bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non-separable solutions of the Helmholtz wave equation
Authors: Moseley Donald S. 
Published: December 2016

A set of solutions not obtainable by the method of separation of variables is presented for the vector Helmholtz wave equation in circular cylindrical coordinates limited to non-angular dependence. These are constructed of Bessel and trigonometric functions. For example, if A is the vector, the

r
r

-component of the simplest member of the set is
\[

A
r

=

C
1

[

m
r

J
0

(

p
r

)

cos
⁡

(

m
z

)

+
p
z

J
1

(

p
r

)

sin
⁡

(

m
z

)

]

e

−
i
w
t

,

{A_r} = {C_1}\left [ {mr{J_0}\left ( {pr} \right )\cos \left ( {mz} \right ) + pz{J_1}\left ( {pr} \right )\sin \left ( {mz} \right )} \right ]{e^{ - iwt}},

\]
where

C
1

{C_1}

is an arbitrary constant,

m
m

and

p
p

are propagation constants, and

ω
\omega

is angular frequency. Brief reference is made to three-dimensional solutions in rectangular coordinates.
Difference methods for a nonlinear elliptic system of partial differential equations
Authors: McAllister G. T. 
Published: December 2016

This paper proves the existence and uniqueness of non-negative solutions to the Dirichlet problem associated with the nonlinear elliptic system
\[

Δ

u
k

=

b
k

∏

l
=
1

m

u
l

n

(
l
)

,
k
=
1
,
.
.
.
,
m

(
∗
)

\Delta {u_k} = {b_k}\prod \limits _{l = 1}^m {u_l^{n\left ( l \right )}} ,k = 1,...,m\left ( * \right )

\]
where the

b
k

{b_k}

and the Dirichlet data

u
k

=

φ
k

{u_k} = {\varphi _k}

are non-negative.
A suggested modification of noise theory
Authors: Keilson Julian 
Published: December 2016

A class of stationary, equilibrium, Markoff processes is demonstrated all of which have the same equilibrium distribution,

W
0

(
x
)

{W_0}\left ( x \right )

, and correlation function

R

(
t
)

=

E
0

exp
⁡

(

−
t

/

τ
0

)

R\left ( t \right ) = {E_0}\exp \left ( { - t/{\tau _0}} \right )

differing from each other in the number of zero crossings of the system per second. The processes are described by an integral equation characterized by a parameter

γ
\gamma

. As

γ
\gamma

approaches 1, the integral equation passes over into the Fokker-Planck equation

τ
0

∂
W

∂
t

=

E
0

∂
2

W

∂

x
2

+

∂

∂
x

(

x
W

)

{\tau _0}\frac {{\partial W}}{{\partial t}} = {E_0}\frac {{{\partial ^2}W}}{{\partial {x^2}}} + \frac {\partial }{{\partial x}}\left ( {xW} \right )

. Since the number of zero crossings per second of the system becomes infinite as

γ
\gamma

goes to one, the degenerate nature of the Fokker-Planck process is made evident.
Multi-mode surface wave diffraction by a right-angled wedge
Authors: Morgan R. C. , Karp S. N. , Karal Jr. 
Published: December 2016

This paper extends the phenomenological theory of multi-mode surface wave diffraction to a right-angled wedge configuration. The solution to a two-mode problem is obtained under the edge condition
\[

∑

j
=
0

2

|

∂
j

u

∂

x
j

|

=
0

(

r

−

[

1
+
h

]

)

,
0
≤
h
>
2

/

3

\sum \limits _{j = 0}^2 {\left | {\frac {{{\partial ^j}u}}{{\partial {x^j}}}} \right | = 0\left ( {{r^{ - \left [ {1 + h} \right ]}}} \right ),0 \le h > 2/3}

\]
as

r
→
0

r \to 0

. It is conjectured that the same procedure may be used to construct the solution to the corresponding

N
N

-mode problem under the edge condition
\[

∑

j
=
0

N

|

∂
j

u

∂

x
j

|

=
0

(

r

−

[

(

2
N
−
1

)

/

3
+
h

]

)

,
0
≤
h
≤
2

/

3

\sum \limits _{j = 0}^N {\left | {\frac {{{\partial ^j}u}}{{\partial {x^j}}}} \right |} = 0\left ( {{r^{ - \left [ {\left ( {2N - 1} \right )/3 + h} \right ]}}} \right ),0 \le h \le 2/3

