bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of an operational algorithm for estimating snow-cover fraction
Authors: Mitkari K. V. , Arora M. K. , Mishra V. D. , Gusain H. S. , Gupta N. K. 
Published: October 2017

Abstract
This article describes an attempt to map snow cover accurately from other land covers using Moderate Resolution Imaging Spectrometer (MODIS) data of 500 m spatial resolution. The workflow includes reflectance modelling, computing snow-cover fraction (SCF) and establishing an empirical relationship between the SCF and normalized difference snow index (NDSI) to map snow cover at operational level. Regression relationships have been developed between the SCF derived from the linear mixture model (LMM) and snow obtained from the NDSI based on two criteria, namely: SCF greater than 0.0 and SCF greater than 0.1. The best regression equation has been selected by examining respective graph plots using statistical measures of mean absolute error, correlation coefficient, root mean square error (RMSE) and uncertainty analysis. The results have been validated against the actual SCF obtained from a high-resolution 15 m Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) visible and near infrared (VNIR) scene and covering a substantial range of snow cover of the same area. The selected regression model SCF = 0.25 + 0.35 × NDSI has been tested on other areas and validation efforts show that the pixel-level SCF relationship provides useful results as measured in independent tests against actual SCF obtained from ASTER scene.
ACh-induced hyperpolarization and decreased resistance in mammalian type II vestibular hair cells
Authors: Poppi Lauren A. , Tabatabaee Hessam , Drury Hannah R. , Jobling Phillip , Callister Robert J. , Migliaccio Americo A. , Jordan Paivi M. , Holt Joseph C. , Rabbitt Richard D. , Lim Rebecca , Brichta Alan M. 
Published: October 2017

In the mammalian vestibular periphery, electrical activation of the efferent vestibular system (EVS) has two effects on afferent activity: 1) it increases background afferent discharge and 2) decreases afferent sensitivity to rotational stimuli. Although the cellular mechanisms underlying these two contrasting afferent responses remain obscure, we postulated that the reduction in afferent sensitivity was attributed, in part, to the activation of α9- containing nicotinic acetylcholine (ACh) receptors (α9*nAChRs) and small-conductance potassium channels (SK) in vestibular type II hair cells, as demonstrated in the peripheral vestibular system of other vertebrates. To test this hypothesis, we examined the effects of the predominant EVS neurotransmitter ACh on vestibular type II hair cells from wild-type (wt) and α9-subunit nAChR knockout (α9−/−) mice. Immunostaining for choline acetyltransferase revealed there were no obvious gross morphological differences in the peripheral EVS innervation among any of these strains. ACh application onto wt type II hair cells, at resting potentials, produced a fast inward current followed by a slower outward current, resulting in membrane hyperpolarization and decreased membrane resistance. Hyperpolarization and decreased resistance were due to gating of SK channels. Consistent with activation of α9*nAChRs and SK channels, these ACh-sensitive currents were antagonized by the α9*nAChR blocker strychnine and SK blockers apamin and tamapin. Type II hair cells from α9−/− mice, however, failed to respond to ACh at all. These results confirm the critical importance of α9nAChRs in efferent modulation of mammalian type II vestibular hair cells. Application of exogenous ACh reduces electrical impedance, thereby decreasing type II hair cell sensitivity. NEW & NOTEWORTHY Expression of α9 nicotinic subunit was crucial for fast cholinergic modulation of mammalian vestibular type II hair cells. These findings show a multifaceted efferent mechanism for altering hair cell membrane potential and decreasing membrane resistance that should reduce sensitivity to hair bundle displacements.
Figure-ground organization in the visual cortex: does meaning matter?
Authors: Ko Hee-kyoung , von der Heydt Rüdiger 
Published: October 2017

