bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patients with problems after ACL reconstruction - what do help MRI and SPECT/CT?
Authors: Mathis Dominic T. , Hirschmann Michael T. , Rasch Helmut , Falkowski Anna , Hirschmann Anna 
Published: March 2016

Aims and Objectives: Magnetic resonance imaging (MRI) and single-photon emission computed tomography/ computed tomography (SPECT/CT) are established diagnostic instruments for symptomatic patients after ACL reconstruction. The purpose of the study was to compare and correlate MRI and SPECT/CT findings of symptomatic patients after ACL reconstruction. Materials and Methods: In a retrospective study 30 knees of symptomatic patients complaining about pain and/or instability after ACL reconstruction were investigated using 99mTc-HDP SPECT/CT and MRI. In MRI signs of a graft tear (partial and complete) were noted. Graft signal intensity, bone bruise, cyst formation in proximal, medial and distal femoral and tibial tunnels, roof impingement, roof osteophytes, graft arthrofibrosis, knee joint effusion and synovial thickness were classified. Measurements were performed by two musculoskeletal radiologists. The agreement of the assessed MR signs were calculated using cohen’s kappa coefficient. These showed excellent (kappa >0.75) to good (kappa >0.40) reproducibility between the readings of the two observers. Quantitative grading of bone tracer uptake (BTU) for each anatomical area of a previously validated localisation scheme was done. Tunnel width was assessed in CT at three different levels for femoral and tibial tunnels. The findings in SPECT/CT and MRI were correlated (p<0.05). Results: Increased BTU in most femoral and tibial knee regions was found in patients with MR findings of knee joint effusion, synovial thickening and bone bruise in various knee regions. A reciprocal correlation was shown for cyst formation in the central and distal area of the femoral tunnel and BTU in the femoral tunnel. MR findings such as graft continuity, graft signal intensity in the femoral and tibial tunnel, roof impingement, roof osteophytes did not show a significant correlation. A reciprocal correlation was revealed for tunnel enlargement in the proximal and central femoral tunnel and MR signal intensity in the entire intra-articular graft. Cyst formation in the femoral tunnel significantly correlated with tunnel enlargement in the proximal and central part of the femoral tunnel. Proximal femoral cyst formation also correlated with tibial tunnel enlargement in the central and distal part. BTU did show a positive correlation with tibial tunnel enlargement and a negative correlation with femoral tunnel enlargement. Conclusion: Both imaging modalities play an important role in postoperative diagnostics of patients with problems after ACL reconstruction. The results of our study could help in clinical decision-making to accurately identify causes of painful ACL reconstructions. MRI will remain the primary imaging modality, but SPECT/CT could be helpful giving information on in-vivo loading of the knee.
Survival and Reoperation Rate Following Osteochondral Allograft Transplantation
Authors: Frank Rachel M. , Levy David , Scalise Pamela Nina , Smith Margaret Elizabeth , Cole Brian J. 
Published: March 2016