\]
as

r
→
0

r \to 0

.
Improved seismic profiling by minimally invasive multimodal surface wave method with standard penetration test source (MMSW-SPT)
Authors: Lin Shibin , Ashlock Jeramy C. 
Published: December 2016

Abstract
Surface waves propagating in layered media inherently possess multimodal dispersion characteristics. However, traditional surface wave testing methods employing measurements at the free surface usually capture only a single apparent dispersion curve, especially when using short geophone arrays common to near surface and geotechnical-scale investigations. Such single-mode or fragmented multimode apparent dispersion curves contain only a fraction of the possible dispersion information, thus limiting the accuracy of inverted profiles. To enable more robust measurement of higher Rayleigh-wave modes, a recently developed hybrid minimally invasive multimodal surface wave method is combined herein with the widely used geotechnical standard penetration test (SPT), which is employed as a practical and ubiquitous downhole source. Upon superimposing surface wave dispersion data for a range of SPT impact depths within the soil, higher modes can be measured more consistently and reliably relative to traditional non-invasive testing methods. As a result, misidentification of multiple dispersion modes can be practically eliminated, significantly improving the accuracy and certainty of inversion results.
Institutional Incentives for Mentoring at the U.S. Department of Veterans Affairs and Universities: Associations With Mentors’ Perceptions and Time Spent Mentoring
Authors: Maisel Natalya C. , Halvorson Max A. , Finney John W. , Bi Xiaoyu , Hayashi Ko P. , Blonigen Daniel M. , Weitlauf Julie C. , Timko Christine , Cronkite Ruth C. 
Published: December 2016

Purpose
Limited empirical attention to date has focused on best practices in advanced research mentoring in the health services research domain. The authors investigated whether institutional incentives for mentoring (e.g., consideration of mentoring in promotion criteria) were associated with mentors’ perceptions of mentoring benefits and costs and with time spent mentoring.

Method
The authors conducted an online survey in 2014 of a national sample of mentors of U.S. Department of Veterans Affairs (VA) Health Services Research and Development Service (HSR&D) mentored career development award recipients who received an award during 2000–2012. Regression analyses were used to examine institutional incentives as predictors of perceptions of benefits and costs of mentoring and time spent mentoring.

Results
Of the 145 mentors invited, 119 (82%) responded and 110 (76%) provided complete data for the study items. Overall, mentors who reported more institutional incentives also reported greater perceived benefits of mentoring (P = .03); however, more incentives were not significantly associated with perceived costs of mentoring. Mentors who reported more institutional incentives also reported spending a greater percentage of time mentoring (P = .02). University incentives were associated with perceived benefits of mentoring (P = .02), whereas VA incentives were associated with time spent mentoring (P = .003).

Conclusions
Institutional policies that promote and support mentorship of junior investigators, specifically by recognizing and rewarding the efforts of mentors, are integral to fostering mentorship programs that contribute to the development of early-career health services researchers into independent investigators.
Symptoms of Depression and Risk of Low Back Pain
Authors: Pinheiro Marina B. , Ferreira Manuela L. , Refshauge Kathryn , Colodro-Conde Lucia , González-Javier Francisca , Hopper John L. , Ordoñana Juan R. , Ferreira Paulo H. 
Published: December 2016

Objectives:
To investigate whether symptoms of depression increase the risk of low back pain (LBP), after adjusting for genetic and environmental influences.

Methods:
Baseline data of 1607 twins from the Murcia Twin Registry (Spain) were collected in 2009 to 2011 and follow-up data in 2013. Twins answered questions on depression-related symptomatology and LBP. Only participants not reporting chronic LBP (pain >6 mo) at baseline were included. The association between symptoms of depression and LBP was investigated using logistic regression analysis including the complete sample. Subsequent matched within-pair case-control analyses were performed with all complete dizygotic twin pairs discordant for LBP, followed by monozygotic twins.

Results:
In the total sample analysis, symptoms of depression did not significantly increase the risk of chronic LBP (odds ratio [OR]=1.40; 95% confidence interval [CI], 0.96-2.03), LBP care seeking (OR=1.21; 95% CI, 0.81-1.81), or activity-limiting LBP (OR=1.09; 95% CI, 0.69-1.72). State depression (participants’ symptoms at the moment of the interview) was significantly associated with future care seeking (OR=1.06; 95% CI, 1.01-1.12) and activity-limiting LBP (OR=1.07; 95% CI, 1.01-1.14). A significant association was found between trait depression and activity-limiting LBP (OR=1.05; 95% CI, 1.01-1.10), but not for the other LBP outcomes. No significant association was observed in any of the subsequent case-control analyses.