Figure-ground organization in the visual cortex is generally assumed to be based partly on general rules and partly on specific influences of object recognition in higher centers as found in the temporal lobe. To see if shape familiarity influences figure-ground organization, we tested border ownership-selective neurons in monkey V1/V2 with silhouettes of human and monkey face profiles and “nonsense” silhouettes constructed by mirror-reversing the front part of the profile. We found no superiority of face silhouettes compared with nonsense shapes in eliciting border-ownership signals overall. However, in some neurons, border-ownership signals differed strongly between the two categories consistently across many different profile shapes. Surprisingly, this category selectivity appeared as early as 70 ms after stimulus onset, which is earlier than the typical latency of shape-selective responses but compatible with the earliest face-selective responses in the inferior temporal lobe. Although our results provide no evidence for a delayed top-down influence from object recognition centers, they indicate sophisticated shape categorization mechanisms that are much faster than generally assumed. NEW & NOTEWORTHY A long-standing question is whether low-level sensory representations in cortex are influenced by cognitive “top-down” signals. We studied figure-ground organization in the visual cortex by comparing border-ownership signals for face profiles and matched nonsense shapes. We found no sign of “face superiority” in the population border-ownership signal. However, some neurons consistently differentiated between the face and nonsense categories early on, indicating the presence of shape classification mechanisms that are much faster than previously assumed.
Layer- and subregion-specific differences in the neurophysiological properties of rat medial prefrontal cortex pyramidal neurons
Authors: Song Chenghui , Moyer James R. 
Published: October 2017

Medial prefrontal cortex (mPFC) is critical for the expression of long-term conditioned fear. However, the neural circuits involving fear memory acquisition and retrieval are still unclear. Two subregions within mPFC that have received a lot of attention are the prelimbic (PL) and infralimbic (IL) cortices (e.g., Santini E, Quirk GJ, Porter JT. J Neurosci 28: 4028–4036, 2008; Song C, Ehlers VL, Moyer JR Jr. J Neurosci 35: 13511–13524, 2015). Interestingly, PL and IL may play distinct roles during fear memory acquisition and retrieval but the underlying mechanism is poorly understood. One possibility is that the intrinsic membrane properties differ between these subregions. Thus, the current study was carried out to characterize the basic membrane properties of mPFC neurons in different layers and subregions. We found that pyramidal neurons in L2/3 were more hyperpolarized and less excitable than in L5. This was observed in both IL and PL and was associated with an enhanced h-current in L5 neurons. Within L2/3, IL neurons were more excitable than those in PL, which may be due to a lower spike threshold and higher input resistance in IL neurons. Within L5, the intrinsic excitability was comparable between neurons obtained in IL and PL. Thus, the heterogeneity in physiological properties of mPFC neurons may underlie the observed subregion-specific contribution of mPFC in cognitive function and emotional control, such as fear memory expression. NEW & NOTEWORTHY This is the first study to demonstrate that medial prefrontal cortical (mPFC) neurons are heterogeneous in both a layer- and a subregion-specific manner. Specifically, L5 neurons are more depolarized and more excitable than those neurons in L2/3, which is likely due to variations in h-current. Also, infralimbic neurons are more excitable than those of prelimbic neurons in layer 2/3, which may be due to differences in certain intrinsic properties, including input resistance and spike threshold.
Calcium dynamics control K-ATP channel-mediated bursting in substantia nigra dopamine neurons: a combined experimental and modeling study
Authors: Knowlton Christopher , Kutterer Sylvie , Roeper Jochen , Canavier Carmen C. 
Published: October 2017

Burst firing in medial substantia nigra (mSN) dopamine (DA) neurons has been selectively linked to novelty-induced exploration behavior in mice. Burst firing in mSN DA neurons, in contrast to lateral SN DA neurons, requires functional ATP-sensitive potassium (K-ATP) channels both in vitro and in vivo. However, the precise role of K-ATP channels in promoting burst firing is unknown. We show experimentally that L-type calcium channel activity in mSN DA neurons enhances open probability of K-ATP channels. We then generate a mathematical model to study the role of Ca2+ dynamics driving K-ATP channel function in mSN DA neurons during bursting. In our model, Ca2+ influx leads to local accumulation of ADP due to Ca-ATPase activity, which in turn activates K-ATP channels. If K-ATP channel activation reaches levels sufficient to terminate spiking, rhythmic bursting occurs. The model explains the experimental observation that, in vitro, coapplication of NMDA and a selective K-ATP channel opener, NN414, is required to elicit bursting as follows. Simulated NMDA receptor activation increases the firing rate and the rate of Ca2+ influx, which increases the activation of K-ATP. The model suggests that additional sources of hyperpolarization, such as GABAergic synaptic input, are recruited in vivo for burst termination or rebound burst discharge. The model predicts that NN414 increases the sensitivity of the K-ATP channel to ADP, promoting burst firing in vitro, and that that high levels of Ca2+ buffering, as might be expected in the calbindin-positive SN DA neuron subpopulation, promote rhythmic bursting pattern, consistent with experimental observations in vivo. NEW & NOTEWORTHY Recently identified distinct subpopulations of midbrain dopamine neurons exhibit differences in their two primary activity patterns in vivo: tonic (single spike) firing and phasic bursting. This study elucidates the biophysical basis of bursts specific to dopamine neurons in the medial substantia nigra, enabled by ATP-sensitive K+ channels and necessary for novelty-induced exploration. A better understanding of how dopaminergic signaling differs between subpopulations may lead to therapeutic strategies selectively targeted to specific subpopulations.
State-dependent rhythmogenesis and frequency control in a half-center locomotor CPG
Authors: Ausborn Jessica , Snyder Abigail C. , Shevtsova Natalia A. , Rybak Ilya A. , Rubin Jonathan E. 
Published: October 2017