Objectives: The purpose of this study was to quantify survival for osteochondral allograft transplantation (OAT) and report findings at reoperation. Methods: A retrospective review of a prospectively collected database of patients who underwent OAT by a single surgeon with a minimum follow-up duration of 2-years was conducted. The reoperation rate, timing of reoperation, procedure performed at reoperation, and findings at surgery were reviewed. Failure was defined by revision OAT, conversion to knee arthroplasty, or gross appearance of graft failure at 2ndlook arthroscopy. Descriptive statistics, log-rank testing, cross-tabulation, and chi-square testing were performed, with P<0.05 set as significant. Results: 100 patients (average age 32.7±10.2 years; 53 males, 47 females) who underwent OAT at an average follow-up of 4.9±2.5 years (range, 2.0 to 11.3) were included. Ninety-five patients (95%) underwent an average of 2.7±1.7 prior surgical procedures on the ipsilateral knee prior to OAT. The average defect size was 452.7±181.6 mm2 and was located on the medial femoral condyle in 63 patients (63%). Fifty-one percent of OATs were isolated, while 49% were performed with concomitant procedures including meniscus allograft transplantation (MAT) in 27 (27%). Fifty-three patients (53%) returned to the operating room at an average 2.8±2.7 years, with 26% of these patients (14/53) undergoing additional reoperations (range, 1-3 additional reoperations). Arthroscopic debridement was performed in 91% of the initial reoperations (48/53); 55% of reoperations (29/53) were performed within 2 years of the index OAT. Twenty patients (20%) were considered failures at an average 4.0±2.7 years following index OAT either due to revision OAT (N=6), conversion to arthroplasty (N=10), or appearance of poorly incorporated allograft at arthroscopy (N=4). Patients requiring multiple reoperations had an odds ratio of 7.25 (95% CI, 1.85 to 28.37) of OAT failure (P=0.004), while patients requiring secondary surgery within 2 years had an odds radio of 1.35 (95% CI, 0.48 to 3.82) for OAT failure (P>0.05). Patients with concomitant MAT and OAT were more likely to progress to failure (odds ratio 2.4, 95% CI 0.87 to 3.28). Excluding the failed patients, statistically and clinically significant improvements were found in all outcomes assessments at final follow-up, including Lysholm, IKDC, KOOS, and SF-12 (P<0.001 for all). Conclusion: In this series, there was a 53% reoperation rate for OAT, with arthroscopic debridement being the most common surgical treatment (91%), and an80% allograft survival rate at average of 5 years. Those requiring additional surgery still benefited, having a 70% allograft survival rate, but were at an increased risk of failure, with patients requiring multiple reoperations having an odds ratio of 7.25 for failure. This information can be used to counsel patients on the risks and implications of reoperation following OAT.
CCDC141 Mutation Identified in Anosmic Hypogonadotropic Hypogonadism (Kallmann Syndrome) Alters GnRH Neuronal Migration
Authors: Hutchins B. Ian , Kotan L. Damla , Taylor-Burds Carol , Ozkan Yusuf , Cheng Paul J. , Gurbuz Fatih , Tiong Jean D. R. , Mengen Eda , Yuksel Bilgin , Topaloglu A. Kemal , Wray Susan 
Published: March 2016

AbstractThe first mutation in a gene associated with a neuronal migration disorder was identified in patients with Kallmann Syndrome, characterized by hypogonadotropic hypogonadism and anosmia. This pathophysiological association results from a defect in the development of the GnRH and the olfactory system. A recent genetic screening of Kallmann Syndrome patients revealed a novel mutation in CCDC141. Little is known about CCDC141, which encodes a coiled-coil domain containing protein. Here, we show that Ccdc141 is expressed in GnRH neurons and olfactory fibers and that knockdown of Ccdc141 reduces GnRH neuronal migration. Our findings in human patients and mouse models predict that CCDC141 takes part in embryonic migration of GnRH neurons enabling them to form a hypothalamic neuronal network to initiate pulsatile GnRH secretion and reproductive function.
Flapping wing aerodynamics: from insects to vertebrates
Authors: Chin Diana D. , Lentink David 
Published: March 2016

ABSTRACTMore than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms – added mass, clap and fling, rotational circulation and wing–wake interactions – have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters – the Reynolds number, Rossby number and advance ratio – govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight.
Phenotypic differences between the sexes in the sexually plastic mangrove rivulus fish (Kryptolebias marmoratus)
Authors: Garcia Mark J. , Ferro Jack M. , Mattox Tyler , Kopelic Sydney , Marson Kristine , Jones Ryan , Svendsen Jon C. , Earley Ryan L. 
Published: March 2016