Discussion:
The magnitude of the association between depression and LBP seems to be small and may be confounded by genetic and early shared environment influences, although firm conclusions could not be made due to small sample size in the case-control analysis. In addition, the observed association is dependent on the method of assessment used for both conditions.
Operative Treatment of Rib Fractures in Flail Chest Injuries: A Meta-analysis and Cost-Effectiveness Analysis
Authors: Swart Eric , Laratta Joseph , Slobogean Gerard , Mehta Samir 
Published: December 2016

Objectives:
Flail chest is a common injury sustained by patients who experience high-energy blunt chest trauma and results in severe respiratory compromise because of altered mechanics of respiration. There has been increased interest in operative fixation of these injuries with the intention of restoring the mechanical integrity of the chest wall, and several studies have shown that ventilation requirements and pulmonary complications may be decreased with operative intervention. The purpose of this study was to evaluate fixation of rib fractures in flail chest injuries using cost-effectiveness analysis, supported by systematic review and meta-analysis.

Methods:
This was a 2-part study in which we initially conducted a systematic literature review and meta-analysis on outcomes after operative fixation of flail chest injuries, evaluating intensive care unit (ICU) stay, hospital length of stay (LOS), mortality, pneumonia, and need for tracheostomy. The results were then applied to a decision-analysis model comparing the costs and outcomes of operative fixation versus nonoperative treatment. The validity of the results was tested using probabilistic sensitivity analysis.

Results:
Operative treatment decreased mortality, pneumonia, and tracheotomy (risk ratios of 0.44, 0.59, and 0.52, respectively), as well as time in ICU and total LOS (3.3 and 4.8 days, respectively). Operative fixation was associated with higher costs than nonoperative treatment ($23,682 vs. $8629 per case, respectively) and superior outcomes (32.60 quality-adjusted life year (QALY) vs. 30.84 QALY), giving it an incremental cost-effectiveness ratio of $8577/QALY.

Conclusions:
Surgical fixation of rib fractures sustained from flail chest injuries decreased ICU time, mortality, pulmonary complications, and hospital LOS and resulted in improved health care–related outcomes and was a cost-effective intervention. These results were sensitive to overall complication rates, and operations should be conducted by surgeons or combined surgical teams comfortable with both thoracic anatomy and exposures as well as with the principles and techniques of internal fixation.

Level of Evidence:
Economic Level III. See Instructions for Authors for a complete description of levels of evidence.
Novel Spiked-Washer Repair Is Biomechanically Superior to Suture and Bone Tunnels for Arcuate Fracture Repair
Authors: Vojdani Saman , Fernandez Laviel , Jiao Jian , Enders Tyler , Ortiz Steven , Lin Liangjun , Qin Yi-Xian , Komatsu David E. , Penna James , Ruotolo Charles J. 
Published: December 2016

Objectives:
Injuries to the posterolateral corner of the knee can lead to chronic degenerative changes, external rotation instability, and varus instability if not repaired adequately. A proximal fibula avulsion fracture, referred to as an arcuate fracture, has been described in the literature, but a definitive repair technique has yet to be described. The objective of this study was to present a novel arcuate fracture repair technique, using a spiked-washer with an intramedullary screw, and to compare its biomechanical integrity to a previously described suture and bone tunnel method.

Methods:
Ten fresh-frozen cadaveric knees underwent a proximal fibula osteotomy to simulate a proximal fibula avulsion fracture. The lateral knee capsule and posterior cruciate ligament were also sectioned to create maximal varus instability. Five fibulas were repaired using a novel spiked-washer technique and the other 5 were repaired using the suture and bone tunnel method. The repaired knees were subjected to a monotonic varus load using a mechanical testing system instrument until failure of the repair or associated posterolateral corner structures.

Results:
Compared with the suture repair group, the spiked-washer repair group demonstrated a 100% increase in stiffness, 100% increase in yield, 110% increase in failure force, and 108% increase in energy to failure.