The spinal locomotor central pattern generator (CPG) generates rhythmic activity with alternating flexion and extension phases. This rhythmic pattern is likely to result from inhibitory interactions between neural populations representing flexor and extensor half-centers. However, it is unclear whether the flexor-extensor CPG has a quasi-symmetric organization with both half-centers critically involved in rhythm generation, features an asymmetric organization with flexor-driven rhythmogenesis, or comprises a pair of intrinsically rhythmic half-centers. There are experimental data that support each of the above concepts but appear to be inconsistent with the others. In this theoretical/modeling study, we present and analyze a CPG model architecture that can operate in different regimes consistent with the above three concepts depending on conditions, which are defined by external excitatory drives to CPG half-centers. We show that control of frequency and phase durations within each regime depends on network dynamics, defined by the regime-dependent expression of the half-centers' intrinsic rhythmic capabilities and the operating phase transition mechanisms (escape vs. release). Our study suggests state dependency in locomotor CPG operation and proposes explanations for seemingly contradictory experimental data. NEW & NOTEWORTHY Our theoretical/modeling study focuses on the analysis of locomotor central pattern generators (CPGs) composed of conditionally bursting half-centers coupled with reciprocal inhibition and receiving independent external drives. We show that this CPG framework can operate in several regimes consistent with seemingly contradictory experimental data. In each regime, we study how intrinsic dynamics and phase-switching mechanisms control oscillation frequency and phase durations. Our results provide insights into the organization of spinal circuits controlling locomotion.
Selective Androgen Receptor Modulator RAD140 Inhibits the Growth of Androgen/Estrogen Receptor–Positive Breast Cancer Models with a Distinct Mechanism of Action
Authors: Yu Ziyang , He Suqin , Wang Dannie , Patel Hitisha K. , Miller Chris P. , Brown Jeffrey L. , Hattersley Gary , Saeh Jamal C. 
Published: October 2017

Abstract
Purpose: Steroidal androgens suppress androgen receptor and estrogen receptor positive (AR/ER+) breast cancer cells and were used to treat breast cancer, eliciting favorable response. The current study evaluates the activity and efficacy of the oral selective AR modulator RAD140 in in vivo and in vitro models of AR/ER+ breast cancer.
Experimental Design: A series of in vitro assays were used to determine the affinity of RAD140 to 4 nuclear receptors and evaluate its tissue-selective AR activity. The efficacy and pharmacodynamics of RAD140 as monotherapy or in combination with palbociclib were evaluated in AR/ER+ breast cancer xenograft models.
Results: RAD140 bound AR with high affinity and specificity and activated AR in breast cancer but not prostate cancer cells. Oral administration of RAD140 substantially inhibited the growth of AR/ER+ breast cancer patient-derived xenografts (PDX). Activation of AR and suppression of ER pathway, including the ESR1 gene, were seen with RAD140 treatment. Coadministration of RAD140 and palbociclib showed improved efficacy in the AR/ER+ PDX models. In line with efficacy, a subset of AR-repressed genes associated with DNA replication was suppressed with RAD140 treatment, an effect apparently enhanced by concurrent administration of palbociclib.
Conclusions: RAD140 is a potent AR agonist in breast cancer cells with a distinct mechanism of action, including the AR-mediated repression of ESR1. It inhibits the growth of multiple AR/ER+ breast cancer PDX models as a single agent, and in combination with palbociclib. The preclinical data presented here support further clinical investigation of RAD140 in AR/ER+ breast cancer patients. Clin Cancer Res; 23(24); 7608–20. ©2017 AACR.
Modulation of Navitoclax Sensitivity by Dihydroartemisinin-Mediated MCL-1 Repression in BCR-ABL+ B-Lineage Acute Lymphoblastic Leukemia
Authors: Budhraja Amit , Turnis Meghan E. , Churchman Michelle L. , Kothari Anisha , Yang Xue , Xu Haiyan , Kaminska Ewa , Panetta John C. , Finkelstein David , Mullighan Charles G. , Opferman Joseph T. 
Published: October 2017