ABSTRACT
To maximize reproductive success, many animal species have evolved functional sex change. Theory predicts that transitions between sexes should occur when the fitness payoff of the current sex is exceeded by the fitness payoff of the opposite sex. We examined phenotypic differences between the sexes in a sex-changing vertebrate, the mangrove rivulus fish (Kryptolebias marmoratus), to elucidate potential factors that might drive the ‘decision’ to switch sex. Rivulus populations consist of self-fertilizing hermaphrodites and males. Hermaphrodites transition into males under certain environmental conditions, affording us the opportunity to generate 40 hermaphrodite–male pairs where, within a pair, individuals possessed identical genotypes despite being different sexes. We quantified steroid hormone levels, behavior (aggression and risk taking), metabolism and morphology (organ masses). We found that hermaphrodites were more aggressive and risk averse, and had higher maximum metabolic rates and larger gonadosomatic indices. Males had higher steroid hormone levels and showed correlations among hormones that hermaphrodites lacked. Males also had greater total mass and somatic body mass and possessed considerable fat stores. Our findings suggest that there are major differences between the sexes in energy allocation, with hermaphrodites exhibiting elevated maximum metabolic rates, and showing evidence of favoring investments in reproductive tissues over somatic growth. Our study serves as the foundation for future research investigating how environmental challenges affect both physiology and reproductive investment and, ultimately, how these changes dictate the transition between sexes.
Starvation stress during larval development facilitates an adaptive response in adult worker honey bees (Apis mellifera L.)
Authors: Wang Ying , Kaftanoglu Osman , Brent Colin S. , Page Robert E. , Amdam Gro V. 
Published: March 2016

ABSTRACT
Most organisms are constantly faced with environmental changes and stressors. In diverse organisms, there is an anticipatory mechanism during development that can program adult phenotypes. The adult phenotype would be adapted to the predicted environment that occurred during organism maturation. However, whether this anticipatory mechanism is present in eusocial species is questionable because eusocial organisms are largely shielded from exogenous conditions by their stable nest environment. In this study, we tested whether food deprivation during development of the honey bee (Apis mellifera), a eusocial insect model, can shift adult phenotypes to better cope with nutritional stress. After subjecting fifth instar worker larvae to short-term starvation, we measured nutrition-related morphology, starvation resistance, physiology, endocrinology and behavior in the adults. We found that the larval starvation caused adult honey bees to become more resilient toward starvation. Moreover, the adult bees were characterized by reduced ovary size, elevated glycogen stores and juvenile hormone (JH) titers, and decreased sugar sensitivity. These changes, in general, can help adult insects survive and reproduce in food-poor environments. Overall, we found for the first time support for an anticipatory mechanism in a eusocial species, the honey bee. Our results suggest that this mechanism may play a role in honey bee queen–worker differentiation and worker division of labor, both of which are related to the responses to nutritional stress.
Broadband noise exposure does not affect hearing sensitivity in big brown bats (Eptesicus fuscus)
Authors: Simmons Andrea Megela , Hom Kelsey N. , Warnecke Michaela , Simmons James A. 
Published: March 2016

ABSTRACTIn many vertebrates, exposure to intense sounds under certain stimulus conditions can induce temporary threshold shifts that reduce hearing sensitivity. Susceptibility to these hearing losses may reflect the relatively quiet environments in which most of these species have evolved. Echolocating big brown bats (Eptesicus fuscus) live in extremely intense acoustic environments in which they navigate and forage successfully, both alone and in company with other bats. We hypothesized that bats may have evolved a mechanism to minimize noise-induced hearing losses that otherwise could impair natural echolocation behaviors. The hearing sensitivity of seven big brown bats was measured in active echolocation and passive hearing tasks, before and after exposure to broadband noise spanning their audiometric range (10–100 kHz, 116 dB SPL re. 20 µPa rms, 1 h duration; sound exposure level 152 dB). Detection thresholds measured 20 min, 2 h or 24 h after exposure did not vary significantly from pre-exposure thresholds or from thresholds in control (sham exposure) conditions. These results suggest that big brown bats may be less susceptible to temporary threshold shifts than are other terrestrial mammals after exposure to similarly intense broadband sounds. These experiments provide fertile ground for future research on possible mechanisms employed by echolocating bats to minimize hearing losses while orienting effectively in noisy biological soundscapes.
Detection of artificial water flows by the lateral line system of a benthic feeding cichlid fish
Authors: Schwalbe Margot A. B. , Sevey Benjamin J. , Webb Jacqueline F. 
Published: March 2016