Conclusions:
The spiked-washer technique offers superior quasi-static biomechanical performance compared with suture repair with bone tunnels for arcuate fractures of the proximal fibula. Further clinical investigation of this technique is warranted and the results of this testing may lead to improved outcomes and patient satisfaction for proximal fibula avulsion fractures.
Internal Rotation Stress Testing Improves Radiographic Outcomes of Type 3 Supracondylar Humerus Fractures
Authors: Bauer Jennifer M. , Stutz Christopher M. , Schoenecker Jonathan G. , Lovejoy Steven A. , Mencio Gregory A. , Martus Jeffrey E. 
Published: December 2016

Background:
The purpose of this study was to determine if routine use of an intraoperative internal rotation stress test (IRST) for type 3 supracondylar humerus fractures will safely improve maintenance of reduction.

Methods:
An intraoperative protocol for type 3 supracondylar humerus fractures was adopted at our institution, consisting of fracture reduction, placement of 2 laterally based divergent pins, and then an IRST to determine the need for additional fixation with a medial column pin placed through a small open approach. Fractures treated with the prospective IRST protocol were compared with a retrospective cohort before adoption of the protocol (pre-IRST). The primary outcomes were differences in Baumann’s angle, lateral humerocapitellar angle, and the rotation index between final intraoperative fluoroscopic images and radiographs at final follow-up. Secondary outcomes were complications such as iatrogenic nerve injury, loss of fixation, or need for reoperation.

Results:
There were 78 fractures in the retrospective cohort (pre-IRST) and 49 in the prospective cohort (IRST). Overall rotational loss of reduction (>6%), measured by lateral rotation percentage, and major rotational loss of reduction (>12%) were less common in the IRST cohort (6/49 vs. 27/78, P=0.007 overall; 0/49 vs. 8/78, P=0.02 major loss). There were no major losses of reduction for Baumann’s angle (>12 degrees) in either cohort. There were 5 subjects in the pre-IRST cohort (6.4%) with a major loss of reduction of the humerocapitellar angle (>12 degrees) and none in the IRST cohort (P=0.16) Loss of proximal fixation with need for reoperation occurred in 3 fractures in the pre-IRST cohort, and none in the IRST cohort (P=0.28). There were no postoperative nerve injuries in either group.

Conclusions:
Intraoperative IRST after placement of 2 lateral pins assists with the decision for additional fixation in type 3 supracondylar humerus fractures. This method improved the final radiographic rotational alignment, and was safely performed using a mini-open approach for medial pin placement.

Level of Evidence:
Level III—prospective cohort compared with a retrospective cohort.
Closure of a Large Thoracolumbar Myelomeningocele Using a Modified Bilateral Keystone Flap
Authors: Jamjoom Hytham , Alnoman Hatem , Almadani Yasser 
Published: December 2016

Summary:
The keystone flap, an emerging reconstructive option that can be used in many parts of the body, is gaining popularity among reconstructive surgeons. These reliable and versatile flaps can be used for large myelomeningocele closure. A modified bilateral keystone flap was used to achieve tension-free closure of a large thoracolumbar myelomeningocele associated with severe kyphosis in a newborn girl. The flap was modified by undermining in the subfascial plane in the medial aspect of the middle third. This undermining was performed to facilitate flap movement while preserving random musculocutaneous perforators captured within the island of tissues. Laterally, we approached the border of the latissimus dorsi and dissected in the submuscular plane instead of the subfascial plane to preserve more muscular fasciocutaneous perforators. We achieved soft-tissue coverage that was durable, stable, and protective. Wound healing was prompt, and the patient had a satisfactory cosmetic result. No postoperative complications were observed, such as flap necrosis, dehiscence, leakage of cerebrospinal fluid, or infection. The proposed modified keystone flap is a promising addition to the armament of reconstructive surgeons that might improve outcomes and minimize complications in myelomeningocele repair. Keystone flaps provide an ideal reconstructive option for large thoracolumbar myelomeningocele repair. They are reliable, robust, and aesthetically acceptable.
De Novo Reconstruction of a Hybrid Patella by Staged Fabrication of a Microvascular Bone Transplant with an Osteointegrated Prosthetic Socket
Authors: Giessler Goetz A. , Hendrich Christian 
Published: December 2016