AbstractPurpose: BCR-ABL+ B-ALL leukemic cells are highly dependent on the expression of endogenous antiapoptotic MCL-1 to promote viability and are resistant to BH3-mimetic agents such as navitoclax (ABT-263) that target BCL-2, BCL-XL, and BCL-W. However, the survival of most normal blood cells and other cell types is also dependent on Mcl-1. Despite the requirement for MCL-1 in these cell types, initial reports of MCL-1–specific BH3-mimetics have not described any overt toxicities associated with single-agent use, but these agents are still early in clinical development. Therefore, we sought to identify approved drugs that could sensitize leukemic cells to ABT-263.Experimental Design: A screen identified dihydroartemisinin (DHA), a water-soluble metabolite of the antimalarial artemisinin. Using mouse and human leukemic cell lines, and primary patient-derived xenografts, the effect of DHA on survival was tested, and mechanistic studies were carried out to discover how DHA functions. We further tested in vitro and in vivo whether combining DHA with ABT-263 could enhance the response of leukemic cells to combination therapy.Results: DHA causes the downmodulation of MCL-1 expression by triggering a cellular stress response that represses translation. The repression of MCL-1 renders leukemic cells highly sensitive to synergistic cell death induced by ABT-263 in a mouse model of BCR-ABL+ B-ALL both in vitro and in vivo. Furthermore, DHA synergizes with ABT-263 in human Ph+ ALL cell lines, and primary patient-derived xenografts of Ph+ ALL in culture.Conclusions: Our findings suggest that combining DHA with ABT-263 can improve therapeutic response in BCR-ABL+ B-ALL. Clin Cancer Res; 23(24); 7558–68. ©2017 AACR.
Extracellular Cyclophilin A Augments Platelet-Dependent Thrombosis and Thromboinflammation
Authors: von Ungern-Sternberg Saskia , Vogel Sebastian , Walker-Allgaier Britta , Geue Sascha , Maurer Andreas , Wild Anna-Maria , Münzer Patrick , Chatterjee Madhumita , Heinzmann David , Kremmer Elisabeth , Borst Oliver , Loughran Patricia , Zernecke Alma , Neal Matthew , Billiar Timothy , Gawaz Meinrad , Seizer Peter 
Published: October 2017

AbstractCyclophilin A (CyPA) is involved in the pathophysiology of several inflammatory and cardiovascular diseases. To our knowledge, there is no specific inhibitor targeting extracellular CyPA without affecting other extracellular cyclophilins or intracellular CyPA functions. In this study, we developed an antibody-based inhibitor of extracellular CyPA and analysed its effects in vitro and in vivo. To generate a specific antibody, mice and rats were immunized with a peptide containing the extracellular matrix metalloproteinase inducer binding site and various antibody clones were selected and purified. At first, antibodies were tested for their binding capacity to recombinant CyPA and their functional activity. The clone 8H7-mAb was chosen for further experiments. 8H7-mAb reduced the CyPA-induced migration of inflammatory cells in vitro and in vivo. Furthermore, 8H7-mAb revealed strong antithrombotic effects by inhibiting CyPA-dependent activation of platelets and thrombus formation in vitro and in vivo. Surprisingly, 8H7-mAb did not influence in vivo tail bleeding time or in vitro whole blood coagulation parameters. Our study provides first evidence that antibody-based inhibition of extracellular CyPA inhibits thrombosis and thromboinflammation without affecting blood homeostasis. Thus, 8H7-mAb may be a promising compound for thrombi modulation in inflammatory diseases to prevent organ dysfunction.
Increasing Incidence and Recurrence Rate of Venous Thromboembolism in Paediatric Oncology Patients in One Single Centre Over 25 Years
Authors: Klaassen Irene , van Els Anne , van de Wetering Marianne , van Ommen C. 
Published: October 2017