ABSTRACT
The mechanosensory lateral line system of fishes detects water motions within a few body lengths of the source. Several types of artificial stimuli have been used to probe lateral line function in the laboratory, but few studies have investigated the role of flow sensing in benthic feeding teleosts. In this study, we used artificial flows emerging from a sandy substrate to assess the contribution of flow sensing to prey detection in the peacock cichlid, Aulonocara stuartgranti, which feeds on benthic invertebrates in Lake Malawi. Using a positive reinforcement protocol, we trained fish to respond to flows lacking the visual and chemical cues generated by tethered prey in prior studies with A. stuartgranti. Fish successfully responded to artificial flows at all five rates presented (characterized using digital particle image velocimetry), and showed a range of flow-sensing behaviors, including an unconditioned bite response. Immediately after lateral line inactivation, fish rarely responded to flows and the loss of vital fluorescent staining of hair cells (with 4-di-2-ASP) verified lateral line inactivation. Within 2 days post-treatment, some aspects of flow-sensing behavior returned and after 7 days, flow-sensing behavior and hair cell fluorescence both returned to pre-treatment levels, which is consistent with the reported timing of hair cell regeneration in other vertebrates. The presentation of ecologically relevant water flows to assess flow-sensing behaviors and the use of a positive reinforcement protocol are methods that present new opportunities to study the role of flow sensing in the feeding ecology of benthic feeding fishes.
Organizational Debut on the Public Stage: Marketing Myopia and Initial Public Offerings
Authors: Saboo Alok R. , Chakravarty Anindita , Grewal Rajdeep 
Published: March 2016

Successful initial public offerings (IPOs) provide firms with access to valuable resources, but also put pressure on firms to impress potential investors with evidence of their current well-being and prospects for future growth. To impress investors IPO firms might curtail their marketing budgets, which appears to inflate current earnings and provide evidence of current well-being. However, curtailing marketing budgets unexpectedly during an IPO may be a myopic practice, in that the immediate benefits of these budget cuts are offset by their longer-term adverse consequences on financial well-being. The extent of these adverse consequences in turn may be moderated by external firm factors, including strategic alliances and key customer relationships, and internal firm factors, such as the strategic emphasis on value creation versus value appropriation. A sample of 1,095 IPOs during 2000–2011 reveals evidence of myopic marketing practices in more than 37% of the sample. Investors seem misled during IPOs, but they correct their beliefs in the three years following the IPO and penalize these firms. The penalty for myopic marketing budgeting practices also increases with more strategic alliances and a strategic emphasis on value creation versus value appropriation, but it decreases in the presence (versus absence) of key customer relationships.Data, as supplemental material, are available at http://dx.doi.org/10.1287/mksc.2015.0970 .
Software-Enabled Distributed Network Governance: The PopMedNet Experience
Authors: Davies Melanie , Erickson Kyle , Wyner Zachary , Malenfant Jessica M. , Rosen Rob , Brown Jeff 
Published: March 2016

Introduction: The expanded availability of electronic health information has led
to increased interest in distributed health data research networks.Distributed Research
Network Model: The distributed research network model leaves data with and under the
control of the data holder. Data holders, network coordinating centers, and researchers
have distinct needs and challenges within this model.Software Enabled Governance:
PopMedNet: The concerns of network stakeholders are addressed in the design and
governance models of the PopMedNet software platform. PopMedNet features include
distributed querying, customizable workflows, and auditing and search capabilities. Its
flexible role-based access control system enables the enforcement of varying governance
policies.Selected Case Studies: Four case studies describe how PopMedNet is used to
enforce network governance models.Issues and Challenges: Trust is an essential component
of a distributed research network and must be built before data partners may be willing
to participate further. The complexity of the PopMedNet system must be managed as
networks grow and new data, analytic methods, and querying approaches are
developed.Conclusions: The PopMedNet software platform supports a variety of network
structures, governance models, and research activities through customizable features
designed to meet the needs of network stakeholders.
The role of "open" in strategic library planning
Authors: Petrides Lisa , Goger Letha , Jimes Cynthia 
Published: March 2016