Summary:
Total patellectomy is sometimes unavoidable but usually results in severely impaired function, pain, and instability in the affected knee. Any patellar prosthetic solutions rely on a certain amount of remaining bone and therefore are not applicable after total patellectomy. Traditionally, reconstruction of a neopatella by avascular or allogeneic bone grafts is hampered by mechanical failure, resorption, or infection. We developed a new, 3-stage approach to reconstruct a hybrid patella composed of a revascularized scapula tip transplant fabricated with a prosthetic socket. The procedure is safe and provides optimal healing and prosthetic osteointegration through viable bone and dynamic stability to the considerable load a patella has to bear in unrestricted mobility. The technique also demonstrates successful integration of orthopedic prosthetic devices into current flap fabrication concepts.
Comparing the Performance of Compass Perimetry With Humphrey Field Analyzer in Eyes With Glaucoma
Authors: Rao Harsha L. , Raveendran Sharanya , James Varsha , Dasari Srilakshmi , Palakurthy Meena , Reddy Hemanth B. , Pradhan Zia S. , Rao Dhanaraj A.S. , Puttaiah Narendra K. , Devi Sathi 
Published: December 2016

Purpose:
To evaluate the reliability indices [fixation losses, false negative response rates (FN) and false positive response rates] and threshold sensitivities obtained from glaucoma patients with a Compass perimeter and to compare the same with the Humphrey field analyzer (HFA).

Methods:
In a cross-sectional study, 97 eyes of 58 subjects (64 glaucoma and 33 glaucoma suspect eyes) underwent visual field examination with Compass and HFA. Any test with a fixation losses, FN or FP of >20% was considered unreliable. Reliability indices and threshold sensitivities between the 2 instruments were compared and the agreement evaluated using Bland and Altman analysis.

Results:
In total, 37 tests (38%) with Compass and 17 (18%) with HFA were unreliable. The number of unreliable tests due to high FN (>20%) was significantly more (P=0.005) with Compass (n=27) than HFA (n=3). The mean difference [95% limits of agreement (LoA)] in mean sensitivity between Compass and HFA in the 51 eyes with reliable Compass and HFA results was −0.7 dB (−5.6, 4.3 dB). The point-wise threshold sensitivities with Compass were lower than that with HFA in central and temporal but higher in the nasal field. The 95% LoA ranged from −8 to +5 dB at one of the central points to −20 to +20 dB at one of the peripheral points.

Conclusions:
The numbers of unreliable tests were higher with Compass compared with HFA. The LoA between Compass and HFA for point-wise threshold sensitivities as well as the global indices were wide, implying that the instruments cannot be used interchangeably.
EMpowerment of PArents in THe Intensive Care Questionnaire: Translation and Validation in Italian PICUs
Authors: Wolfler Andrea , Giannini Alberto , Finistrella Martina , Salvo Ida , Calderini Edoardo , Frasson Giulia , Dall’Oglio Immacolata , Di Furia Michela , Iuzzolino Rossella , Musicco Massimo , Latour Jos M. 
Published: December 2016

Objectives:
To translate and validate the EMpowerment of PArents in THe Intensive Care questionnaire to measure parent satisfaction and experiences in Italian PICUs.

Design:
Prospective, multicenter study.

Setting:
Four medical/surgical Italian PICUs in three tertiary hospitals.

Patients:
Families of children, 0–16 years old, admitted to the PICUs were invited to participate. Inclusion criteria were PICU length of stay greater than 24 hours and good comprehension of Italian language by parents/guardians. Exclusion criteria were readmission within 6 months and parents of a child who died in the PICU.

Interventions:
Distribution, at PICU discharge, of the EMpowerment of PArents in THe Intensive Care questionnaire with 65 items divided into five domains and a six-point rating scale: 1 “ certainly no” to 6 “certainly yes.”

Measurements and Main Results:
Back and forward translations of the EMpowerment of PArents in THe Intensive Care questionnaire between Dutch (original version) and Italian languages were deployed. Cultural adaptation of the instrument was confirmed by a consultation with a representative parent group (n = 10). Totally, 150 of 190 parents (79%) participated in the study. On item level, 12 statements scored a mean below 5.0. The Cronbach’s α, measured for internal consistency, on domain level was between 0.67 and 0.96. Congruent validity was measured by correlating the five domains with four gold standard satisfaction measures and showed adequate correlations (r
s, 0.41–0.71; p < 0.05). No significant differences occurred in the nondifferential validity testing between three children’s characteristics and the domains; excepting parents with a child for a surgical and planned admission were more satisfied on information and organization issues.

Conclusions:
The Italian version of the EMpowerment of PArents in THe Intensive Care questionnaire has satisfactory reliability and validity estimates and seems to be appropriate for Italian PICU setting. It is an important instrument providing benchmark data to be used in the process of quality improvement toward the development of a family-centered care philosophy within Italian PICUs.