine primary sources addressing the use of ketamine as an alternative to opioid analgesia and post-operative pain control. Our findings indicate a positive correlation between perioperative ketamine administration and postoperative pain control. While this information provides insight on opioid-free analgesia, it also revealed the limited amount of research conducted in this area of practice. The strategies for several of the clinical trials limited ketamine administration to a small niche of patients. The included studies provided evidence for lower pain scores, reductions in opioid consumption, and better patient outcomes.
Implications for Nursing Practice Based on the results of the studiesâ randomized controlled trials and meta-analyses, the effects of ketamine are shown as an adequate analgesic alternative to opioids postoperatively. The cited resources showed that ketamine can be used as a sole agent, or combined effectively with reduced doses of opioids for multimodal therapy. There were noted limitations in some of the research articles. Not all of the cited studies were able to include definitive evidence of proper blinding techniques or randomization methods. Small sample sizes and the inclusion of specific patient populations identified within several of the studies can skew data in one direction or another; therefore, significant clinical results cannot be generalized to patient populations across the board
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Observations of enhanced OTR signals from a compressed electron beam
The Advanced Photon Source (APS) injector complex includes an option for photocathode (PC) gun beam injection into the 450-MeV S-band linac. At the 150-MeV point, a 4-dipole chicane was used to compress the micropulse bunch length from a few ps to sub 0.5 ps (FWHM). Noticeable enhancements of the optical transition radiation (OTR) signal sampled after the APS chicane were then observed as has been reported in LCLS injector commissioning. A FIR CTR detector and interferometer were used to monitor the bunch compression process and correlate the appearance of localized spikes of OTR signal (5 to 10 times brighter than adjacent areas) within the beam image footprint. We have done spectral dependency measurements at 375 MeV with a series of band pass filters centered in 50-nm increments from 400 to 700 nm and observed a broadband enhancement in these spikes. Discussions of the possible mechanisms will be presented
The Impact of SGLT2 Inhibitors, Compared with Insulin, on Diabetic Bone Disease in a Mouse Model of Type 1 Diabetes
Skeletal co-morbidities in type 1 diabetes include an increased risk for fracture and delayed fracture healing, which are intertwined with disease duration and the presence of other diabetic complications. As such, chronic hyperglycemia is undoubtedly a major contributor to these outcomes, despite standard insulin-replacement therapy. Therefore, using the streptozotocin (STZ)-induced model of hypoinsulinemic hyperglycemia in DBA/2J male mice, we compared the effects of two glucose lowering therapies on the fracture resistance of bone and markers of bone turnover. Twelve week-old diabetic (DM) mice were treated for 9 weeks with: 1) oral canagliflozin (CANA, dose range ~10-16 mg/kg/day), an inhibitor of the renal sodium-dependent glucose co-transporter type 2 (SGLT2); 2) subcutaneous insulin, via minipump (INS, 0.125 units/day); 3) co-therapy (CANA + INS); or 4) no treatment (STZ, without therapy). These groups were also compared to non-diabetic control groups. Untreated diabetic mice experienced increased bone resorption and significant deficits in cortical and trabecular bone that contributed to structural weakness of the femur mid-shaft and the lumbar vertebra, as determined by three-point bending and compression tests, respectively. Treatment with either canagliflozin or insulin alone only partially rectified hyperglycemia and the diabetic bone phenotype. However, when used in combination, normalization of glycemic control was achieved, and a prevention of the DM-related deterioration in bone microarchitecture and bone strength occurred, due to additive effects of canagliflozin and insulin. Nevertheless, CANA-treated mice, whether diabetic or non-diabetic, demonstrated an increase in urinary calcium loss; FGF23 was also increased in CANA-treated DM mice. These findings could herald ongoing bone mineral losses following CANA exposure, suggesting that certain CANA-induced skeletal consequences might detract from therapeutic improvements in glycemic control, as they relate to diabetic bone disease
Kinetic Theory of a Dilute Gas System under Steady Heat Conduction
The velocity distribution function of the steady-state Boltzmann equation for
hard-core molecules in the presence of a temperature gradient has been obtained
explicitly to second order in density and the temperature gradient. Some
thermodynamical quantities are calculated from the velocity distribution
function for hard-core molecules and compared with those for Maxwell molecules
and the steady-state Bhatnagar-Gross-Krook(BGK) equation. We have found
qualitative differences between hard-core molecules and Maxwell molecules in
the thermodynamical quantities, and also confirmed that the steady-state BGK
equation belongs to the same universality class as Maxwell molecules.Comment: 36 pages, 4 figures, 5 table
The identification of salient beliefs concerning university studentsâ decision to participate in sport
The aim of this study was to identify salient beliefs toward university-provided recreational sport in first-year undergraduate students. A purposive sample of 76 students (36 males, 40 females; mean age: 19.2â±â1.7 years) undertaking various degree subjects at a higher education institution in the North of England, United Kingdom, was used in the study. The instrument was a theory-based open-ended questionnaire informed by the Theory of Planned Behavior, addressing behavioral, normative, and control beliefs. Thematic content analysis and coding was conducted on 30 randomly selected questionnaires followed by a frequency count to identify the modal salient beliefs. The modal set revealed 17 beliefs from a possible 53: six behavioral, five normative, and six control. These beliefs were related to health benefits, enjoyment, friendships, time constraints, study workloads, awareness, and the perception of family, friends, and academics. The results highlight the factors that should be targeted for intervention and provide data to be utilized for a second main quantitative study which will identify more specific belief targets. Due to equivocal intervention success, this formative research can serve to help increase the number of students participating in university recreational spor
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