Academic libraries are undergoing evolutionary change as emerging technologies and new philosophies about how information is created, distributed, and shared have disrupted traditional operations and services. Additionally, the population that the academic library serves is increasingly distributed due to distance learning opportunities and new models of teaching and learning. This article, the first in this special issue, suggests that in today’s increasingly networked and distributed information environment, the strategic integration of open curation and collection development practices can serve as a useful means for organizing and providing structure to the diverse mass of available digital information, so that individual users of the library have access to coherent contexts for meaningful engagement with that information. Building on insights from extant research and practice, this article proposes that colleges and universities recognize a more inclusive open access environment, including the integration of resources outside of those owned or created by the institution, and a shift toward policies that consider open access research and open educational resources as part of the library’s formal curatorial workflow and collection building. At the conclusion on this article, authors Lisa Petrides and Cynthia Jimes offer a commentary on the six remaining articles that comprise this special issue on Models of Open Education in Higher Education, discussing the significant role that “open” policy and practice play in shaping teaching, learning, and scholarship in the global context of higher education.
The deubiquitinase Usp27x stabilizes the BH3‐only protein Bim and enhances apoptosis
Authors: Weber Arnim , Heinlein Melanie , Dengjel Jörn , Alber Claudia , Singh Prafull Kumar , Häcker Georg 
Published: March 2016

AbstractBim is a pro‐apoptotic Bcl‐2 family member of the BH3‐only protein subgroup. Expression levels of Bim determine apoptosis susceptibility in non‐malignant and in tumour cells. Bim protein expression is downregulated by proteasomal degradation following ERK‐dependent phosphorylation and ubiquitination. Here, we report the identification of a deubiquitinase, Usp27x, that binds Bim upon its ERK‐dependent phosphorylation and can upregulate its expression levels. Overexpression of Usp27x reduces ERK‐dependent Bim ubiquitination, stabilizes phosphorylated Bim, and induces apoptosis in PMA‐stimulated cells, as well as in tumour cells with a constitutively active Raf/ERK pathway. Loss of endogenous Usp27x enhances the Bim‐degrading activity of oncogenic Raf. Overexpression of Usp27x induces low levels of apoptosis in melanoma and non‐small cell lung cancer (NSCLC) cells and substantially enhances apoptosis induced in these cells by the inhibition of ERK signalling. Finally, deletion of Usp27x reduces apoptosis in NSCLC cells treated with an EGFR inhibitor. Thus, Usp27x can trigger via its proteolytic activity the deubiquitination of Bim and enhance its levels, counteracting the anti‐apoptotic effects of ERK activity, and therefore acts as a tumour suppressor.
Triallelic Population Genomics for Inferring Correlated Fitness Effects of Same Site Nonsynonymous Mutations
Authors: Ragsdale Aaron P , Coffman Alec J , Hsieh PingHsun , Struck Travis J , Gutenkunst Ryan N 
Published: March 2016

Abstract
The distribution of mutational effects on fitness is central to evolutionary genetics. Typical univariate distributions, however, cannot model the effects of multiple mutations at the same site, so we introduce a model in which mutations at the same site have correlated fitness effects. To infer the strength of that correlation, we developed a diffusion approximation to the triallelic frequency spectrum, which we applied to data from Drosophila melanogaster. We found a moderate positive correlation between the fitness effects of nonsynonymous mutations at the same codon, suggesting that both mutation identity and location are important for determining fitness effects in proteins. We validated our approach by comparing it to biochemical mutational scanning experiments, finding strong quantitative agreement, even between different organisms. We also found that the correlation of mutational fitness effects was not affected by protein solvent exposure or structural disorder. Together, our results suggest that the correlation of fitness effects at the same site is a previously overlooked yet fundamental property of protein evolution.