AbstractVenous thromboembolism (VTE) is a serious complication in paediatric oncology patients. To identify the incidence, risk factors and recurrence rate of VTE in paediatric oncology patients, an observational, retrospective cohort study of all consecutive children (≤18 years) with malignancies, treated at the Emma Children's Hospital Academic Medical Centre between January 1989 and December 2013, was done. A matched case–control study in children with lymphomas was performed, to identify thrombotic risk factors. Cumulative recurrence-free survival after first VTE was estimated by the Kaplan–Meier method. Of the 2,183 children included (male: female = 1.4:1.0; median age, 6.6 years) with cancer, 78 patients developed VTE (3.6%; 95% confidence interval [CI], 2.8–4.4). The incidence increased from 0.8% (4/478, 95% CI, 0.0–1.6) between 1989 and 1993 to 10.4% (44/423, 95% CI, 7.6–13.4) between 2009 and 2013. Independent risk factors for VTE were age ≥ 12 years, acute lymphoblastic leukaemia (ALL) and lymphoma. The case–control study in lymphoma patients showed a trend for increased VTE incidence in stage IV lymphoma. Twelve (15.4%) patients developed recurrent thrombosis, 7 patients while on therapeutic or prophylactic anticoagulation. The cumulative recurrence-free survival after first VTE was 88.5, 87.1 and 80.6% after 1, 5 and 10 years, respectively. In conclusion, we demonstrated an increasing incidence of VTE in children with malignancies, with age ≥ 12 years, ALL and lymphoma as independent risk factors. The elevated recurrence rate underlines the importance of full anticoagulant therapy and might warrant prophylactic anticoagulation after first VTE during cancer treatment.
ОСНОВНІ ПІДХОДИ ДО ФОРМУЛЯЦІЇ ПАРЕНТЕРАЛЬНОЇ СУСПЕНЗІЇ НА ОСНОВІ СУБСТАНЦІЇ ГІДРОКОРТИЗОНУ АЦЕТАТ У КОМБІНАЦІЇ ІЗ МІСЦЕВИМ АНЕСТЕТИКОМ ЛІДОКАЇНУ ГІДРОХЛОРИДОМ
Authors: Kachaput O. I. , Gureyeva S. M. 
Published: October 2017

Мета роботи. Науково обґрунтувати вибір оптимальних кількостей допоміжних речовин в рамках формуляції парентеральної суспензії на основі субстанції гідрокортизону ацетат у комбінації із місцевим анестетиком лідокаїну гідрохлоридом, враховуючи вимоги настанови ICH Q8 «Фармацевтична розробка».Матеріали і методи. При дослідженні були застосовані підходи, описані в настанові ICH Q8 «Фармацевтична розробка», та використані наступні аналітичні методи: високоефективна рідинна хроматографія (ДФУ 2.2.29), потенціометричне титрування (ДФУ 2.2.20), лазерна дифракція (ДФУ 2.9.31), потенціометричне визначення рН (ДФУ 2.2.3), в’язкість (ДФУ 2.2.8), мікробіологічні випробування (ДФУ 2.6.1, 2.6.14).Результати й обговорення. В рамках проведених досліджень згідно з настановою ICH Q8 «Фармацевтична розробка» було розроблено цільовий профіль якості парентеральної суспензії «Гідрокортизону ацетат + лідокаїну гідрохлорид» та проведено оцінку із визначення критичних показників якості. Всі ідентифіковані ризики формуляції було обґрунтовано і ті з них, що мали «середній» та «високий» рівень згідно з оцінкою, шляхом варіабельності змінних при експериментальних дослідженнях були знижені до рівня «низький».Продемонстровано підхід до вибору концентрацій компонентів буферної системи та експериментально підтверджено оптимальність меж рН суспензії на рівні діапазону 5,0 – 7,0 для забезпечення стабільності готової лікарської форми.Після проведення всього спектра досліджень було проведено переоцінку ризиків, що підтвердила зниження встановлених вище ризиків до прийнятних шляхом повної відповідності за основними показниками якості готової лікарської форми.Висновки. На основі проведених досліджень науково обґрунтовано вибір оптимальних кількостей допоміжних речовин у рамках формуляції парентеральної суспензії на основі субстанції гідрокортизону ацетат у комбінації із місцевим анестетиком лідокаїну гідрохлоридом, враховуючи вимоги настанови ICH Q8 «Фармацевтична розробка».